JPH06167701A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To uniformalize display characteristics without varying the retardation regulated by the double refractive indices of liquid crystals and cell thicknesses by providing substrates after sticking with plural grooves for the liquid crystals in the horizontal direction of a screen. CONSTITUTION:Plural wire-shaped light emitting sources Y1 to Yn are arranged along a direction Y on the one glass substrate and plural wire-shaped electrodes X1 to Xm are arranged in a direction X so as to intersect therewith on these light sources. The respective wire-shaped light emitting sources Y1 to Yn are constituted of light emitting parts 1 and wire-shaped optical waveguides 2 for transmitting the light from these light emitting parts 1. The plural grooves for the liquid crystals are formed in the horizontal direction of the screen on the substrates after sticking. Walls are eventually formed to prevent the fall of the liquid crystals by their own weight and the cell gaps of the liquid crystals are assured (nearly d1=d2) and the display uniform over the entire part of the screen is therefore possible.

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, and more particularly to a large capacity, large screen liquid crystal display device.

[0002]

2. Description of the Related Art Matrix type liquid crystal display devices (LCDs) are required to have a large capacity and are required to be larger than the size of a display screen. There has been proposed a liquid crystal display device in which an electric signal is used to increase a pixel drive current in order to solve the former problem by causing a delay of an electric signal due to capacitance and non-uniformity of display on a panel ( Toray Industries, Inc. Kaihei 1-1730
16, Casio Computer Co., Ltd. Kaihei 2-89029, Seiko-Epson Co., Ltd. Kaihei 2-134617, Sharp Corp. Application No. 3-26394
7, etc.).

FIG. 13 is a schematic plan view of the above-mentioned photo-address type drive matrix type liquid crystal display device, and FIG.
3 is a schematic cross-sectional view of the matrix type liquid crystal display device taken along the line A. FIG. In FIG. 13, the glass substrate, transparent electrode, liquid crystal layer, and seal material shown in FIG. 14 are omitted.

13 and 14, one glass substrate 5a
A plurality of linear light sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n
Are arranged in parallel along the direction (vertical direction in FIG. 1), and a plurality of linear electrodes X ₁ , X ₂ , ...
_m-1 and X _m are arranged in parallel along the X direction (horizontal direction in FIG. 13).

Each linear light emitting source Y ₁ , Y ₂ , ... Y _n-1 , Y
_n , for example, a linear light-emitting source Y1 is a light-emitting diode (LED) array element or a laser diode (LD) array element, which is a light-emitting section 1 and a linear optical waveguide for transmitting light from the light-emitting section 1. The light is propagated through the optical waveguide 2 by causing the light emitting unit 1 to emit light.

The linear emission sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n and the linear electrodes X ₁ , X ₂ , ... X _m-1 , X _m intersect with each other to produce linear emission. Sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n and linear electrodes
Adjacent to each intersection with X ₁ , X ₂ , ... X _m-1 , X _m ,
Optical switch elements 3 each composed of a photoconductor layer are provided.

The linear electrodes X ₁ , X ₂ , ... X _m-1 , X _m and the picture element electrodes 4 for driving a display medium such as a liquid crystal are formed on the same plane. ₁ , X ₂ , ... X
_The above-mentioned optical switch element 3 is provided between _m-1 , X _m and the pixel electrode 4, respectively.

A transparent electrode 6 is provided on the other glass substrate 5b, and a liquid crystal layer 8 is sealed between the substrate and the seal material 7 described above.

When the optical switch element 3 is irradiated with light, that is, when the linear light source Y1 emits light and the light propagating through the optical waveguide 2 is incident on the switch element 3, the optical switch element 3 receives the light. The electric resistance is reduced and the signal from the linear electrode X1 is applied to the pixel electrode 4, and the alignment state of the liquid crystal is changed.

