JP2007193085A - Liquid crystal display element using nematic liquid crystal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display element using a nematic liquid crystal, which is easily fabricated, which has a memory property and a wide viewing angle display characteristic compatible with each other, which is highly precise and which has a wide viewing angle and low power consumption. <P>SOLUTION: In the liquid crystal display element using the nematic liquid crystal, which has: a pair of transparent substrates SUB1, SUB2; a liquid crystal layer LCL disposed between the pair of substrates SUB1, SUB2; a group of electrodes for applying an electric field with a component nearly parallel to surfaces of the substrates to the liquid crystal layer LCL; and an alignment layer, subjected to liquid crystal alignment control treatment in two directions, disposed between the liquid crystal layer LCL and at least one out of the pair of substrates SUB1, SUB2, the liquid crystal alignment control treatment of the alignment layer is irradiation treatment with light generating a chemical reaction of the alignment layer on the substrate surface as linearly polarized light, and the alignment layer is composed of a photo-reactive material of which the direction to control liquid crystal alignment is that corresponding to a polarization direction of linearly polarized light of final irradiation with respect to multiple times of linearly polarized light irradiation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display element using a nematic liquid crystal, and more particularly to a liquid crystal display element using a nematic liquid crystal with low power consumption and high definition.

  Conventionally, as a display element of a portable information terminal such as a mobile phone, a liquid crystal display element mainly using a nematic liquid crystal has been used taking advantage of its low driving voltage and low power consumption characteristics. With rapid spread, the production volume is expanding. At the same time, the display function is required to have higher display performance such as an increase in the number of display pixels (characters). On the other hand, since it is necessary to maintain or extend the continuous use time using a battery as a portable device, not only the above-mentioned high-definition display functions but also low power consumption can be achieved at the same time. Technology to do is needed.

  As one of such techniques, various techniques using a liquid crystal display element having a so-called display memory characteristic in which a display is maintained even when a voltage applied to the liquid crystal display element is turned off have been proposed. By using memory characteristics, in principle, the power consumption can be reduced to 0 when the display content does not change, and the display content can be changed by applying a voltage only to the pixel whose display content has changed for each pixel. By doing so, power consumption can be reduced. Further, when the conventional twisted nematic (TN) method or the super twisted nematic (STN) method is driven in a simple matrix, there is an upper limit on the number of pixels that can be displayed due to the limitation of the duty ratio, as is well known. The limitation on the number of pixels can be eliminated by utilizing the memory property.

Specific examples of the prior art having such display memory properties include, for example, (1) those using ferroelectric liquid crystals (see Non-Patent Document 1 and Patent Document 1), and (2) nematic liquid crystals. A combination of liquid crystal alignment layers subjected to grating treatment (see Patent Document 2), (3) An alignment layer having an alignment pattern composed of subregions having liquid crystal alignment control directions in two different directions on the substrate surface is used. Therefore, the one using the surface multiple orientation stability (see Patent Document 3) has been proposed.
JP-A-56-107216 Japanese National Patent Publication No. 11-513809 International Publication Number WO02 / 006887 Applied Physics Letters, 36,899 (1980)

  However, in the prior art described above, the one using the ferroelectric (chiral smectic C) liquid crystal of (1) has a fast response due to the ferroelectric effect, and is in the substrate plane between two homogeneous alignment states. However, it is difficult to control the alignment because of the layer structure unique to the smectic liquid crystal compared to the general liquid crystal display element using nematic liquid crystal. Has a problem that it is difficult to recover once it is broken due to mechanical shock, and has not been put into widespread use.

  On the other hand, the one using the nematic liquid crystal (2) and the liquid crystal alignment layer subjected to fine grating processing switches between the two states of homeotropic (vertical) alignment and hybrid alignment using the flexoelectric effect. However, there is a problem that display viewing angle characteristics deteriorate in a specific direction due to the hybrid orientation. Further, in this liquid crystal display element, a liquid crystal material having a sufficiently large flexoelectric coefficient is required to lower the drive voltage. However, since such a liquid crystal material is not generally known, the drive voltage and There is also a problem that power consumption becomes high, and this technology has not been put into widespread use.

