JP2003156726A - Method and device for evaluating alignment uniformity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive evaluation device which evaluates the uniformity of an alignment layer subjected to alignment processing and makes measurement easy. SOLUTION: A method for evaluating alignment uniformity is characterized in that the uniformity of the alignment is evaluated from variation in the quantity of transmitted light when a voltage is applied to a liquid crystal cell. The liquid crystal cell is constituted by sealing p type nematic liquid crystal (or n type nematic liquid crystal) into a space between two opposite electrode substrates held by two polarizing plates whose transmission axes cross each other at right angles, and horizontally (or vertically) aligning the liquid crystal. The cell has the alignment direction of the liquid crystal nearly in parallel to or nearly at right angles to the polarizing plate transmission axes, and to provide a device for evaluating the alignment uniformity.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method and apparatus for evaluating the uniformity of a liquid crystal alignment film.

[0002]

2. Description of the Related Art An optical modulator including a liquid crystal element is thin and lightweight and has low power consumption, and is widely used for displays such as calculators, personal computers and televisions. In addition to display applications, they are also used as lenses, filters, and optical operation elements that can be controlled by an external electric field, and the demand for them is expected to increase in the future.

As a method of aligning a liquid crystal cell,
Various methods such as a rubbing method, an oblique deposition method, an ion beam method, a monomolecular film method, a light irradiation method, a stamp method, and a magnetic field applying method have been proposed so far, but practically, most of them are rubbing processing methods. The alignment process is performed by.

[0004]

This rubbing treatment method is a method of carrying out an orientation treatment by rubbing the surface of the orientation film with a rayon cloth, nylon cloth, or cotton cloth having a fiber diameter of about 5 μm to 20 μm. Yes, it is often used as an extremely inexpensive process.

However, the alignment mechanism of liquid crystal molecules by this method has not been sufficiently clarified, and display unevenness and display defects due to non-uniformity of the alignment treatment often cause a serious problem in manufacturing.

In view of such a situation, a method for evaluating the uniformity of the alignment film subjected to the alignment treatment has been proposed. For example, a method of measuring the film retardation in the plane of the alignment film or the distribution of birefringence is described by Hirosawa et al.
T. Matushita, H .; Miuiriri,
and S. Saito, Jpn. J. App
l. Phys. , 38, 2851 (199
9)) has been proposed, but it has problems such as requiring a long time for measurement and an expensive ellipsometer.

As a method for evaluating the state of the alignment film surface, a method for evaluating the pretilt angle, surface anchoring energy, or repose angle has been established, but no information is obtained on the in-plane distribution of the alignment film characteristics. I can't.

[0008]

In order to solve the above-mentioned problems, the present invention provides, as a first means for solving the problems, it is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other, and they are opposed to each other. A liquid crystal cell in which a p-type nematic liquid crystal is sealed between two electrode substrates and horizontally aligned, and a liquid crystal cell in which the alignment orientation of the liquid crystal is substantially parallel or substantially vertical to the transmission axis orientation of the polarizing plate is applied. The present invention proposes an alignment uniformity evaluation method characterized in that the uniformity of alignment is evaluated by the change in the amount of transmitted light when a voltage is applied. As a second solution, the transmission axis directions are mutually Two orthogonal
A liquid crystal cell sandwiched between a pair of polarizing plates and having an n-type nematic liquid crystal enclosed between two opposing electrode substrates and vertically aligned. The liquid crystal refractive index ellipsoid is orthographically projected onto the substrate surface. Alignment uniformity characterized by evaluating the uniformity of alignment by the change in the amount of transmitted light when a voltage is applied to a liquid crystal cell whose long axis direction is substantially parallel or perpendicular to the transmission axis direction of the polarizing plate. As a third means for solving the problem, a p-type p-type substrate which is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other and which is opposed to each other is provided. Voltages V1, V2, V3, ... Are applied to liquid crystal cells in which nematic liquid crystal is enclosed and horizontally aligned, and the liquid crystal cells in which the alignment direction of the liquid crystal is substantially parallel to or perpendicular to the transmission axis direction of the polarizing plate. , Vn when transmitted light The present invention proposes an alignment uniformity evaluation method characterized in that the alignment uniformity is evaluated by the sum of the above, and as a fourth solution thereof, two polarizing plates whose transmission axis directions are orthogonal to each other are proposed. A liquid crystal cell sandwiched between and sandwiching n-type nematic liquid crystal between two opposing electrode substrates, and having a vertical alignment, and a long axis when the liquid crystal refractive index ellipsoid is orthographically projected onto the substrate surface. The uniformity of alignment is evaluated by the total amount of transmitted light when voltages V1, V2, V3, ..., Vn are applied to a liquid crystal cell whose direction is substantially parallel to or perpendicular to the transmission axis direction of the polarizing plate. The present invention proposes an orientation uniformity evaluation method characterized by

