JPH1062772A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain stereoscopic images and a bright screen by setting the directions of the absorption axes of polarizing plates in such a manner that the directions are paralleled with or intersected orthogonally with the orientation direction of liquid crystal molecules in the one stable state of the two stable state of respective liquid crystal cells. SOLUTION: This liquid crystal display device has the plural liquid crystal cells 30A to 30D and are constituted by laminating the respective liquid crystal cells 30A to 30D in superposition on each other and arranging the polarizing plates 41, 42 respectively both surfaces of this laminate. With this liquid crystal display device, the orientation direction of the liquid crystal molecules in the first stable state of the respective ferroelectric liquid crystal cells 30A to 30B and the orientation direction of the liquid crystal molecules in the second stable state are respectively aligned to each other, by which the directions of the absorption axes of the polarizing plates 41, 42 are nearly paralleled or intersected nearly orthogonally with the orientation direction of the liquid crystal molecules in either one stable state of the first and second stable states of the respective liquid crystal cells 30A to 30D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device for displaying a three-dimensionally viewed image.

[0002]

2. Description of the Related Art Hitherto, the following configuration has been considered as a liquid crystal display device for displaying a three-dimensional image. FIG. 3 is a sectional view of a conventional liquid crystal display device. This liquid crystal display device has a plurality of (four in FIG. 3) liquid crystal cells 1.
OA, 10B, 10C, and 10D are stacked with polarizing plates 22, 23, and 24 interposed therebetween, and polarizing plates 21 and 25 are arranged on both surfaces of the stacked body.

The above liquid crystal cells 10A, 10B, 10C,
10D has a liquid crystal 18 sealed between a pair of transparent substrates 11 and 12 having transparent electrodes 13 and 14 made of an ITO film or the like formed on the inner surface thereof and alignment films 15 and 16 formed thereon. The pair of substrates 11 and 12 are joined via a frame-shaped sealing material 17, and the liquid crystal 18 is filled in a region between the substrates 11 and 12 surrounded by the sealing material 17.

These liquid crystal cells 10A, 10B, 10
C and 10D are of a simple matrix type, for example, and the transparent electrodes 13 formed on the back substrate 11 of each of the liquid crystal cells 10A, 10B, 10C and 10D are a plurality of signal electrodes formed along the column direction. The transparent electrodes 14 of the front substrate 12 are a plurality of scanning electrodes formed in parallel with each other along the row direction.

[0005] The liquid crystal 18 is a nematic liquid crystal to which a chiral agent is added.
The molecules of the liquid crystal 18 of B, 10C, and 10D change the alignment directions in the vicinity of the substrates 11 and 12 respectively to the alignment film 1.
In a state where the substrates are inclined at a slight pretilt angle with respect to the surfaces of the substrates 11 and 12, the substrates 11 and 12 are twist-oriented at a predetermined twist angle between the substrates 11 and 12.

FIG. 4 shows the above-mentioned liquid crystal cells 10A, 10B,
The orientation of liquid crystal molecules in the vicinity of the substrates 10 and 10C and the polarizers 21, 22, 23, 24 and 2
5 is a view of the direction of an optical axis (absorption axis in this case) as viewed from the front side of the liquid crystal display device.

As shown in FIG. 4, each liquid crystal cell 10A, 1
The orientation directions of the liquid crystal molecules in the vicinity of the substrates 11 and 12 of the substrates 0B, 10C, and 10D respectively correspond to the orientation directions 12a of the liquid crystal molecules in the vicinity of the front substrate 12.
Is approximately 90 ° counterclockwise as viewed from the front side with respect to the orientation direction 11a of the liquid crystal molecules in the vicinity of the liquid crystal molecules 10A, 10B, 10C, and 10D. As shown by the dashed arrow in the figure, the liquid crystal is twist-oriented from the back substrate 11 to the front substrate 12 at a twist angle of approximately 90 ° clockwise as viewed from the front side.

Further, each of the liquid crystal cells 10A, 10B,
The alignment directions of the liquid crystal molecules in the vicinity of both substrates 11 and 12 of 10C and 10D are the alignment directions of the liquid crystal molecules in the vicinity of the adjacent substrates of two liquid crystal cells sandwiching polarizing plates 22, 23 and 24, respectively. Are set substantially parallel to each other, and therefore, each of the liquid crystal cells 10A,
The alignment states of the liquid crystal molecules of 10B, 10C, and 10D are shifted by about 90 ° in the stacking order in the same direction as the twist direction of the liquid crystal cell.

