JPH0915639A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: To provide a liquid crystal display device capable of displaying stereoscopic images to a user. CONSTITUTION: Two pieces of upper and lower side liquid crystal cells 1a, 1b formed by superposing a pair of transparent insulating substrates 2a, 3a, 2b, 3b respectively provided with transparent electrodes and oriented films on respective opposite surfaces on each other part prescribed spacings and sealing liquid crystal molecules 5 contg. dyestuff molecules 4 of a slender shape therebetween are arranged on an illumination light source 8 while superposing above and below. The major axis direction of the liquid crystal molecules 5 of the upper liquid crystal cell 1b and the major axis direction of the liquid crystal molecules 5 of the lower liquid crystal cell 1a are respectively oriented in parallel in such a manner that the both directions intersect orthogonally with each other when viewed from the direction perpendicular to the substrate surfaces in a state where voltage is not applied. Two sheets of polarizing plates, 6a, 6b are lined up on the right and left and are so arranged that the respective polarization axis directions 7a, 7b intersect orthogonally with each other in alignment to the respective major axis directions of the liquid crystal molecules 5 of the upper and lower liquid crystal cells 1a, 1b by placing a distance on the upper liquid crystal cell 1b.

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 having a liquid crystal cell in which a liquid crystal containing elongated dye molecules is sealed as a constituent element.

[0002]

2. Description of the Related Art When dye molecules having an elongated shape are dissolved in liquid crystal, the dye molecules are aligned in the same direction as the liquid crystal molecules. That is, the dye molecules can be arranged in the same direction as the electric field by changing the alignment state of the liquid crystal molecules by the electric field. In this case, the liquid crystal host
The dye is called a guest, and such an electro-optical effect is called a “guest-host (GH) effect”.

When a guest dye having different light absorption characteristics in the major axis direction and the minor axis direction of the molecule (called a dichroic dye) is used, absorption by the dye by applying a voltage to the liquid crystal cell, that is, The hue of light transmitted through the liquid crystal cell can be changed.

The operation principle of a homogeneously aligned GH liquid crystal cell using a nematic liquid crystal having a positive dielectric anisotropy as a host and a dye that strongly absorbs light oscillating in the long axis direction of the molecule will be described below. A polarizer having a polarization axis in the same direction as the alignment direction of the liquid crystal molecules of the liquid crystal cell when no voltage is applied, that is, the long axis direction of the dye molecule is arranged between the incident (white) light and the liquid crystal cell. .

When no voltage is applied, the polarization direction of the incident light and the alignment direction of the liquid crystal molecules, that is, the long axis direction of the guest dye molecule, are coincident with each other. It looks colored. On the other hand, when a voltage higher than the threshold voltage is applied to the liquid crystal cell, the liquid crystal molecules are in a homeotropic alignment state, and the dye molecules are also aligned in the electric field direction. Therefore, since the polarization direction of the incident light becomes orthogonal to the strong absorption direction of the dye molecule, the light absorption disappears, and the incident light passes through the liquid crystal cell without being absorbed. However, in practice, the arrangement of the liquid crystal molecules and the dye molecules is not in an ideal state, so that some coloring often remains.

[0006] As a display element based on the GH effect, another one applying the cholesteric / nematic phase transition effect, which is called a "White-Taylor type" GH liquid crystal cell in the name of the inventor. There is.

When no voltage is applied, the liquid crystal is in a cholesteric liquid crystal state having a helical structure, and the dye molecules of the guest are also arranged in a helical shape, and are oriented in various directions.
The liquid crystal cell looks colored due to the strong light absorption effect.
When a voltage is applied and the liquid crystal enters a homeotropically aligned nematic state, the dye molecules also line up in the direction of the electric field, and absorption by the dye disappears. The white tailor type GH element has a problem that the contrast is slightly small, but since a polarizing plate is not required, a bright display can be obtained.

