Liquid crystal apparatus and driving method therefor

Claim 2

In an improved liquid crystal apparatus of the type comprising: a liquid crystal device comprising a matrix electrode structure including scanning electrodes and data electrodes intersecting each other and forming a pixel at each intersection, and a ferroelectric liquid crystal disposed between the scanning electrodes and the data electrodes, said ferroelectric liquid crystal showing either a first or a second optical state at each pixel depending on a polarity of voltage applied thereto; and means for applying to a pixel on a selected scanning electrode a bipolar pulse for causing a conversion from one to the other of the first and second optical states at the pixel, the improvement wherein; said ferroelectric liquid crystal has a negative dielectric anisotropy and shows a minimum value of τ min of a current response time τ 0 , and said bipolar pulse includes a unit pulse of one polarity which has a duration set to be shorter than the minimum value τ min .

Claim 3

An apparatus according to claim 1, wherein said unit pulse having a duration shorter than the minimum value τ min has a wavelight providing an electric field intensity higher than an electric field intensity E 1 giving the minimum value τ min of the current response time τ 0 .

Claim 4

An apparatus according to claim 1, wherein said unit pulse having a duration shorter than the minimum value τ min is disposed in a former half of the bipolar data pulse.

Claim 5

An apparatus according to claim 1, wherein said unit pulse having a duration shorter than the minimum value τ min is disposed in a latter half of the bipolar data pulse.

Claim 6

An apparatus according to claim 1, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

Claim 7

In an improved liquid crystal apparatus of the type comprising: a liquid crystal device comprising a matrix electrode structure including scanning electrodes and data electrodes intersecting each other and forming a pixel at each intersection, and a ferroelectric liquid crystal disposed between the scanning electrodes and the data electrodes, and showing either a first or a second optical state at each pixel depending on a polarity of voltage applied thereto; and means for applying to non-selected pixels an AC voltage not causing a conversion between the first and second optical states at the non-selected pixels and applying to a pixel on a selected scanning electrode a bipolar pulse for causing a conversion from one to the other of the first and second optical states at the pixel, the improvement wherein; said ferroelectric liquid crystal has a negative dielectric anisotropy and shows a minimum value of τ min of a current response time τ 0 , and said bipolar pulse includes a unit pulse of one polarity which has a duration set to be shorter than the minimum value τ min .

Claim 8

In an improved liquid crystal apparatus of the type comprising: a liquid crystal device comprising a matrix electrode structure including scanning electrodes and data electrodes intersecting each other and forming a pixel at each intersection, and a ferroelectric liquid crystal disposed between the scanning electrodes and the data electrodes, and showing either a first or a second optical state at each pixel depending on a polarity of voltage applied thereto; and means for applying to non-selected pixels an AC voltage not causing a conversion between the first and second optical states at the non-selected pixels and applying to a pixel on a selected scanning electrode a bipolar pulse for causing a conversion from one to the other of the first and second optical states at the pixel, the improvement wherein; said ferroelectric liquid crystal has a negative dielectric anisotropy and shows a minimum value of τ min of a current response time τ 0 , and said bipolar pulse includes a unit pulse of one polarity which has a duration set to be shorter than the minimum value τ min .

Claim 9

An apparatus according to claim 6, wherein said unit pulse having a duration shorter than the minimum value τ min has a waveheight providing an electric field intensity higher than an electric field intensity E 1 giving the minimum value ρ min of the current response time τ 0 .

Claim 10

An apparatus according to claim 6, wherein said unit pulse having a duration shorter than the minimum value τ min is disposed in a former half of the bipolar data pulse.

Claim 11

An apparatus according to claim 6, wherein said unit pulse having a duration shorter than the minimum value τ min is disposed in a latter half of the bipolar data pulse.