  In the case of using an alignment layer having an alignment pattern composed of sub-regions having liquid crystal alignment regulation directions in two different directions on the substrate surface in (3), as a method of creating an alignment pattern composed of a plurality of regions. A photomask with a square checkerboard pattern in which a linearly polarized ultraviolet light is obtained by a polarizing element using a Brewster angle using a mercury lamp or the like as a ultraviolet light source, and the size of each square small region is approximately 1 μm square. The two linearly polarized ultraviolet irradiations are rotated by 90 degrees with respect to each other, and at the same time, the portion of the photomask checkerboard pattern that strikes black is the first and the portion that strikes white is the second polarized ultraviolet irradiation region. It is described to do so. However, in this method, it is necessary to change the positional relationship of the opening portion of the photomask between the first and second light irradiations, as described above, black for the first checkerboard pattern and white for the second time. Therefore, it is necessary to either replace two masks with different openings in black and white, or move the same mask in the horizontal and vertical directions, respectively, by moving the square approximately 1 μm. In this case, since the positioning / alignment accuracy of less than about 1 μm, which is the size of this square, is required, there is a practical problem that the production is difficult or the apparatus becomes large.

  As described above, in the prior art, a liquid crystal display element using a nematic liquid crystal that does not have a layer structure and is easy to control the orientation, a liquid crystal display element that achieves both low power consumption due to memory characteristics and wide viewing angle display. It has been difficult to produce and provide it simply.

  In view of the above situation, the present invention provides a liquid crystal display element using nematic liquid crystal that can be easily manufactured and has both high memory performance and wide viewing angle display characteristics, and has high definition, wide viewing angle, and low power consumption. Objective.

  In order to achieve the above object, the present invention starts with subregions having liquid crystal alignment regulating directions in two different directions on the substrate surface, similar to the one disclosed in Patent Document 3 as a prior art. In order to solve the problems in the production of the above-mentioned prior art at the same time, an alignment layer having the above-mentioned alignment pattern is prepared by using linearly polarized ultraviolet light as a method for producing the above-mentioned alignment layer. Using a so-called photo-alignment method that irradiates a surface pre-coated with a photosensitive material having sensitivity, the liquid crystal alignment regulation direction determined by the polarization direction of the irradiated polarized light is applied by multiple times of polarized light irradiation. A resettable (rewritable) material is used.

  That is, a pair of substrates at least one of which is transparent, and an electrode group formed on at least one of the pair of substrates for applying an electric field having a component substantially parallel to the substrate surface to the liquid crystal layer, A liquid crystal layer disposed between the pair of substrates, and an alignment layer disposed between at least one of the liquid crystal layer and the pair of substrates and subjected to a liquid crystal alignment regulation process in two directions. In the liquid crystal display element, the liquid crystal alignment regulating process of the alignment layer is a process of irradiating light that can give a chemical reaction to the alignment layer on the substrate surface as linearly polarized light, and the alignment layer is a plurality of straight lines. It is characterized by comprising a photoreactive material whose liquid crystal alignment regulating direction is the liquid crystal alignment regulating direction corresponding to the polarization direction of the linearly polarized light irradiated last with respect to polarized light irradiation.

  FIG. 1 is a schematic diagram showing the principle of the present invention.

  By using an alignment layer using a material in which the liquid crystal alignment regulation direction can be reset (rewritten), the first time is an area to be processed as shown in FIG. Irradiation with linearly polarized ultraviolet light (LUV1) is performed uniformly without using a photomask or the like, and the second linearly polarized ultraviolet light (LUV2) is rotated 90 degrees as shown in FIG. 1B. Only at the time of irradiation, only a part of the region to be processed is selectively irradiated with the second linearly polarized ultraviolet light through the photomask (PMASK), and the liquid crystal alignment control of the selected region is performed as shown in FIG. Only the direction can be set (rewritten), and the problem of photomask positioning and alignment accuracy can be solved.

  Here, the same effect can be obtained by using light incident in an oblique direction with respect to the substrate normal instead of the above-mentioned linearly polarized light as the ultraviolet light irradiated to the alignment layer. Instead of this, the liquid crystal alignment regulating direction can be controlled by changing the oblique incident direction.

