JP2988332B2 - LCD panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal panel in which an antiferroelectric liquid crystal is sealed between two electrode substrates.

[0002]

2. Description of the Related Art Recently, attention has been paid to a liquid crystal panel using an antiferroelectric liquid crystal having a higher response speed and a memory property as compared with a generally used TN type liquid crystal. This liquid crystal panel utilizes the stability of the molecular alignment state of the antiferroelectric liquid crystal. Here, the antiferroelectric liquid crystal has a smectic layer structure and has three stability in a molecular alignment state. The arrangement direction of the liquid crystal molecules of the antiferroelectric liquid crystal changes according to the electric field.

In such an antiferroelectric liquid crystal, the first
Is a state in which a strong electric field in one direction is applied to the liquid crystal layer. At this time, the spontaneous polarization of the liquid crystal molecules acts on the applied electric field, and all the liquid crystal molecules
As shown in (a), tilt is uniformly arranged in one direction with respect to the normal line L of the smectic layer structure. The second stable state is a state when a strong electric field having a reverse polarity is applied to the liquid crystal layer. At this time, the spontaneous polarization of the liquid crystal molecules acts on the reverse electric field, the liquid crystal molecules are inverted, and all the liquid crystal molecules are converted into a smectic layer structure with respect to the normal line L as shown in FIG. One is uniformly arranged in the direction opposite to the stable state at the tilt angle θ.

A third stable state is a state when there is no electric field or when a weak electric field is applied. In this state, as shown in FIG. 8B, the liquid crystal molecules are alternately arranged in the opposite direction at the same tilt angle θ with respect to the normal line L of the smectic layer structure (alternately arranged in each layer). . Therefore, the average alignment direction of the liquid crystal molecules (optical axis direction in the antiferroelectric phase) in the entire liquid crystal layer in the state where no electric field or a weak electric field is applied is in the normal direction of the smectic phase structure.

FIG. 9 is an exploded perspective view showing the structure of a conventional liquid crystal panel 1. As shown in FIG. The liquid crystal panel 1 has a configuration in which polarizing plates 2 and 3 are disposed on the light incident surface side and the light emitting surface side, respectively. This liquid crystal panel 1 has a pair of transparent substrates 1a and 1b overlapped with an antiferroelectric liquid crystal (not shown) sealed therebetween via a band-shaped seal (not shown). Although not shown, a plurality of transparent electrodes are respectively formed on the surfaces facing each other, and an orientation process for regulating the direction of the normal line of the smectic phase structure is performed thereon.

In FIG. 9, reference numerals Pa and Pb indicate the orientation directions of the transparent substrates 1a and 1b, and reference numerals 2a and 3a indicate the directions of the transmission axes of the polarizing plates 2 and 3, respectively. I have. In this liquid crystal panel 1, the orientation directions Pa and Pb of the transparent substrates 1a and 1b are made parallel to each other, and the direction of the transmission axis 2a of one polarizing plate 2 is changed to the direction of the orientation process of the transparent substrate 1a on the side of the polarizing plate 2. The direction of the transmission axis 3a of the other polarizing plate 3 is made substantially orthogonal to the direction of the transmission axis 2a of the polarizing plate 2 while making the direction substantially parallel or almost perpendicular to Pa (orthogonal in the figure).

The liquid crystal panel 1 controls and displays the molecular arrangement state of the antiferroelectric liquid crystal in the above three stable states, and applies a voltage between the transparent electrodes of the transparent substrates 1a and 1b. In a state where the voltage is not applied or a state where the applied voltage is low, the liquid crystal molecules are arranged in the third stable state shown in FIG. 8B, and the display is turned off (dark). Also, when an ON voltage having a polarity in one direction is applied between the transparent electrodes of the transparent substrates 1a and 1b,
The liquid crystal molecules are arranged in the first stable state of FIG. 8A, and the display is turned on (bright).

