Method for driving optical modulation device

Claim 2

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a chiral smectic liquid crystal disposed between the scanning electrodes and signal electrodes; and driving means for a) applying a scanning selection signal comprising a former voltage of one polarity and a latter voltage of the other polarity to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the former voltage of one polarity are non-selectively erased into one display state and the picture elements on the particular scanning electrode supplied with the latter voltage of the other polarity are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage of the other polarity, the voltage polarities being determined with respect to the voltage level of a scanning electrode to which the scanning selection signal is not applied; and b) applying the former voltage of one polarity of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; wherein the scanning electrodes are provided in a number N, and said former voltage and said latter voltage are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 3

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns; and a chiral smectic liquid crystal; the picture elements in each row being selectively supplied with either a voltage for orienting the chiral smectic liquid crystal to one display state, or another voltage for orienting the chiral smectic liquid crystal to another display state; said driving method comprising the steps of: applying a scanning selection signal comprising a former voltage of one polarity and a latter voltage of the other polarity to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage of one polarity are non-selectively erased into one display state and the picture elements on the particular scanning electrode supplied with the voltage of the other polarity are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage of the other polarity, the voltage polarities being determined with respect to the voltage level of a scanning electrode to which the scanning selection signal is not applied; and applying the former voltage of one polarity of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; wherein the scanning electrodes are provided in a number N, and said former voltage and said latter voltage are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 4

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns; and a chiral smectic liquid crystal; the picture elements in each row being selectively supplied with either a voltage for orienting the chiral smectic liquid crystal to one display state, or another voltage for orienting the chiral smectic liquid crystal to another display state; said driving method comprising the steps of: applying a scanning selection signal comprising a former voltage of one polarity and a latter voltage of the other polarity to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage of one polarity are non-selectively erased into one display state and the picture elements on the particular scanning electrode supplied with the voltage of the other polarity are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage of the other polarity, the voltage polarities being determined with respect to the voltage level of a scanning electrode to which the scanning selection signal is not applied; and applying the former voltage of one polarity of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; wherein the scanning electrodes are provided in a number N, and said former voltage and said latter voltage are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 5

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal assuming plural orientation states in response to voltages applied thereto disposed between the scanning electrodes and signal electrodes; and driving means for a) applying a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrodes and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and b) applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 6

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal assuming plural orientation states in response to voltages applied thereto disposed between the scanning electrodes and signal electrodes; and driving means for a) applying a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrodes and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and b) applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 7

An apparatus according to claim 3, wherein said plural orientation states are bistable orientation states.

Claim 8

An apparatus according to claim 3, wherein said liquid crystal is a liquid crystal developing ferroelectricity.

Claim 9

An apparatus according to claim 3, wherein said liquid crystal is placed at a temperature at which the liquid crystal assumes a chiral smectic phase.

Claim 10

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in columns; and a liquid crystal assuming plural orientation states in response to voltages applied thereto; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to a first orientation state, or another voltage for orienting the liquid crystal to a second orientation state; said driving method comprising the steps of: applying a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state based on the first orientation stage and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 11

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in columns; and a liquid crystal assuming plural orientation states in response to voltages applied thereto; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to a first orientation state, or another voltage for orienting the liquid crystal to a second orientation state; said driving method comprising the steps of: applying a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state based on the first orientation stage and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 12

A method according to claim 7, wherein said plural orientation states are bistable orientation states.

Claim 13

A method according to claim 7, wherein said liquid crystal is a liquid crystal developing ferroelectricity.

Claim 14

A method according to claim 7, wherein said liquid crystal is placed at a temperature at which the liquid crystal assumes a chiral smectic phase.

Claim 15

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and b) applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT l (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 16

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and b) applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT l (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 17

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns; and a liquid crystal having a memory characteristic; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to a first orientation state, or another voltage for orienting the liquid crystal to a second orientation state; said driving method comprising the steps of: applying a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state based on the first orientation stage and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the later voltage signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 21 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 18

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns; and a liquid crystal having a memory characteristic; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to a first orientation state, or another voltage for orienting the liquid crystal to a second orientation state; said driving method comprising the steps of: applying a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state based on the first orientation stage and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the later voltage signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 21 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 19

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns, and a liquid crystal having a memory characteristic; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to one display state, or another voltage for orienting the liquid crystal to another display state; said driving method comprising the steps of: applying a scanning selection signal comprising a former voltage signal of a first voltage and a latter voltage signal of a second voltage different from the first voltage to particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and a selected picture element on the particular scanning electrode supplied with the latter voltage signal is placed in either the one display state or the other display state depending on the information signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode.

Claim 20

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns, and a liquid crystal having a memory characteristic; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to one display state, or another voltage for orienting the liquid crystal to another display state; said driving method comprising the steps of: applying a scanning selection signal comprising a former voltage signal of a first voltage and a latter voltage signal of a second voltage different from the first voltage to particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and a selected picture element on the particular scanning electrode supplied with the latter voltage signal is placed in either the one display state or the other display state depending on the information signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode.

