Method and apparatus for driving a liquid crystal display panel

Claim 3

A method of driving a liquid crystal display panel recited in claim 1, wherein said change is provided by reduction of said first quantity from said second quantity.

Claim 4

A method of driving a liquid crystal display panel recited in claim 2, wherein said reduction is carried out by counting a third quantity of data bits changing from said second logical level to said first logical level; counting a fourth quantity of data bits changing from said second logical level to said first logical level; and reducing said fourth quantity from said third quantity.

Claim 5

A method of driving a liquid crystal display panel recited in claim 1, wherein said compensation voltage is a spike pulse generated by differentiating a DC voltage generated in accordance to said first or second quantity.

Claim 6

A method of driving a liquid crystal display panel recited in claim 1, wherein said compensation voltage is constant during a period selecting a single scan electrode.

Claim 7

A method of driving a liquid crystal display panel recited in claim 1, wherein said compensation voltage is a spike having the substantially same waveform and the substantially same amplitude as those of said induced spike voltage.

Claim 8

A method of driving a liquid crystal display panel recited in claim 1, wherein said predetermined relation is said compensation voltage in proportion to said change.

Claim 9

A method of driving a liquid crystal display panel recited in claim 1, wherein said predetermined relation is that said compensation voltage is non linear to said change.

Claim 10

A method of driving a liquid crystal display panel recited in claim 8, wherein said predetermined relation is stored in a read-only memory device.

Claim 11

A method of driving a liquid crystal display panel recited in claim 1, wherein said compensation voltage is generated in accordance with a predetermined adjustment relation to a voltage which controls brightness of said cell.

Claim 12

A method of driving a liquid crystal display panel recited in claim 1, wherein an arrangement of said cells is divided in two groups along row of said scan electrodes; data electrodes in each group are applied with voltages from each independent data driver; scan electrodes on equal scan order in each group are applied with same voltages from said scan driver; and said compensation voltage is generated in accordance to a sum of said changes respectively in said two groups.

Claim 15

A method of driving a liquid crystal display panel recited in claim 12, wherein said change is provided by reduction of said first quantity from said second quantity.

Claim 16

A method of driving a liquid crystal display panel recited in claim 13, wherein said reduction is carried out by counting a third quantity of data bits changing from said second logical level to said first logical level; counting a fourth quantity of data bits changing from said second logical level to said first logical level; and reducing said fourth quantity from said third quantity.

Claim 17

A method of driving a liquid crystal display panel recited in claim 12, wherein said compensation voltage is a spike pulse generated by differentiating a DC voltage generated in accordance to said first or second quantity.

Claim 18

A method of driving a liquid crystal display panel recited in claim 12, wherein said compensation voltage is constant during a period selecting a single scan electrode.

Claim 19

A method of driving a liquid crystal display panel recited in claim 12, wherein said compensation voltage is a spike having the substantially same waveform and the substantially same amplitude as those of said induced spike voltage.

Claim 20

A method of driving a liquid crystal display panel recited in claim 12, wherein said predetermined relation is said compensation voltage in proportion to said change.

Claim 21

A method of driving a liquid crystal display panel recited in claim 12, wherein said predetermined relation is that said compensation voltage is non linear to said change.

Claim 22

A method of driving a liquid crystal display panel recited in claim 19, wherein said predetermined relation is stored in a read-only memory device.

Claim 23

A method of driving a liquid crystal display panel recited in claim 12, wherein said compensation voltage is generated in accordance with a predetermined adjustment relation to a voltage which controls brightness of said cell.

Claim 24

A method of driving a liquid crystal display panel recited in claim 12, wherein an arrangement of said cells is divided in two groups along row of said scan electrodes; data electrodes in each group are applied with voltages from each independent data driver; scan electrodes on equal scan order in each group are applied with same voltages from said scan driver; and said compensation voltage is generated in accordance to a sum of said changes respectively in said two groups.