The guest dye has a large dichroic ratio,
It is required to be well soluble in the host liquid crystal and stable. It is possible to display two colors by selecting a guest dye, but if a mixture of several dyes is used as a black dye that absorbs light in the wavelength range of visible light, white and black display may also be performed. it can. When a host liquid crystal with a positive dielectric anisotropy is used, it has a "negative type" display characteristic in that the color disappears only in the part where a voltage is applied.
From the viewpoint of visibility, a "positive type" display in which only a portion to which a voltage is applied is colored is desired. Positive type display characteristics can be obtained by using a host liquid crystal having a negative dielectric anisotropy or by using a guest dye having a large absorption effect in the short axis direction of the molecule. However, the performance of the display seems to be inferior to that of the negative type (literature name: "Liquid crystal and its applications") Author: Susumu Sato Publisher: Sangyo Tosho Co., Ltd. Publication date: October 18, 1984 First edition Heisei 9th edition, January 30, 3rd).

[0009]

[Problems to be Solved by the Invention] Conventionally, as described above,
In a liquid crystal display device using a liquid crystal containing elongated dye molecules, a pair of transparent insulating substrates, each having a transparent electrode and an alignment film that has been subjected to an alignment treatment, are stacked on opposite surfaces at predetermined intervals. In addition, a GH liquid crystal cell in which liquid crystals containing elongated dye molecules are sealed and a single polarizing plate are provided therebetween. However, the image displayed is
The configuration was such that the image was seen on a plane as seen from the eyes of the user (observer), and no stereoscopic image was seen.

An object of the present invention is to provide a liquid crystal display device using a liquid crystal containing elongated dye molecules and capable of displaying a stereoscopic image to a user.

[0011]

In order to achieve the above object, the present invention provides a pair of transparent insulating substrates each having a transparent electrode and an alignment-treated film on each opposing surface at predetermined intervals. Two upper liquid crystal cells and two lower liquid crystal cells, in which liquid crystal molecules containing elongated dye molecules are sealed, are placed on top of each other (in the case of a reflection type, a reflection plate or the like is used). Placed on top of each other, and with no voltage applied, in the direction of the major axis of the liquid crystal molecules of the upper liquid crystal cell,
The long axis direction of the molecules of the liquid crystal of the lower liquid crystal cell, when viewed from a direction perpendicular to the substrate surface, are aligned in parallel so as to be orthogonal to each other, with a distance above the upper liquid crystal cell. According to the major axis directions of the liquid crystal molecules, the two polarizing plates are arranged side by side so that the respective polarization axis directions are orthogonal to each other.

Further, it is characterized in that the upper liquid crystal cell and the lower liquid crystal cell are respectively caused to display images which are displaced from each other by a viewing angle viewed from one eye of the user.

Further, it is characterized in that eyeglasses are constituted by the two polarizing plates.

[0014]

According to the present invention, a liquid crystal display device is constituted by the upper and lower two liquid crystal cells sealed with liquid crystals containing elongated dye molecules and the two polarizing plates corresponding to the respective liquid crystal cells. An image shifted from each user's one eye is displayed on each liquid crystal cell, and the images of the two liquid crystal cells are displayed on different polarizing plates, so that the images can be viewed through the respective polarizing plates. A stereoscopic image can be displayed to the user.

[0015]

EXAMPLES Examples of the liquid crystal display device of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic perspective view for explaining an example of the operating principle of the liquid crystal display device of the present invention.

Reference numeral 8 is an illumination light source (backlight), 2a, 2
b is a lower transparent insulating substrate made of glass or the like, 3
a, 3b are upper transparent insulating substrates each made of glass or the like, 4 are elongated dye molecules, 5 are liquid crystal molecules, 1a,
1b is a lower liquid crystal cell and an upper liquid crystal cell, 6
Reference numerals a and 6b denote two polarizing plates, and reference numerals 7a and 7b denote polarization axis directions of the polarizing plates 6a and 6b, respectively.