  That is, one of the two liquid crystal alignment regulation processes is a process uniformly applied to the entire area to be processed, and the other liquid crystal alignment regulation process is performed on only a part of the area to be processed. The process may be selectively performed. In order for the alignment pattern thus produced to exhibit memory properties, the two different liquid crystal alignment regulating directions are substantially orthogonal within the substrate plane, and the rising angle from the substrate plane in at least one liquid crystal alignment regulating direction is May be characterized in that all are substantially 0 degrees. The liquid crystal layer may be made of a liquid crystal material containing an asymmetric molecule as a composition component. Further, the liquid crystal layer may be made of a liquid crystal material that can take both positive and negative depending on the frequency of the alternating electric field to which the sign of dielectric anisotropy is applied. Furthermore, it is good also as having the electrode which becomes a pair arrange | positioned on each board | substrate of a pair of said board | substrate separately from the said comb-tooth electrode. Alternatively, a light reflecting plate may be arranged on one of the pair of substrates.

  According to the present invention, in a liquid crystal display element using nematic liquid crystal, a liquid crystal display element that achieves both low power consumption due to memory characteristics and wide viewing angle display can be more easily manufactured.

  The liquid crystal display element using the nematic liquid crystal according to the present invention has a pair of substrates at least one of which is transparent and an electric field formed on at least one of the pair of substrates and having a component substantially parallel to the substrate surface. An electrode group for applying to the liquid crystal layer, a liquid crystal layer disposed between the pair of substrates, and two directions disposed between at least one of the liquid crystal layer and the pair of substrates. In a liquid crystal display device having an alignment layer subjected to a liquid crystal alignment control process, the liquid crystal alignment control process of the alignment layer is a process of irradiating light that can give a chemical reaction to the alignment layer on the substrate surface as linearly polarized light. From the photoreactive material in which the alignment layer has a liquid crystal alignment regulating direction corresponding to the polarization direction of the last linearly polarized light irradiated to the linearly polarized light irradiated a plurality of times. Become.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 2 is a diagram showing the configuration of the liquid crystal display element according to the first embodiment of the present invention.

  In this figure, as the substrates SUB1 and SUB2, two transparent glass substrates having a thickness of 1.1 mm and polished on the surface were used. On the substrate SUB1, a pair of comb electrodes EL2A and EL2B are formed by patterning a transparent conductive layer made of the same ITO (Indium Tin Oxide) formed on the substrate, and further made of silicon nitride thereon. An insulating protective film IL1 having a thickness of 600 nm was formed. Similarly, another set of comb-shaped electrodes EL1A and EL1B is patterned by patterning a transparent conductive layer made of the same ITO formed on the insulating film IL1 in a direction substantially orthogonal to the comb-shaped electrode EL2. Further, an insulating protective film IL2 made of silicon nitride and having a thickness of 200 nm was formed thereon. LCL is a liquid crystal layer. The electrode longitudinal directions of the comb electrodes EL1 and EL2 are the y-axis and x-axis directions, respectively, in the coordinate system in the figure. In addition, the electrode width of these comb-tooth electrodes EL1 and EL2 is 6 μm, the electrode spacing is 4 μm, and the number of comb-tooth gaps in the figure is schematically shown in three parts for simple explanation. The element was divided into 8 parts.

  Next, on the insulating film IL2, as a photosensitive material, [Chemical Formula 1] containing an azobenzene group is dissolved in N, N-dimethylformamide to form a 1% solution. The solvent was removed to obtain a dense photosensitive film.

ここで、感光性材料として、〔化１〕の代わりに同様にアゾベンゼン基を含有する高分子材料〔化２〕を用いてもよい。

Here, instead of [Chemical Formula 1], a polymer material containing an azobenzene group [Chemical Formula 2] may be used as the photosensitive material.

紫外光等の照射により液晶配向規制方向を形成する、いわゆる光配向用の感光性材料としては、紫外光照射による光化学反応の形態による分類、つまり光重合型、光分解型、光異性化型が一般的に知られている。この分類中では、光異性化型に分類されるものが、上記のような液晶配向規制方向がリセット（書き換え）可能な感光性材料として好適であり、具体的にはアゾ基、スチルベン基等を含有する低分子・高分子材料が好ましい。

The so-called photo-alignment photosensitive materials that form the liquid crystal alignment regulation direction by irradiation with ultraviolet light, etc. are classified according to the form of photochemical reaction by ultraviolet light irradiation, that is, photopolymerization type, photolysis type, photoisomerization type. Generally known. Among these classifications, those classified as photoisomerization types are suitable as photosensitive materials whose liquid crystal alignment control direction can be reset (rewritten) as described above. Specifically, azo groups, stilbene groups, etc. The low-molecular / high-molecular material contained is preferable.