Claim 25

A liquid crystal display driving system comprising: a panel having a plurality of liquid crystal cells arranged, in matrix, between a plurality of data electrodes and a plurality of scan electrodes, said data electrodes and said scan electrodes intersecting each other, ON-STATE and OFF-STATE of each cell being determined by cell voltage which is a difference between voltages of data electrode and scan electrode respectively connected said each cell, cell voltage to select ON-STATE being in a first polarity during a first voltage application mode, cell voltage to select ON-STATE being in a second polarity opposite to said first polarity during a second voltage application mode; mode selecting means for outputting a mode selecting signal which selects said voltage application mode, so as to switch said voltage application mode in a predetermined cycle; power sources for outputting selective voltages to select ON-STATE for the first and second voltage application modes, respectively, and unselective voltages to select OFF-STATE for said first and second modes, respectively; a scan driver, for selectively applying said selective and unselective voltages output from said power source to each of said scan electrodes, said selective and unselective voltages being selected depending on said mode selecting signal; a data driver for selectively applying said selective and unselective voltages output from said power source to each of said data electrodes, said selective and unselective voltages being selected depending on said mode selecting signal; logic converting means for converting a first logical level in data to be displayed on a scan electrode into a second logical level opposite to said first logical level during said first voltage application mode, and converting a second logical level in said data into said first logical level during said second voltage application mode; data difference detecting means for reducing a first quantity of logical level 1 output from said logic converting means displayed on a just previous scan electrode from a second quantity of logical level 1 output from said logic converting means to be displayed on a present scan electrode; compensation voltage generating means for generating a compensation voltage having a level in accordance to a predetermined relation to a change output from said data difference detecting means; and feedback means for superposing said compensation voltage onto voltages to be supplied via said scan driver to other unselected scan electrodes than said next scan electrode in synchronization with selection of said present scan electrode, so as to cancel undesirable spike pulse induced on said unselected scan electrodes on an application of selective and unselective voltages onto each data electrode.

Claim 26

A liquid crystal display driving system comprising: a panel having a plurality of liquid crystal cells arranged, in matrix, between a plurality of data electrodes and a plurality of scan electrodes, said data electrodes and said scan electrodes intersecting each other, ON-STATE and OFF-STATE of each cell being determined by cell voltage which is a difference between voltages of data electrode and scan electrode respectively connected said each cell, cell voltage to select ON-STATE being in a first polarity during a first voltage application mode, cell voltage to select ON-STATE being in a second polarity opposite to said first polarity during a second voltage application mode; mode selecting means for outputting a mode selecting signal which selects said voltage application mode, so as to switch said voltage application mode in a predetermined cycle; power sources for outputting selective voltages to select ON-STATE for the first and second voltage application modes, respectively, and unselective voltages to select OFF-STATE for said first and second modes, respectively; a scan driver, for selectively applying said selective and unselective voltages output from said power source to each of said scan electrodes, said selective and unselective voltages being selected depending on said mode selecting signal; a data driver for selectively applying said selective and unselective voltages output from said power source to each of said data electrodes, said selective and unselective voltages being selected depending on said mode selecting signal; logic converting means for converting a first logical level in data to be displayed on a scan electrode into a second logical level opposite to said first logical level during said first voltage application mode, and converting a second logical level in said data into said first logical level during said second voltage application mode; data difference detecting means for reducing a first quantity of logical level 1 output from said logic converting means displayed on a just previous scan electrode from a second quantity of logical level 1 output from said logic converting means to be displayed on a present scan electrode; compensation voltage generating means for generating a compensation voltage having a level in accordance to a predetermined relation to a change output from said data difference detecting means; and feedback means for superposing said compensation voltage onto voltages to be supplied via said scan driver to other unselected scan electrodes than said next scan electrode in synchronization with selection of said present scan electrode, so as to cancel undesirable spike pulse induced on said unselected scan electrodes on an application of selective and unselective voltages onto each data electrode.