That is, a pair of transparent insulating substrates 2a and 3a, and a pair of transparent insulating substrates 2a and 3a, each having a transparent electrode (not shown) and an alignment film (not shown) subjected to an alignment treatment on each opposing surface.
b and 3b are vertically overlapped at a predetermined interval, and a liquid crystal molecule 5 containing the dye molecule 4 is sealed by a sealing material (not shown) provided in a frame shape around the edge of the substrate therebetween. Lower and upper liquid crystal cells 1a and 1b are configured. The two liquid crystal cells 1a and 1b are arranged on the illumination light source 8 in a vertically overlapping manner. It should be noted that, with no voltage applied, the major axis direction (alignment direction) of the liquid crystal molecules 5 of the upper liquid crystal cell 1b and the major axis direction of the liquid crystal molecules 5 of the lower liquid crystal cell 1a are from the direction perpendicular to the substrate surface. When viewed, they are oriented in parallel so that they are orthogonal to each other. In addition, a distance is placed on the upper liquid crystal cell 1b so as to be aligned with the major axis directions of the liquid crystal molecules 5 of the lower and upper liquid crystal cells 1a and 1b.
Further, the two polarizing plates 6a and 6b are arranged side by side so that the respective polarization axis directions 7a and 7b are orthogonal to each other.

(A) When an electric field is applied to the lower liquid crystal cell 1a and no electric field is applied to the upper liquid crystal cell 1b, the lower liquid crystal cell 1
In a, the liquid crystal molecules 5 and the dye molecules 4 are perpendicular to the surfaces of the transparent insulating substrates 2a and 3a due to the electric field. At this time, in the upper liquid crystal cell 1b to which no electric field is applied, the liquid crystal molecules 5 and the dye molecules 4 are in a horizontal state with the surfaces of the transparent insulating substrates 2b and 3b, and the polarization axis (transmission axis) is in the long axis direction of the dye molecules 4.
When the user looks through the polarizing plate 6b having the same direction, the screen is colored by the upper liquid crystal cell 1b. However, when viewed from the polarizing plate 6a, the polarizing axis direction 7a of the polarizing plate 6a and the major axis direction of the dye molecule 4 of the upper liquid crystal cell 1b are not aligned, and thus the coloring does not occur.

(B) When an electric field is applied to the upper liquid crystal cell 1b and no electric field is applied to the lower liquid crystal cell 1a, the upper liquid crystal cell 1
In b, the liquid crystal molecules 5 and the dye molecules 4 are in a state perpendicular to the surfaces of the transparent insulating substrates 2b and 3b due to the electric field. At this time, in the lower liquid crystal cell 1a to which no electric field is applied, the liquid crystal molecules 5
And the dye molecule 4 are in a horizontal state with the surfaces of the transparent insulating substrates 2a and 3a, and when the user looks through the polarizing plate 6a whose polarization axis (transmission axis) is aligned with the major axis direction of the dye molecule 4, the The screen appears colored by the side liquid crystal cell 1a. However, when viewed from the polarizing plate 6b, the polarization axis direction 7b of the polarizing plate 6b and the long axis direction of the dye molecule 4 of the lower liquid crystal cell 1a are not aligned, and thus the coloring does not occur.

(C) Lower liquid crystal cell 1a and upper liquid crystal cell 1
When no electric field is applied to b, the liquid crystal molecules 5 and the dye molecules 4 of the liquid crystal cells 1a and 1b are transparent insulating substrates 2a, 3a, and 2b.
b and 3b are in a horizontal state, the long axis direction of the dye molecule 4 of the liquid crystal cell 1a coincides with the polarization axis direction 7a of the polarizing plate 6a, and the long axis direction of the dye molecule 4 of the liquid crystal cell 1b is the polarizing plate 6b.
Of the polarizing plates 6a and 6b, which correspond to the polarization axis direction 7b of
It looks colored even if you look through it.