As a more specific means for solving the problem, as a first means for solving the problem, it is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other, and between two electrode substrates facing each other. A liquid crystal cell in which a p-type nematic liquid crystal is enclosed and horizontally aligned, wherein the liquid crystal cell has a uniform alignment direction having means for applying a voltage to the liquid crystal cell in which the alignment direction of the liquid crystal is substantially parallel to or perpendicular to the transmission axis direction of the polarizing plate. As a second means for solving the problem, a property evaluation device is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other,
A liquid crystal cell in which an n-type nematic liquid crystal is sealed between two electrode substrates facing each other and vertically aligned, and the long axis direction when the liquid crystal refractive index ellipsoid is orthogonally projected onto the substrate surface is the polarizing plate. An alignment uniformity evaluation apparatus having a means for applying a voltage to a liquid crystal cell that is substantially parallel or substantially perpendicular to the transmission axis direction is used.
A liquid crystal cell in which a p-type nematic liquid crystal is sealed between two facing electrode substrates and horizontally aligned, and the alignment direction of the liquid crystal is substantially parallel to or perpendicular to the transmission axis direction of the incident light side polarizing plate. An alignment uniformity evaluation apparatus having a means for applying a voltage to the cell and a means for measuring the phase difference of the liquid crystal cell is used. As a fourth solving means therefor, an n-type between two opposing electrode substrates is used. A liquid crystal cell in which a nematic liquid crystal is enclosed and vertically aligned, and the long axis direction when the liquid crystal refractive index ellipsoid is orthographically projected onto the substrate surface is substantially parallel to or substantially perpendicular to the transmission axis direction of the incident light side polarizing plate. An alignment uniformity evaluation apparatus having means for applying a voltage to a liquid crystal cell and means for measuring the phase difference of the liquid crystal cell is used.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 2 is an external view of the configuration of a liquid crystal cell used for verification of an alignment uniformity evaluation method and an alignment uniformity evaluation apparatus of the present invention. Liquid crystal cell A (p-type nematic liquid crystal)
Was produced.

Here, the p-type nematic liquid crystal refers to a liquid crystal molecule in which the dipole moment direction is parallel to the long axis direction of the liquid crystal molecule, while the dipole moment direction is Those parallel to the minor axis direction of liquid crystal molecules are called n-type nematic liquid crystals.

On two glass substrates 1 and 8 having transparent electrodes 2 and 7, a polyimide alignment film paint SE-7792 manufactured by Nissan Chemical Industries, Ltd. was applied by a spin coating method, and 180 ° C. in a constant temperature bath, 1 Let dry and harden for hours. After that, after subjecting the substrate to orientation treatment using a rayon rubbing cloth, Sekisui Fine Chemical Co., Ltd. spacer 5 and Structbond 352A (Mitsui Toatsu Co., Ltd.) are used so that the liquid crystal orientation on the opposing substrate is anti-parallel. A liquid crystal cell 9 was manufactured by using a seal resin (trade name, manufactured by Kagaku Co., Ltd.) and adhering the substrates so that the distance between the substrates was 5.0 μm.

