JPH07128671A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide the liquid crystal display device which has a inconspicuous and homogeneous screen with the inconspicuous boundaries between plural liquid crystal panels and is decreased in the number of sheets of the liquid crystal panels to be used by using a material which is transparent and is optically isotropic to constitute the sealing part of the other panel facing one display region in the part where plural sheets of the liquid crystal display panels are superposed on each other. CONSTITUTION:The overlapped where the adjacent liquid crystal panels 1 partially superposed on each other is so formed that the display region of the one liquid crystal panel 1 and the sealing part 4 of the other liquid crystal panel 1 overlap on each other. The sealing part 4 is formed of the transparent and optically isotropic material. An orifice 9 consisting of a UV curing resin is installed as a part of the transparent and optically isotropic sealing part 4 on the one transparent substrate 11 and is then printed with a sealing material 10, by which the sealing part 4 having high positional accuracy is formed. Of a pair of the transparent substrates 1, the transparent substrate 1 on the inner side in contact with the other adjacent liquid crystal panel is formed the thickness smaller than the thickness of the transparent substrate 1 on the outer side.

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 composed of a plurality of liquid crystal panels.

[0002]

2. Description of the Related Art As one method of realizing a large-sized liquid crystal display device, there is a method of assembling a plurality of liquid crystal panels (Mitsubishi Electric Technical Report 5-7, No. 12 (1988) P. 85).
4, video information (I) No. 11 (1988) P.I. 5
8). Each of these forms a liquid crystal panel formed of several hundreds to several thousand pixels as one unit, and several tens to several hundreds of liquid crystal panel units are formed.
A large screen was realized by combining them individually.

[0003]

However, the above-mentioned prior art has the following problems.

1. A large number of liquid crystal panels (dozens of sheets) and complicated driving circuits are required to form one large liquid crystal display device, which makes the system very expensive.

2. The surfaces where multiple LCD panel units contact each other are visually recognized as joints, resulting in discontinuous screens. In addition, the need for special optical system materials such as optical fibers and plastics as a means to overcome this.

Therefore, the present invention solves such a problem, and an object thereof is to provide a liquid crystal having a uniform screen in which the boundary between a plurality of liquid crystal panels is not conspicuous and the number of liquid crystal panels used is reduced. It is to provide a display device.

[0007]

A liquid crystal display device according to the present invention has a structure in which a plurality of liquid crystal display panels, each of which has a liquid crystal sandwiched between a pair of transparent substrates, are overlapped with each other, and the liquid crystal display panels are partially overlapped with each other. The overlapping portion of the two liquid crystal panels is composed of a display area and a sealing portion, and the sealing portion of the other liquid crystal panel facing the display area of one liquid crystal panel is transparent and optically isotropic. It is characterized in that the display region and the sealing portion are made of a material of which the accuracy is set to an error smaller than one pixel width.

[0008]

The operation of the present invention will be described. A liquid crystal device (for example, a twisted nematic liquid crystal device or a birefringence control type liquid crystal device) having a liquid crystal layer whose polarization plane is changed with respect to linearly polarized light is partially overlapped. In the composite liquid crystal panel described above, since the sealing part that constitutes a part of the overlapping part and faces the liquid crystal layer is transparent and optically isotropic, the transmitted light beam should be modulated in the sealing part. Without passing through the overlapping section. That is, since the liquid crystal layer is modulated only once, it is possible to perform a display similar to that of other liquid crystal filling areas in the overlapping portion.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, embodiments of the present invention will be conceptually described with reference to the drawings.

FIG. 2 is a sectional view of a superposed portion of two adjacent liquid crystal panels. This overlapping part is the sealing part 4.
And the liquid crystal layer 1, and the sealing portion 4 is made of a colorless and transparent material that is optically isotropic. For this reason,
In the composite liquid crystal panel of the present invention, the light ray passes through the liquid crystal layer only once in the entire display area including the overlapping portion.