The same applies to the case where an ON voltage having a reverse polarity is applied between the transparent electrodes of the transparent substrates 1a and 1b. At this time, the liquid crystal molecules are arranged in the second stable state shown in FIG. 8C, and the display is turned on (bright). When driving the liquid crystal panel 1, the polarity of the applied voltage is inverted at a predetermined cycle in order to prevent the decomposition of the antiferroelectric liquid crystal.
It is also known that so-called AC drive is required (see Japanese Patent Application Laid-Open No. 2-173724).

However, when such an AC driving is performed, the alignment of the liquid crystal molecules of the antiferroelectric liquid crystal changes between two stable states (both in a bright state) with the reversal of the polarity of the applied voltage. On the other hand, when the liquid crystal panel 1 is viewed from a specific direction, the light transmission characteristics of the liquid crystal panel 1 in the two bright states are different. For this reason, when the liquid crystal panel 1 is AC-driven, a flicker (so-called flicker) of the screen appears as if the display image is driven according to the reversal cycle, and there is a problem that the display quality is reduced.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. Hei 6-130425, the upper and lower polarizers 2 and 3 have a stretching axis which is parallel to the absorption axis (the axis in the direction perpendicular to the transmission axis). A method has been proposed in which a phase plate is provided between the transparent substrate 1a and the polarizing plate 2 and between the transparent substrate 1b and the polarizing plate 3, thereby suppressing flicker.

Here, the transmission axis of the polarizing plate 2 and the stretching axis of the upper phase plate are set to be orthogonal to each other, and the transmission axis of the polarizing plate 3 and the stretching axis of the lower phase plate are set to be orthogonal to each other. ing. The optical axis of the liquid crystal panel 1 is set perpendicular to the transmission axis of the polarizing plate 2 and parallel to the transmission axis 3a of the polarizing plate 3.
The display operation of such a liquid crystal panel will be described.
When no voltage is applied between the transparent electrodes of the transparent substrates 1a and 1b or when the applied voltage is low, the liquid crystal molecules are arranged in the third stable state shown in FIG. )
State.

In this case, the molecules of the antiferroelectric liquid crystal in the liquid crystal panel are arranged in a state where the direction of the normal of the smectic layer structure is uniform over the entire thickness of the liquid crystal layer. The direction of the liquid crystal molecules viewed from the layer thickness direction (perpendicular to the normal to the smectic layer structure) is substantially uniform over the entire thickness of the liquid crystal layer. Therefore, of the pair of polarizing plates 2 and 3 arranged on the incident side and the emitting side such that the transmission axis directions thereof are substantially orthogonal to each other, the direction of the transmission axis 2a of the incident side polarizing plate (polarizing plate 2) is changed to the transparent substrate. By setting as described above in accordance with the direction of the normal L of the smectic layer structure regulated by the alignment treatment of 1a, the polarization direction of the polarization direction substantially parallel to or substantially orthogonal to the direction of the normal L of the smectic layer structure is determined. When the linearly polarized light is incident on the liquid crystal layer, the alignment state of the liquid crystal molecules becomes third.
In the stable state, most of the incident light exits the liquid crystal layer as linearly polarized light, and is absorbed by the polarizing plate 3 on the exit side. Therefore, the amount of polarized light in the off state (the state in which the liquid crystal molecules are aligned in the third stable state) is significantly reduced as compared with a conventional liquid crystal panel that does not employ a phase plate.

On the other hand, when an ON voltage having a unidirectional polarity is applied between the transparent electrodes of the transparent substrates 1a and 1b, the liquid crystal molecules are arranged in the first stable state shown in FIG. In the first stable state, the alignment direction of the liquid crystal molecules is tilted with respect to the polarization direction of the linearly polarized light incident on the liquid crystal layer (direction almost parallel to or almost perpendicular to the normal direction of the smectic layer structure). The angle is almost the same as the angle. For this reason, the linearly polarized light incident on the liquid crystal layer becomes elliptically polarized light due to the birefringence effect of the liquid crystal layer, and among the light emitted from the liquid crystal layer, the light of the polarization component along the direction of the transmission axis 3a of the polarizing plate 3 on the emission side is converted. Then, the light is emitted from the liquid crystal panel, and the display is turned on (bright).