Next, 4'-cyano-was added to the prepared liquid crystal cell.
Liquid crystal cell A was obtained by injecting 4-pentylbiphenyl (manufactured by Merck & Co., Inc.) by a vacuum injection method.

A liquid crystal cell B having a cell structure similar to that shown in FIG. 2 and exhibiting non-uniform alignment is prepared by the following method.
(P type) was produced.

On two glass substrates 1 and 8 having transparent electrodes 2 and 7, a polyimide alignment film paint SE-7792 manufactured by Nissan Chemical Industries, Ltd. was applied by a spin coating method, and 180 ° C. in a constant temperature bath, 1 Let dry and harden for hours. After that, after performing a substrate orientation treatment using a rayon rubbing cloth, FIG.
The alignment film surface was irradiated with ultraviolet light having a wavelength of 313 nm at 500 mJ / cm ² through the mask shown in FIG. Then, using Sekisui Fine Chemical Co., Ltd. spacer 5 and StructBond 352A (trade name of Mitsui Toatsu Chemical Co., Ltd. seal resin) so that the liquid crystal alignment directions on the opposing substrates are anti-parallel. To be 5.0 μm, and a liquid crystal cell 9 was produced.

Next, 4'-cyano-was added to the prepared liquid crystal cell.
4-Pentylbiphenyl (manufactured by Merck) was injected by a vacuum injection method to obtain a liquid crystal cell B. On the surface of the substrate of the liquid crystal cell B, the polymer chains of the alignment film are torn in the region irradiated with ultraviolet rays, and the pretilt angle is lower than that in the region not irradiated with ultraviolet rays. The pretilt angle in the region not irradiated with ultraviolet rays and the pretilt angle in the region irradiated with ultraviolet rays were 10.7 degrees and 4.6 degrees, respectively, as measured by a liquid crystal cell prepared separately.

Next, the produced liquid crystal cell A or liquid crystal cell B was held in the alignment uniformity evaluation apparatus of the present invention shown in FIG. 4 and its voltage-luminance characteristic was measured. Here, the liquid crystal cell 9 is sandwiched between the two polarizing plates 11 and 12, and the arrangement angle is as shown in FIG. 1
Reference numeral 0 is a light source, 13 is a photodetector, and 14 is a power source.
Further, reference numerals 15 and 16 respectively indicate the alignment treatment directions of the light source side and the observation side substrate, and 17 and 18 respectively indicate the polarization axis directions of the polarizer and the analyzer.

FIG. 5 shows the voltage-luminance characteristics when a 30 Hz rectangular wave is applied to the liquid crystal cells A and B. In the liquid crystal cell with high alignment uniformity (liquid crystal cell A), the applied voltage value is increased. Even though the transmitted light brightness hardly changes, the transmitted light brightness increases in the low voltage region in the liquid crystal cell (liquid crystal cell B) having low alignment uniformity.

The reason why the alignment uniformity can be evaluated by the alignment uniformity evaluation apparatus of the present invention will be described below.

Conventionally, it is believed that even if an external electric field is applied to a liquid crystal cell having a p-type nematic liquid crystal between two opposing electrode substrates and having the optical arrangement of FIG. 1, incident light does not pass through. It was being done. It was also considered that light transmission could not occur even by numerical calculation.

However, the inventors of the present invention, in the above structure, when there is a distribution of characteristics such as pretilt angle, anchoring energy, and angle of repose that affect the voltage-luminance characteristics of the liquid crystal cell in the plane of the alignment film. The inventors have found that light is emitted from the analyzer in the low voltage region, and have completed the present invention.