Further, each of the polarizing plates 21, 22, 23, 2
Of the liquid crystal cells 4 and 25, the absorption axis 21a of the polarizing plate 21 disposed on the rear surface of the rearmost liquid crystal cell 10A is substantially parallel to the orientation direction 11a of the liquid crystal molecules in the vicinity of the rear substrate 11 of the rear liquid crystal cell 10A. Absorption axes 22a, 23a, 24 of the polarizers 22, 23, 24 disposed between the adjacent liquid crystal cells 10A, 10B, 10C, 10D.
a is in a direction substantially parallel to the alignment directions 11a and 12a (substantially parallel to each other) of the liquid crystal molecules in the vicinity of the substrates 11 and 12 on the adjacent side of the two liquid crystal cells sandwiching the polarizing plate, respectively. , The most front side liquid crystal cell 10D
The absorption axis 25a of the polarizing plate 25 disposed on the surface of the liquid crystal cell 10D is substantially parallel to the alignment direction 12a of the liquid crystal molecules in the vicinity of the front substrate 12 of the front liquid crystal cell 10D.

That is, this liquid crystal display device is basically a TN-type liquid crystal cell comprising a liquid crystal cell in which liquid crystal molecules are twisted at a twist angle of approximately 90 ° and a pair of polarizing plates disposed therebetween. A plurality of liquid crystal display elements are stacked in such a manner that a front polarizing plate of one adjacent liquid crystal display element and a rear polarizing plate of the other liquid crystal display element are shared by one polarizing plate.

This liquid crystal display device displays a three-dimensionally visible image by a combination of pixels displayed by each of the stacked liquid crystal display elements.
When the liquid crystal molecules 10B, 10C, and 10D are in the initial twist alignment state in which the liquid crystal molecules are most inclined with respect to the surfaces of the substrates 11 and 12 over the entire area of the liquid crystal layer, light incident on the liquid crystal display device from the back side (from the backlight). Is emitted to the front side, and the entire screen becomes white.

That is, when the light incident on the liquid crystal display device passes through the polarizing plate 21 on the back side, the light of the polarization component along its absorption axis 21a is absorbed and becomes linearly polarized light. , 10B, 10C, and 10D are in the initial twisted state, the light incident on these liquid crystal cells 10A, 10B, 10C, and 10D is rotated by approximately 90 ° and incident on the next polarizing plate. The light that has passed through the rear polarizer 21 and entered the liquid crystal cell 10
A, the polarizing plate 22, the liquid crystal cell 10B, the polarizing plate 23, the liquid crystal cell 10C, the polarizing plate 24, the liquid crystal cell 10D, and the polarizing plate 25 are sequentially transmitted and emitted to the front side of the liquid crystal display device.

On the other hand, the liquid crystal cells 10A, 10B, 10
When an ON electric field that causes liquid crystal molecules to rise and is applied between the electrodes 13 and 14 of an arbitrary pixel portion of one of the liquid crystal cells of C and 10D, application of the electric field of each pixel portion of the liquid crystal cell causes the application of the electric field. Is incident on the next polarizing plate without being rotated, and the light is absorbed by the polarizing plate, and a black pixel is displayed.

The same applies to the case where an ON electric field is applied to the pixel portion of another liquid crystal cell. The pixel is caused by the absorption of light by the polarizing plate on the emission side (front side) of the liquid crystal cell to which the ON electric field is applied. Is displayed.

When these display pixels are viewed from the front side of the liquid crystal display device, each of the stacked liquid crystal cells 10A, 1A is viewed.
A pixel displayed by applying an ON electric field to the pixel portion of the liquid crystal cell on the back side of OB, 10C, and 10D looks far away, and a pixel displayed by applying the ON electric field to the pixel portion of the liquid crystal cell on the front side. Can be viewed close to each other, and by controlling the application of the ON electric field to each of the liquid crystal cells 10A, 10B, 10C, and 10D, a three-dimensionally visible image can be displayed.

