JPH0688959A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide the liquid crystal display device which is reduced and uniformalized in dot pitch and is improved in opening rate by eliminating the inconvenience of the non-display regions around respective liquid crystal display element units even if the liquid crystal display device of a large screen is constituted by arraying the many units. CONSTITUTION:Two sheets of transparent substrates 1a, 1b respectively formed with transparent electrodes capable of driving respective dots, dot by dot, are adhered by holding a liquid crystal material therebetween and a light transmission plate 3 and an antireflection film 6 are disposed via a polarizing plate 2a on the display surface side thereof. A light transmission parts 8 for leading out the light by each of the respective dots enclosed by light shielding parts 9 are formed on the light transmission plate 3. The respective light transmission parts 8 reflect the light rays of the respective dots and lead out the light rays up to the peripheral end edges, thereby expanding the display screen region up onto the non-display region which is the adhesive part of the transparent substrates.

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 element unit and a liquid crystal display device using the unit. More specifically, the present invention relates to a liquid crystal display device capable of improving the image quality of a large screen formed by arranging a large number of liquid crystal display element units by making the pixel pitch (hereinafter, dot pitch) of each effective display unit small and uniform.

[0002]

2. Description of the Related Art Conventionally, in order to form a large screen in a liquid crystal display device, as shown in FIG. 4, a drive substrate 52 and a light source 53 are attached to a liquid crystal display portion 51 formed of a transparent substrate sandwiching a liquid crystal material. It is usual that a plurality of liquid crystal display element units 50 are arranged and joined together. On the other hand, each liquid crystal display unit 51 is provided with a bonding seal portion 54 for enclosing the liquid crystal material around the substrate (see FIG. 5), and this portion is a non-display portion that does not function as a display portion. Therefore, in this case, as shown in FIG. 5, the pitch Xb, Y across the seal portion 54 is more than the pitch Xa, Ya between the pixels (hereinafter, referred to as dots) 55 which are effective display portions in each unit 50.
b becomes large and uneven pitch occurs. If Xa = Xb and Ya = Yb are set in order to eliminate this nonuniformity, the dot pitch becomes large overall and the aperture ratio becomes extremely small.

When the aperture ratio is 70% or more in order to actually obtain good display performance, the dot widths Xd and Yd are
It is necessary to make each of the intervals Xp and Yp between 55 units more than about 6 times, but at present, the intervals Xs and Ys between the edge of the unit 50 and the dots 55 can be reduced to only about 1.5 mm, so the dot width Xd. , Yd becomes 18 mm or more as shown below.

Xd> 6Xp = 6 × (2Xs) = 18 mm Yd> 6Yp = 6 × (2Ys) = 18 mm

[0005]

As described above, in the large-screen liquid crystal display device using the conventional liquid crystal display element unit, the dot pitch becomes non-uniform, while in order to make the dot pitch uniform, It was necessary to increase the dot area and the spacing between dots. As a result, when displaying a large capacity, there is a problem that the size becomes very large. For example, in the case of forming a screen of 256 × 256 dots, if the dot pitch is set to 21 mm from the necessity of 18 mm or more, the size will be about 5 m square.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal display element unit capable of forming a large screen with a small and uniform dot pitch and an improved aperture ratio. To do.

[0007]

A liquid crystal display unit according to the present invention holds two transparent substrates each having a transparent electrode which can be driven for each pixel, and holds the two transparent substrates at a constant gap. A sealing agent that adheres to each other, a liquid crystal material filled in a gap between the two transparent substrates, a polarizing plate disposed on the outside of each of the two transparent substrates, and an opposite side of the display surface of the transparent substrate. A liquid crystal display element unit having a backlight arranged, wherein a light guide plate for guiding light of each pixel is disposed on the display surface side of the transparent substrate, and an antireflection film is further provided on the surface of the light guide plate. Is provided.

The light guide plate is preferably made of a white material.

Further, it is preferable that the light guide portion of the light guide plate is enlarged toward the surface side and enlarged and projected on the antireflection film.

Further, the liquid crystal display device of the present invention is characterized in that the liquid crystal display element units are arranged in a matrix.

[0011]

According to the liquid crystal display element unit of the present invention (hereinafter, simply referred to as a unit), the light projected from each dot is refracted by the light guide portion of the light guide plate provided on the surface of the liquid crystal display element to surround the liquid crystal display element. Since the projection is performed so as to spread in the direction, dots are projected to the vicinity of the peripheral edge of each unit in the antireflection film on the surface of the light guide plate. As a result, the width of the visible connecting portion at the peripheral edge of the unit can be made relatively narrower than the width of the dot, and the aperture ratio is improved. Therefore, by changing the size of the light guide plate, the width of the connecting portion of the unit on the surface can be adjusted, so that the dot pitch over the entire screen can be easily made uniform without increasing the dot width and dot pitch. .
As a result, the image quality to be displayed is improved, and large-capacity display is possible with a relatively small size.

[0012]

The unit of the present invention will be described below with reference to the accompanying drawings. 1 is a cross-sectional view of a main part of a unit of a liquid crystal display device of the present invention, FIG. 2 is a schematic plan view of a liquid crystal display device formed by connecting a plurality of units of FIG. 1, and FIG.
FIG.

In FIG. 1, 1a and 1b are transparent substrates such as a glass substrate on which transparent electrodes that can be driven for each pixel are formed, and a liquid crystal material is filled between them, and a polarizing plate 2a is provided on both outer sides thereof. 2b are provided.
The light guide plate 3 is formed on the upper surface, and the illumination lamp 4 and the drive substrate (not shown) are provided below the light guide plate 3 to form the liquid crystal display unit 5.