Claim 21

A driving method according to claim 13, wherein the voltage waveform of the information signal is varied depending on given gradation data.

Claim 22

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrode, each data signal comprising an information signal for selecting display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and a picture element on the particular scanning electrode supplied with the second voltage signal is placed in either the one display state or the other display state depending upon an information signal; and b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the data signals for selecting the display states of the pixels on said particular scanning electrode.

Claim 23

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrode, each data signal comprising an information signal for selecting display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and a picture element on the particular scanning electrode supplied with the second voltage signal is placed in either the one display state or the other display state depending upon an information signal; and b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the data signals for selecting the display states of the pixels on said particular scanning electrode.

Claim 24

An optical modulation apparatus according to claim 15, which includes means for varying the voltage waveform of the information signal depending on given gradation area.

Claim 25

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrodes, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; and c) applying an AC voltage which does not change the selected display states of the picture elements on the particular scanning electrode to the pixels when the particular scanning electrode is not supplied with the scanning selection signal.

Claim 26

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrodes, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; and c) applying an AC voltage which does not change the selected display states of the picture elements on the particular scanning electrode to the pixels when the particular scanning electrode is not supplied with the scanning selection signal.

Claim 27

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and the signal electrodes; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal having a voltage waveform which varies depending on given gradation data so that (i) the picture elements on the particular scanning electrode supplied with the former voltage of one polarity are non-selectively erased into an erased state and (ii) the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in gradational display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the scanning selection signal to said particular scanning electrode; and c) applying an AC voltage to preclude changing the selected display states of the picture elements on the particular scanning electrode while the particular scanning electrode is not supplied with the scanning selection signal.

Claim 28

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and the signal electrodes; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal having a voltage waveform which varies depending on given gradation data so that (i) the picture elements on the particular scanning electrode supplied with the former voltage of one polarity are non-selectively erased into an erased state and (ii) the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in gradational display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the scanning selection signal to said particular scanning electrode; and c) applying an AC voltage to preclude changing the selected display states of the picture elements on the particular scanning electrode while the particular scanning electrode is not supplied with the scanning selection signal.

Claim 29

In a matrix line-at-a-time driving apparatus for a liquid crystal device having a liquid crystal having a memory characteristic interposed between X and Y electrodes and pixels arranged in lines, a liquid crystal driving apparatus comprising: first driving means for applying a first voltage signal simultaneously to the pixels for one line to bring said pixels into a first light transmission state; and second driving means for applying a second voltage signal to each of said pixels in said line, said second voltage signals being either effective to bring said pixels into a second light transmission state or effective to hold the first light transmission state in accordance with display signals, and wherein said pixels on a subsequently selected line are driven by said first driving means when said pixels on a currently selected line are driven by said second driving means.

Claim 30

In a matrix line-at-a-time driving apparatus for a liquid crystal device having a liquid crystal having a memory characteristic interposed between X and Y electrodes and pixels arranged in lines, a liquid crystal driving apparatus comprising: first driving means for applying a first voltage signal simultaneously to the pixels for one line to bring said pixels into a first light transmission state; and second driving means for applying a second voltage signal to each of said pixels in said line, said second voltage signals being either effective to bring said pixels into a second light transmission state or effective to hold the first light transmission state in accordance with display signals, and wherein said pixels on a subsequently selected line are driven by said first driving means when said pixels on a currently selected line are driven by said second driving means.

Claim 31

An apparatus as defined in claim 19, wherein the first driving means voltage is effective for causing each liquid crystal pixel in a line to have a light ON state and the driving voltage from the second driving means is effective for causing a liquid crystal pixel previously in a light ON state to transfer to a light OFF state.

Claim 32

In a matrix line-at-a-time driving apparatus for a liquid crystal device having a liquid crystal having a memory characteristic interposed between X and Y electrodes and pixels arranged in lines, a liquid crystal driving apparatus comprising: first driving means for applying a first voltage signal simultaneously to the pixels for one line to bring said pixels into a first light transmission state; second driving means responsive to signals relating to information that is to be displayed, said second driving means being effective to apply one of two voltages to each pixel in said one line, one of said voltages being effective to hold the first light transmission state, and the other of said voltages being effective to bring a pixel into a second light transmission state; and means advancing the first driving means to apply its voltage simultaneously to the pixels of a second line in said matrix during the same time interval that the pixels of said one line are driven by said second driving means.

Claim 33

In a matrix line-at-a-time driving apparatus for a liquid crystal device having a liquid crystal having a memory characteristic interposed between X and Y electrodes and pixels arranged in lines, a liquid crystal driving apparatus comprising: first driving means for applying a first voltage signal simultaneously to the pixels for one line to bring said pixels into a first light transmission state; second driving means responsive to signals relating to information that is to be displayed, said second driving means being effective to apply one of two voltages to each pixel in said one line, one of said voltages being effective to hold the first light transmission state, and the other of said voltages being effective to bring a pixel into a second light transmission state; and means advancing the first driving means to apply its voltage simultaneously to the pixels of a second line in said matrix during the same time interval that the pixels of said one line are driven by said second driving means.