Claim 27

A liquid crystal display driving system recited in claim 23, wherein said data difference detecting means comprises: memory means for storing an output of said logic converting means during a period selecting a single scan electrode; and data change detecting means for reducing a third quantity of bits changing from logic level 1 to logic level 0 from a fourth quantity of bits changing from logic level 0 to logic level 1, in comparing each of corresponding bits of an output from said logic converting means outputting a data to be displayed on said present scan electrode and an output from said memory means outputting a data displayed on previous scan electrode.

Claim 28

A liquid crystal display driving system recited in claim 23 wherein said compensation voltage generating means outputs a constant voltage during a period selecting a single scan electrode.

Claim 29

A liquid crystal display driving system recited in claim 23, wherein said compensation voltage generating means outputs a spike voltage having the substantially same waveform and the substantially same amplitude as those of said undesirable spike pulse.

Claim 30

A liquid crystal display driving system recited in claim 23, wherein said predetermined relation is such that said compensation voltage is in proportion to said change.

Claim 31

A liquid crystal display driving system recited in claim 23, wherein said predetermined relation is such that said compensation voltage is non linear to said change and is provided in a read-only memory device.

Claim 32

A liquid crystal display driving system comprising: a panel having a plurality of liquid crystal cells arranged, in matrix, between a plurality of data electrodes and a plurality of scan electrodes, said data electrodes and said scan electrodes intersecting each other, ON-STATE and OFF-STATE of each cell being determined by cell voltage which is a difference between voltages of data electrode and scan electrode respectively connected said each cell, cell voltage to select ON-STATE being in a first polarity during a first voltage application mode, cell voltage to select ON-STATE being in a second polarity opposite to said first polarity during a second voltage application mode; mode selecting means for outputting a mode selecting signal which selects said voltage application mode, so as to switch said voltage application mode in a predetermined cycle; power sources for supplying selective voltages to select ON-STATE for the first and second voltage application modes, respectively, and unselective voltages to select OFF-STATE for said first and second modes, respectively; a scan driver, for selectively applying said selective and unselective voltages output from said power source to each of said scan electrodes, said selective and unselective voltages being selected depending on said mode selecting signal; a data driver for selectively applying said selective and unselective voltages output from said power source to each of said data electrodes, said selective and unselective voltages being selected depending on said mode selecting signal; logic converting means for converting a first logical level in data to be displayed on a scan electrode into a second logical level opposite to said first logical level during said first voltage application mode, and converting a second logical level in said data into said first logical level during said second voltage application mode; data difference detecting means for reducing a first quantity of logical level 1 output from said logic converting means displayed on a just previous scan electrode from a second quantity of logical level 1 output from said logic converting means to be displayed on a present scan electrode; compensation voltage generating means for generating a compensation voltage having a level in accordance to a predetermined relation to a change output from said data difference detecting means; and feedback means for superposing said compensation voltage onto voltages to be supplied via said data driver to each of said data electrodes in synchronization with selection of said present scan electrode, so as to cancel undesirable spike pulse induced on said unselected scan electrodes on an application of selective and unselective voltages onto each data electrode.