Thereafter, a high-pressure mercury lamp was used as an ultraviolet light source, passed through a filter near 365 nm, and the entire surface of the substrate was uniformly irradiated as linearly polarized ultraviolet light by a polarizing element using a Brewster angle. The irradiation light intensity on the film surface at this time is about 15 mW / cm ² .

Next, the linear polarization direction is rotated by 90 degrees with respect to the first light irradiation described above, and the size of each divided square small region as shown in FIG. 1B is approximately 1 μm square. Second irradiation was performed with an irradiation light intensity of about 20 mW / cm ² through a photomask having a square checkerboard pattern (white portion is an opening).

  These polarized ultraviolet light irradiations were made to be perpendicularly incident on the substrate surface so that the pretilt angle of the liquid crystal alignment provided thereby was approximately 0 degrees.

  As a result of the above-mentioned two irradiations with linearly polarized ultraviolet light, the black (mask non-opening) portion of the used checkerboard pattern becomes the liquid crystal alignment regulating direction orthogonal to the linearly polarized light direction at the first light irradiation, and the checkerboard pattern After the first light irradiation, the white (mask opening) part of the liquid crystal is reset (rewritten) by the second light irradiation in which the polarization direction is rotated by 90 degrees. The direction of liquid crystal alignment is perpendicular to each other.

  As described above, by using the alignment film material [Chemical Formula 1] having a reset (rewrite) function in the liquid crystal alignment control direction for a plurality of times of light irradiation, irradiation through the mask for forming the alignment pattern is performed once. Therefore, it is possible to solve the problem of the first and second mask alignment, which becomes a problem when the irradiation through the mask is performed twice.

  Note that these pattern shapes and irradiation light intensities are merely examples, and are adjusted in accordance with the photosensitive material used, the characteristics of the liquid crystal material, and the like. The grid direction of the checkerboard pattern and the local orientation regulating directions LAL1A and LAL1B in each grid form an angle of about 45 degrees with the x axis and the y axis, respectively, when expressed in the coordinate system in FIG. Set to direction.

  The alignment layer AL1 formed in this way and having a plurality of regions having two liquid crystal alignment easy axis directions arranged in the substrate surface results in the ALD1A and ALD1B directions in the coordinate system x-axis and y-axis directions in the figure. An alignment layer having easy alignment axes in two directions is obtained.

  The other substrate SUB2 was coated with a solution of SE7210 (Nissan Chemical Co., Ltd.), a solvent-soluble polyimide precursor, heated to 200 ° C., left for 30 minutes to remove the solvent, and the dense substrate SUB2. After the polyimide film is obtained, the alignment film surface is rubbed with a buff cloth attached to a rubbing roller to give a liquid crystal alignment ability having a single easy alignment axis represented by ALD2 in the x-axis direction of the coordinate axis in FIG. did.

  Next, a cell was assembled by interposing spacers made of dispersed spherical polymer beads and a peripheral sealant between these two substrates with their liquid crystal alignment surfaces facing each other. It was.

  Next, between the substrates of this liquid crystal cell, a nematic liquid crystal composition ZLI-4535 (manufactured by Merck & Co., Inc.) (dielectric anisotropy Δε is positive and its value is 14.8, and refractive index anisotropy Δn is 0.0865. ) Was injected in a vacuum and sealed with a sealing material made of an ultraviolet curable resin to obtain a liquid crystal panel. At this time, the thickness of the liquid crystal layer was adjusted to 6.4 μm in the liquid crystal sealed state by the above-mentioned spacer. Therefore, the retardation (Δnd) of the liquid crystal display element of this example is 0.5 μm.

  Next, this panel is sandwiched between two polarizing plates POL1 and POL2 (G1220DU manufactured by Nitto Denko Corporation), and the polarizing transmission axis POL of one polarizing plate is substantially parallel to the rubbing direction ALD2, and the other POL is orthogonal to it. Arranged. Thereafter, a drive circuit, a backlight, and the like were connected to obtain a liquid crystal display element. Next, the same liquid crystal composition as described above is used between the same pair of substrates in which an alignment layer is formed by the same process using the same alignment film material as that used on the substrate SUB1 side of the liquid crystal display element thus obtained. A liquid crystal cell was prepared by enclosing the product ZLI-4535, and the pretilt angle in each direction at the liquid crystal interface between the alignment layer having the easy alignment axis in two directions and the liquid crystal cell was measured by a crystal rotation method. It was confirmed that the pretilt angle was approximately 0 degrees within the range of the measurement accuracy within the range of degrees.

