JP2002116466A - Liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation in color reproducibility in a color display liquid crystal panel. SOLUTION: When no electric field is applied on a liquid crystal panel 2, the average molecular axis of the liquid crystal 21 is in the direction denoted as 21a shown in Figure. The light irradiating a polarizer 4 is converted into linearly polarized light as propagating through the polarizer 4, then rotated into the direction denoted as 21c as propagating through the liquid crystal panel 2, and further rotated into the direction denoted as 3b as propagating through a uniaxial phase compensation member 3. The light passes a polarizer 5 to produce a white display state. On the other hand, when an electric field is applied on the liquid crystal panel 2 to align the average molecular axis of the liquid crystal into the position denoted as 21b, the light is rotated into the same direction as the sign 4a as propagating the liquid crystal panel 2 and the uniaxial phase compensation member 3. The light can not pass the polarizer 5, which produces a black display state. By driving the device as above described, degradation in the color reproducibility is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal device having a liquid crystal element and displaying various information.

[0002]

2. Description of the Related Art (1) Conventionally, a nematic liquid crystal has been used for a liquid crystal panel (liquid crystal element). However, this nematic liquid crystal has a problem that its response speed is slow. Hereinafter, this point will be described in detail.

Conventionally, as a liquid crystal panel using a nematic liquid crystal, an active matrix type liquid crystal panel (that is, an active matrix type liquid crystal panel)
(A type in which an active element such as a transistor is arranged in each pixel) is being developed. As a mode of a nematic liquid crystal used in this active matrix type liquid crystal panel, twisted nematic (Twis)
A ted Nematic mode is widely known.
The details of this mode are described in, for example, Applied Physs by M. Schadt and Double Hellrich (w. Helfrich).
ics Letters, Vol. 18, No. 4, pp. 127-128 (issued February 15, 1971).

However, in such a twisted nematic mode, since the response speed of the liquid crystal is as slow as several tens of milliseconds, the liquid crystal cannot respond to the video rate and is not suitable for displaying a moving image.

(2) Unlike such a nematic liquid crystal, a smectic liquid crystal such as a ferroelectric liquid crystal or an antiferroelectric liquid crystal can perform a reversal switching by spontaneous polarization, so that the response speed can be increased. Application to such applications is expected. Hereinafter, the liquid crystal will be described.

An element in which the liquid crystal exhibits bistability (SSFLC /
Surface Stabilized FLC was purchased from Clark and Lagerw.
all) (JP-A-56-1072).
No. 16, US Pat. No. 4,367,924). As the liquid crystal exhibiting the bistability, a ferroelectric liquid crystal exhibiting a chiral smectic C phase is generally used. In this ferroelectric liquid crystal, when a voltage is applied, a voltage acts on the spontaneous polarization of the liquid crystal molecules, and the molecules undergo inversion switching, so that a very fast response speed is obtained and a bistable state with memory properties is developed. Can be done. Further, since the viewing angle characteristics are also excellent, it is considered that they are suitable as a high-speed, high-definition, large-area display element or a light valve.

Hereinafter, a liquid crystal panel (SSFLC) using a bistable ferroelectric liquid crystal will be briefly described. FIG. 4 shows the most typical element configuration. In the figure, reference numerals 24 and 25 denote polarizers having polarization axes in the directions of 24a and 25a, respectively. The liquid crystal average molecular axis in the liquid crystal panel 22 is located at the position 22a or 22b according to the polarity of the voltage applied between the electrode plates. Here, strictly speaking, the liquid crystal average molecular axis indicates one of a high refractive index axis and a low refractive index axis in the liquid crystal layer plane of the refractive index ellipsoid formed by the liquid crystal layer.

When the average molecular axis of the liquid crystal is at 22a, the light beam passing through the polarizer 24 passes through the liquid crystal panel 22 and reaches the polarizer 25 while maintaining the polarization state. Polarization direction 25a and light polarization direction 22
Since it is orthogonal to a, the light beam cannot pass through the polarizer 25 and assumes a black state. On the other hand, when the average molecular axis of the liquid crystal is at 22b, the light beam passing through the polarizer 24 is rotated by the birefringence characteristic of the liquid crystal panel 22 to take the direction indicated by reference numeral 25a. 25
To give a white state. The transmittance at this time is represented by sin ² (2θ) · sin ² (π · Δnd / λ) (see “Liquid Crystal Device Handbook (edited by the 142nd Committee of the Japan Society for the Promotion of Science)”). Here, θ is the cone angle of the chiral smectic liquid crystal, Δn is the birefringence of the liquid crystal, d is the distance between the substrates, and the input is the wavelength of the light. In the design of a display element, a wavelength near 550 nm, which is the peak wavelength of a human relative luminous efficiency curve, is often used. This is because this wavelength range most affects the light intensity and contrast felt by humans. At this time, the retardation amount Δn · d of the liquid crystal panel is
Preferably, it is set to half of 550 nm.

