Kabushiki Kaisha Toshiba

Mitsui Chemicals, Inc.

Kohki Takatoh

Tatsuo Saishu

Rieko Fukushima

Rei Hasegawa

Hajime Yamaguchi

Haruhiko Okumura

Hiroyuki Nagata

Masanori Sakamoto

Yasushi Kawata

Masahiko Akiyama

Kouhei Suzuki

Hisao Fujiwara

Rieko Iida

Harry Coles

Takeshi Yamaguchi

Akira Kinno

Yujiro Hara

Kazuyuki Sunohara

Miki Mori

Yoshihisa Mizutani

Hideo Hama

Seizaburo Shimizu

Yukari Sakai

Petra Kloess

Marcus J Coles

Philip Cox

Hitoshi Kobayahi

A display includes a ferroelectric liquid crystal material having an asymmetric polarity response property, a section which applies an image signal to a pixel of the material for every two fields forming one frame, and a controller which reverses the polarity of the signal in one frame period. Particularly, the controller is configured that the polarity of the signal is reversed in a selected one of first and second manners, the first manner initiating a signal amplitude change from a polarity in which a larger response of the material is obtainable, the second manner initiating a signal amplitude change from a polarity in which a smaller response of the material is obtainable, and the selected manner being smaller in the total of brightness deviation generated in a frame immediately after the change for each of predetermined brightness transitions.

Liquid crystal display and driving method of the same

Disclosed is a method for driving an active matrix type liquid crystal display device including a first electrode, a second electrode, and a liquid crystal layer interposed between the first and the second electrodes, and the liquid crystal layer having a larger polarization when a voltage of a first polarity is applied to the first electrode against the second electrode than that when a voltage of a second polarity different from the first polarity is applied to the first electrode against the second electrode, the method comprising dividing a frame into a first field and a second field, applying a first voltage of the first polarity to the first electrode during the first field, generating a second voltage from the first voltage by changing its polarity, a magnitude of the second voltage being modified by an amount of &#x394;V (&#x394;V&#x2260;0) based on a magnitude of the first voltage in a direction of the first polarity when the first voltage is not zero, and applying the second voltage to the first electrode during the second field.

Liquid-crystal display driving method using asymmetric driving voltage

There is a liquid crystal display element capable of obtaining a good display performance which is not influenced by the deterioration with the time course and the history of applied voltage. The liquid crystal display element comprises: a first electrode substrate having a first transparent substrate, a first electrode formed on the first substrate, and a first alignment layer formed on the first substrate so as to cover the first electrode; a second electrode substrate having a second transparent substrate, a second electrode formed on the second substrate, and a second alignment layer formed on the second substrate so as to cover the second electrode; and a light modulating layer of an anti-ferroelectric liquid crystal material which is sandwiched between the first and second electrode substrates covered with alignment layers and which has a thresholdless voltage-transmittance characteristic, wherein the first and second alignment layers are combined with the liquid crystal material so that a shifted angle between the optical axis &#x3b8;and an optical axis &#x3b8;of a batonnet is within &#xb1;1 degree.

Liquid crystal display element with particular angle of the optical axis of the batonnet

There is a liquid crystal display element capable of obtaining a good display performance which is not influenced by the deterioration with the time course and the history of applied voltage. The liquid crystal display element comprises: a first electrode substrate having a first transparent substrate, a first electrode formed on the first substrate, and a first alignment layer formed on the first substrate so as to cover the first electrode; a second electrode substrate having a second transparent substrate, a second electrode formed on the second substrate, and a second alignment layer formed on the second substrate so as to cover the second electrode; and a light modulating layer of an anti-ferroelectric liquid crystal material which is sandwiched between the first and second electrode substrates covered with alignment layers and which has a thresholdless voltage-transmittance characteristic, wherein the first and second alignment layers are combined with the liquid crystal material so that a shifted angle between the optical axis &thgr; and an optical axis &thgr; of a batonnet is within &plusmn;1 degree.

Liquid crystal display element

There is provided a liquid crystal display which is capable of preventing light from leaking out from the peripheral portion of pixels and which has a high display performance. The liquid crystal display comprises: an array substrate including a plurality of scanning lines and a plurality of signal lines, a plurality of switching elements, a plurality of pixel electrodes, and a first alignment layer which is formed on the first substrate so as to cover the pixel electrodes; a counter substrate including a counter electrode and a second alignment layer which is formed on the second substrate so as to cover the counter electrode; and a light control layer sandwiched between the array substrate and the counter substrate, and including a liquid crystal material having a spontaneous polarization and having a nematic phase or an isotropic phase on a high-temperature side of a chiral smectic C phase, an optical axis of liquid crystal molecules in the light control layer substantially staying when no electric field or a first electric field of a first polarity are applied to said liquid crystal material, and the optical axis of the liquid crystal molecules responding in accordance with a magnitude of a second electric field of a second polarity different from the first polarity when the second electric field is applied to said liquid crystal material, wherein an electric field between the scanning lines and the counter electrode has the first polarity when the switching elements turn on.