[0016]

However, the above-mentioned conventional liquid crystal display device has a plurality of liquid crystal cells 10A, 10B, 10A.
Since C and 10D are laminated with polarizing plates 22, 23 and 24 interposed therebetween, and polarizing plates 21 and 25 are disposed on both sides of the laminate, the screen becomes considerably dark. I have a problem.

That is, looking at the transmittance of light when the liquid crystal molecules in one liquid crystal display element are in the initial twist alignment state, at this time, the light passes through the polarizing plate on the incident side and becomes linearly polarized light. When the incident light is incident, the light of the polarization component along the absorption axis of the polarizing plate is absorbed and the light quantity is reduced by approximately 50%. Thereafter, the incident light is rotated by approximately 90 ° by the liquid crystal layer of the liquid crystal cell, and the light is emitted. The light enters the polarizing plate on the side as linearly polarized light in a direction substantially perpendicular to the absorption axis thereof (along the transmission axis of the polarizing plate), and passes through the emitting side polarizing plate to be emitted.

However, even if the light incident on the output-side polarizing plate is linearly polarized light in a direction substantially orthogonal to the absorption axis of the polarizing plate, not all of the light is transmitted but a certain degree. Light is absorbed by the polarizer.

In the above-mentioned conventional liquid crystal display device, the light which has passed through the polarizing plate 25 on the back side and whose light amount has been reduced by about 50% is alternately stacked in each of the liquid crystal cells 10D, 10C, 1C.
0B and 10A and the respective polarizing plates 24, 23, 22, and 21 are sequentially transmitted and emitted.
The light is absorbed each time the light passes through 23, 22, and 21, and the screen becomes considerably dark due to the accumulation of the light absorption.

An object of the present invention is to provide a liquid crystal display device which can display a three-dimensionally visible image and can obtain a bright screen by minimizing light absorption by a polarizing plate. Things.

[0021]

According to the liquid crystal display device of the present invention, a ferroelectric liquid crystal is sealed between a pair of substrates having electrodes and an alignment film formed on an inner surface thereof. A plurality of ferroelectric liquid crystal cells in which liquid crystal molecules are aligned in a first stable state when an electric field in a direction is applied and liquid crystal molecules are aligned in the second stable state when an electric field in a reverse direction is applied. Stacking these ferroelectric liquid crystal cells, arranging a polarizing plate on at least the surface of the stack on which light is incident, and forming a liquid crystal molecule in the first stable state of each of the ferroelectric liquid crystal cells. The alignment direction and the alignment direction of the liquid crystal molecules in the second stable state are made substantially coincide with each other, and the direction of the absorption axis of the polarizing plate is changed between the first and second stable states of each liquid crystal cell. Liquid crystal molecules in either stable state Or substantially parallel to the orientation direction or is characterized in that is substantially perpendicular.

According to the liquid crystal display device of the present invention, the liquid crystal molecules of all the ferroelectric liquid crystal cells are aligned in one of the first and second stable states over the entire area of the liquid crystal layer. In this case, the light (linearly polarized light) that has passed through the polarizing plate on the incident side and entered the liquid crystal display device passes through all the liquid crystal cells and exits.

On the other hand, one of the ferroelectric liquid crystal cells
An electric field for switching the alignment state of liquid crystal molecules is applied between the electrodes of an arbitrary pixel portion of one liquid crystal cell, and the liquid crystal molecules of the pixel portion are aligned in the other stable state of the first and second stable states. Then, at this time, light (linearly polarized light) incident on the pixel portion of the liquid crystal cell is absorbed by the liquid crystal, and the pixel is displayed. This is the same when the liquid crystal molecules in the pixel portion of the other liquid crystal cell are aligned in the other stable state. Indicated by absorption of

When these display pixels are viewed from the front side of the liquid crystal display device, the pixels displayed by the light absorption by the liquid crystal of the liquid crystal cell on the back side of the stacked liquid crystal cells appear far away, and the liquid crystal on the front side is viewed. Since the pixel displayed by the light absorption by the liquid crystal of the cell looks closer, by controlling the application to each ferroelectric liquid crystal cell, a three-dimensionally visible image can be displayed.