Claim 33

A liquid crystal display driving system comprising: a panel having a plurality of liquid crystal cells arranged, in matrix, between a plurality of data electrodes and a plurality of scan electrodes, said data electrodes and said scan electrodes intersecting each other, ON-STATE and OFF-STATE of each cell being determined by cell voltage which is a difference between voltages of data electrode and scan electrode respectively connected said each cell, cell voltage to select ON-STATE being in a first polarity during a first voltage application mode, cell voltage to select ON-STATE being in a second polarity opposite to said first polarity during a second voltage application mode; mode selecting means for outputting a mode selecting signal which selects said voltage application mode, so as to switch said voltage application mode in a predetermined cycle; power sources for supplying selective voltages to select ON-STATE for the first and second voltage application modes, respectively, and unselective voltages to select OFF-STATE for said first and second modes, respectively; a scan driver, for selectively applying said selective and unselective voltages output from said power source to each of said scan electrodes, said selective and unselective voltages being selected depending on said mode selecting signal; a data driver for selectively applying said selective and unselective voltages output from said power source to each of said data electrodes, said selective and unselective voltages being selected depending on said mode selecting signal; logic converting means for converting a first logical level in data to be displayed on a scan electrode into a second logical level opposite to said first logical level during said first voltage application mode, and converting a second logical level in said data into said first logical level during said second voltage application mode; data difference detecting means for reducing a first quantity of logical level 1 output from said logic converting means displayed on a just previous scan electrode from a second quantity of logical level 1 output from said logic converting means to be displayed on a present scan electrode; compensation voltage generating means for generating a compensation voltage having a level in accordance to a predetermined relation to a change output from said data difference detecting means; and feedback means for superposing said compensation voltage onto voltages to be supplied via said data driver to each of said data electrodes in synchronization with selection of said present scan electrode, so as to cancel undesirable spike pulse induced on said unselected scan electrodes on an application of selective and unselective voltages onto each data electrode.

Claim 34

A liquid crystal display driving system recited in claim 29, wherein said data difference detecting means comprises: memory means for storing an output of said logic converting means during a period selecting a single scan electrode; and data change detecting means for reducing a third quantity of bits changing from logic level 1 to logic level 0 from a fourth quantity of bits changing from logic level 0 to logic level 1, in comparing each of corresponding bits of an output from said logic converting means outputting a data to be displayed on said present scan electrode and an output from said memory means outputting a data displayed on previous scan electrode.

Claim 35

A liquid crystal display driving system recited in claim 29, wherein said compensation voltage generating means outputs a constant voltage during a period selecting a single scan electrode.

Claim 36

A liquid crystal display driving system recited in claim 29, wherein said compensation voltage generating means outputs a spike voltage having the substantially same waveform and the substantially same amplitude as those of said undesirable spike pulse.

Claim 37

A liquid crystal display driving system recited in claim 29, wherein said predetermined relation is such that said compensation voltage is in proportion to said change.

Claim 38

A liquid crystal display driving system recited in claim 29, wherein said predetermined relation is such that said compensation voltage is non linear to said change and is provided in a read-only memory device.

Claim 41

A method of driving a liquid crystal display panel recited in claim 35, wherein polarity of said cell voltage to select said ON-STATE is altered in a predetermined period.

Claim 44

A method of driving a liquid crystal display panel recited in claim 37, wherein polarity of said cell voltage to select said ON-STATE is altered in a predetermined period.

Claim 45

A liquid crystal display driving system comprising: a panel having a plurality of liquid crystal cells arranged, in matrix, between a plurality of data electrodes and a plurality of scan electrodes, said data electrodes and said scan electrodes intersecting each other; a data driver connected to each of said data electrodes, for applying selective and unselective voltages to each of said data electrodes; a scan driver connected to each of said scan electrodes, for applying selective and unselective voltages to each of said scan electrodes; power sources for supplying each of said selective and unselective voltage to said data driver and said scan driver; and detecting means connected to one of said scan electrodes as a sample scan electrode, for detecting a spike voltage induced on said sample scan electrode, and outputting a compensation voltage in an opposite polarity to said spike voltage; feedback means for superposing said compensation voltage onto voltages to be applied to unselected scan electrodes from said power sources.