Recently, attention has been paid to an antiferroelectric liquid crystal exhibiting a three-stable state, in addition to a ferroelectric liquid crystal exhibiting the above-described bistability.

In the antiferroelectric liquid crystal, as in the case of the ferroelectric liquid crystal, reversal switching of molecules is performed by the action on the spontaneous polarization of liquid crystal molecules, so that a very fast response speed can be obtained. This liquid crystal material is characterized in that, when no voltage is applied, the liquid crystal molecules have a molecular arrangement structure in which the spontaneous polarization cancels each other, and therefore, there is no spontaneous polarization when no voltage is applied.

As a liquid crystal different from the above-mentioned liquid crystal, we have disclosed a chiral smectic liquid crystal showing only one stable state (Japanese Patent Application No. 10-117145).
In this liquid crystal, when no voltage is applied, the average molecular axis of the liquid crystal assumes a monostable state position, and when a voltage of one polarity is applied, the average molecular axis has an angle corresponding to the magnitude of the applied voltage. Tilt to one side from the mono-stabilized position with
When a voltage of the other polarity is applied, the average molecular axis tilts to the opposite side. Moreover, the maximum tilt angle when a voltage of one polarity is applied is different from the maximum tilt angle when a voltage of the other polarity is applied.

[0012]

However, in the case of the above-mentioned smectic liquid crystal mode, since the birefringence of the liquid crystal is used instead of the optical rotation as in the twisted nematic mode, the There is a problem that the relationship between the voltage and the light transmittance differs depending on the wavelength of the light to be irradiated. Therefore, when white light is applied to a liquid crystal panel on which no color filter is arranged, light of all wavelengths is not transmitted uniformly through the liquid crystal panel, but its transmittance varies depending on the wavelength. However, there is a problem that the image displayed on the liquid crystal panel appears colored instead of white. There is also a problem that the contrast is reduced. This is because the transmittance in the white state is designed to have a maximum value at a wavelength near 550 nm, and the wavelength at other wavelengths deviates from the maximum condition of the transmittance.

In order to solve this coloring, there is a design guideline for suppressing the retardation value of the liquid crystal to 200 nm.
This causes another problem that the maximum transmitted light amount is reduced to about 83%.

In the invention disclosed in Japanese Patent Application No. 2-314244, the influence of a change in characteristics due to temperature is reduced by overlapping two bistable ferroelectric liquid crystal panels whose rubbing directions are orthogonal to each other. However, the problem of coloring in white display caused by a transmittance difference due to a wavelength difference has not been solved.

When a color filter is arranged on the liquid crystal panel in the above-described state, the brightness of R and B cannot be secured, so that the brightness of G is reduced (that is, the maximum transmittance is sacrificed) to display an image. Alternatively, there is a method of expanding the wavelength range of the transmitted light of the R or B color filter. However, according to the latter method, although the brightness of R and B can be secured, there is a problem that the color purity is deteriorated.

Accordingly, an object of the present invention is to provide a liquid crystal device which prevents color reproducibility from deteriorating.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and provides a liquid crystal device having a liquid crystal element, a uniaxial phase compensation member, and at least one polarizer. Have a pair of substrates disposed with a predetermined gap therebetween, a monostable or bistable smectic liquid crystal disposed between the pair of substrates, and a voltage applied to the liquid crystal so as to sandwich the liquid crystal. And a pair of electrodes to which the liquid crystal is applied, the birefringence of the uniaxial phase compensating member and the birefringence of the liquid crystal are set to be substantially equal, and the maximum tilt angle of the average molecular axis of the liquid crystal is substantially When an angle of 45 degrees is formed and the liquid crystal exhibits monostable, the average molecular axis of the liquid crystal in a monostable position or in a state where an electric field is applied and the slow axis of the uniaxial phase compensation member are approximately 90 degrees. And the liquid crystal is When exhibiting stability, one of the stable positions and the slow axis of the uniaxial phase compensating member are set to form an angle of about 90 °, and the polarization axis of the polarizer is positioned at the center of the liquid crystal molecule cone. Approximately the same direction or approximately 90 °
Direction.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2,
An embodiment of the present invention will be described.