FIG. 3 shows a state in which a plurality of liquid crystal panels assumed in the present invention are overlapped with each other, and a slanted line indicates an overlapping portion. (A) is a case where two liquid crystal panels are combined, and one of the four sides of each liquid crystal panel is overlapped. On the other hand, (b) shows a case where four liquid crystal panels are combined, and two of the four sides of each liquid crystal panel are overlapped.

It is considered that the maximum number of panels is four. This is because in order to extract the row electrodes and the column electrodes that drive the simple matrix, it is necessary that two of the four sides of each liquid crystal panel are not joined to the other adjacent panel. .

With such a structure, the number of panels used can be reduced, the cost can be reduced accordingly, and the joint between a plurality of liquid crystal panels is hardly visible.

In order to further improve such an effect, of the two transparent substrates constituting the liquid crystal panel, the thickness of the inner substrate which is in contact with another adjacent liquid crystal panel is made equal to the thickness of the other outer substrate. Set it thinner than the thickness. By taking such a structure, when the display screen is viewed obliquely,
Compared to the case where the two substrates have the same thickness, the joints between the panels are more difficult to be visually recognized, and parallax is reduced.

Further, by setting the accuracy of the facing display area and the sealing portion forming the overlapping portion of two adjacent liquid crystal panels so that the error is smaller than the width of one pixel, the discontinuity of the joint portion is set. The feeling is reduced.

The row electrodes or column electrodes can be taken out by
Since it is performed from one of the two opposite sides of the liquid crystal panel, it is desirable to reduce the resistance of the electrodes in order to obtain a uniform and uniform display. Therefore, it is also effective to install a metal auxiliary wiring on each electrode.

FIG. 4 is a diagram showing that several pixels in the central portion are invalidated when four liquid crystal panels are stacked. By adopting such a method, the total thickness of the composite panel can be reduced to two panels, that is, half the thickness.

However, in order to realize such a structure, it is necessary to control the sealing region with an accuracy of one pixel order. Such a highly accurate sealing method is performed by the sealing material 4
It is realized by photolithography and panel substrate lithography.

As a result of the above, a liquid crystal panel having a uniform screen comparable to one panel was realized.

A more detailed embodiment will be described below.

Example 1 Example 1 is an example of a composite liquid crystal panel using four twisted nematic (hereinafter referred to as TN) liquid crystal simple matrix panels.

FIG. 1 shows the structure of a composite liquid crystal panel,
This is an example when four N simple matrix panels 5 are overlapped. At this time, the sealing portion 4 is overlapped with the configuration shown in FIG. 2 and an optically isotropic adhesive is used. As a result, the two transparent substrates are fixed. The liquid crystal layer 1 is
When viewed from the front, the entire display surface of the composite panel is filled without gaps.

Reference numerals 6 and 7 are row electrodes and column electrodes for driving the simple matrix, respectively. Reference numeral 8 is a spacer for filling a thickness gap generated by stacking a plurality of TN simple matrix panels. further,
The polarizing plate (not shown) is characterized in that it is arranged outside the overlapped composite liquid crystal panel.

Here, by making the sealing portion 4 colorless and transparent and having an optically isotropic property, light rays passing through the composite panel pass through the liquid crystal layer only once.
It is necessary to receive the modulation only once. This is because when the light ray passes through the liquid crystal layer twice or more, the polarized light is double-rotated or elliptically polarized, so that the display of the region is likely to be inverted or colored. Therefore, in order to avoid such an influence, it is necessary to make the liquid crystal layer transmit the light rays only once in any region, and the overlapping portion of the panel is required to have very high accuracy.