Moreover, the liquid crystal display device of the present invention transmits light by switching the alignment state of the liquid crystal molecules of each ferroelectric liquid crystal cell between the first stable state and the second stable state. Since the liquid crystal absorbs light to display pixels, there is no need to dispose a polarizing plate between the stacked liquid crystal cells as in a conventional liquid crystal display device. , And a bright screen can be obtained.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the liquid crystal display device of the present invention, it is preferable that the polarizing plates are disposed on both sides of the ferroelectric liquid crystal cell stack. The directions of the absorption axes may be substantially matched with each other.

As described above, the polarizing plates are arranged on both sides of the laminated body of the ferroelectric liquid crystal cell, and if the directions of the absorption axes of these polarizing plates are substantially coincident with each other, the light passes through the polarizing plate on the incident side. When the liquid crystal molecules of all of the stacked liquid crystal cells are aligned in one of the stable states, the light transmitted through these liquid crystal cells is transmitted through the polarizing plate on the opposite side. When the liquid crystal molecules in one of the liquid crystal cells are aligned in the other stable state, the leakage light generated when the liquid crystal in the liquid crystal cell absorbs light is absorbed by the opposite polarizer. Therefore, the contrast of the displayed image can be increased.

[0028]

FIG. 1 is a sectional view of a liquid crystal display device according to an embodiment of the present invention. The liquid crystal display device includes a plurality (here, four) of liquid crystal cells 30A, 30B, 30C, and 30D. Liquid crystal cells 30A, 30B, 30C, 30
D is stacked on top of each other, and polarizing plates 41 and 42 are arranged on both sides of the laminate.

Each of the liquid crystal cells 30A, 30B, 30C,
In each of 30D, a ferroelectric liquid crystal 38 is sealed between a pair of transparent substrates 31 and 32 in which transparent electrodes 33 and 34 made of an ITO film or the like are formed on the inner surface and alignment films 35 and 36 are formed thereon. Liquid crystal cells, and each liquid crystal cell 3
A pair of substrates 31, 32 of 0A, 30B, 30C, 30D
Are joined via a frame-shaped sealing material 37, and the ferroelectric liquid crystal 38 is sealed between the substrates 31 and 32 in a region surrounded by the sealing material 37. Each liquid crystal cell 30
Substrates 31, 32 of A, 30B, 30C, 30D are resin film substrates to reduce the thickness of the liquid crystal cell.

The ferroelectric liquid crystal cells 30A, 30B, 3
0C and 30D are electrodes 33 and 3 of both substrates 31 and 32, respectively.
When a unidirectional electric field is applied between the ferroelectric liquid crystal 3 and the
8 are oriented in a first stable state, and the liquid crystal molecules are oriented in the second stable state when an electric field in a reverse direction is applied.

That is, the ferroelectric liquid crystal cell has bistability in the arrangement state of the molecules of the ferroelectric liquid crystal.
When an electric field in one direction equal to or more than the threshold is applied to the ferroelectric liquid crystal, the liquid crystal molecules are aligned in one direction (first stable state), and the alignment state is maintained even after the application of the electric field is stopped. When an electric field is applied in a direction opposite to the electric field and equal to or higher than the threshold value of the liquid crystal, the liquid crystal molecules are moved by about 4 with respect to the previous alignment direction.
It is oriented in the direction rotated by 5 ° (second stable state), and keeps its orientation even after the application of the electric field is cut off.

Note that these ferroelectric liquid crystal cells 30A,
30B, 30C, 30D are, for example, of a simple matrix type, and each of the liquid crystal cells 30A, 30B, 30C,
The transparent electrode 33 formed on the back substrate 31 of the 30D includes a plurality of signal electrodes formed along the column direction, and the front substrate 3
The two transparent electrodes 34 are a plurality of scanning electrodes formed in parallel with each other along the row direction.

In this liquid crystal display device, the first ferroelectric liquid crystal cells 30A, 30B, 30C and 30D have the first
The alignment directions of the liquid crystal molecules in the stable state and the alignment directions of the liquid crystal molecules in the second stable state are substantially matched to each other, and the directions of the absorption axes of the polarizing plates 41 and 42 are adjusted to the respective liquid crystal cells 30A and 30B. , 30C, and 30D are substantially parallel to or substantially perpendicular to the alignment direction of the liquid crystal molecules in one of the first and second stable states.

FIG. 2 shows each of the above ferroelectric liquid crystal cells 30A,
The orientation directions of the liquid crystal molecules in the first and second stable states of 30B, 30C, and 30D, and the orientations of the absorption axes of the polarizing plates 41 and 42 disposed on the back and front surfaces of the liquid crystal cell stack are set to the front side of the liquid crystal display device FIG.