Claim 34

An apparatus as defined in claim 21, wherein the first driving means voltage is effective for causing each liquid crystal pixel in a line to have a light ON state and the driving voltage from the second driving means is effective for causing a liquid crystal pixel previously in light ON state to transfer to a light OFF state.

Claim 37

A method according to claim 23, further comprising the steps of: providing a second pattern of voltages which pattern includes different voltages in accordance with a desired display for said second line with the voltages being effective to being associated pixels within a second light transmission state; and applying said pattern of voltages during a third time interval to the pixels of said second line to produce a stable display according to the second applied voltage pattern while concurrently applying a first voltage simultaneously to all of the pixels in a third line of said matrix to bring all of the pixels in said third line into the first uniform light transmission state.

Claim 38

A driving method for an optical modulation device of the type in which a group of scanning electrodes and a group of signal electrodes are so arranged that picture elements are defined at the respective intersections of the scanning and signal electrodes, and in which a liquid crystal having a memory characteristic is interposed between the group of scanning electrodes and the group of signal electrodes, the driving method comprising the steps of, in a writing period for a currently selected scanning electrode having at least a first phase and a second phase: applying to the currently selected scanning electrode a scanning selection signal having a first voltage signal of one voltage in the first phase and another voltage in the second phase; applying to a subsequently selected scanning electrode a signal having a second voltage signal of one voltage in a phase after the first phase during the writing period for the currently selected scanning electrode; in the first phase, orienting the chiral smectic liquid crystal at the picture elements on the currently selected scanning electrode to one orientation state thereof by applying a combination of scanning selection signal having the first voltage signal of said one voltage to the currently selected scanning electrode and a voltage signal to a plurality of signal electrodes intersecting the currently selected scanning electrode, and simultaneously applying a signal having a voltage not exceeding a threshold voltage of the chiral smectic liquid crystal to the picture elements on the subsequently selected scanning electrode; in the second phase, orienting the chiral smectic liquid crystal at a selected picture element on the currently selected scanning electrode to another orientation state thereof by applying a combination of the scanning selection signal having the first voltage signal of said another voltage to the currently selected scanning electrode and a voltage signal to a signal electrode intersecting the currently selected scanning electrode; in the phase after the first phase, orienting the chiral smectic liquid crystal at the picture elements on the subsequently selected scanning electrode to one orientation state thereof by applying a combination of the signal having the second voltage signal of said one voltage to the subsequently selected scanning electrode and voltage signal to a plurality of signal electrodes intersecting the subsequently selected scanning electrode; and in the writing period for the currently selected scanning electrode, applying a signal having a voltage not exceeding the threshold of the liquid crystal to the picture elements on the non-selected scanning electrode.

Claim 39

A driving method for an optical modulation device of the type in which a group of scanning electrodes and a group of signal electrodes are so arranged that picture elements are defined at the respective intersections of the scanning and signal electrodes, and in which a liquid crystal having a memory characteristic is interposed between the group of scanning electrodes and the group of signal electrodes, the driving method comprising the steps of, in a writing period for a currently selected scanning electrode having at least a first phase and a second phase: applying to the currently selected scanning electrode a scanning selection signal having a first voltage signal of one voltage in the first phase and another voltage in the second phase; applying to a subsequently selected scanning electrode a signal having a second voltage signal of one voltage in a phase after the first phase during the writing period for the currently selected scanning electrode; in the first phase, orienting the chiral smectic liquid crystal at the picture elements on the currently selected scanning electrode to one orientation state thereof by applying a combination of scanning selection signal having the first voltage signal of said one voltage to the currently selected scanning electrode and a voltage signal to a plurality of signal electrodes intersecting the currently selected scanning electrode, and simultaneously applying a signal having a voltage not exceeding a threshold voltage of the chiral smectic liquid crystal to the picture elements on the subsequently selected scanning electrode; in the second phase, orienting the chiral smectic liquid crystal at a selected picture element on the currently selected scanning electrode to another orientation state thereof by applying a combination of the scanning selection signal having the first voltage signal of said another voltage to the currently selected scanning electrode and a voltage signal to a signal electrode intersecting the currently selected scanning electrode; in the phase after the first phase, orienting the chiral smectic liquid crystal at the picture elements on the subsequently selected scanning electrode to one orientation state thereof by applying a combination of the signal having the second voltage signal of said one voltage to the subsequently selected scanning electrode and voltage signal to a plurality of signal electrodes intersecting the subsequently selected scanning electrode; and in the writing period for the currently selected scanning electrode, applying a signal having a voltage not exceeding the threshold of the liquid crystal to the picture elements on the non-selected scanning electrode.