First, the overall structure of the liquid crystal device according to the present invention will be described with reference to FIGS. Here, FIG. 1 is a cross-sectional view showing the entire configuration of the liquid crystal device according to the present invention, and FIG. 2 is a diagram for explaining a liquid crystal average molecular axis position and the like.

As shown in FIG. 1, the liquid crystal device 1 according to the present invention includes a liquid crystal element 2, a uniaxial phase compensation member 3, and at least one polarizer 4 (or 5).

The liquid crystal element 2 includes a pair of substrates 20a and 20b disposed with a predetermined gap therebetween, and a monostable or bistable smectic liquid crystal disposed between the pair of substrates 20a and 20b. 21, and a pair of electrodes (not shown) arranged so as to sandwich the liquid crystal 21 and apply a voltage to the liquid crystal 21.

The birefringence of the uniaxial phase compensating member 3 and the birefringence of the liquid crystal 21 are set to be substantially equal. Here, the total birefringence of the liquid crystal 21 is preferably adjusted to half the wavelength of the incident light. Since the light wavelength that most affects the light intensity felt by humans is light near 550 nm, the total birefringence of the liquid crystal 21 is preferably set to about 270 nm. Therefore, it is preferable that the birefringence amount of the uniaxial phase compensation member 3 is also set to around 270 nm. Further, it is preferable that the maximum tilt angle of the average molecular axis of the liquid crystal 21 forms an angle of approximately 45 degrees.

Further, when the liquid crystal 21 exhibits a monostable state, the average molecular axis 21b (maximum open position) of the liquid crystal 21 in a monostable position or in a state where an electric field is applied and the uniaxial phase compensating member 3 The slow axis 3a is approximately 9
The angle is set to 0 ° (see FIG. 2). When the liquid crystal 21 exhibits bistability, one of the stable positions and the slow axis 3a of the uniaxial phase compensating member 3 are set to make an angle of about 90 °.

Furthermore, the polarization axis 4a of the polarizer 4
Is approximately the same direction as the center direction of the liquid crystal molecular cone or approximately 90 °
Direction.

When two polarizers are used (reference numerals 4,
5), the polarization axes 4a and 5a may be arranged substantially parallel to each other or at an angle of about 90 °.

Further, as the uniaxial phase compensating member 3, a liquid crystal element having the same characteristics and manufactured by the same method as the liquid crystal element 2 may be used. Is also good.

Further, in the apparatus shown in FIG. 1, the liquid crystal element 2 is disposed on the light irradiation side rather than the uniaxial phase compensation member 3, but the present invention is not limited to this, and may be reversed.

Further, at least one of the pair of substrates described above is preferably subjected to a uniaxial alignment process for aligning the liquid crystal 21.

Next, effects of the present embodiment will be described.

According to the present embodiment, the transmittance in the white display state can be kept high, the transmittance in the black state can be kept almost 0, and good color reproducibility and high contrast can be obtained. A liquid crystal display device for displaying an image is obtained.

Further, since θ is set to 22.5 °, a display without coloring can be realized in both white and black.

[0032]

The present invention will be described below in more detail with reference to examples.

Example 1 In this example, a liquid crystal device 1 shown in FIG. 1 was manufactured.

In this embodiment, an active matrix type liquid crystal panel (hereinafter, referred to as "display liquid crystal panel") is used as the liquid crystal element 2. In this display liquid crystal panel 2,
The liquid crystal average molecular axis takes a position indicated by reference numeral 21a when no electric field is applied (a monostable state position and a position forming an angle Θ = 22.5 ° with the incident polarization direction 4a), and is indicated by reference numeral 21b when an electric field is applied. A maximum open position (a position at an angle θ = 22.5 ° opposite to the incident polarization direction 4a) can be taken.

A single-pixel liquid crystal panel was used as the uniaxial phase compensation member 3 (hereinafter referred to as a "phase compensation liquid crystal panel").
And).

The liquid crystal panels 2 and 3 are arranged so that the rubbing direction is 45 degrees. In the liquid crystal panel 3 for phase compensation, the position of the liquid crystal average molecular axis indicated by reference numeral 3a (that is, the liquid crystal panel 2 for display). Opening position 2 when applying electric field
1b).