(D) Lower liquid crystal cell 1a and upper liquid crystal cell 1
When an electric field is applied to b, the liquid crystal molecules 5 and the dye molecules 4 of each liquid crystal cell 1a, 1b are transparent insulating substrates 2a, 3a, 2
In the state perpendicular to the planes b and 3b, the long axis direction of the dye molecule 4 does not coincide with the polarization axis directions 7a and 7b of the respective polarizing plates 6a and 6b, and the coloring does not occur even when viewed from either of the polarizing plates 6a and 6b. can not see.

In this way, the image of the lower liquid crystal cell 1a can be displayed on the polarizing plate 6a, and the image of the upper liquid crystal cell 1b can be displayed on the polarizing plate 6b, and the display images of the liquid crystal cells 1a and 1b can be displayed on different polarizing plates. It can be displayed on 6a and 6b. Therefore, the transparent insulating substrates 2a, 3 of the liquid crystal cells 1a, 1b are
A large number of pixels are formed by the transparent electrodes formed on the surfaces a, 2a, and 3b, and the above operation is performed by the liquid crystal cells 1a and 1b.
In 1 pixel units, and the liquid crystal cells 1a and 1b are each provided with a shifted image corresponding to the viewing angle viewed from one eye of the user.
If the two types of images of the two liquid crystal cells 1a and 1b are displayed on the different polarizing plates 6a and 6b, the respective polarizing plates 6a and 6b are displayed.
A stereoscopic image can be displayed to the user looking through both eyes via a and 6b. If the polarizing plates 6a and 6b are attached to the lens portion of the spectacles to form the spectacles, a plurality of persons can simultaneously see the stereoscopic image.

FIG. 2 is an exploded perspective view of essential parts of a liquid crystal display module which is an example of the liquid crystal display device of the present invention.

Reference numeral 8 denotes an illumination light source (backlight), 1a, 1
b is a lower liquid crystal cell and an upper liquid crystal cell, 9a,
9b is the long axis direction (alignment direction) of the liquid crystal molecules and the dye molecules in a state where no voltage is applied to the liquid crystal cells 1a and 1b,
2a and 2b are lower transparent insulating substrates of liquid crystal cells 1a and 1b, 3a and 3b are upper transparent insulating substrates of liquid crystal cells 1a and 1b, 10a and 10b are liquid crystal cells 1 respectively.
a tape carrier package (TCP) having a driving IC chip for applying an electric field to transparent electrodes (not shown) formed on the lower transparent insulating substrates 2a and 2b,
a and 11b are tape carrier packages each having a driving IC chip for applying an electric field to the transparent electrodes formed on the upper transparent insulating substrates 3a and 3b of the liquid crystal cells 1a and 1b, and 12 is the lower side of the liquid crystal cells 1a and 1b, respectively. The transparent insulating substrates 2a, 2b and the upper transparent insulating substrates 3a, 3b intersect each other with a plurality of strip-shaped transparent electrodes formed in parallel so as to be orthogonal (intersecting) to each other when viewed from a direction perpendicular to the substrate surfaces. A large number of pixels composed of regions, 6a and 6b are 2
The polarizing plates 7a and 7b are oriented along the polarization axes of the polarizing plates 6a and 6b, respectively.