FIG. 6 schematically shows an example of the state of liquid crystal alignment on the liquid crystal cell B substrate used for verification of the alignment uniformity evaluation apparatus of the present invention. Region I is a region with a relatively high pretilt angle, and region II is a region with a relatively low pretilt angle. Now, when an external electric field is applied in the vertical direction of the substrate, the liquid crystal molecules rise so as to be aligned in the electric field direction in all regions, but the tilt angle of the liquid crystal molecules at that time varies depending on the regions. That is, the tilt angle of the liquid crystal molecules in the region I is larger than the tilt angle of the liquid crystal molecules in the region II. At this time, in the regions I and II, the orientation of the liquid crystal molecules is parallel to the transmission axis of the polarizing plate, so the cell transmitted light is completely blocked by the analyzer. However, in the boundary region between the region I and the region II, the alignment direction of the liquid crystal molecules is displaced from the alignment treatment direction (rubbing treatment direction) as shown in FIG. A part passes through the analyzer.

Although the difference between the region I and the region II has been described above by the difference in the pretilt angle, the difference in the pretilt angle is not necessarily required. That is, it is important that liquid crystal molecules rise differently depending on voltage application, and even if the pretilt angle, surface anchoring energy, repose angle, surface energy, alignment film thickness, or liquid crystal layer thickness is different in the two regions. It goes without saying that the same effect can be obtained.

In the first embodiment, as a method for evaluating the alignment uniformity of the liquid crystal cells A and B, the voltage-
Although the comparison was carried out by comparing the brightness characteristics, it is preferable to obtain the sum of the brightness values at each applied voltage in the quantification. As a simpler method, it is appropriate to evaluate the brightness at a specific applied voltage value or the standardized brightness.

In order to confirm the validity of the alignment uniformity evaluation method of the present invention, exactly the same as liquid crystal cell A and liquid crystal cell B except that the liquid crystal material to be enclosed is a guest host liquid crystal ZLI-3735 manufactured by Merck. Specifications liquid crystal cell GH-A
A liquid crystal cell GH-B was prepared, and a polarizing plate was arranged only on the incident light side so that its deflection axis was parallel to the alignment treatment direction of the alignment film, and the luminance ratio at 10.0 V and 2.0 V ( The contrast ratio) was determined. The measurement result is the liquid crystal cell GH-A.
The contrast ratio of the liquid crystal cell B was 80: 1, the contrast ratio of the liquid crystal cell B was 12.7: 1, and it was confirmed that the alignment uniformity of the liquid crystal cell GH-B was poor.

(Embodiment 2) A liquid crystal cell C (p-type) was manufactured in exactly the same manner as the liquid crystal cell B in Embodiment 1 except that the liquid crystal orientation was different. The relationship between the axial direction of the polarizing plate and the direction of liquid crystal alignment is set as shown in FIG.
In the orientation uniformity evaluation apparatus of the present invention shown in FIG.
When the luminance characteristics were measured, the same result as in the case of the liquid crystal cell B was obtained.

(Embodiment 3) FIG. 2 is an external view of the configuration of a liquid crystal cell used for verification of the alignment uniformity evaluation method and alignment uniformity evaluation apparatus of the present invention. The following method is used as a liquid crystal cell exhibiting uniform alignment. Then, a liquid crystal cell D (n type) was produced.

On the two glass substrates 1 and 8 having the transparent electrodes 2 and 7, a polyimide alignment film paint JAL manufactured by JSR Co., Ltd.
S-650 was applied by spin coating, and then in a constant temperature bath.
Dry and cure at 0 ° C. for 1 hour. After that, after subjecting the substrate to orientation treatment using a nylon rubbing cloth, the spacer 5 made by Sekisui Fine Chemical Co., Ltd. and the struct bond 352A (Mitsui Toatsu Co., Ltd.) are arranged so that the liquid crystal orientation on the opposing substrate becomes antiparallel. A liquid crystal cell 9 was manufactured by using a seal resin (trade name, manufactured by Kagaku Co., Ltd.) and adhering the substrates so that the distance between the substrates was 5.5 μm. Next, MLC-2038 (manufactured by Merck & Co., Inc.) was injected into the manufactured liquid crystal cell 9 by a vacuum injection method to obtain a liquid crystal cell D.