Further, a pair of polarizers 4 and 5 were arranged so as to sandwich the two panels 2 and 3. Hereinafter, the detailed configuration will be described.

(Preparation of Liquid Crystal Panel for Phase Compensation) First, the production of the liquid crystal panel 3 for phase compensation will be described.

A pair of glass substrates having a thickness of 1.1 m is prepared, and almost all of the glass substrates are covered with a 700-mm-thick IT.
A transparent electrode made of an O film (indium tin oxide film) was formed. Then, a polyimide precursor having the following repeating unit PI-A is applied by a spin coating method so as to cover those transparent electrodes, pre-dried at a temperature of 80 ° C. for 5 minutes, and then heated at a temperature of 200 ° C. For 1 hour to form a polyimide film (alignment control film) having a thickness of 200 °.

[0040]

Embedded image

Subsequently, these polyimide films were subjected to a rubbing treatment with a nylon cloth as a uniaxial orientation treatment. For the rubbing treatment, a nylon cloth (NF
Rubbing roll (diameter 10-77 / Teijin)
cm), the pushing amount is 0.3 m, and the feeding speed is 10 cm.
/ Sec, the number of rotations was 1000 rpm, and the number of times of feeding was 4 times.

Then, silica beads having an average particle diameter of 20 μm are sprayed as spacers on one of the glass substrates on which the electrodes and the polyimide film are formed, so that the rubbing directions are antiparallel to each other. The two substrates were bonded to obtain a cell having a uniform gap.

On the other hand, the following liquid crystal compound was mixed to prepare a liquid crystal composition LC-1. The numerical values described in the structural formula are weight ratios at the time of mixing.

[0044]

Embedded image

Then, the liquid crystal composition LC-1 was injected into the gap between the substrates at a temperature of an isotropic phase, and the liquid crystal was cooled to a temperature showing a chiral smectic liquid crystal phase.
Before and after the SmC * phase transition, a cooling process was performed by applying an offset voltage (DC) voltage of -5 V to obtain a liquid crystal panel 3 for phase compensation.

The panel 3 obtained as described above was driven by applying a rectangular wave voltage, and the movement of the liquid crystal average molecular axis was observed by a polarizing microscope. It was moved, and it was confirmed that almost the desired liquid crystal panel was obtained.

(Preparation of Display Liquid Crystal Panel) Next, a display liquid crystal panel 2 was prepared. The liquid crystal panel 2 was formed of a transparent electrode, a polyimide film, and a liquid crystal composition LC-1 of the same material as the above-described phase compensation liquid crystal panel 3,
Instead of a single pixel, a large number of pixels were used, and each pixel was provided with an active element.

(Driving of the liquid crystal device 1) The present inventor determined the position of the liquid crystal average molecular axis of the display liquid crystal panel 2 in a state where no voltage was applied and in a state where a voltage was applied by using a polarizing microscope (a polarizing microscope under crossed Nicols). Observed by Less than,
This will be described.

In the state where no electric field is applied, the liquid crystal average molecular axis of the display liquid crystal panel 2 takes the direction indicated by reference numeral 21a in FIG. 2, and the liquid crystal average molecular axis of the phase compensation liquid crystal panel 3 is indicated by reference numeral 3a in FIG. Take the direction shown.

When a voltage is applied to the display liquid crystal panel 2 in this state, the liquid crystal average molecular axis is rotated by 45 degrees and the reference numeral 2 is applied.
It was confirmed that the orientation shown in 1b was taken.

Next, (1) when the wavelength of the incident light is 550 nm, (2) when it is smaller than 550 nm, (3)
The behavior of light when it is larger than 550 nm will be described.

(1) First, the optical behavior when the wavelength of the incident light is 550 nm will be described.

The light applied to the polarizer 4 becomes linearly polarized light in the direction of the polarization axis 4a.

When no electric field is applied, the average molecular axis of the liquid crystal in the liquid crystal 21 assumes the position indicated by reference numeral 21a, and the linearly polarized light has an azimuth symmetric with respect to the position 21a (the direction indicated by reference numeral 21c; (A direction inclined by 45 degrees with respect to). When passing through the liquid crystal panel 3 for phase compensation, the light that has passed through the liquid crystal 21 is azimuthally symmetric with respect to the slow axis 3a (the azimuth indicated by reference numeral 3b and tilts 90 degrees with respect to the polarization axis 4a). Rotation). Now, both polarizers 4,
When the polarization axes 4a and 5a of 5 are orthogonal to each other,
The light that has passed through the liquid crystal panel 3 for phase compensation also passes through the polarizer 5, and a white state is displayed.