Linear light sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n
Optical scanning is performed by sequentially emitting light from Y ₁ to Y _n ,
Correspondingly, an electric signal is sent to the linear electrodes X ₁ , X ₂ , ... X.
_It is applied to _m-1 and X _m . Linear light source Y ₁ , Y ₂ , ... Y
_{While n−1} and Y _n are emitting light, the optical switching element 3 on the light emitting source is in the ON state, so that the linear electrodes X ₁ and X
₂ , ... The electric signals from X _m-1 , X _m are applied to the respective picture element electrodes 4. That is, the optical switch element 3 is scanned by the optical signals from the linear light emitting sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n instead of the electrical gate signal of the TFT element.

[0011]

In a large-screen display device, as shown in FIG. 15, liquid crystal accumulates in the lower part of the screen due to the weight of the liquid crystal, and the cell gap is different between the upper and lower parts of the screen (cell gap d1 at the upper part of the screen). Is smaller than the cell gap d2 at the bottom of the screen), crystal birefringence (△ n) and cell thickness
Since the retardation (Δnd) defined by (d) is different in the plane, there is a problem that the display characteristics become non-uniform.

An object of the present invention is to provide a liquid crystal display device in which the retardation defined by the birefringence index of the liquid crystal and the cell thickness does not vary in the plane and the display characteristics are uniform.

[0013]

SUMMARY OF THE INVENTION The invention is constructed such that two substrates, each having an electrode, are arranged between the substrates and each pixel of the layer is driven by an applied signal. And a plurality of liquid crystal grooves formed in the horizontal direction of the screen on the bonded substrate.

[0014]

[Function] Since a plurality of liquid crystal grooves are formed in the horizontal direction of the screen on the substrate after bonding, a wall is formed so that the liquid crystal does not descend downward due to its own weight, and the cell gap of the liquid crystal is guaranteed. (Approximately d1 = d2), and therefore uniform display is possible over the entire screen.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a view for explaining a liquid crystal groove formed in the horizontal direction of the screen. As shown in FIG. 2, a liquid crystal groove is formed in the horizontal direction of the screen, and there is a wall so that the liquid crystal does not descend downward due to its own weight.

FIG. 1 is a plan view showing the basic structure of an optically addressed drive type LCD which is a first embodiment of the liquid crystal display device according to the present invention, and FIGS. 3 to 5 show the liquid crystal display device according to the present invention. FIG. 3 is a cross-sectional view showing the basic structure of an optical addressing type drive LCD which is the first embodiment. 3 is a schematic sectional view taken along line DD of FIG. 1, FIG. 4 is a schematic sectional view taken along line EE of FIG. 1, and FIG. 5 is a schematic sectional view taken along line FF of FIG.

As shown in FIGS. 1 and 3 to 5, a plurality of linear light emitting sources Y ₁ , Y ₂ , ... Y _n-1 , Y are provided on one glass substrate 5a.
_n are arranged along the Y direction in FIG. 1, and a plurality of linear electrodes X ₁ , X ₂ , ... X _m-1 , intersecting these are arranged.
X _m are arranged in the X direction of 1 in the figure.

Each linear light-emitting source Y ₁ , Y ₂ , ... Y _n-1 , Y
_n , for example, the linear light source Y ₂ is a light emitting diode (LED)
It is composed of an array element or a laser diode (LD) array element as a light emitting section 1 and a linear optical waveguide 2 for transmitting light from the light emitting section 1. By making the light emitting section 1 emit light, The light propagates in the optical waveguide 2, and the light is partially extracted by using a method of partially scratching the optical waveguide 2.

Each linear light-emitting source Y ₁ , Y ₂ , ... Y _n-1 , Y _n
And the linear electrodes X ₁ , X ₂ , ... X _m-1 , X _m at the intersections, that is, the linear emission sources Y ₁ , Y ₂ , ... Y _n-1 , Y _m.
Optical switch elements 3 each made of a photoconductive layer are provided adjacent to the intersections of _n and each of the linear electrodes X ₁ , X ₂ , ... X _m-1 , X _m . Linear electrodes X ₁ , X ₂ , ... X _m-1 , X
A pixel electrode 4 for driving a display medium such as _m and a liquid crystal
Are formed on the same plane, and the linear electrodes X ₁ , X
The optical switch elements 3 described above are provided between ₂ , ... X _m-1 , X _m and the picture element electrode 4, respectively.