  Incidentally, the same liquid crystal composition ZLI− as described above is used between the same pair of substrates in which the alignment layer is formed under the same rubbing conditions using the same alignment film material and process as those used on the substrate SUB2 side in this example. A liquid crystal cell was prepared by enclosing 4535, and the pretilt of this liquid crystal cell was measured by a crystal rotation method and found to be 5 degrees.

  The switching characteristics of the liquid crystal display element of the first embodiment will be described with reference to FIG. In the figure, V1 and V2 are voltage waveforms applied between the first comb-tooth electrodes EL1A and EL1B and the second comb-tooth electrodes EL2A and EL2B, and Tr represents a change in the transmittance of the liquid crystal element associated therewith.

As shown in FIG. 3, it can be seen that the liquid crystal element shown in this embodiment can be switched between two bright and dark memory states by selectively applying an alternating voltage as V1 or V2. Switching AC voltage in this embodiment (frequency 1kHz) is 6V _pp as 8V _pp, V2 as V1, slight driving voltage asymmetry was observed.

  FIG. 4 shows a schematic diagram of the liquid crystal alignment state in the liquid crystal layer corresponding to the dark state (see FIG. 4A) and the bright state (see FIG. 4B), respectively.

  As shown in this figure, switching between these two states is performed by liquid crystal molecule alignment switching substantially in the substrate plane.

  Next, when the viewing angle characteristics of the liquid crystal display element of this example were measured using a liquid crystal viewing angle measuring device CV-1000 (manufactured by Minolta Co., Ltd.), the contrast ratio was 140 ° up and down and 140 ° left and right. A wide viewing angle characteristic of 10: 1 or more and no gradation inversion was obtained.

  In visual image quality inspection, a large change in display color was not seen even when viewed from an oblique direction, and a highly uniform display was obtained.

  Next, a second embodiment of the present invention will be described.

  In the first embodiment, the same as Example 1 except that the liquid crystal material was CB-15 (manufactured by Merck) as a chiral dopant so that the helical pitch length of the composition was about 15 μm. In this manner, a liquid crystal display element was produced and used as the second example.

  FIG. 5 is a diagram showing the electro-optical characteristics of this example corresponding to FIG.

In this embodiment, the switching AC voltage is 5 V _pp as V 1 and 4.8 V _pp as V 2, and the drive voltage asymmetry of V 1 and V 2 is almost equal due to the energy stabilization effect of the twisted planar state by adding the chiral dopant. I was able to resolve it.

  In the same viewing angle measurement as in the first example, a highly uniform display having the same wide viewing angle characteristic as in the first example was obtained.

  Next, a third embodiment of the present invention will be described.

  In the first embodiment, TX2A (made by Merck) is used as the liquid crystal material, and as shown in FIG. 6, the first embodiment except that a dual frequency drive circuit is used as a configuration having only one pair of comb electrodes. A liquid crystal display device was produced in the same manner as in the example, and the third example was obtained.

  The liquid crystal composition TX2A is a nematic composition for two-frequency driving in which the dielectric anisotropy (Δε) is positive at a low frequency and negative at a high frequency, and the crossover frequency is 6 kHz.

FIG. 7 shows drive waveforms and electro-optical characteristics of this example. As shown in this figure, in this embodiment, for switching from the dark (homogeneous) state to the light (twisted planer) state, 4 kHz, 8 V _pp AC voltage with which Δε of TX2A is positive, and reverse switching are used. Switching between the two states was possible with a pair of comb electrodes by using an alternating voltage of 8 kHz and 10 V _pp at which Δε is sometimes negative as V1.

  Also in the present example, the same viewing angle measurement as in the first example gave a highly uniform display having the same wide viewing angle characteristics as in the first example.

  Further, in the same manner as in Example 1, the pretilt angle at the liquid crystal interface between the alignment layer having the easy alignment axes in two directions of the liquid crystal cell using the same alignment layer and the same liquid crystal material TX2A was measured by the crystal rotation method. However, it was confirmed that the pretilt angle was approximately 0 degrees within the range of measurement accuracy at 2 degrees or less.