Claim 12

An apparatus according to claim 6, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

Claim 13

In an improved liquid crystal apparatus of the type comprising: providing a liquid crystal device comprising a matrix electrode structure including scanning electrodes and data electrodes intersecting each other and forming a pixel at each intersection, and a ferroelectric liquid crystal disposed between the scanning electrodes and the data electrodes, and showing either a first or a second optical state at each pixel depending on a polarity of voltage applied thereto; and applying to a pixel on a selected scanning electrode a bipolar pulse for causing a conversion from one to the other of the first and second optical states at the pixel, the improvement wherein; said ferroelectric liquid crystal has a negative dielectric anisotropy and shows a minimum value of τ min of a current response time τ 0 , and said bipolar pulse includes a unit pulse of one polarity which has a duration set to be shorter than the minimum value τ min .

Claim 14

In an improved liquid crystal apparatus of the type comprising: providing a liquid crystal device comprising a matrix electrode structure including scanning electrodes and data electrodes intersecting each other and forming a pixel at each intersection, and a ferroelectric liquid crystal disposed between the scanning electrodes and the data electrodes, and showing either a first or a second optical state at each pixel depending on a polarity of voltage applied thereto; and applying to a pixel on a selected scanning electrode a bipolar pulse for causing a conversion from one to the other of the first and second optical states at the pixel, the improvement wherein; said ferroelectric liquid crystal has a negative dielectric anisotropy and shows a minimum value of τ min of a current response time τ 0 , and said bipolar pulse includes a unit pulse of one polarity which has a duration set to be shorter than the minimum value τ min .

Claim 15

An apparatus according to claim 11, wherein said unit pulse having a duration shorter than the minimum value τ min has a waveheight providing an electric field intensity higher than an electric field intensity E 1 giving the minimum value ρ min of the current response time τ 0 .

Claim 16

An apparatus according to claim 11, wherein said unit pulse having a duration shorter than the minimum value τ min is disposed in a former half of the bipolar data pulse.

Claim 17

An apparatus according to claim 11, wherein said unit pulse having a duration shorter than the minimum value τ min is disposed in a latter half of the bipolar data pulse.

Claim 18

An apparatus according to claim 11, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

Claim 19

In an improved liquid crystal apparatus of the type comprising: providing a liquid crystal device comprising a matrix electrode structure including scanning electrodes and data electrodes intersecting each other and forming a pixel at each intersection, and a ferroelectric liquid crystal disposed between the scanning electrodes and the data electrodes, and showing either a first or a second optical state at each pixel depending on a polarity of voltage applied thereto; applying to non-selected pixels an AC voltage not causing a conversion between the first and second optical states at the non-selected pixels, and applying to a pixel on a selected scanning electrode a bipolar pulse for causing a conversion from one to the other of the first and second optical states at the pixel, the improvement wherein: said ferroelectric liquid crystal has a negative dielectric anisotropy and shows a minimum value of τ min of a current response time τ 0 , and said bipolar pulse includes a unit pulse of one polarity which has a duration set to be shorter than the minimum value τ min .

Claim 20

In an improved liquid crystal apparatus of the type comprising: providing a liquid crystal device comprising a matrix electrode structure including scanning electrodes and data electrodes intersecting each other and forming a pixel at each intersection, and a ferroelectric liquid crystal disposed between the scanning electrodes and the data electrodes, and showing either a first or a second optical state at each pixel depending on a polarity of voltage applied thereto; applying to non-selected pixels an AC voltage not causing a conversion between the first and second optical states at the non-selected pixels, and applying to a pixel on a selected scanning electrode a bipolar pulse for causing a conversion from one to the other of the first and second optical states at the pixel, the improvement wherein: said ferroelectric liquid crystal has a negative dielectric anisotropy and shows a minimum value of τ min of a current response time τ 0 , and said bipolar pulse includes a unit pulse of one polarity which has a duration set to be shorter than the minimum value τ min .

Claim 21

An apparatus according to claim 16, wherein said unit pulse having a duration shorter than the minimum value τ min has a waveheight providing an electric field intensity higher than an electric field intensity E 1 giving the minimum value ρ min of the current response time τ 0 .

Claim 22

A method according to claim 16, wherein said unit pulse having a duration shorter than the minimum value τ min is disposed in a former half of the bipolar data pulse.

Claim 23

A method according to claim 16, wherein said unit pulse having a duration shorter than the minimum value τ min is disposed in a latter half of the bipolar data pulse.

Claim 24

A method according to claim 16, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.