A transparent electrode 6 is provided on the other glass substrate 5b, and a liquid crystal layer 8 is sealed between the substrate and the sealant 7 described above.

When the optical switch element 3 is irradiated with light, that is, when the linear light source Y ₂ emits light, the impedance of the optical switch element 3 is reduced, and the signal from the linear electrode X ₁ is transmitted to the pixel electrode. 4 and thus changes the alignment state of the liquid crystal.

The glass substrates 5a and 5b are examples of the two substrates of the present invention, and the optical switch element 3 is an example of the photoconductor layer of the present invention.

The linear emission sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n are
Optical scanning is performed by sequentially emitting light from Y ₁ to Y _n ,
Correspondingly, an electric signal is sent to the linear electrodes X ₁ , X ₂ , ... X.
_It is applied to _m-1 and X _m . Linear light source Y ₁ , Y ₂ , ... Y
_{While n-1} and Y _n are emitting light, the optical switching element on the linear light emitting source is turned on, so that the linear electrodes X ₁ and X
₂ , ... Electric signals from X _m-1 and X _m are picture element electrodes 4 respectively
Applied to. That is, the optical switch 3 is scanned by the optical signals from the linear light emitting sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n instead of the electrical gate signal of the TFT element.

As described above, according to the above-described embodiment, since the scanning signal is light, there is no inconvenience that the scanning (gate signal) flows through the electric capacity of the element as in the case of the TFT element. Further, since the cell gap of the liquid crystal is kept uniform, a uniform display can be performed over the entire screen.

The production method of the embodiment will be described in detail below.

A glass substrate as shown in FIG.
A patterned resist is formed on 5a, and a groove is formed by using a sandblast method, and a glass fiber z (light-shielding layer 11 is formed in the groove as shown in FIGS. 7A, 7B, and 7C). , Clad 1
(2, composed of core 13) is fitted and fused, and a part of the light shielding layer 11 and the clad 12 of the fiber on the substrate surface is polished and removed. At this time, in the clad on the surface of the substrate, light propagating in the waveguide is not reflected on the surface (depending on the refractive index of the core and the clad, for example, 1 μm).
Or more) leave. Then, the fiber surface is scratched so that the core comes into contact with the photoconductor layer 3, and the light from the light emitting source 1 is guided to the photoconductor layer 3.

Although the cross-sectional shape of the groove is shown as a quadrangle in FIGS. 6 and 7 (a), (b) and (c), it may be a semi-circle or a V-shape. As a method for forming a groove in a glass substrate, in machining, in addition to the sandblast method shown in this embodiment, a blasting method is used.
Although there is a method of using a metal and an etching method is used as the chemical processing, both the mechanical processing and the chemical processing are effective, and it is preferable to perform the chemical processing after performing the mechanical processing. In this embodiment, a part of the fiber clad portion on the substrate surface is left, but the clad portion may be removed to expose the core portion on the substrate surface, and the film having a lower refractive index than the core portion may be patterned.

At the intersections of the linear light sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n and the linear electrodes X ₁ , X ₂ , ... X _m-1 , X _m , the linear light source Y ₁ , Y ₂ , ... Y _n−1 , Y _n , the conductor layer 3 is formed in the vicinity thereof. The conductor layer 3 is formed by forming a hydrogenated amorphous silicon (a-Si: H) film by using a plasma chemical vapor deposition (P-CVD) method and patterning it by etching. As the photoconductor layer 3, in addition to a-Si: H, hydrogenated amorphous silicon germanium (a-SiGe:
H), hydrogenated amorphous silicon carbide (a-SiC: H)
, Hydrogenated amorphous silicon oxide (a-SiO: H)
, Hydrogenated amorphous silicon nitride (a-SiN: H)
Etc. can be used according to the wavelength of the light emitting source 1.

After that, the linear electrodes X ₁ , X ₂ , ... X _m-1 ,
A metal such as Al is formed as X _m by the EB vapor deposition method, and is patterned by etching. As the linear electrode, in addition to Al, metals such as Mo, Cr and Ti and indium are used.
-A transparent electrode such as tin oxide (ITO) may be used.