Claim 40

The driving method according to claim 25, wherein each of the first and second phases has a duration of T and the period for application of the scanning selection signal has a duration of T 1 satisfying the relation of T 1 =2T.

Claim 41

An optical modulation device comprising: a group of scanning electrodes and a group of signal electrodes so arranged that picture elements are defined at the respective intersections of said scanning and signal electrodes, and a liquid crystal having a memory characteristic is interposed between said group of scanning electrodes and said group of signal electrodes; said optical modulation device employing a driving method comprising the steps of, in a writing period for a currently selected scanning electrode including at least a first phase and a second phase: applying to said currently selected scanning electrode a scanning selection signal having a first voltage signal of one voltage in the first phase and another voltage in the second phase; applying to a subsequently selected scanning electrode a scanning selection signal having a second voltage signal of one voltage in a phase after the first phase during the writing period for said currently selected scanning electrode; in the first phase, orienting the liquid crystal at said picture elements on said currently selected scanning electrode to one orientation state thereof by applying a combination of the scanning selection signal having said first voltage signal of said one voltage and a voltage signal to a plurality of signal electrodes intersecting said currently selected scanning electrode, and simultaneously applying a signal having a voltage not exceeding a threshold voltage of the liquid crystal to said picture elements on said subsequently selected scanning electrode; in the second phase, orienting the liquid crystal at a selected picture element on said currently selected scanning electrode to another orientation state thereof by applying a combination of the scanning selection signal having said another voltage and a voltage signal to a signal electrode intersecting said currently selected scanning electrode; in the phase after the first phase, orienting the liquid crystal at said picture elements on said subsequently selected scanning electrode to one orientation state thereof by applying a combination of the signal having the second voltage signal of said one voltage and a voltage signal to a plurality of signal electrodes intersecting said selected N-th+1 scanning electrode; and in the writing period for said currently selected scanning electrode, applying a signal having a voltage not exceeding the threshold of the liquid crystal to said picture elements on said non-selected scanning electrode.

Claim 42

An optical modulation device comprising: a group of scanning electrodes and a group of signal electrodes so arranged that picture elements are defined at the respective intersections of said scanning and signal electrodes, and a liquid crystal having a memory characteristic is interposed between said group of scanning electrodes and said group of signal electrodes; said optical modulation device employing a driving method comprising the steps of, in a writing period for a currently selected scanning electrode including at least a first phase and a second phase: applying to said currently selected scanning electrode a scanning selection signal having a first voltage signal of one voltage in the first phase and another voltage in the second phase; applying to a subsequently selected scanning electrode a scanning selection signal having a second voltage signal of one voltage in a phase after the first phase during the writing period for said currently selected scanning electrode; in the first phase, orienting the liquid crystal at said picture elements on said currently selected scanning electrode to one orientation state thereof by applying a combination of the scanning selection signal having said first voltage signal of said one voltage and a voltage signal to a plurality of signal electrodes intersecting said currently selected scanning electrode, and simultaneously applying a signal having a voltage not exceeding a threshold voltage of the liquid crystal to said picture elements on said subsequently selected scanning electrode; in the second phase, orienting the liquid crystal at a selected picture element on said currently selected scanning electrode to another orientation state thereof by applying a combination of the scanning selection signal having said another voltage and a voltage signal to a signal electrode intersecting said currently selected scanning electrode; in the phase after the first phase, orienting the liquid crystal at said picture elements on said subsequently selected scanning electrode to one orientation state thereof by applying a combination of the signal having the second voltage signal of said one voltage and a voltage signal to a plurality of signal electrodes intersecting said selected N-th+1 scanning electrode; and in the writing period for said currently selected scanning electrode, applying a signal having a voltage not exceeding the threshold of the liquid crystal to said picture elements on said non-selected scanning electrode.

Claim 43

An optical modulation device according to claim 27, wherein each of the first and second phases has a duration of ΔT and the period for application of the scanning selection signal has a duration of T 1 satisfying the relation of T 1 =2ΔT.

Claim 44

An optical modulation apparatus, comprising; an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal assuming plural orientation states in response to voltages applied thereto disposed between the scanning electrodes and signal electrodes; and driving mean for a) applying periodically a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and b) applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 45

An optical modulation apparatus, comprising; an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal assuming plural orientation states in response to voltages applied thereto disposed between the scanning electrodes and signal electrodes; and driving mean for a) applying periodically a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and b) applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 46

An apparatus according to claim 29, wherein said plural orientation states are bistable orientation states.

Claim 47

An apparatus according to claim 29, wherein said liquid crystal is a liquid crystal developing ferroelectricity.

Claim 48

An apparatus according to claim 29, wherein said liquid crystal is placed at a temperature at which the liquid crystal assumes a chiral smectic phase.