  Next, a fourth embodiment of the present invention will be described.

  In the third embodiment, as shown in FIG. 8, a liquid crystal display device was manufactured in the same manner as the third embodiment except that a pair of parallel plate electrodes was added to each of the substrate SUB1 and the substrate SUB2. The fourth example was adopted.

  The parallel plate electrodes as a pair are made of ITO transparent electrodes and connected to a drive circuit to which an AC voltage V2 is applied.

The electro-optical characteristics and viewing angle characteristics of this embodiment are almost the same as those of the third embodiment. However, by applying an AC voltage of 4 kHz and 20 V _pp between the added parallel plate electrodes, two pixels are brightened at a time. Refresh display was possible from the state to the dark state.

  Next, a fifth embodiment of the present invention will be described.

  In the third embodiment, as shown in FIG. 9, the light reflecting plate REF and the λ / 4 plate QP are added on the substrate SUB1, the cell gap is reduced to 3.2 μm, and the alignment layer is formed. Two easy liquid crystal alignment axes ALD1A and ALD2A that form an angle of 45 degrees with respect to AL1 by adjusting the intensity of ultraviolet polarized light when forming two local alignment control directions LAL1A and LAL1B in each checkerboard pattern of AL1 A reflective liquid crystal display device was produced in the same manner as in the third example except that the alignment layer provided with the above was used.

  In this embodiment, the direction of the delay axis of the λ / 4 plate QP is set at an angle of approximately 45 degrees with the transmission axis of the polarizing plate POL2, the orientation easy axis ALD1A of the orientation layer AL1 is in the same direction as ALD2, and ALD1B is in ALD2. The direction is 45 degrees rotated.

  With the configuration of the alignment layer AL1 described above, the alignment state of the two stable liquid crystal layers in this embodiment is a 45-degree twisted structure as shown in FIG. 4B, and the transmission type configuration of FIG. As well as dark in the uniform orientation state and bright in the (45 degrees) twisted planar state.

  The electro-optical characteristics and viewing angle characteristics of the present embodiment are almost the same as those of the third embodiment, except that the optical characteristics are obtained as reflectance rather than transmittance.

Also in this example, the pretilt angle at the liquid crystal interface between the alignment layer having the easy alignment axes in two directions of the liquid crystal cell using the same alignment layer and the same liquid crystal material and the liquid crystal interface is obtained by the crystal rotation method in the same manner as in Example 1. When measured, it was confirmed that the pretilt angle was approximately 0 degrees within the range of measurement accuracy within 2 degrees.
Next, a sixth embodiment of the present invention will be described.

  In the first embodiment, two linearly polarized ultraviolet rays are used by using two photomasks having a checkerboard pattern similar to that of the first embodiment as alignment layers on both sides of the two substrates sandwiching the liquid crystal layer. In addition, the angle between the two easy axes of the resulting alignment layer is 45 degrees, as in Example 5, by using the alignment layer irradiated with UV and further changing the intensity of the two ultraviolet light irradiations. A liquid crystal display device was produced in the same manner as in Example 1 except for the above, and a sixth example was obtained.

  As a form of switching in this embodiment, since two alignment directions in which two alignment directions are energetically stable are arranged on both substrates, in-plane switching (switching angle of 45 degrees) occurs at the interface between both substrates. This and the two polarizing plates arranged in crossed Nicol form a display in a birefringent optical mode between homogeneous states with different in-plane orientations.

  The electro-optical characteristics and viewing angle characteristics of this embodiment are almost the same as those of the first embodiment, except that the optical characteristics are obtained as the transmittance in the birefringence mode as described above.

  Also in this example, the pretilt angle at the liquid crystal interface between the alignment layer having the easy alignment axes in two directions of the liquid crystal cell using the same alignment layer and the same liquid crystal material and the liquid crystal interface is obtained by the crystal rotation method in the same manner as in Example 1. As a result of the measurement, it was confirmed that the pretilt angle was approximately 0 degrees within the range of the measurement accuracy within 2 degrees.

  In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, These are not excluded from the scope of the present invention.

  The liquid crystal display device of the present invention can be used for a low power consumption, high definition liquid crystal display element used for a portable information terminal such as a cellular phone.