On the other hand, the pixel electrode 4 is formed by depositing an ITO film by sputtering and patterning it by etching.

Although the linear electrode X and the pixel electrode 4 are formed on the photoconductor layer 3 here, the photoconductive layer 3 may be formed on the linear electrode X and the pixel electrode 4. Although the linear electrode X, the photoconductive layer 3, and the pixel electrode 4 are of the planar type, they may have a sandwich structure.

An orientation layer 9a is formed on these layers. The alignment layer 9a is formed by rubbing a polyimide film formed by a spinner. Although the orientation layer 9a is formed by using a spinner here, it may be formed by a printing method.

A pattern resist as shown in FIG. 8 is formed on the other glass substrate 5b and processed by the sandblast method. This pattern is formed by forming a resist having a pattern as shown in FIGS. 9 (a) and 9 (b) and processing it by sandblasting. This pattern is shown in Figures 9 (a) and 9 (b).
As shown in Fig. 2, the optical switch part is created in the recessed part and finally the liquid crystal injection port is in the horizontal direction of the screen as shown in Figs. 1 to 6 and 10. Designed to be formed on-line. Where (1 x
The line of the liquid crystal layer was created so that the picture element of (m) could be covered, but by changing the pattern of the substrates 5a and 5b ((2 x
m), (3 xm), etc. can be created arbitrarily. The transparent electrode 6 is provided on the glass substrate 5b. This transparent electrode 6 is formed by depositing ITO by a sputtering method.

A light-shielding layer 10 is formed on the transparent electrode 6 so as to match the pattern of the optical switch element composed of the photoconductor layer 3 formed on the opposing substrate. The light shielding layer 10 is formed by forming Al by EB vapor deposition and etching. In addition to Al, a metal such as Mo, Cr, or Ti, an organic pigment-dispersed resin, or an inorganic pigment-dispersed resin may be used as the light-shielding layer 10. or,
Although it is formed on the transparent electrode 6 here, it may be formed on the back surface of the glass substrate 5b.

Further, an alignment layer 9b is formed on these.
The alignment layer 9b is formed by rubbing a polyimide film formed by a spinner. The orientation layer 9b is formed by using a spinner here, but may be formed by a printing method.

Spacers (not shown) are dispersed between the substrates on which the respective layers have been formed in this way, and the sealant 7 is printed by a pattern using a printing method so that grooves for liquid crystals are formed. Attach both substrates.

Since the substrates bonded as described above have liquid crystal grooves formed on both sides in the horizontal direction, the liquid crystal is formed in this space to form the liquid crystal layer 8.
The thickness of the liquid crystal layer 8 is about 5 micrometers, and the display mode is
The Do is a normally white type of Twisted Nematic (TN). As the liquid crystal material, for example, PCH manufactured by Merck
Liquid crystal ZLI-1565 is used, and the liquid crystal layer 8 is formed by vacuum injection.

When the optical switch element 3 is irradiated with light, that is, when the linear light source Y ₂ emits light, the impedance of the optical switch element 3 is reduced, and the signal from the linear electrode X ₁ is displayed. It is applied to the elementary electrode 4, and therefore the alignment state of the liquid crystal changes. At that time, the wall of the horizontal groove made for the liquid crystal prevents the liquid crystal from trying to descend to the bottom of the screen,
Since the cell gap can be made uniform, uniform display can be performed on the screen.

In this embodiment, an optical addressing type LCD is used.
However, even in a general active matrix type (for example, thin film transistor type (TFT) or metal insulator metal (MIM) structure LCD, the effect of making the cell gap uniform is the same.