Claim 49

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns; and a liquid crystal assuming plural orientation states in response to voltages applied thereto; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to a first orientation state, or another voltage for orienting the liquid crystal to a second orientation state; said driving method comprising the steps of: applying periodically a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state based on the first orientation stage and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 50

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns; and a liquid crystal assuming plural orientation states in response to voltages applied thereto; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to a first orientation state, or another voltage for orienting the liquid crystal to a second orientation state; said driving method comprising the steps of: applying periodically a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state based on the first orientation stage and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 51

A method according to claim 33, wherein said plural orientation states are bistable orientation states.

Claim 52

A method according to claim 33, wherein said liquid crystal is a liquid crystal developing ferroelectricity.

Claim 53

A method according to claim 33, wherein said liquid crystal is placed at a temperature at which the liquid crystal assumes a chiral smectic phase.

Claim 54

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying periodically a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and b) applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 55

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying periodically a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and b) applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 56

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns; and a liquid crystal having a memory characteristic; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to a first orientation state, or another voltage for orienting the liquid crystal to a second orientation state; said driving method comprising the steps of: applying periodically a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state based on the first orientation state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 57

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns; and a liquid crystal having a memory characteristic; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to a first orientation state, or another voltage for orienting the liquid crystal to a second orientation state; said driving method comprising the steps of: applying periodically a scanning selection signal comprising a former voltage signal and a latter voltage signal having a voltage different from that of the former voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state based on the first orientation state and the picture elements on the particular scanning electrode supplied with the latter voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the latter voltage signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode, wherein the scanning electrodes are provided in a number N, and said former voltage signal and said latter voltage signal are set to have pulse durations ΔT 1 (sec) and ΔT 2 (sec), respectively, satisfying: ΔT 1 +ΔT 2 >T 1 , wherein T 1 is a time given as one frame scanning period (sec)/N.

Claim 58

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns, and a liquid crystal having a memory characteristic; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to one display state, or another voltage for orienting the liquid crystal to another display state; said driving method comprising the steps of: applying periodically a scanning selection signal comprising a former voltage signal of a first voltage and a latter voltage signal of a second voltage different from the first voltage to a particular one of the seaming electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and a selected picture element on the particular scanning electrode supplied with the latter voltage signal is placed in either the one display state or the other display state depending on the information signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode.

Claim 59

A driving method for driving an optical modulation device comprising: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by the intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns, and a liquid crystal having a memory characteristic; the picture elements in each row being selectively supplied with either a voltage for orienting the liquid crystal to one display state, or another voltage for orienting the liquid crystal to another display state; said driving method comprising the steps of: applying periodically a scanning selection signal comprising a former voltage signal of a first voltage and a latter voltage signal of a second voltage different from the first voltage to a particular one of the seaming electrodes to select that particular scanning electrode; applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the former voltage signal are non-selectively erased into an erased state and a selected picture element on the particular scanning electrode supplied with the latter voltage signal is placed in either the one display state or the other display state depending on the information signal; and applying the former voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode.

Claim 60

A driving method according to claim 39, wherein the voltage waveform of the information signal is varied depending on given gradation data.

Claim 61

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic; and driving means for a) applying periodically a scanning selection signal comprising a first voltage signal and a second voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrode, each data signal comprising an information signal for selecting display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and a picture element on the particular scanning electrode supplied with the second voltage signal is placed in either the one display state or the other display state depending upon an information signal; and b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the data signals for selecting the display states of the pixels on said particular scanning electrode.

Claim 62

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic; and driving means for a) applying periodically a scanning selection signal comprising a first voltage signal and a second voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrode, each data signal comprising an information signal for selecting display state of a picture element on the particular scanning electrode whereby the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and a picture element on the particular scanning electrode supplied with the second voltage signal is placed in either the one display state or the other display state depending upon an information signal; and b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the data signals for selecting the display states of the pixels on said particular scanning electrode.

Claim 63

An optical modulation apparatus according to claim 41, which includes means for varying the voltage waveform of the information signal depending on given gradation area.

Claim 64

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying periodically a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; and c) applying an AC voltage which does not change the selected display states of the picture elements on the particular scanning electrode to the pixels when the particular scanning electrode is not supplied with the scanning selection signal.

Claim 65

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying periodically a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; and c) applying an AC voltage which does not change the selected display states of the picture elements on the particular scanning electrode to the pixels when the particular scanning electrode is not supplied with the scanning selection signal.

Claim 66

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and the signal electrodes; and driving means for a) applying periodically a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal having a voltage waveform which varies depending on given gradation data so that (i) the picture elements on the particular scanning electrode supplied with the former voltage of one polarity are non-selectively erased into an erased state and (ii) the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in gradational display states depending on the information signals applied in synchronism with the second voltage signal; and b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the scanning selection signal to said particular scanning electrode; and c) applying an AC voltage to preclude changing the selected display states of the picture elements on the particular scanning electrode while the particular scanning electrode is not supplied with the scanning selection signal.