On the other hand, when an electric field is applied, the liquid crystal average molecular axis takes a position indicated by reference numeral 21b. Here, the liquid crystal average molecular axis 21b and the slow axis 3a of the phase compensation liquid crystal panel 3
Are set so as to be orthogonal to each other.
1 and the total amount of birefringence of the phase compensation liquid crystal panel 3 is 0 in total.
Becomes Here, the incident light becomes linearly polarized light by passing through the polarizer 4, and is rotated when passing through the liquid crystal 21 and the phase compensation liquid crystal panel 3.
The light reaches the polarizer 5 in the state of the polarization direction a. Since the polarization axis 5a of the polarizer 5 is orthogonal to the polarization direction 4a, light cannot pass through the polarizer 5 and a black state is displayed.

(2) Next, the wavelength of the incident light is 550 nm.
The optical behavior when smaller is described. In such a case, the light that has passed through the liquid crystal 21 when no electric field is applied becomes elliptically polarized light. Therefore, description will be made not from the viewpoint of rotation of linearly polarized light but from the viewpoint of polarization analysis using a Poincare sphere. When fully polarized light is represented by a Stokes vector and displayed in polar coordinates,
All polarization states fall on a sphere of radius 1. This sphere is called the Poincare sphere ("Applied Optics", Ichiro Yamaguchi: Ohmsha). The change in the polarization state due to the uniaxial birefringent medium is explained by the rotation of a point on the sphere. Here, an image near the equator of the Poincare sphere is shown in FIG. 3 and will be described with reference to FIG.

The horizontal axis in FIG. 3 corresponds to the equator on the Poincare sphere, and each numerical value on the horizontal axis represents the azimuth. For simplicity, it is assumed that the coordinate axis is not twice as large as the azimuth angle but is one time, and the angle of the polarizer 4 through which light first passes is set to 0 °.

Here, before describing the behavior of light having a wavelength smaller than 550 nm, the behavior of light having a wavelength of 550 nm will be described.

The polarization state of the light immediately after passing through the polarizer 4 is shown by a point 31 in FIG. Light in this polarization state
The liquid crystal panel 21 is rotated about the point 32 representing the liquid crystal average molecular axis 21a by the phase difference π radian between the ordinary light and the extraordinary light, and the polarization state indicated by the reference numeral 33 is obtained. That is, due to the birefringence of the display liquid crystal panel 2, the polarization is 4
It becomes a linearly polarized light corresponding to the azimuth 21c in FIG. 2 rotated by 5 degrees.

Thereafter, the light rotates around the point 36 corresponding to the liquid crystal panel 3 for phase compensation by the phase difference π radians of the liquid crystal panel 3 for phase compensation, and reaches the point 34. That is, the light becomes linearly polarized light that is rotated by 90 ° with respect to the first polarizer 4. Therefore, a cross nicol exhibits a white state, and a balanicol exhibits a black state.

On the other hand, in the case of light having a wavelength smaller than 550 nm, the phase difference of the liquid crystal panel 21 increases, and the rotation angle about the point 32 increases. At this time, the point 33 deviates from the equator of the Poincare sphere by including the elliptically polarized light component due to the rotation, and shifts in the direction of 35b in FIG. However, the rotation angle corresponding to the phase difference of the next phase compensation liquid crystal panel 3 also increases by the same amount. Can be canceled. Therefore, as in the case of the light wavelength of 550 nm, the crossed Nicols exhibit a white state, and the Baranicols exhibit a black state.

(3) Next, consider a case where the wavelength of light is larger than 550 nm.

At this time, since the phase difference of the display liquid crystal panel 21 becomes smaller, the rotation angle about the point 32 becomes smaller. At this time, the rotation causes the point 33 to be 35 in FIG.
It shifts in the direction of a. However, the rotation angle corresponding to the next phase difference of the phase compensation liquid crystal panel 3 is also reduced by the same amount, and as a result, the movement of the point 34 by the rotation about the point 36 can be canceled. For this reason,
The polarization direction of the light can be rotated by 90 ° regardless of the wavelength of the light. As in the case of the light wavelength of 550 nm, the crossed Nicols exhibit a white state, and the balanicols exhibit a black state.