An embodiment of an optical scanning type liquid crystal display device in which a simple matrix driving method which is another driving method of the present invention is used with reference to FIGS. 11 and 12 and an optical waveguide is also formed on a counter substrate. Show. Here, the manufacturing process, conditions, and materials of the liquid crystal display device in this embodiment are as described in the above embodiments. 11 is a plan view showing the basic structure of a simple matrix drive type LCD which is an embodiment of the optical scanning type liquid crystal display device according to the present invention, and FIG. 12 is a schematic sectional view taken along the line GG in FIG. . In FIG. 11, the glass substrate 5a of FIG. 12,
5b, the liquid crystal layer 8 including a spacer, and the seal 7 are omitted. In FIG. 12, the leftmost pattern (glass substrates 5a, 5b,
And the code entry portion except the seal 7) is repeated.

One glass substrate as shown in FIGS. 11 and 12.
A plurality of linear light emitting sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n are provided on 5b.
Are arranged along the Y direction, and a plurality of common linear electrodes C ₁ , C ₂ , ... C _k−1 , C _k are arranged in parallel in the Y direction. Linear light source Y ₁ , Y ₂ , ... Y _n-1 , Y
_n and the common linear electrodes C ₁ , C ₂ , ... C _k-1 , C _k are arranged on the same plane, and at least two common lines are provided between the two linear light emitting sources. Electrodes (j) are formed.
Each of the linear light-emitting sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n , for example, the linear light-emitting source Y ₂ is a light emitting section 1 formed by an LED array element or an LD array element and a line for transmitting light from the light emitting section 1. The linear light source ₂ emits light on a line by causing the light emitting section 1 to emit light.

A plurality of linear electrodes are provided on the other glass substrate 5a.
X ₁ , X ₂ , ... X _m-1 , X _m are formed on the glass substrate 5a by a plurality of linear light emitting sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n , and a common linear electrode C ₁ , C ₂ , ... C _k−1 , C _k, and so on, that is, along the x direction. or,
The pixel electrodes are patterned in an island shape so as to be driven by one linear light emitting source and j common linear electrodes.

Each linear light emission source Y ₁ , Y ₂ , ... Y _n-1 , Y _n
And the linear electrodes X ₁ , X ₂ , ... X _m-1 , X _m at the intersections, that is, the linear emission sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n.
Optical switch elements 3 made of a photoconductor layer are provided adjacent to the intersections of the linear electrodes X ₁ , X ₂ , ... X _m-1 , X _m . Linear electrodes X ₁ , X ₂ , ... X _m-1 , X _m
The pixel electrodes 4 for driving a display medium such as a liquid crystal are formed on the same plane, and the linear electrodes X ₁ , X ₂ , ... X are formed.
_m-1, X _m and above of the optical switch 3 between the pixel electrode 4 are provided respectively. The above-mentioned two substrates and sheets
The liquid crystal layer 8 is sealed between the adhesives 7. When the optical switch element 3 is irradiated with light, i.e., when the linear light-emitting source Y2 emitting, optical switching element 3 is the Inpi - applied to the signal is the picture element electrode 4 from the dance reduced linear electrodes X ₁ Is
Therefore, the alignment state of the liquid crystal changes.

The linear light emitting sources Y ₁ , Y ₂ , ... Y _n-1 , Y _n
Optical scanning is performed by sequentially emitting light from Y ₁ to Y _n ,
Correspondingly, an electric signal is sent to the linear electrodes X ₁ , X ₂ , ... X.
_It is applied to _m-1 and X _m . Linear light source Y ₁ , Y ₂ , ... Y
_{While n-1} and Y _n are emitting light, the optical switching element on the linear light emitting source is turned on, so that the linear electrodes X ₁ and X
₂ , ... Electric signals from X _m-1 and X _m are picture element electrodes 4 respectively
Applied to. That is, the display area constituted by j common linear electrodes is set as one unit block, and each block is selected by the linear light emitting source. As a result, the duty ratio (l
/ j) can drive (jxm) scan lines.

As described above, according to the above-described embodiment, it is possible to display with high contrast and large capacity with the minimum required number of drivers as compared with a general simple matrix drive type liquid crystal display device. In addition, the wall of the horizontal groove made for the liquid crystal can prevent the liquid crystal from descending to the lower side of the screen and make the cell gap uniform, so that a uniform display can be made on the screen. In this embodiment, an optical address drive type LCD is shown, but the effect of making the cell gap uniform is the same in a general simple matrix type LCD.