In this embodiment, the highly accurate sealing portion 4 is used.
In order to obtain the above, an orifes of the sealing material made of an ultraviolet curable resin was provided as a part of the sealing portion. FIG. 5 shows a manufacturing process of a panel using an orifes. An ultraviolet curable resin (epoxy acrylate or the like) is roll-coated and is applied so as to have a thickness almost equal to the panel gap or slightly thinner. Next, ultraviolet rays are irradiated to the orientation part through the photomask,
The uncured portion is removed. In this way, the orientation 9 shown in FIG. 5A is formed on the lower glass 11.
Next, the sealing material 10 is printed by screen printing (FIG. 5B). As the sealing material, a colorless and transparent resin that is optically isotropic, such as a thermosetting epoxy resin, can be used. Next, the upper glass is pressure bonded (see FIG. 5).
(C)), heated and bonded. Reference numeral 13 is a glass fiber that controls the gap of the panel. In this way, the edge 15 of the sealing portion 4 can be obtained.

FIG. 6 is an enlarged plan view of an end of the simple matrix panel obtained as described above, in which the sealing portion is formed for the pixel 14 with an accuracy of one pixel width or less. is there.

The composite panel is fixed by using an adhesive similar to the sealing material and performing alignment between the panels as shown in FIG.

The above is an example of the case where four panels are combined, but the same can be applied to the case of two or three panels.

Further, as shown in FIG. 5C, the substrate on the side that overlaps with another panel (in this case, the upper glass 1
2) is set to be thinner than the other substrate (lower glass 11 in this case), and the liquid crystal layers of the overlapping panels are brought close to each other, so that the joints between the panels are more conspicuous when the display screen is viewed obliquely. It can be eliminated and parallax can be reduced.

(Embodiment 2) In Embodiment 2, when four panels are combined, the thickness of the whole composite panel is simply overlapped by selecting the shape of the sealing portion at the center and the panel shape. This is an example of half of the case of combining.

FIG. 4 is a plan view of the central portion, showing a panel A and a panel C of four panels arranged on the same plane. Panels B and D are arranged in the same way,
The panels A and C are overlapped on the lower side so as to intersect with each other. The sealing portion 4 and the liquid crystal layer 1 are precisely divided by the same method as in Example 1, and the edge 15 is provided between the panels A, B, C, and D.
Are aligned and bonded as shown in FIG.

As shown in FIG. 4, the central pixel 16 is incomplete due to the sealing portion. Therefore, it is necessary to make the central sealing portion as small as possible. FIG. 4 is an example thereof, and the shape need not be limited to this.

In this way, the total thickness of the composite panel can be suppressed and the parallax due to the glass thickness can be suppressed.

As described above, according to this embodiment, first of all, the overlapping portion of the simple matrix liquid crystal panel is made transparent and optically isotropic, and the liquid crystal layer is exposed to light rays only once. By adopting such a structure as to pass through, it is possible to configure a large-sized liquid crystal display device having a uniform screen in which the joints between the panels are difficult to visually recognize with a small number of panels.

Secondly, by making the precision of the sealing portion of the central portion and the overlapping portion smaller than the width of one pixel, it is possible to make the joint more difficult to be visually recognized.

Thirdly, by placing the orifice on the transparent substrate at the time of forming the sealing portion, it is possible to obtain a highly accurate overlapping portion.

Fourthly, the substrate on the side of the pair of transparent substrates which overlaps another panel adjacent to the transparent substrate is set thinner than the other substrate, and the liquid crystal layers of the overlapping panels are brought close to each other, thereby widening. It is also possible to make the joints of the panels less visible in the viewing angle range.

Further, the composite structure of the panel has an effect of increasing the strength of the entire apparatus.

Furthermore, the thinness characteristic of the liquid crystal panel is not impaired. Therefore, there is also an advantage that natural light or indoor illumination light can be used as the light source.

[0040]

According to the structure of the present invention, in a portion where a plurality of liquid crystal display panels are overlapped, the sealing portion of the other panel facing one display area is transparent and optically isotropic. Since it is made of a material, the transmitted light is modulated only once in the liquid crystal display area, and it is possible to display even in the overlapping portion of the panel, and there is no display unevenness over the entire screen of the panel, as if it were a single panel. This has an effect that a uniform display similar to that of the screen can be obtained.

When forming the sealing portion, an orifes made of an ultraviolet curable resin is placed on the transparent substrate as a part of the transparent and optically isotropic sealing portion, and then the sealing material is formed. This also has the effect of obtaining a highly accurate sealing portion.