Claim 67

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and the signal electrodes; and driving means for a) applying periodically a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal having a voltage waveform which varies depending on given gradation data so that (i) the picture elements on the particular scanning electrode supplied with the former voltage of one polarity are non-selectively erased into an erased state and (ii) the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in gradational display states depending on the information signals applied in synchronism with the second voltage signal; and b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the scanning selection signal to said particular scanning electrode; and c) applying an AC voltage to preclude changing the selected display states of the picture elements on the particular scanning electrode while the particular scanning electrode is not supplied with the scanning selection signal.

Claim 68

In a matrix line-at-a-time driving apparatus for periodically driving a liquid crystal device having a liquid crystal having a memory characteristic interposed between X and Y electrodes and pixels arranged in lines, a liquid crystal driving apparatus comprising: first driving means for applying a first voltage signal simultaneously to the pixels for one line to bring said pixels into a first light transmission state; and second driving means for applying a second voltage signal to each of said pixels in said line, said second voltage signals being either effective to bring said pixels into a second light transmission state or effective to hold the first light transmission state in accordance with display signals, and wherein said pixels on a subsequently selected line are driven by said first driving means when said pixels on a currently selected line are driven by said second driving means.

Claim 69

In a matrix line-at-a-time driving apparatus for periodically driving a liquid crystal device having a liquid crystal having a memory characteristic interposed between X and Y electrodes and pixels arranged in lines, a liquid crystal driving apparatus comprising: first driving means for applying a first voltage signal simultaneously to the pixels for one line to bring said pixels into a first light transmission state; and second driving means for applying a second voltage signal to each of said pixels in said line, said second voltage signals being either effective to bring said pixels into a second light transmission state or effective to hold the first light transmission state in accordance with display signals, and wherein said pixels on a subsequently selected line are driven by said first driving means when said pixels on a currently selected line are driven by said second driving means.

Claim 70

An apparatus as defined in claim 45, wherein the first driving means voltage is effective for causing each liquid crystal pixel in a line to have a light ON state and the driving voltage from the second driving means is effective for causing a liquid crystal pixel previously in a light ON state to transfer to a light OFF state.

Claim 71

In a matrix line-at-a-time driving apparatus for periodically driving a liquid crystal device having a liquid crystal having a memory characteristic interposed between X and Y electrodes and pixels arranged in lines, a liquid crystal driving apparatus comprising: first driving means for applying a first voltage signal simultaneously to the pixels for one line to bring said pixels into a first light transmission state; second driving means responsive to signals relating to information that is to be displayed, said second driving means being effective to apply one of two voltages to each pixel in said one line, one of said voltages being effective to hold the first light transmission state, and the other of said voltages being effective to bring a pixel into a second light transmission state; and means advancing the first driving means to apply its voltage simultaneously to the pixels of a second line in said matrix during the same time interval that the pixels of said one line are driven by said second driving means.

Claim 72

In a matrix line-at-a-time driving apparatus for periodically driving a liquid crystal device having a liquid crystal having a memory characteristic interposed between X and Y electrodes and pixels arranged in lines, a liquid crystal driving apparatus comprising: first driving means for applying a first voltage signal simultaneously to the pixels for one line to bring said pixels into a first light transmission state; second driving means responsive to signals relating to information that is to be displayed, said second driving means being effective to apply one of two voltages to each pixel in said one line, one of said voltages being effective to hold the first light transmission state, and the other of said voltages being effective to bring a pixel into a second light transmission state; and means advancing the first driving means to apply its voltage simultaneously to the pixels of a second line in said matrix during the same time interval that the pixels of said one line are driven by said second driving means.

Claim 73

An apparatus as defined in claim 47, wherein the first driving means voltage is effective for causing each liquid crystal pixel in a line to have a light ON state and the driving voltage from the second driving means is effective for causing a liquid crystal pixel previously in a light ON state to transfer to a light OFF state.

Claim 76

A method according to claim 49, further comprising the steps of: providing a second pattern of voltages which pattern includes different voltages in accordance with a desired display for the second line with the voltages being effective to bring associated pixels within a second light transmission state; and applying the pattern of voltages during a third time interval to the pixels of the second line to produce a stable display according to the second applied voltage pattern while concurrently applying a first voltage simultaneously to all of the pixels in a third line of the matrix to bring all of the pixels in the third line into the first uniform light transmission state.