The same applies to the case where an ON voltage of the opposite polarity is applied between the transparent electrodes of the transparent substrates 1a and 1b. At this time, the liquid crystal molecules are arranged in the second stable state shown in FIG. 8C. Even in this second stable state, the linearly polarized light incident on the liquid crystal layer becomes elliptically polarized light due to the birefringence effect of the liquid crystal layer. Among them, the light of the polarization component along the transmission axis direction of the emission-side polarizing plate 3 becomes the emission light of the liquid crystal panel, and the display is turned on (bright).

[0015]

However, with respect to the optical axis of the antiferroelectric phase, the transmission axes of the upper and lower polarizers 2 and 3 (the axes perpendicular to the absorption axis) and the extension of the upper and lower phase plates are extended. It is industrially difficult to accurately set the axes orthogonally to each other. Further, there is a problem in that the contrast, which is the most important characteristic of the liquid crystal panel, changes due to the deviation of the optical axis from the orthogonal direction with respect to each transmission axis.

On the other hand, the present inventors have examined the manufacturing steps of the polarizing plate and the phase plate in detail and found the following conclusion. Usually, a polarizing plate is produced by uniaxially stretching a PVA-based resin having iodine adsorbed and oriented by a uniaxial stretching machine. Here, the transmission axis of the polarizing plate is determined by the stretching direction of the polarizing plate.

The phase plate is made of polycarbonate or PV.
It is produced by uniaxially stretching a polymer film such as A by a uniaxial stretching machine. Here, the stretching axis of the phase plate is determined by the stretching direction of the phase plate. Accordingly, when the polarizing plate and the phase plate are integrally formed with the transmission axis and the stretching axis parallel as described above, the stretching of the phase plate is effectively performed by effectively utilizing the uniaxial stretching direction by the uniaxial stretching machine. As compared with the case where the axis and the transmission axis of the polarizing plate are orthogonal to each other, the deviation of the angle between the transmission axis and the stretching axis can be reduced.

In this case, the polarizing plate and the phase plate are not individually uniaxially stretched, but the polarizing plate and the phase plate are integrated before stretching and then uniaxially stretched by a uniaxial stretching machine. Is performed, it is possible to make the angle deviation between the transmission axis and the stretching axis substantially 0 °. In view of the above, the present invention focuses on the above, and in a liquid crystal panel in which antiferroelectric liquid crystal is sealed, by setting the transmission axis of the polarizing plate and the stretching axis of the phase plate in parallel, the transmission axis An object of the present invention is to obtain a good contrast by accurately suppressing an angle deviation from a stretching axis.

[0019]

According to the first to fifth aspects of the present invention, a first phase plate (14) is provided with a first phase plate (14).
The stretching axis (1) attached between the polarizing plate (15) and the first electrode substrate (10) and parallel to the transmission axis (15a) of the first polarizing plate.
4a). Further, a second phase plate (24) is attached between the second polarizing plate (25) and the second electrode substrate (10), and a stretching axis (25) parallel to the transmission axis (25a) of the second polarizing plate. 24
a).

In this case, the transmission axis of the first polarizing plate and the stretching axis of the first phase plate coincide with each other in the uniaxial stretching directions of the polarizing plate and the phase plate, so that they become parallel. Further, the transmission axis of the second polarizing plate and the stretching axis of the second phase plate coincide with each other in the uniaxial stretching directions of the polarizing plate and the phase plate, so that they become parallel. By making the transmission axis and the stretching axis parallel by utilizing the uniaxial stretching directions of the polarizing plate and the phase plate in this way, it is possible to accurately suppress the angle deviation between the two axes.

As a result, the contrast of the liquid crystal panel in which the anti-ferroelectric liquid crystal is sealed can be secured well. Here, as in the invention according to claim 2, the first phase plate is formed as an integrated film with the first polarizing plate such that the first phase plate has a stretching axis parallel to the transmission axis of the first polarizing plate. The second phase plate is adhered to the outer surface of the one electrode substrate, and is formed as an integral film with the second polarizer so that the second phase plate has a stretching axis parallel to the transmission axis of the second polarizer. When it is stuck on the outer surface of the electrode substrate, the angle shift between the transmission axis and the stretching axis can be suppressed with higher accuracy.