The optical response when an electric field is applied to the liquid crystal 21 and the average molecular axis of the liquid crystal is at the position 21b. The birefringence of the liquid crystal 21 and the phase compensation liquid crystal panel 3 at an arbitrary visible region wavelength is small. If they match, as in the case of the wavelength of 550 nm, the total birefringence of the liquid crystal 21 and the phase compensating liquid crystal panel 3 is 0, so that regardless of the wavelength, the crossed Nicols exhibit a black state and the paranicols exhibit a white state.

Next, the effect of this embodiment will be described.

According to this embodiment, the design wavelength 550 is set.
A good image with excellent color reproducibility can be obtained not only in nm but also in light of 550 nm or more or 550 nm or less. That is, the transmittance in the white display state can be kept high, the transmittance in the black state can be kept almost 0, and a liquid crystal display element that displays a good image with high color reproducibility and high contrast can be obtained. Can be

A contrast measurement using a polarizing microscope and a photomultiplier system yielded a result of 200, confirming that a white state and a black state without coloring were realized with the naked eye.

Comparative Example As a comparative example, a liquid crystal device shown in FIG. 4 was manufactured. That is, the liquid crystal device is configured by stacking a single liquid crystal panel 22 and a pair of polarizing plates 24 and 25 disposed so as to sandwich the liquid crystal panel 22,
In the same manner as in the above example, the display state when no voltage was applied and when a voltage was applied were examined. As a result, the contrast is 14
It was confirmed that it had dropped to zero. Further, it was confirmed that the white state was colored by the naked eye, and that there was light leakage in the black state.

[0069]

As described above, according to the present invention,
The transmittance in the white display state can be kept high, and the transmittance in the black state can be kept almost 0,
A liquid crystal display device that displays a good image with good color reproducibility and high contrast can be obtained.

Further, since the maximum tilt angle of the average molecular axis of the liquid crystal is set to approximately 45 degrees, a display without coloring in both white and black can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating the overall configuration of a liquid crystal device according to the present invention.

FIG. 2 is a diagram for explaining a liquid crystal average molecular axis position and the like.

FIG. 3 is a diagram for explaining the behavior of light.

FIG. 4 is a diagram showing a configuration of a conventional liquid crystal device.

[Explanation of symbols]

Reference Signs List 1 liquid crystal device 2 display liquid crystal panel (liquid crystal element) 20a, 20b glass substrate (substrate) 21 smectic liquid crystal 3 phase compensation liquid crystal panel (uniaxial phase compensation member) 4,5 polarizer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirohide Munakata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoji Asao 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Takeshi Kadoba 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) 2H049 BA06 BA46 BB03 BB42 BB48 BC04 BC22 2H091 FA08X FA08Z FA11X FA12X FB02 FD06 FD09 FD10 FD24 GA13 HA12 KA05 KA10 LA17 LA20 4H027 BA06 BD18 BD20 BE02 DE01 DE03 DE09 DH01 5C094 AA08 BA43 EB02 ED14

Claims (2)

[Claims] 1. A liquid crystal device comprising a liquid crystal element, a uniaxial phase compensating member, and at least one polarizer, wherein the liquid crystal element has a pair of substrates arranged with a predetermined gap therebetween, and a pair of the substrates. A monostable or bistable smectic liquid crystal arranged between the substrates, and a pair of electrodes arranged to sandwich the liquid crystal and apply a voltage to the liquid crystal,
The birefringence of the uniaxial phase compensating member and the birefringence of the liquid crystal are set to be substantially equal, and the maximum tilt angle of the average molecular axis of the liquid crystal forms an angle of approximately 45 degrees, When the liquid crystal exhibits monostable, the average molecular axis of the liquid crystal in a monostable position or in a state where an electric field is applied and the slow axis of the uniaxial phase compensating member form substantially 90 degrees, and the liquid crystal is bistable. Is set so that one of the stable positions and the slow axis of the uniaxial phase compensating member make an angle of about 90 °, and the polarizing axis of the polarizer is in the center direction of the liquid crystal molecule cone. A liquid crystal device, wherein the liquid crystal device has a direction substantially the same as that of the liquid crystal or a direction of approximately 90 °. 2. The liquid crystal device according to claim 1, wherein the uniaxial phase compensating member is a liquid crystal element having the same characteristics as the liquid crystal element.