Claim 77

A driving method for periodically scanning an optical modulation device of the type in which a group of scanning electrodes and a group of signal electrodes are so arranged that picture elements are defined at the respective intersections of the scanning and signal electrodes, and in which a liquid crystal having a memory characteristic is interposed between the group of scanning electrodes and the group of signal electrodes, the driving method comprising the steps of: in a writing period for a currently selected scanning electrode having at least a first phase and a second phase: applying to the currently selected scanning electrode a scanning selection signal having a first voltage signal of one voltage in the first phase and another voltage in the second phase; applying to a subsequently selected scanning electrode a signal having a second voltage signal of one voltage in a phase after the first phase during the writing period for the currently selected scanning electrode; in the first phase, orienting the liquid crystal at the picture elements on the currently selected scanning electrode to one orientation state thereof by applying a combination of scanning selection signal having the first voltage signal of the one voltage to the currently selected scanning electrode and a voltage signal to a plurality of signal electrodes intersecting the currently selected scanning electrode, and simultaneously applying a signal having a voltage not exceeding a threshold voltage of the liquid crystal to the picture elements on the subsequently selected scanning electrode; in the second phase, orienting the liquid crystal at a selected picture element on the currently selected scanning electrode to another orientation state thereof by applying a combination of the scanning selection signal having the first voltage signal of the other voltage to the currently selected scanning electrode and a voltage signal to a signal electrode intersecting the currently selected scanning electrode; in the phase after the first phase, orienting the liquid crystal at the picture elements on the subsequently selected scanning electrode to one orientation state thereof by applying a combination of the signal having the second voltage signal of the one voltage to the subsequently selected scanning electrode and voltage signal to a plurality of signal electrodes intersecting the subsequently selected scanning electrode; and in the writing period for the currently selected scanning electrode, applying a signal having a voltage not exceeding the threshold of the liquid crystal to the picture elements on the non-selected scanning electrode.

Claim 78

A driving method for periodically scanning an optical modulation device of the type in which a group of scanning electrodes and a group of signal electrodes are so arranged that picture elements are defined at the respective intersections of the scanning and signal electrodes, and in which a liquid crystal having a memory characteristic is interposed between the group of scanning electrodes and the group of signal electrodes, the driving method comprising the steps of: in a writing period for a currently selected scanning electrode having at least a first phase and a second phase: applying to the currently selected scanning electrode a scanning selection signal having a first voltage signal of one voltage in the first phase and another voltage in the second phase; applying to a subsequently selected scanning electrode a signal having a second voltage signal of one voltage in a phase after the first phase during the writing period for the currently selected scanning electrode; in the first phase, orienting the liquid crystal at the picture elements on the currently selected scanning electrode to one orientation state thereof by applying a combination of scanning selection signal having the first voltage signal of the one voltage to the currently selected scanning electrode and a voltage signal to a plurality of signal electrodes intersecting the currently selected scanning electrode, and simultaneously applying a signal having a voltage not exceeding a threshold voltage of the liquid crystal to the picture elements on the subsequently selected scanning electrode; in the second phase, orienting the liquid crystal at a selected picture element on the currently selected scanning electrode to another orientation state thereof by applying a combination of the scanning selection signal having the first voltage signal of the other voltage to the currently selected scanning electrode and a voltage signal to a signal electrode intersecting the currently selected scanning electrode; in the phase after the first phase, orienting the liquid crystal at the picture elements on the subsequently selected scanning electrode to one orientation state thereof by applying a combination of the signal having the second voltage signal of the one voltage to the subsequently selected scanning electrode and voltage signal to a plurality of signal electrodes intersecting the subsequently selected scanning electrode; and in the writing period for the currently selected scanning electrode, applying a signal having a voltage not exceeding the threshold of the liquid crystal to the picture elements on the non-selected scanning electrode.

Claim 79

The driving method according to claim 51, wherein each of the first and second phases has a duration of ΔT and the period for application of the scanning selection signal has a duration of T 1 satisfying the relation of T 1 =2ΔT.

Claim 80

An optical modulation device comprising: a group of scanning electrodes and a group of signal electrodes so arranged that picture elements are defined at the respective intersections of said scanning and signal electrodes, and a liquid crystal having memory characteristic is interposed between said group of scanning electrodes and said group of signal electrodes; said optical modulation device employing a periodical driving method comprising the steps of: in a writing period for a currently selected scanning electrode including at least a first phase and a second phase: applying to said currently selected scanning electrode a scanning selection signal having a first voltage signal of one voltage in the first phase and another voltage in the second phase; applying to a subsequently selected scanning electrode a scanning selection signal having a second voltage signal of one voltage in a phase after the first phase during the writing period for said currently selected scanning electrode; in the first phase, orienting the liquid crystal at said picture elements on said currently selected scanning electrode to one orientation state thereof by applying a combination of the scanning selection signal having said first voltage signal of said one voltage and a voltage signal to a plurality of signal electrodes intersecting said currently selected scanning electrode, and simultaneously applying a signal having a voltage not exceeding a threshold voltage of the liquid crystal to said picture elements on said subsequently selected scanning electrode; in the second phase, orienting the liquid crystal at a selected picture element on said currently selected scanning electrode to another orientation state thereof by applying a combination of the scanning selection signal having said another voltage and a voltage signal to a signal electrode intersecting said currently selected scanning electrode; in the phase after the first phase, orienting the liquid crystal at said picture elements on said subsequently selected scanning electrode to one orientation state thereof by applying a combination of the signal having the second voltage signal of said one voltage and a voltage signal to a plurality of signal electrodes intersecting said selected N-th+1 scanning electrode; and in the writing period for said currently selected scanning electrode, applying a signal having a voltage not exceeding the threshold on the liquid crystal to said picture elements on said non-selected scanning electrode.