As a result, the contrast of the liquid crystal panel in which the antiferroelectric liquid crystal is sealed can be further improved. Further, as in the invention according to claim 5, an angle φ between an orthogonal axis orthogonal to the optical axis of the antiferroelectric liquid crystal and one of the transmission axes of the first and second polarizing plates is ± 2 °. The angle α between the transmission axis of the polarizing plate and the stretching axis of the phase plate on one side of the first and second electrode substrates and the optical axis of the antiferroelectric liquid crystal is ± 2 °.
The angle γ between the transmission axis of the first polarizing plate and the stretching axis of the first phase plate and the angle γ between the transmission axis of the second polarizing plate and the stretching axis of the second phase plate are both ± 1.5 °. Within this range, the necessary minimum contrast 10 in the liquid crystal panel can be secured.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a liquid crystal panel P for a liquid crystal display device to which the present invention is applied.
Is a band-shaped seal 30 between the pair of electrode substrates 10 and 20.
The anti-ferroelectric liquid crystal 40 is sealed in the structure.

The electrode substrate 10 includes a transparent substrate 11 made of glass. On the inner surface of the transparent substrate 11, a plurality of transparent electrodes 12 and an alignment film 13 are sequentially formed. On the outer surface of the electrode substrate 10, the phase plate 14 is
5 and integrally formed as an integrated film. On the other hand, the electrode substrate 20 includes a transparent substrate 21 made of glass, and a plurality of transparent electrodes 22 and an alignment film 23 are sequentially formed on the inner surface of the transparent substrate 21. Here, the plurality of transparent electrodes 22 constitute a grid electrode together with the plurality of transparent electrodes 12. On the outer surface of the electrode substrate 10, a phase plate 24 is integrally formed and adhered to the polarizing plate 25 as an integrated film.

Here, the liquid crystal panel P is manufactured as follows. First, ITO (Indium) is deposited on each surface of the transparent substrates 11 and 21 by a method such as evaporation or sputtering.
A transparent conductive film made of Tin Oxide or Tin Oxide is formed. Next, both transparent conductive films 12 and 22 are formed by etching both transparent conductive films in a stripe shape. The direction of the stripe is a direction in which the two or more transparent electrodes 12 and 22 form a grid-like electrode when the two electrode substrates 10 and 20 are overlapped.

Thereafter, an alignment film 1 for aligning liquid crystal molecules of the antiferroelectric liquid crystal 30 is formed on the inner surface of the electrode substrate 10.
3 are formed with a plurality of transparent electrodes 12 interposed therebetween. On the other hand, an alignment film 23 for aligning liquid crystal molecules of the antiferroelectric liquid crystal 30 is provided on the inner surface of the electrode substrate 20 with a plurality of transparent electrodes 2.
2 are formed. As the alignment films 13 and 23, a film obtained by rubbing a polymer film such as polyimide in one direction,
Alternatively, a known material such as an obliquely deposited SiO film can be used. In addition, you may implement by abolishing one of both alignment films 13 and 23.

Subsequently, the two electrode substrates 10 and 20 are opposed to each other with the transparent electrodes 12 and 22 at an interval of 2 μm.
Then, an antiferroelectric liquid crystal 40 is sealed between the two electrode substrates 10 and 20. When enclosing the antiferroelectric liquid crystal 40, the antiferroelectric liquid crystal 40, for example,
4- (1-trifluoromethylheptoxycarbonylphenyl) -4'-octyloxycarbonylphenyl-
The 4-carboxylate is heated and injected as an isotropic liquid between the two electrode substrates 10 and 20 by utilizing the capillary phenomenon. Thereafter, the entire liquid crystal panel P is gradually cooled at a rate of about 1 ° C. per minute to be cooled to an antiferroelectric liquid crystal phase (SmC _A ^* phase).