Liquid crystal display and method for producing the same

A liquid crystal display element including a first electrode substrate having a first transparent substrate, a first electrode formed on the first substrate, and a first alignment layer formed on the first substrate. The liquid crystal display element further includes a second electrode substrate having a second transparent substrate, a second electrode formed on the second substrate, and a second alignment layer formed on the second substrate. The liquid crystal display element also has a light modulating layer of a smectic liquid crystal material which is sandwiched between the first and second electrode substrates and which has a thresholdless voltage-transmittance characteristic and a spontaneous polarization of 120 nC/cm or less. Further, the polarity force component of the surface free energy of each of the first and second alignment layers is 13 dyn/cm or less.

Liquid crystal display element with thresholdless voltage transmittance characteristic

In a liquid crystal display in which a liquid crystal having spontaneous polarization is sandwiched between substrates, liquid crystal alignment which achieves a wide viewing angle and hardly causes alignment destruction is readily formed. A common electrode is formed by a pair of meshed comb electrodes, and rubbing alignment is performed in the logitudinal direction of teeth of these comb electrodes. When the liquid crystal material transits from a nematic phase or an isotropic phase to a chiral smectic C phase, a positive DC voltage, for example, is applied between a pixel electrode and one of the comb common electrodes, and a negative voltage is applied between a pixel electrode and the other comb common electrode. This readily accomplishes liquid crystal alignment in which smectic layers bend horizontally with respect to the substrate surface in space portions between the interdigitated teeth of the comb electrodes.

Liquid crystal display and method of manufacturing the same

In a method for driving a liquid crystal display apparatus which includes liquid crystal having spontaneous polarization disposed between a plurality of pixel electrodes arranged in a matrix form and a common electrode disposed to face the pixel electrodes, the method for driving the liquid crystal display apparatus includes a polarity inversion of periodically inverting polarities of at least one part of voltages applied between the plurality of pixel electrodes and the common electrode, and a write-in operation of applying the voltages to the pixel electrodes to hold display voltages, respectively, corresponding to the applied voltages on the pixel electrode, wherein the polarity inversion is effected to satisfy the expression of TS/TF&gE;2 when a frame period is set to TF and a period for effecting the polarity inversion is set to TS.

Liquid crystal display apparatus and method for driving the same

The present invention of reflective liquid crystal display device include in: substrate having a surface; a pixel electrode on the surface; a first liquid crystal layer provided on the substrate; a second liquid crystal layer provided on the first liquid crystal layer; a counter electrode formed on the second liquid crystal layer; and a separating member provided between the first liquid crystal layer and the second liquid crystal layer. The first and second liquid crystal layers constituted by liquid crystal material having Bragg reflection(selective reflection in the same twist direction. The separating layer constituted optical compensator.

Reflective liquid crystal display device

A pixel electrode is connected to a signal line via an n-channel TFT element for writing image signals and the pixel electrode is connected to an auxiliary storage capacitance line via p-channel TFT element for resetting the pixel electrode, wherein gate electrodes of the n-channel and p-channel TFT elements provided in a pixel region are commonly connected to a corresponding scanning line of the pixel region or to the corresponding scanning line and an adjacent scanning line, respectively.

Active matrix type liquid crystal display

The present invention is a liquid crystal including a ferroelectric liquid crystal compound and a siloxane compound represented by the following general formula (I). ##STR1## (where m is an integer of 0 to 20, n is an integer of 0 to 8, p is 0 or 1, q is an integer of 0 to 2, R is an alkyl group such as methyl group, ethyl group or propyl group, or an organic residue group represented by the following general formula (II) ##STR2## where R* is an alkyl group having optical activity center and X is halogen).

Liquid crystal material and liquid crystal display device using the same

It is an object of this invention to provide an active matrix type liquid crystal display which uses a ferroelectric liquid crystal or antiferroelectric liquid crystal, which has a high response speed, a wide angle of field, and a high contrast, and which does not cause a 'step response' phenomenon. An active matrix type liquid crystal display according to this invention includes pixel electrodes arranged in a matrix form, first switching devices arranged in a one-to-one correspondence with the pixel electrodes, signal lines for transmitting an image signal to the pixel electrodes via the first switching devices, scanning lines arranged to cross the signal lines to transmit a scanning signal for turning on the first switching devices, storage capacitance lines arranged parallel to the scanning lines to form storage capacitances between the storage capacitance lines and the pixel electrodes, and second switching devices arranged in a one-to-one correspondence with the pixel electrodes to connect pixel electrodes assigned to one scanning line to a storage capacitance line, while another scanning line is being selected, thereby resetting the pixel electrodes.

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Yokohama, Japan

Kohki Takatoh