Claim 81

An optical modulation device comprising: a group of scanning electrodes and a group of signal electrodes so arranged that picture elements are defined at the respective intersections of said scanning and signal electrodes, and a liquid crystal having memory characteristic is interposed between said group of scanning electrodes and said group of signal electrodes; said optical modulation device employing a periodical driving method comprising the steps of: in a writing period for a currently selected scanning electrode including at least a first phase and a second phase: applying to said currently selected scanning electrode a scanning selection signal having a first voltage signal of one voltage in the first phase and another voltage in the second phase; applying to a subsequently selected scanning electrode a scanning selection signal having a second voltage signal of one voltage in a phase after the first phase during the writing period for said currently selected scanning electrode; in the first phase, orienting the liquid crystal at said picture elements on said currently selected scanning electrode to one orientation state thereof by applying a combination of the scanning selection signal having said first voltage signal of said one voltage and a voltage signal to a plurality of signal electrodes intersecting said currently selected scanning electrode, and simultaneously applying a signal having a voltage not exceeding a threshold voltage of the liquid crystal to said picture elements on said subsequently selected scanning electrode; in the second phase, orienting the liquid crystal at a selected picture element on said currently selected scanning electrode to another orientation state thereof by applying a combination of the scanning selection signal having said another voltage and a voltage signal to a signal electrode intersecting said currently selected scanning electrode; in the phase after the first phase, orienting the liquid crystal at said picture elements on said subsequently selected scanning electrode to one orientation state thereof by applying a combination of the signal having the second voltage signal of said one voltage and a voltage signal to a plurality of signal electrodes intersecting said selected N-th+1 scanning electrode; and in the writing period for said currently selected scanning electrode, applying a signal having a voltage not exceeding the threshold on the liquid crystal to said picture elements on said non-selected scanning electrode.

Claim 82

An optical modulation device according to claim 53, wherein each of the first and second phases has a duration of ΔT and the period for application of the scanning selection signal has a duration of T 1 satisfying the relation of T 1 =2ΔT.

Claim 83

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; and c) applying an AC voltage which does not change the selected display states of the picture elements on the particular scanning electrode to the pixels when the particular scanning electrode is not supplied with the scanning selection signal.

Claim 84

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and signal electrodes; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, so that the picture elements on the particular scanning electrode supplied with the first voltage signal are non-selectively erased into an erased state and the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to the particular scanning electrode during the period of applying the data signals for selecting the display states of the picture elements on said particular scanning electrode; and c) applying an AC voltage which does not change the selected display states of the picture elements on the particular scanning electrode to the pixels when the particular scanning electrode is not supplied with the scanning selection signal.

Claim 85

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and the signal electrodes; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal having a voltage waveform which varies depending on given gradation data so that (i) the picture elements on the particular scanning electrode supplied with the former voltage of one polarity are non-selectively erased into an erased state and (ii) the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in gradational display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the scanning selection signal to said particular scanning electrode; and c) applying an AC voltage to preclude changing the selected display states of the picture elements on the particular scanning electrode while the particular scanning electrode is not supplied with the scanning selection signal.

Claim 86

An optical modulation apparatus, comprising: an optical modulation device having: a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns; scanning electrodes arranged in rows and signal electrodes arranged in columns defining said matrix of picture elements; and a liquid crystal having a memory characteristic disposed between the scanning electrodes and the signal electrodes; and driving means for a) applying a scanning selection signal comprising a first voltage signal and a second voltage signal different from the first voltage signal to a particular one of the scanning electrodes to select that particular scanning electrode, and applying data signals to the signal electrodes, each data signal comprising an information signal having a voltage waveform which varies depending on given gradation data so that (i) the picture elements on the particular scanning electrode supplied with the former voltage of one polarity are non-selectively erased into an erased state and (ii) the picture elements on the particular scanning electrode supplied with the second voltage signal are respectively selected in gradational display states depending on the information signals applied in synchronism with the second voltage signal; b) applying the first voltage signal of a subsequent scanning selection signal to a scanning electrode selected subsequent to said particular scanning electrode during the period of applying the scanning selection signal to said particular scanning electrode; and c) applying an AC voltage to preclude changing the selected display states of the picture elements on the particular scanning electrode while the particular scanning electrode is not supplied with the scanning selection signal.

Claim 87

An optical modulation apparatus according to claim 56, wherein a picture element which is supplied with the voltage waveform which varies depending on given gradation data comprises liquid crystal molecules in different orientation states.