A liquid crystal cell E having a non-uniform orientation was prepared by the following method.

On the two glass substrates 1 and 8 having the transparent electrodes 2 and 7, a polyimide alignment film paint JAL manufactured by JSR Co., Ltd.
S-240 was applied by spin coating method, and kept in a constant temperature bath for 18
Dry and cure at 0 ° C. for 1 hour. After that, the substrate was subjected to the alignment treatment using a nylon rubbing cloth, and then the alignment film surface was irradiated with ultraviolet light having a wavelength of 313 nm through the mask shown in FIG. 3 at 500 mJ / cm ² . Then, using Sekisui Fine Chemical Co., Ltd. spacer 5 and StructBond 352A (trade name of Mitsui Toatsu Chemical Co., Ltd. seal resin) so that the liquid crystal alignment directions on the opposing substrates are anti-parallel. To be 5.5 μm, and a liquid crystal cell 9 was produced. Next, MLC-2038 (manufactured by Merck & Co., Inc.) was injected into the manufactured liquid crystal cell 9 by a vacuum injection method to obtain a liquid crystal cell E.

Next, the produced liquid crystal cell D or liquid crystal cell E was held in the alignment uniformity evaluation apparatus of the present invention shown in FIG. 9 and its voltage-phase difference characteristic was measured. In addition,
Reference numeral 19 indicates a rotary analyzer. Others are shown in Figure 4.
The description is omitted because it is the same as. Here, the alignment treatment directions of the liquid crystal cell D and the liquid crystal cell E and the deflection axis direction of the incident light side polarization plate were arranged to be parallel to each other.
FIG. 10 shows voltage-phase difference characteristics when a 30 Hz rectangular wave is applied to the liquid crystal cells D and E.

As is clear from these embodiments,
According to the alignment uniformity evaluation apparatus of the present invention, the alignment uniformity on the surface of the alignment film can be easily measured and evaluated, and its practical value is extremely large.

(Embodiment 4) FIG. 2 is an external view of the configuration of a liquid crystal cell used for verification of the alignment uniformity evaluation method and alignment uniformity evaluation apparatus of the present invention.

On two glass substrates 1 and 8 having transparent electrodes 2 and 7, 3.3 wt.% Of an equimolar mixture of 2,3,5-cyclopentyltricarboxyl dianhydride and 4,4'-diaminodiphenylmethane. % N-methyl-
A 2-pyrrolidone solution is applied by spin coating and dried and cured at 180 ° C. for 1 hour in a constant temperature bath. After that, using a rayon rubbing cloth, the substrates are subjected to the alignment treatment under mutually different alignment treatment conditions, and then the liquid crystal alignment directions on the opposing substrates are made antiparallel to each other by Sekisui Fine Chemical Co., Ltd. Spacer 5 and struct bond 35
2A (trade name of sealing resin manufactured by Mitsui Toatsu Chemicals, Inc.) was used to bond the substrates so that the distance between the substrates was 5.0 μm.
A mold type liquid crystal cell 9 was produced.

Next, a liquid crystal ZLI-4792 manufactured by Merck Ltd. was injected into the prepared liquid crystal cell by a vacuum injection method to obtain a liquid crystal cell F.
Liquid crystal cell J was used. Table 1 shows the correspondence between the alignment treatment conditions and the liquid crystal cell numbers at this time.

[0037]

[Table 1]

Then, the voltage-luminance characteristic was measured by the alignment uniformity evaluation apparatus of the present invention in the same manner as in the first embodiment. The applied voltage is 0.1V to 5.0V, 0.1
It is for each V, and the sum of brightness S at each applied voltage value was used as an index of orientation uniformity. Table 2 shows the measurement results.