As shown in FIG. 2, each ferroelectric liquid crystal cell 3
The alignment directions (solid line directions) 38a of the liquid crystal molecules in the first stable state of 0A, 30B, 30C, and 30D are substantially the same, and the alignment direction of the liquid crystal molecules in the second stable state (the direction of the broken line). ) 38b are substantially 45 ° rotated in the same direction (clockwise in the figure) with respect to the alignment direction 38a of the liquid crystal molecules in the first stable state.

This liquid crystal display device is of a transmissive type in which the transmission of light from a backlight disposed on the back side thereof is controlled and displayed. The direction of the absorption axis 41a of the back-side polarizing plate 41 arranged on the back side which is the light incident side of the back side is determined by the alignment direction of the liquid crystal molecules in the first stable state of each of the liquid crystal cells 30A, 30B, 30C, 30D. 38a, and the direction of the absorption axis 42a of the front-side polarizing plate 42 disposed on the surface that is the light exit surface is changed to the direction of the back-side polarizing plate 41.
And the direction of the absorption axis 41a.

This liquid crystal display device displays a three-dimensionally visible image by controlling the electric field applied to each pixel unit by the stacked ferroelectric display cells 30A, 30B, 30C, 30D. When an electric field in one direction is applied to all the pixel portions of these liquid crystal cells, that is, the liquid crystal molecules of all the ferroelectric liquid crystal cells 30A, 30B, 30C, and 30D are in the first stable state (over the entire liquid crystal layer). When the liquid crystal is aligned in the alignment direction 38a) shown by the solid line in FIG. 2, light (linearly polarized light) transmitted through the rear polarizing plate 41 and incident on the liquid crystal display device is applied to all of the liquid crystal cells 30A, 30B, 3.
0C and 30D, and furthermore, the light passes through the front-side polarizing plate 42 and exits, and the entire screen becomes white.

On the other hand, each of the ferroelectric liquid crystal cells 30A, 3A
An electric field for switching the alignment state of the liquid crystal molecules (an electric field in the opposite direction) is applied between the electrodes 33 and 34 of any one of the liquid crystal cells of one of the liquid crystal cells 0B, 30C and 30D, and the liquid crystal molecules of the pixel part are changed. When the liquid crystal is aligned in the second stable state (the alignment direction 38b indicated by a broken line in FIG. 2), light (linearly polarized light) incident on the pixel portion of the liquid crystal cell is absorbed by the liquid crystal 38, and the pixel is Is displayed.

This is the same when the liquid crystal molecules in the pixel portion of another liquid crystal cell are aligned in the other stable state.
The pixels are displayed by the absorption of light by the liquid crystal of a liquid crystal cell in which liquid crystal molecules are aligned in the other stable state.

The light transmittance of the above liquid crystal display device when displaying black is determined by each of the ferroelectric liquid crystal cells 30A, 30B and 30.
Looking at one liquid crystal cell of C and 30D, the light transmittance T _ON of this one liquid crystal cell is expressed by the following equation (1).

T _ON = (１ ／) cos ² π (Δnd / λ) (1) Δn; apparent birefringence of liquid crystal d; liquid crystal layer thickness λ; wavelength of transmitted light, where Δnd = [( (1/2) + m] λ (2) If (m is an integer), then T _ON = 0 in the above equation (1), and a black pixel is displayed.

Specifically, when λ = 550 nm and the value of m is 1 or 2, when these values are substituted into the above (2), the value of Δnd becomes 825 nm or 1375 nm.
Becomes

Accordingly, each of the above ferroelectric liquid crystal cells 30
The value of the product Δnd of the apparent birefringence Δn of the liquid crystal 38 of A, 30B, 30C, and 30D and the liquid crystal layer thickness d is 825 nm.
In this case, the product Δn of these ferroelectric liquid crystal cells 30A, 30B, 30C and 30D is desirable.
When the value of d is 825 nm ± 20 nm or 1375 nm ± 2
If it is 0 nm, a black pixel can be displayed.