Further, among the pair of transparent substrates constituting each liquid crystal panel, the thickness of the inner transparent substrate which comes into contact with the other adjacent liquid crystal panel is set to be thinner than the thickness of the outer transparent substrate, and the panels are overlapped with each other. By bringing the respective liquid crystal layers close to each other, it is also possible to make it difficult to visually recognize the joints of the panel in a wide viewing angle range.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a case where four liquid crystal panels are combined.

FIG. 2 is a sectional view of a superposed portion.

FIG. 3 is a schematic view of a composite panel. (A) is an example of two composite panels, and (b) is an example of four composite panels.

FIG. 4 is a plan view of a central portion of a composite panel having a reduced thickness.

5 (a) to 5 (c) are views showing steps for performing precise sealing.

FIG. 6 is a plan view of an overlapping portion of the simple matrix panel of the present invention.

[Explanation of symbols]

 1 ... Liquid crystal layer 2 ... Superposed part (including sealing part) 4 ... Sealing part 9 ... Orifes 10 ... Sealing material 15 ... Edge part 16: Incomplete pixel

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 23, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

Means for Solving the Problems] The liquid crystal display device of the present invention, double with formed by sandwiching a liquid crystal between a pair of transparent substrates
It has a structure in which a plurality of liquid crystal display panels each having a number of pixel electrodes are stacked, and the overlapping portion of two adjacent liquid crystal panels that are partially overlapped is the display of one liquid crystal panel.
The area and the sealing part of the other liquid crystal panel should overlap each other.
In addition to the above, the sealing portion is made of a transparent and optically isotropic material, and ultraviolet rays are formed on one transparent substrate.
An orifes made of cured resin is transparent and optically isotropic
It is installed as a part of the encapsulation part that has the property to print encapsulant
By forming a sealing part with high positional accuracy
Is characterized by. Further, the liquid crystal display device of the present invention has a plurality of
Of the pair of transparent substrates that make up each of the liquid crystal panels, the adjacent
Inner transparent substrate in contact with the other liquid crystal panel in contact
Is set to be thinner than the thickness of the outer transparent substrate .

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

The operation of the present invention will be described. A liquid crystal device (for example, a twisted nematic liquid crystal device or a birefringence control type liquid crystal device) having a liquid crystal layer whose polarization plane is changed with respect to linearly polarized light is partially overlapped. In the composite liquid crystal panel described above, since the sealing part that constitutes a part of the overlapping part and faces the liquid crystal layer is transparent and optically isotropic, the transmitted light beam should be modulated in the sealing part. Without passing through the overlapping section. That is, since the liquid crystal layer is modulated only once, it is possible to perform a display similar to that of other liquid crystal filling areas in the overlapping portion. Also, the sealing part
At the time of formation, it is colorless and transparent like the encapsulant, and optically
An orientation that is anisotropic and has the property of being cured by ultraviolet light.
Place the festival in place on one transparent substrate
By printing the encapsulant with
It is possible to form a sealed part with high positional accuracy.
You can In addition, a pair of transparent panels that make up each panel.
Of the bright substrates that come in contact with the other adjacent LCD panel
The thickness of the transparent substrate on the side is smaller than the thickness of the transparent substrate on the outside.
By setting it thin, each of the overlapping LCD panels
The liquid crystal layers of the
Even when viewed from a degree, the joint is wide in a wide viewing angle range.
It becomes hard to be visually recognized.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, embodiments of the present invention will be schematically described with reference to the drawings.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

In order to further improve such an effect, of the two transparent substrates constituting the liquid crystal panel, the thickness of the inner substrate which is in contact with another adjacent liquid crystal panel is made equal to the thickness of the other outer substrate. Set it thinner than the thickness. By taking such a structure, when the display screen is viewed obliquely,
Both facing compared to when the two substrates in the same thickness
Since the liquid crystal layers are close to each other, the joints between the panels are less likely to be visually recognized, and parallax is reduced.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