That is, a plurality of transparent electrodes and an alignment film, each of which is formed in a strip shape in a direction orthogonal to each other on each of the facing surfaces, are provided, and each pixel is formed by the overlapping portion of the transparent electrodes. Substrates 2a and 3a, and 2b and 3b are vertically overlapped with a predetermined space therebetween, and liquid crystal molecules containing dye molecules are sealed by a sealing material provided in a frame shape around the edges of the substrates therebetween. Lower and upper liquid crystal cells 1a and 1b are configured. The two liquid crystal cells 1a and 1b are arranged on the illumination light source 8 in a vertically overlapping manner. It should be noted that, with no voltage applied, the major axis direction (alignment direction) of the liquid crystal molecules of the upper liquid crystal cell 1b and the major axis direction of the liquid crystal molecules of the lower liquid crystal cell 1a were viewed from a direction perpendicular to the substrate surface. In this case, they are oriented in parallel so as to be orthogonal to each other. Further, the two polarizing plates 6a and 6b are arranged at a distance above the upper liquid crystal cell 1b so that the respective polarization axis directions 7a and 7b are orthogonal to each other according to the long axis directions 9a and 9b of the liquid crystal molecules. Are arranged side by side. Although illustration of a holding mechanism for the polarizing plates 6a and 6b is omitted, the holding mechanism is held integrally with a shield case (frame) of the liquid crystal display module or another holding member at a predetermined distance from the upper liquid crystal cell 1b. The liquid crystal display module may be attached to the lens portion of the spectacles that is separate from the liquid crystal display module. In the latter case, multiple persons can view the stereoscopic image at the same time.

In the liquid crystal display module having such a structure, a stereoscopic image can be displayed to the user according to the principle described with reference to FIG.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the scope of the invention. is there. For example, the present invention can be applied to both a simple matrix type liquid crystal display device and an active matrix type liquid crystal display device. Further, the module configuration may be various ones other than the one shown in FIG.

[0029]

As described above, according to the present invention,
A liquid crystal display device capable of displaying a stereoscopic image with a simple configuration can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view for explaining an example of the operating principle of a liquid crystal display device of the present invention.

FIG. 2 is an exploded perspective view of a main part of a liquid crystal display module which is an example of the liquid crystal display device of the present invention.

[Explanation of symbols]

1a ... Lower liquid crystal cell, 1b ... Upper liquid crystal cell, 2a, 2b
... Lower transparent insulating substrate, 3a, 3b ... Upper transparent insulating substrate,
4 ... elongated dye molecules, 5 ... liquid crystal molecules, 6a, 6b
... Polarizing plates, 7a, 7b ... Polarizing axis direction of polarizing plates, 8 ... Illumination light source (backlight), 9a, 9b ... Long axis direction (alignment direction) of liquid crystal molecules and dye molecules in a state where no voltage is applied,
10a, 10b ... Drive IC chip mounted tape carrier package (TC) for applying an electric field to the lower transparent insulating substrate
P), 11a, 11b ... Drive IC chip mounted tape carrier package for applying an electric field to the upper transparent insulating substrate, 1
2 ... Pixel.

Claims (3)

[Claims] 1. A transparent electrode and a pair of transparent insulating substrates each provided with a film subjected to an alignment treatment on each opposite surface are laminated at a predetermined interval, and an elongated dye molecule is contained between them. An upper liquid crystal cell with liquid crystal molecules sealed, a transparent electrode on each facing surface, and a pair of transparent insulating substrates each provided with an alignment-treated film are superposed at a predetermined interval, and an elongated shape is formed between them. The lower liquid crystal cell encapsulating liquid crystal molecules containing the dye molecules is placed one on top of the other, and in the state in which no voltage is applied, the long axis direction of the liquid crystal molecules of the upper liquid crystal cell and the lower liquid crystal cell The long axis direction of the molecules of the liquid crystal of the liquid crystal cell, when viewed from a direction perpendicular to the substrate surface,
Two polarizing plates are aligned in parallel so as to be orthogonal to each other, and are spaced apart from each other on the upper liquid crystal cell so that the respective polarization axis directions are orthogonal to each other in alignment with the long axis directions of the liquid crystal molecules. A liquid crystal display device having a structure in which the two are arranged side by side. 2. The liquid crystal display device according to claim 1, wherein the upper liquid crystal cell and the lower liquid crystal cell each display a shifted image corresponding to a viewing angle viewed from one eye of a user. 3. The liquid crystal display device according to claim 1, wherein eyeglasses are constituted by the two polarizing plates.