[0039]

[Table 2]

It can be seen from Tables 1 and 2 that when the amount of pushing in the rubbing treatment is small, the degree of contact of the rubbing cloth with the surface of the alignment film is not uniform, resulting in insufficient alignment uniformity. Here, the S value of the liquid crystal cell F is smaller than the S value of the liquid crystal cell G because the pretilt angle of the liquid crystal cell F is large and the nonuniformity in the alignment film plane is reduced. It seems that it is due to a thing.

As described above, the alignment uniformity evaluation method and the alignment uniformity evaluation apparatus of the present invention can easily know the state of the alignment treatment of the alignment film and have great practical value.

[0042]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a p-type nematic liquid crystal (or a p-type nematic liquid crystal is sandwiched between two electrode substrates which are sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other. , N-type nematic liquid crystal) is enclosed and horizontally aligned (or vertically aligned), and a voltage is applied to the liquid crystal cell in which the alignment direction of the liquid crystal is substantially parallel to or perpendicular to the transmission axis direction of the polarizing plate. The present invention provides an alignment uniformity evaluation method characterized by evaluating the uniformity of alignment by the change in the amount of transmitted light when a voltage is applied, and an apparatus therefor. It is possible to provide a good alignment uniformity evaluation apparatus.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an optical arrangement of each element of a liquid crystal cell A and a liquid crystal cell B used in a first embodiment of an alignment uniformity evaluation apparatus according to the present invention.

FIG. 2 is a diagram conceptually showing a cross-sectional structure of a liquid crystal cell A used in the first embodiment of the alignment uniformity evaluation apparatus according to the present invention.

FIG. 3 is a diagram for explaining a photomask pattern used in manufacturing the liquid crystal cell B used in the first embodiment of the alignment uniformity evaluation apparatus according to the present invention.

FIG. 4 is a diagram for explaining a configuration example of an alignment uniformity evaluation apparatus according to the present invention.

FIG. 5 is a diagram for explaining voltage-luminance characteristics of the liquid crystal cell A and the liquid crystal cell B measured by the alignment uniformity evaluation apparatus according to the present invention.

FIG. 6 is a diagram for explaining the state of liquid crystal alignment on the liquid crystal cell B substrate used in the first embodiment of the alignment uniformity evaluation apparatus according to the present invention.

FIG. 7 is a diagram for explaining the principle that enables orientation uniformity evaluation in the present invention.

FIG. 8 is a diagram for explaining the optical arrangement of each element of the liquid crystal cell C used in the second embodiment of the alignment uniformity evaluation apparatus according to the present invention.

FIG. 9 is a diagram for explaining an example of the configuration of an alignment uniformity evaluation apparatus according to the present invention.

FIG. 10 is a diagram for explaining the voltage-phase difference characteristics of the liquid crystal cell D and the liquid crystal cell E measured by the alignment uniformity evaluation apparatus according to the present invention.

[Explanation of symbols]

1,8 glass substrate 2,7 transparent electrode 3,6 Alignment film 4 Liquid crystal layer 5 spacers 9 Liquid crystal cell 10 light sources 11,12 Polarizer 13 Photodetector 14 power supply 15 Orientation direction of light source side substrate 16 Observer-side substrate orientation processing direction 17 Polarizer polarization direction 18 Direction of polarization axis of analyzer 19 Rotation analyzer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuhiro Nishiyama             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 2G086 EE10                 2H049 BA02 BB03 BC23                 2H088 FA11 FA30 HA01 HA18 HA28                       JA06 MA20                 2H090 HB08Y JB02 KA06 LA02                       LA09 LA16 MA01 MA02 MA16                       MB01 MB03 MB06 MB09 MB12                 2H091 FA08X FA08Z FA41Z GA01                       GA08 LA30

Claims (11)