It is a schematic diagram which shows the principle of this invention. It is a figure which shows the structure of the liquid crystal display element which shows 1st Example of this invention. It is a figure which shows the switching characteristic of the liquid crystal display element which shows 1st Example of this invention. It is a figure which shows the schematic diagram of the orientation state in the liquid crystal corresponding to the dark state and bright state which show 1st Example of this invention. It is a figure which shows the electro-optical characteristic of 2nd Example corresponding to FIG. It is a figure which shows the structure of the liquid crystal display element which shows 3rd Example of this invention. It is a figure which shows the drive waveform and electro-optical characteristic of the liquid crystal display element which show 3rd Example of this invention. It is a figure which shows the structure of the liquid crystal display element which shows 4th Example of this invention. It is a figure which shows the structure of the liquid crystal display element which shows 5th Example of this invention.

Explanation of symbols

SUB1, SUB2 Substrate EL1, EL1A, EL1B, EL2, EL2A, EL2B Comb electrode IL1, IL2 Insulating protective film LAL1A, LAL1B Liquid crystal alignment regulating direction in each alignment pattern AL1, AL2 Alignment layer POL1, POL2 Polarizing plate ALD2 Rubbing direction REF Light reflection plate QP λ / 4 plate ALD1A, ALD1B Liquid crystal alignment easy axis LCL Liquid crystal layer LUV1, LUV2 Linear polarization direction of irradiated ultraviolet light PMASK Photomask

Claims (9)

A pair of substrates at least one of which is transparent; an electrode group formed on at least one of the pair of substrates for applying an electric field having a component substantially parallel to the substrate surface to the liquid crystal layer; A liquid crystal display comprising: a liquid crystal layer disposed between the substrates; and an alignment layer disposed between the liquid crystal layer and at least one of the pair of substrates and subjected to liquid crystal alignment regulation processing in two directions. In the element
The liquid crystal alignment regulating process of the alignment layer is a process of irradiating light that can give a chemical reaction to the alignment layer on the substrate surface as linearly polarized light,
The alignment layer is made of a photoreactive material whose liquid crystal alignment regulating direction is a liquid crystal alignment regulating direction corresponding to the polarization direction of the last irradiated linearly polarized light with respect to a plurality of times of the linearly polarized light irradiation. A liquid crystal display element using a nematic liquid crystal characterized by the above. At least one of the liquid crystal alignment regulation treatments of the alignment layer is a direction oblique to non-polarized light with respect to the substrate normal instead of irradiating light that can give a chemical reaction to the alignment layer on the substrate surface as linearly polarized light. Irradiating as incident light from
From the photoreactive material in which the alignment layer has a liquid crystal alignment regulation direction corresponding to the oblique incidence direction of the obliquely incident light irradiated last, with respect to the multiple incidences of the oblique incident light irradiation. The liquid crystal display element using the nematic liquid crystal according to claim 1. One of the two liquid crystal alignment regulation processes is a process uniformly applied to the entire area to be processed, and the other liquid crystal alignment regulation process is selected only for a part of the area to be processed. 3. A liquid crystal display element using a nematic liquid crystal according to claim 1, wherein the liquid crystal display element is a treatment applied automatically. The two different liquid crystal alignment regulating directions are substantially perpendicular to each other in the substrate surface, and the rising angle from the substrate surface in at least one liquid crystal alignment regulating direction is substantially 0 degree. 3. A liquid crystal display device using the nematic liquid crystal according to 3. 5. The liquid crystal display element using a nematic liquid crystal according to claim 1, wherein the liquid crystal layer is made of a liquid crystal material containing an asymmetric molecule as a composition component. The liquid crystal layer is made of a liquid crystal material that can take both positive and negative depending on the frequency of an alternating electric field to which the sign of dielectric anisotropy is applied. 5. A liquid crystal display device using the nematic liquid crystal according to 5. The liquid crystal display element using a nematic liquid crystal according to claim 1, wherein at least a part of the electrodes constituting the electrode group is a comb-like electrode. The liquid crystal using nematic liquid crystal according to claim 7, wherein the at least part has a pair of electrodes disposed on each of the pair of substrates separately from the comb-like electrodes. Display element. 9. A liquid crystal using a nematic liquid crystal according to claim 1, wherein a light reflecting plate is disposed on one of the pair of substrates. Display element.

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