Further, the positions of the display area and the sealing portion facing each other constituting the overlapping portion of two adjacent liquid crystal panels are precisely adjusted.
By setting the degree so that the error is smaller than the width of one pixel, the discontinuity at the joint is reduced.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

However, in order to realize such a structure, it is necessary to control the sealing region with a positional accuracy of one pixel order. Such a highly accurate sealing method is realized by photolithography of the sealing material 4 or lithography of the panel substrate.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

Here, by making the sealing portion 4 colorless and transparent and having an optically isotropic property, light rays passing through the composite panel pass through the liquid crystal layer only once.
It is necessary to receive the modulation only once. This is because when the light ray passes through the liquid crystal layer twice or more, the polarized light is double-rotated or elliptically polarized, so that the display of the region is likely to be inverted or colored. Therefore, in order to avoid such an influence, it is necessary to make the liquid crystal layer transmit the light ray only once in any region, and the superposition portion of the panel requires very high positional accuracy. To be done.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

In the present embodiment, in order to obtain the sealing portion 4 with high positional accuracy , the orifice of the sealing material made of the ultraviolet curing resin is provided as a part of the sealing portion. FIG. 5 shows a manufacturing process of a panel using an orifes. An ultraviolet curable resin (epoxy acrylate or the like) is roll-coated and is applied so as to have a thickness almost equal to the panel gap or slightly thinner. Next, the orientation portion is irradiated with ultraviolet rays through a photomask, and the non-cured portion is removed. In this way, the orientation 9 shown in FIG. 5A is formed on the lower glass 11. Next, the sealing material 10 is printed by screen printing (FIG. 5B). As the sealing material, a colorless and transparent resin that is optically isotropic, such as a thermosetting epoxy resin, can be used. Next, the upper glass is pressure bonded (see FIG. 5).
(C)), heated and bonded. Reference numeral 13 is a glass fiber that controls the gap of the panel. In this way, the edge 15 of the sealing portion 4 can be obtained.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

FIG. 6 is an enlarged plan view of an end portion of the simple matrix panel obtained as described above, in which the sealing portion is formed in the pixel 14 with a positional accuracy of one pixel width or less. Is.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction content]

Secondly, the sealing portion of the central portion and the overlapping portion
By making the positional accuracy smaller than the width of one pixel, it is possible to make the joint more difficult to be visually recognized.

[Procedure Amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

Thirdly, by placing the orifice on the transparent substrate at the time of forming the sealing portion, it is possible to obtain the overlapping portion with high positional accuracy .

[Procedure Amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction content]

When forming the sealing portion, an orifes made of an ultraviolet curable resin is placed on the transparent substrate as a part of the transparent and optically isotropic sealing portion, and then the sealing material is formed. This also has the effect of obtaining a sealed portion with high positional accuracy .

Claims (2)

[Claims] 1. A liquid crystal display device in which a plurality of liquid crystal display panels, each of which has a liquid crystal sandwiched between a pair of transparent substrates, are superposed on each other. One of the transparent substrates is composed of a display area and a sealing portion, and the sealing portion of the other liquid crystal panel facing the display area of one liquid crystal panel is made of a transparent and optically isotropic material. A highly accurate sealing part was formed by printing an encapsulant on top of which a transparent and optically isotropic sealing part made of UV-curing resin was placed as part of the sealing part. Liquid crystal display device characterized by. 2. In a liquid crystal display device in which a plurality of liquid crystal display panels each having a liquid crystal sandwiched between a pair of transparent substrates are superposed, a superimposing portion of two liquid crystal panels which are adjacent to each other partially overlap each other, Each of the liquid crystal panels includes a display area and a sealing portion, and the sealing portion of the other liquid crystal panel facing the display area of one liquid crystal panel is made of a transparent and optically isotropic material. The liquid crystal display device, wherein the thickness of the inner transparent substrate, which is in contact with the other adjacent liquid crystal panel, is set to be smaller than the thickness of the outer transparent substrate.