[Claims] 1. A liquid crystal cell which is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other, and in which a p-type nematic liquid crystal is sealed between two electrode substrates facing each other and which is horizontally aligned. And the uniformity of alignment is evaluated by the change in the amount of transmitted light when a voltage is applied to a liquid crystal cell in which the alignment direction of the liquid crystal is substantially parallel or substantially perpendicular to the polarizing plate transmission axis direction. Orientation uniformity evaluation method. 2. A liquid crystal cell which is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other, and in which n-type nematic liquid crystal is sealed between two electrode substrates facing each other, and which is vertically aligned. And the change in the amount of transmitted light when a voltage is applied to a liquid crystal cell whose major axis direction when the n-type nematic liquid crystal is orthographically projected onto the substrate surface is substantially parallel or substantially perpendicular to the transmission axis direction of the polarizing plate. A method for evaluating alignment uniformity, which comprises evaluating the uniformity of alignment. 3. A liquid crystal cell which is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other, and in which a p-type nematic liquid crystal is sealed between two electrode substrates facing each other and which is horizontally aligned. The total amount of transmitted light when voltages V1, V2, V3, ..., Vn are applied to a liquid crystal cell in which the orientation of the liquid crystal is substantially parallel or substantially perpendicular to the transmission axis orientation of the polarizing plate. A method for evaluating alignment uniformity, which comprises evaluating the uniformity of alignment. 4. A liquid crystal cell which is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other, and in which n-type nematic liquid crystal is sealed between two electrode substrates facing each other, and which is vertically aligned. The voltage V1, V2 is applied to the liquid crystal cell whose major axis direction when the n-type nematic liquid crystal is orthographically projected onto the substrate surface is substantially parallel or substantially perpendicular to the polarizing plate transmission axis direction.
An alignment uniformity evaluation method characterized in that the alignment uniformity is evaluated by the total amount of transmitted light when V3, ..., Vn is applied. 5. A liquid crystal cell which is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other, and in which a p-type nematic liquid crystal is sealed between two electrode substrates facing each other and which is horizontally aligned. An alignment uniformity evaluation apparatus having means for applying a voltage to a liquid crystal cell in which the alignment direction of the liquid crystal is substantially parallel or substantially perpendicular to the transmission axis direction of the polarizing plate. 6. A liquid crystal cell which is sandwiched between two polarizing plates whose transmission axis directions are orthogonal to each other, and in which n-type nematic liquid crystal is sealed between two electrode substrates facing each other, and which is vertically aligned. Alignment uniformity evaluation having means for applying a voltage to a liquid crystal cell whose major axis direction when the liquid crystal refractive index ellipsoid is orthographically projected onto a substrate surface is substantially parallel or substantially perpendicular to the transmission axis direction of the polarizing plate apparatus. 7. The alignment uniformity evaluation apparatus according to claim 5, further comprising a photodetector. 8. A liquid crystal cell in which a p-type nematic liquid crystal is enclosed between two opposing electrode substrates and horizontally aligned, and the alignment orientation of the liquid crystal is substantially parallel to the transmission axis orientation of the incident light side polarizing plate, or An alignment uniformity evaluation apparatus having means for applying a voltage to a liquid crystal cell which is substantially vertical, and means for measuring a phase difference of the liquid crystal cell. 9. A liquid crystal cell in which an n-type nematic liquid crystal is enclosed between two electrode substrates facing each other and vertically aligned, and the major axis direction when the liquid crystal refractive index ellipsoid is orthographically projected onto the substrate surface. An alignment uniformity evaluation apparatus having means for applying a voltage to a liquid crystal cell that is substantially parallel or substantially perpendicular to the transmission axis direction of the incident light side polarizing plate, and means for measuring the phase difference of the liquid crystal cell. 10. The alignment uniformity evaluation apparatus according to claim 1, wherein the liquid crystal cell is an anti-parallel alignment cell. 11. The liquid crystal cell is a parallel alignment cell, wherein the liquid crystal cell is a parallel alignment cell.
Alternatively, the alignment uniformity evaluation apparatus according to claim 9.