The antiferroelectric liquid crystal 40 also includes 4- (1-trifluoromethylnonyloxycarbonylphenyl) -4'-octylbiphenyl-4-carboxylate and 4- (1-trimethyl Fluoromethyldecyloxycarbonyl) -4'-biphenyl-2-fluoro-
Various antiferroelectric liquid crystals such as 4-octylbenzoate or 4- (1-methylhepticalcarbonylphenyl) -4'-octylbiphenyl-4-carboxylate can be used.

Thereafter, an integrated film in which the phase plate 14 and the polarizing plate 15 are integrated is manufactured, and an integrated film in which the phase plate 24 and the polarizing plate 25 are integrated is manufactured. At this time, the stretching axis 14a of the phase plate 14 and the transmission axis 15a of the polarizing plate 15 are set in the direction of the arrow shown in FIG. 2 while the stretching axis 24a of the phase plate 24 is set to the transmission axis 2 of the polarizing plate 25.
5A together with the arrow 5a (the direction perpendicular to the stretching axis 14a) in FIG.

In other words, the phase plate 14 and the polarizing plate 15 are integrated with each other so that the stretching axis 14a of the phase plate 14 and the transmission axis 15a of the polarizing plate 15 are parallel to each other. The phase plate 24 and the polarizing plate 25 are integrated with each other so that the transmission axis 25a of the polarizing plate 25 is parallel to the transmission axis 24a. This will be described in more detail. First, both polarizing plates 15 and 25 are produced by uniaxially stretching a PVA-based resin in which iodine is adsorbed and oriented. here,
Transmission axis 15a of polarizing plate 15 and transmission axis 25 of polarizing plate 25
a is determined by the stretching direction of both polarizing plates 15 and 25.

The phase plates 14 and 24 are formed by uniaxially stretching a polymer film such as polycarbonate or PVA. Here, the stretching axis 14a of the phase plate 14 and the stretching axis 24a of the phase plate 24 are determined by the stretching direction of the phase plates 14, 24. Therefore, when the polarizing plate and the phase plate are integrally formed with the transmission axis and the stretching axis parallel as described above, the polarizing plate and the phase plate are aligned in the uniaxial stretching direction so that the transmission axis and the stretching plate are stretched. The polarizing plate and the phase plate are integrated with the axes parallel to each other. For this reason, as compared with the case where the stretching axis of the phase plate and the transmission axis of the polarizing plate are orthogonal to each other, it is possible to suppress the deviation of the angle between the transmission axis and the stretching axis with higher accuracy.

Also, instead of uniaxially stretching the polarizing plate and the phase plate individually, the polarizing plate and the phase plate are integrated before stretching and then uniaxially stretched to perform uniaxial stretching. It is possible to make the angle deviation between the transmission axis and the stretching axis substantially 0 °, and also to reduce the number of steps. In the present embodiment, NPF-239 type phase plate manufactured by Nitto Denko Corporation is adopted as both phase plates 14 and 24. Here, the NPF-239 type phase refers to a product having a retardation R of 239 mm. The polarizing plates 15 and 25 are NPF-G1 manufactured by Nitto Denko Corporation.
A 220DU type polarizing plate was employed. Then, an integrated film in which the stretching axis of the phase plate and the transmission axis of the polarizing plate were adhered in parallel was used.

The integrated film of the phase plate 14 and the polarizing plate 15 produced as described above is placed on the stretching axis 1 of the phase plate 14.
4a is adhered to the outer surface of the transparent substrate 11 while being held parallel to the optical axis Q. The integrated film of the phase plate 24 and the polarizing plate 25 produced as described above is
Is attached to the outer surface of the transparent substrate 21 while holding the stretching axis 24a of the above at right angles to the optical axis Q.

In this case, before attaching the two integrated films, the optical axis Q of the antiferroelectric liquid crystal 40 and the transmission axes 15a and 25a of both polarizing plates 15 and 25 are measured in advance by a polarizing microscope. Further, each stretching axis 1 of both phase plates 14 and 24
4a and 24a are measured by a birefringence measuring device in advance. Thus, the fabrication of the liquid crystal panel P is completed.