When displaying white, the amount of light is reduced by approximately 50% when the light passes through the back-side polarizing plate 41 and enters as linearly polarized light, and the light is reduced by approximately 50% in each of the ferroelectric liquid crystal cells 30A, 30A.
After passing through 30B, 30C, and 30D, the front-side polarizing plate 42
Since light is only slightly absorbed by this polarizing plate when transmitting white light, the transmittance of light when displaying white is a value close to 50%.

When these display pixels are viewed from the front side of the liquid crystal display device, the stacked liquid crystal cells 30A, 3A
The pixels displayed by light absorption by the liquid crystal of the liquid crystal cell on the back side of OB, 30C, and 30D appear distant, and the pixels displayed by light absorption by the liquid crystal of the liquid crystal cell on the front side appear close. Cells 30A, 30B,
By controlling the application to 30C and 30D, a stereoscopically visible image can be displayed.

In addition, this liquid crystal display device switches the alignment state of the liquid crystal molecules of each of the ferroelectric liquid crystal cells 30A, 30B, 30C and 30D between the first stable state and the second stable state, thereby transmitting light. Transmit or the liquid crystal 3
8, a pixel is displayed by absorbing light. Therefore, it is not necessary to arrange a polarizing plate between the stacked liquid crystal cells as in a conventional liquid crystal display device. A bright screen can be obtained with as little as possible.

Further, in the liquid crystal display device of the above embodiment, the surface (front surface) opposite to the incident surface of the liquid crystal cell laminate.
A polarizing plate 42, and an absorption axis 42a of the rear polarizing plate 41 in which the absorption axis 42a of the front polarizing plate 42 is disposed on the incident side.
a, almost all of the stacked liquid crystal cells 3 out of the light transmitted through the polarizing plate 41 on the incident side and incident.
When the molecules of the liquid crystals 38 of 0A, 30B, 30C, and 30D are oriented in one of the stable states, light transmitted through these liquid crystal cells is transmitted through the front-side polarizing plate 42 and emitted. When the molecules of the liquid crystal of the liquid crystal cell are aligned in the other stable state, the leakage light generated when light is absorbed by the liquid crystal of the liquid crystal cell can be absorbed by the front polarizer 42. Can be higher.

Further, in the liquid crystal display device, each of the liquid crystal cells 30A, 30B, 30C, 30D is provided with a ferroelectric liquid crystal 3D.
8, the ferroelectric liquid crystal 38 has a fast response speed to an electric field, and when an electric field in a reverse direction is applied, the liquid crystal rapidly changes from an alignment state in one direction to an alignment state in another direction. , The ferroelectric liquid crystal cells 30A, 30B, 30C, and 30D can be driven in a time-division manner with a high time-division number, so that the number of pixels can be increased to increase the resolution. .

In the above embodiment, the polarizing plates 41 and 42 are used.
Of the absorption axes 41a and 42a of the liquid crystal cells 30A, 30B, 30C and 30D are almost parallel to the alignment directions 38a of the liquid crystal molecules in the first stable state of the ferroelectric liquid crystal cells 30A, 30B, 30C and 30D. The absorption axes 41a and 42a may be substantially orthogonal to the alignment direction 38a of the liquid crystal molecules in the first stable state, and the transmission axis may be arranged to be parallel to the alignment direction 38a.

Further, the absorption axis 4 of the polarizing plates 41 and 42
The directions of 1a and 42a are the same as those of the ferroelectric liquid crystal cells 30A and 3A.
0B, 30C and 30D in the second stable state may be substantially parallel to or substantially perpendicular to the alignment direction 38b of the liquid crystal molecules.
When the liquid crystal molecules of A, 30B, 30C, and 30D are aligned in the second stable state over the entire area of the liquid crystal layer, the incident light passes through all the liquid crystal cells and is emitted, and any of the liquid crystal cells has When an electric field for switching the alignment state of the liquid crystal molecules is applied between the electrodes of an arbitrary pixel portion, and the liquid crystal molecules of the pixel portion are aligned in the second stable state, the light enters the pixel portion of the liquid crystal cell. The emitted light is absorbed by the liquid crystal, and the pixel is displayed.

In the liquid crystal display device of the above embodiment, four ferroelectric liquid crystal cells 30A, 30B, 30C, and 30D are stacked, but the number of stacked liquid crystal cells may be arbitrary. By increasing the number of images, an image with a more three-dimensional effect can be displayed.