[0047]

EFFECTS OF THE INVENTION Since a plurality of liquid crystal grooves are formed in the screen horizontal direction on the substrates after bonding, a wall is formed so that the liquid crystal does not descend downward due to its own weight, and the cell gap of the liquid crystal can be guaranteed. A uniform display can be provided over the entire screen.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an embodiment of a liquid crystal display device of the present invention.

FIG. 2 is a schematic perspective view of an embodiment of the liquid crystal display device of the present invention.

FIG. 3 is a schematic cross-sectional view taken along the line DD of FIG.

FIG. 4 is a schematic sectional view taken along line EE of FIG.

5 is a schematic cross-sectional view taken along the line FF of FIG.

FIG. 6 is a pattern diagram of a glass substrate.

FIG. 7 is a diagram illustrating a method of creating an optical waveguide.

FIG. 8 is a pattern diagram of another glass substrate.

FIG. 9 is a diagram illustrating another method for producing a glass substrate.

FIG. 10 is a diagram illustrating the bonding of the optical scanning liquid crystal display device.

FIG. 11 is a schematic plan view of another embodiment of the liquid crystal display device of the present invention.

12 is a cross-sectional view taken along the line GG of FIG.

FIG. 13 is a schematic plan view of a general optical scanning liquid crystal display device.

14 is a cross-sectional view taken along the line AA of FIG.

FIG. 15 is a schematic perspective view of a general optical scanning liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Light emission source 2 Optical waveguide 3 Photoconductor 4 Picture element electrode 5a, 5b Substrate 6 Transparent electrode 7 Sealing agent 8 Liquid crystal layer 9a, 9b Alignment layer 10, 11 Light shielding layer 12 Cladding part 13 Core part 14 Spacer C ₁ , C ₂ , ... C _k-1 , C _k common electrode X ₁ , X ₂ ... X _m-1 , X _m linear electrode Y ₁ , Y ₂ ... Y _n-1 , Y _n linear emission source Z light fiber

Claims (9)

[Claims] 1. Two substrates, each having an electrode, a liquid crystal disposed between the substrates and configured so that each pixel of the layer is driven by an applied signal, and after bonding A liquid crystal display device for a large screen, comprising a plurality of liquid crystal grooves formed on the substrate in a horizontal direction of the screen. 2. The substrate includes a plurality of linear light emitting sources arranged in parallel with each other, a plurality of linear electrodes arranged in parallel with each other in a direction intersecting the plurality of linear light emitting sources, and the plurality of linear electrodes. Between a plurality of pixel electrodes formed on the same substrate as the plurality of linear electrodes adjacent to a position where the linear light emitting source and the plurality of linear electrodes intersect with each other, and And a plurality of photoconductor layers each of which is switched by light from the plurality of linear light emitting sources, and a liquid crystal is applied by a signal applied through the linear electrodes and the photoconductor layer. 2. The liquid crystal display device for a large screen according to claim 1, wherein each of the picture elements is driven. 3. A liquid crystal display for a large screen according to claim 2, wherein the optical switch section composed of the plurality of photoconductor layers and the plurality of pixel electrodes has a planar structure. apparatus. 4. The optical switch section composed of the plurality of photoconductor layers, the plurality of picture element electrodes, and the plurality of linear electrodes has a sandwich structure. Liquid crystal display device for large screens. 5. The liquid crystal display device for a large screen according to claim 2, wherein the driving method is active matrix driving. 6. The liquid crystal display device for a large screen according to claim 2, wherein the driving method is simple matrix driving. 7. The light emitting diode comprises a plurality of linear light emitting sources.
The liquid crystal display device for a large screen according to claim 2, wherein the liquid crystal display device is a dry array. 8. The liquid crystal display device for a large screen according to claim 2, wherein the plurality of linear light emitting sources are laser diode arrays. 9. The liquid crystal display device for a large screen according to claim 2, wherein a part of the plurality of liquid crystal grooves is formed of an optical waveguide material.