Next, the dependence of the contrast of the liquid crystal panel P on each axis shift will be described. For example, FIG.
, The transmission axis 25a of the polarizing plate 25 and the phase plate 2
4 is shifted from the optical axis Q of the antiferroelectric liquid crystal 40 by an angle α, incident light from below the polarizing plate 25 causes the polarizing plate 25 and the phase plate 24 to be linearly polarized. pass. However, since the light enters the antiferroelectric liquid crystal 40 at an angle α with respect to the optical axis Q, this incident light is
Due to the birefringence effect of the antiferroelectric liquid crystal 40, the light becomes elliptically polarized light, and is not absorbed by the polarizing plate 15 on the emission side.
(Light leakage) is generated.

As shown in FIG. 3B, when the transmission axis 25a of the polarizing plate 25 and the extending axis 24a of the phase plate 24 are shifted by an angle β, the light enters from below the polarizing plate 25. The light passes through the polarizing plate 25 as linearly polarized light, but enters at an angle β with respect to the stretching axis 24 a of the phase plate 24.
Therefore, this incident light becomes elliptically polarized light due to the birefringence effect of the phase plate 24 and enters the antiferroelectric liquid crystal 40.
Therefore, the light that has entered the antiferroelectric liquid crystal 40 in this manner is not absorbed by the polarizing plate 15 on the emission side, and light passing through the polarizing plate 15 (light leakage) is generated.

Here, in the present embodiment, dark display is performed in the state shown in FIG.
Since the brightness is defined as bright display (white) luminance / dark display (black) luminance, it is understood that the light leakage at this time greatly affects the contrast. Then, when a range in which the contrast of the liquid crystal panel P satisfies 10 or more and a range in which the contrast satisfies 30 or more were obtained, results as shown in FIG. 5 were obtained.

However, as shown in FIG. 4A, when the orthogonal direction to the optical axis Q of the antiferroelectric liquid crystal 40 is set as the orthogonal axis Q1, the orthogonal axis Q1 and the transmission axis 15a of the polarizing plate 15 are set. Is φ. Further, as shown in FIG. 4B, the angle between the stretching axis 14a of the phase plate 14 and the transmission axis 15a of the polarizing plate 15 and the angle between the stretching axis 24a of the phase plate 24 and the transmission axis 25a of the polarizing plate 25 are shown. Each of the angles is γ.

Further, since the angles α and φ are not industrially shifted by 3 ° or more, the maximum measurement range in the present embodiment is ± 3 °. Further, in FIGS. 3 and 4, the clockwise angular deviation is defined as positive, and the counterclockwise angular deviation is defined as negative. According to FIG. 5, in order to satisfy the minimum required contrast 10 generally required for a liquid crystal panel, the angle φ and the angle α are both set to within ± 2 °, and each angle γ is set to ± 1.5. It can be seen that it is necessary to set within °.

Further, in order to satisfy 30 or more, which is generally required as a contrast which can be viewed as inferior to a CRT which is currently the mainstream display for OA equipment, each of the angles φ and α is ± 1.0 °. Within, the angle γ is ±
It can be seen that it is necessary to set the angle within 0.5 °. FIG. 6 shows the transmission axis 15a of the polarizing plate 15 and the polarizing plate 25.
, The transmission axes 25a are held perpendicular to each other, and the change in contrast when the angle φ and the angle α (= φ) and each angle γ are changed is shown.

As can be seen from this result, the contrast is highest when all the angles α, φ, and γ are 0 °, and the contrast decreases with the angle shift. FIG. 7 shows a parallel setting pattern in which the transmission axis 15a of the polarizing plate 15 is parallel to the stretching axis 14a of the phase plate 14 and the transmission axis 25a of the polarizing plate 25 is parallel to the stretching axis 24a of the phase plate 24. Thus, both patterns 1 and 2 can be considered. In the above experiment, the example performed with pattern 1 was described. However, even with pattern 2, the same result as with pattern 1 is obtained.

The liquid crystal panel according to the present invention can be used as a liquid crystal panel suitable for use in various liquid crystal devices such as a liquid crystal display device and a liquid crystal switch.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a liquid crystal panel showing one embodiment of the present invention.

FIG. 2 is an exploded perspective view of the liquid crystal panel of FIG.