Claim 46

A liquid crystal display driving system comprising: a panel having a plurality of liquid crystal cells arranged, in matrix, between a plurality of data electrodes and a plurality of scan electrodes, said data electrodes and said scan electrodes intersecting each other; a data driver connected to each of said data electrodes, for applying selective and unselective voltages to each of said data electrodes; a scan driver connected to each of said scan electrodes, for applying selective and unselective voltages to each of said scan electrodes; power sources for supplying each of said selective and unselective voltage to said data driver and said scan driver; and detecting means connected to one of said scan electrodes as a sample scan electrode, for detecting a spike voltage induced on said sample scan electrode, and outputting a compensation voltage in an opposite polarity to said spike voltage; feedback means for superposing said compensation voltage onto voltages to be applied to unselected scan electrodes from said power sources.

Claim 47

A liquid crystal display driving system recited in claim 39, wherein said detecting means comprises: reference means outputting the same voltage as said voltage to be applied to said sample scan electrodes as a reference voltage; reduction means for outputting a reduction of said reference voltage from a voltage of said sample scan electrode; and inverting means for inverting polarity of said reduction; and said feedback means comprises adder circuits for adding an output of said detecting means to unselective voltages to be supplied to said unselected scan electrodes.

Claim 48

A liquid crystal display driving system recited in claim 39, wherein said power sources provides selective and unselective voltages to be supplied to data electrodes and scan electrodes, both for positive and negative voltage application modes, where said positive voltage application mode is such that a cell is selected by a positive cell voltage with respect to data electrode potential and said negative voltage application mode is such that a cell is selected by a negative cell voltage with respect to data electrode potential; and mode switching means is further comprised, for switching said voltage application modes in a predetermined cycle.

Claim 49

A liquid crystal display driving system comprising: a panel having a plurality of liquid crystal cells arranged, in matrix, between a plurality of data electrodes and a plurality of scan electrodes, said data electrodes and said scan electrodes intersecting each other; a data driver connected to each of said data electrodes, for applying selective and unselective voltages to each of said data electrodes; a scan electrodes connected to each of said scan electrodes, for applying selective and unselective voltages to each of said scan electrodes; power sources for supplying each of said selective and unselective voltage to said data driver and said scan driver; and detecting means connected to one of said scan electrodes as a sample scan electrode, for detecting a spike voltage induced on said sample scan electrode, and outputting a compensation voltage in the same polarity as said spike voltage; feedback means for superposing said compensation voltage onto voltages to be applied to each of data electrodes from said power sources.

Claim 50

A liquid crystal display driving system comprising: a panel having a plurality of liquid crystal cells arranged, in matrix, between a plurality of data electrodes and a plurality of scan electrodes, said data electrodes and said scan electrodes intersecting each other; a data driver connected to each of said data electrodes, for applying selective and unselective voltages to each of said data electrodes; a scan electrodes connected to each of said scan electrodes, for applying selective and unselective voltages to each of said scan electrodes; power sources for supplying each of said selective and unselective voltage to said data driver and said scan driver; and detecting means connected to one of said scan electrodes as a sample scan electrode, for detecting a spike voltage induced on said sample scan electrode, and outputting a compensation voltage in the same polarity as said spike voltage; feedback means for superposing said compensation voltage onto voltages to be applied to each of data electrodes from said power sources.

Claim 51

A liquid crystal display driving system recited in claim 42, wherein said detecting means comprises: reference means outputting the same voltage as said voltage to be applied to said sample scan electrodes as a reference voltage; reduction means for outputting a reduction of said reference voltage from a voltage of said sample scan electrode; and inverting means for inverting polarity of said reduction; and said feedback means comprises adder circuits for adding an output of said detecting means to voltages to be supplied to each of said data electrodes.

Claim 52

A liquid crystal display driving system recited in claim 42, wherein said power sources provides selective and unselective voltages to be supplied to data electrodes and scan electrodes, both for positive and negative voltage application modes, where said positive voltage application mode is such that a cell is selected by a positive cell voltage with respect to data electrode potential and said negative voltage application mode is such that a cell is selected by a negative cell voltage with respect to data electrode potential; and mode switching means for switching said voltage application modes in a predetermined cycle is further comprised.