Further, the liquid crystal display device of the above embodiment is of a transmission type in which the transmission of light from the backlight is controlled and displayed. The present invention can also be applied to a reflection-type liquid crystal display device in which incident external light (natural light, indoor illumination light, or the like) is reflected by the reflection plate for display. In that case, the polarizing plate 41 on the back side can be omitted, so that the polarizing plate may be arranged at least on the surface (front side) of the stacked body of the ferroelectric liquid crystal cells on which light is incident.

[0053]

According to the liquid crystal display device of the present invention, a ferroelectric liquid crystal is sealed between a pair of substrates having electrodes formed on the inner surface, and when a unidirectional electric field is applied between the electrodes of both substrates. A plurality of ferroelectric liquid crystal cells in which the liquid crystal molecules are oriented in a first stable state and the liquid crystal molecules are oriented in the second stable state when an electric field in the opposite direction is applied. The cells are stacked, and a polarizing plate is arranged on at least the surface of the stack on which light is incident, and the alignment direction of the liquid crystal molecules in the first stable state of each of the ferroelectric liquid crystal cells and the second The alignment directions of the liquid crystal molecules in the stable state are substantially matched with each other, and the direction of the absorption axis of the polarizing plate is adjusted in one of the first and second stable states of each of the liquid crystal cells. Almost parallel to the alignment direction of liquid crystal molecules Luke or from those obtained by substantially orthogonal, it is possible to display an image that looks three-dimensional,
In addition, a bright screen can be obtained by minimizing the absorption of light by the polarizing plate.

In the liquid crystal display of the present invention,
Polarizing plates are arranged on both sides of the laminate of the ferroelectric liquid crystal cell, respectively, and if the directions of the absorption axes of these polarizing plates are made to substantially coincide with each other, of the light transmitted through the polarizing plate on the incident side and incident thereon, When the liquid crystal molecules of all the stacked liquid crystal cells are oriented in one of the stable states, light transmitted through these liquid crystal cells is transmitted through the opposite polarizing plate and emitted, and When the molecules of the liquid crystal of the liquid crystal cell are aligned in the other stable state, the leakage light generated when light is absorbed by the liquid crystal of the liquid crystal cell can be absorbed by the polarizing plate on the opposite side. The contrast can be increased.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a liquid crystal molecule alignment direction and a transmission axis direction of each polarizing plate in the vicinity of both substrates of each liquid crystal cell of the liquid crystal display device of the embodiment.

FIG. 3 is a cross-sectional view of a conventional liquid crystal display device.

FIG. 4 is a view showing a liquid crystal molecule alignment direction and a transmission axis direction of each polarizing plate in the vicinity of both substrates of each liquid crystal cell of a conventional liquid crystal display device.

[Explanation of symbols]

 30A, 30B, 30C, 30D: Ferroelectric liquid crystal cell 38a: Alignment direction of liquid crystal molecules in the first stable state 38b: Alignment direction of liquid crystal molecules in the first stable state 41, 42: Polarizing plates 41a, 42a: Absorption axis

Claims (2)

[Claims] 1. A liquid crystal display device for displaying a three-dimensionally visible image, wherein a ferroelectric liquid crystal is sealed between a pair of substrates having electrodes formed on an inner surface thereof, and one electrode is provided between the electrodes of the two substrates. A plurality of ferroelectric liquid crystal cells in which liquid crystal molecules are aligned in a first stable state when an electric field in a direction is applied and liquid crystal molecules are aligned in the second stable state when an electric field in a reverse direction is applied. Stacking these ferroelectric liquid crystal cells, disposing a polarizing plate on at least a surface of the stack on which light is incident, and forming a liquid crystal molecule in the first stable state of each of the ferroelectric liquid crystal cells. The alignment direction and the alignment direction of the liquid crystal molecules in the second stable state are made substantially coincide with each other, and the direction of the absorption axis of the polarizing plate is changed between the first and second stable states of each liquid crystal cell. Liquid crystal content in either stable state A liquid crystal display device according to the orientation direction, characterized in that or is substantially perpendicular to substantially parallel. 2. The polarizing plate is disposed on both sides of the ferroelectric liquid crystal cell laminated body, and the directions of the absorption axes of these polarizing plates substantially coincide with each other. The liquid crystal display device according to claim 1. Is each