FIGS. 3 (a) and 3 (b) are diagrams for explaining an angle relationship between each transmission axis of both polarizing plates and a stretching axis of both phase plates with reference to the optical axis of the antiferroelectric liquid crystal, respectively. It is a schematic diagram.

FIG. 4A is a schematic view showing an angle relationship between an antiferroelectric optical axis and a transmission axis of both polarizing plates with reference to an orthogonal axis orthogonal thereto, and FIG. FIG. 3 is a schematic diagram showing an angle relationship between a transmission axis of a polarizing plate and a stretching axis of a phase plate.

FIG. 5 is a diagram for explaining the relationship between the angle γ between the transmission axis and the stretching axis, the angle φ between the orthogonal axis and the transmission axis, the angle α between the optical axis and the transmission axis, and the contrast range.

FIG. 6 is a graph showing respective characteristic curves showing a relationship between an angle α having an angle φ as a parameter and a contrast of a liquid crystal panel.

FIG. 7 is a schematic diagram showing the relationship between each transmission axis of both polarizing plates, each stretching axis of both phase plates, and the antiferroelectric optical axis.

FIGS. 8 (a), (b) and (c) are schematic diagrams for explaining liquid crystal molecular alignments of the antiferroelectric liquid crystal showing first, third and second stable states, respectively. .

FIG. 9 is a schematic exploded perspective view of a conventional liquid crystal panel in which an antiferroelectric liquid crystal is sealed.

[Explanation of symbols]

10, 20 ... electrode substrate, 14, 24 ... phase plate,
14a, 24a: transmission axis, 15, 25: polarizing plate, 15a, 25a: stretching axis, Q: optical axis.

Claims (5)

(57) [Claims] A first electrode substrate enclosing an antiferroelectric liquid crystal; and a transmission axis provided on each of outer surfaces of the first and second electrode substrates, the transmission axes being orthogonal to each other. A liquid crystal panel comprising first and second polarizers, wherein one of the transmission axes of the first and second polarizers is parallel to the optical axis of the antiferroelectric liquid crystal; A first phase plate attached to the first electrode substrate and having an extension axis parallel to the transmission axis of the first polarizing plate; and an adhesive layer attached to the second polarizing plate and the second electrode substrate. A second phase plate attached and having a stretching axis parallel to a transmission axis of the second polarizing plate. 2. A semiconductor device comprising: first and second electrode substrates enclosing an antiferroelectric liquid crystal; first and second polarizers; and a stretching axis parallel to a transmission axis of the first polarizer. A first phase plate formed as an integrated film with the first polarizing plate and adhered to an outer surface of the first electrode substrate, and a stretching axis parallel to a transmission axis of the second polarizing plate. And a second phase plate formed as an integrated film and adhered to the outer surface of the second electrode substrate, wherein the transmission axes of the first and second polarizing plates are mutually A liquid crystal panel which is orthogonal and one of these transmission axes is parallel to the optical axis of the antiferroelectric liquid crystal. 3. The method according to claim 1, wherein the extension axis of the phase plate attached to the electrode substrate on the light incident side of the first and second electrode substrates is parallel to the optical axis of the antiferroelectric liquid crystal. The liquid crystal panel according to claim 1. 4. An extension axis of a phase plate attached to an electrode substrate on a light incident side of the first and second electrode substrates, wherein an extension axis is orthogonal to an optical axis of the antiferroelectric liquid crystal. The liquid crystal panel according to claim 1 or 2, wherein 5. An angle between an orthogonal axis orthogonal to an optical axis of the antiferroelectric liquid crystal and one of transmission axes of the first and second polarizers is φ, and the first and second electrode substrates are provided. The angle between the transmission axis of the polarizing plate and the stretching axis of the phase plate on one side and the optical axis of the antiferroelectric liquid crystal is α, and the transmission axis of the first polarizing plate is When both the angle formed by the stretching axis and the angle formed by the transmission axis of the second polarizing plate and the stretching axis of the second phase plate are γ, φ ≦ ± 2 °, α ≦ ± 2 ° and γ ≦ ± 1. The liquid crystal panel according to claim 1, wherein the angle is 5 °.