On the surface of the light guide plate 3, there is provided an antireflection film 6 made of vinyl chloride, acrylic, polycarbonate or the like, the surface of which is subjected to antireflection treatment.

This unit 5 has the same construction as the conventional one except that the light guide plate 3 provided with the antireflection coating 6 is provided.

As shown in the cross section of FIG. 1, the light guide plate 3 has a light guide portion 8 having a light transmitting property for each dot (pixel) 7 formed of the transparent electrode film provided on the transparent substrates 1a and 1b. Have a shape in which they are aligned in a grid pattern by the light-shielding portion 9 having a grid shape. The light guide section 8 leads out the display area of each dot formed on the transparent substrate 1a to the outer peripheral end side of the antireflection film 6 by a frame-shaped light shielding section 9.
The light transmitted through the transparent substrate 1a passes through the light guide portion 8 and is projected onto the antireflection film 6, and when viewed from the surface of the antireflection film, each dot is displayed on the antireflection film. You can see.

The display area on the transparent substrate is narrow because there is a non-display area around the transparent sealant as described above, but the display area is wide because the outer peripheral edge can be used on the antireflection film. Since the outer peripheral end portion is used, the light guide portion 8 guides light to the outer peripheral side as shown in the cross-sectional explanatory view in FIG. 1, and the dots at the end portion are led out in an oblique direction.

The light guide plate 3 is integrally formed of, for example, a plastic material, and the length of the light guide portion (thickness of the light guide plate) is formed to about 5 to 10 mm, and the width of the light shielding portion 9 is formed. Is about 1 mm, and the area of the light guide portion is the size of a dot. For example, a liquid crystal display unit of 100 mm × 100 mm of 24 × 24 dots has a size of about 3 mm × 3 mm. This light guide plate 3
Is, for example, a transparent substrate 1 to which polarizing plates 2a and 2b are attached.
The a and 1b are arranged so as to be sandwiched from the outside, and the antireflection film 6 is attached to the upper surface thereof.

The antireflection film 6 is the same as that used in a liquid crystal display device which is normally used in a bright place, and is surface-treated so as not to reflect external light. For example, a plastic plate or the like is subjected to non-glare treatment. Made to have a roughened surface can be used. This antireflection film becomes like a screen, and the light emitted from the transparent substrate 1a is projected and displayed.

The light emitted from the illumination lamp 4 passes through only the dots selected by the transparent electrode film and enters the corresponding light guide portion, so that it is enlarged and projected on the surface of the light guide plate 3. In this case, as shown in FIG. 1, the direction of projection enlargement in the light guide portion 8 is the peripheral direction of the unit 5. Therefore, as shown in FIG. 2, even when a plurality of the units 5 are connected to form a large screen, the image is enlarged to the connection side of the unit 5. As a result, in the image displayed on the surface of the light guide plate 3, the seal portion 54 (see FIG. 5), which is the non-display portion shown in the prior art, becomes extremely narrow as shown in FIG.

As described above, in the present unit 5, since the non-display portion on the periphery can be freely reduced, the dot pitches Xa and Ya can be made uniform without the need to be enlarged as shown in FIG. That is, in FIG. 3, Xa = Xb,
It can be set to Ya = Yb.

If the above unit 5 is used, for example, if the dot pitch is 2 mm, the size can be about 1.3 m × 0.8 m even if the screen has 640 × 400 dots.

Further, if the light-shielding portion 9 of the light guide plate 3 becomes thinner toward the antireflection film 6, the dot pitch can be further reduced.

Further, by forming the light guide plate from a white material, for example, white plastic such as vinyl chloride or acryl, there is no discomfort when looking at the display screen, and the display characteristics are improved. Even if the color of the light guide plate is black plastic, it can be used without a relatively uncomfortable feeling.

[0025]

According to the liquid crystal display device of the present invention, the non-display area due to the sealant can be reduced at the peripheral edge portion of the liquid crystal display unit, a small dot pitch and a uniform display screen can be obtained, and the aperture ratio is high. Therefore, the illumination power can be reduced and high-brightness display can be performed, and the displayed image quality is improved.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view of an essential part of one unit of a liquid crystal display device of the present invention.

FIG. 2 is a schematic plan view of a liquid crystal display device formed by connecting a plurality of units shown in FIG.

FIG. 3 is an enlarged view of part A of FIG.

FIG. 4 is a schematic perspective view showing a part of an example of a conventional liquid crystal display device formed by connecting a plurality of liquid crystal display units.

5 is a partially enlarged plan view of FIG.

[Explanation of symbols]

 1a, 1b Transparent substrate 3 Light guide plate 4 Illumination lamp 5 Unit 6 Antireflection film 7 Pixel (dot) 8 Light guide part

Claims (4)

[Claims] 1. Two transparent substrates each having a transparent electrode that can be driven for each pixel, a sealant for holding the two transparent substrates in a fixed gap and adhering them, and the two transparent substrates. A liquid crystal display device unit having a liquid crystal material filled in the gap between the two transparent substrates, polarizing plates respectively disposed on the outer sides of the two transparent substrates, and a backlight disposed on the side opposite to the display surface of the transparent substrates. A liquid crystal display element unit in which a light guide plate for guiding light of each pixel is disposed on the display surface side of the transparent substrate, and an antireflection film is further disposed on the surface of the light guide plate. 2. The liquid crystal display element unit according to claim 1, wherein the light guide plate is made of a white material. 3. The liquid crystal display element unit according to claim 1, wherein the light guide portion of the light guide plate is enlarged toward the surface and enlarged and projected onto the antireflection film. 4. A liquid crystal display device comprising liquid crystal display element units arranged in a matrix, wherein the liquid crystal display element unit is the liquid crystal display unit according to claim 1.