JP4022541B2 - Color light source type liquid crystal display - Google Patents

Description

The present invention relates to a color light source type liquid crystal display, and more particularly to a color light source type liquid crystal display suitable for a large screen or a case where a plurality of people view the screen.

Conventionally, various types of liquid crystal display are known. In particular, a liquid crystal display using a TN type liquid crystal display element has a simple structure because of a simple matrix driving method, and is easy to manufacture and low in cost. There is an advantage that it can be manufactured at a price. As an example of this type of liquid crystal display, for example, a color light source type liquid crystal display using a sequential color illumination method is known (for example, see Non-Patent Document 1).

  Currently, liquid crystal display displays of 21-inch or larger are being prototyped and studied. For example, for use as a wall-mounted TV or a large-sized display for workstations, where multiple screens are used, It is indispensable to develop a product having a wide viewing angle with a reduction in manufacturing cost.

  However, the TN liquid crystal display has a narrow vertical viewing angle due to the refractive index anisotropy of the liquid crystal, and the viewing angle dependency in the halftone is particularly severe. There has been a problem with viewing angle dependency that the display content becomes invisible due to darkness and that a light-dark reversal phenomenon occurs.

  In this case, not only can the display not be seen from the front side, but also when looking at a large screen from a short distance, the colors and brightness will look different at both ends of the screen even when viewed from the front side. There was a problem.

  Therefore, in order to obtain a wide viewing angle of a liquid crystal display, there is a method called a pixel division method that gives different voltage-transmittance characteristics to divided pixels, a method called an alignment division method that gives different alignment directions to divided pixels, and the like. Has been developed.

However, all of these methods have complicated processes at the time of manufacture, so that the manufacture is difficult, the cost is increased, and the stability of the product is problematic.
Color LCD, Sangyo Tosho Co., Ltd., March 1, 1994, 3rd printing, p. 70-71, 94-97, 108-113

An object of the present invention is to provide a color light source type liquid crystal display capable of obtaining a clear display image.

In order to achieve the above object, the present invention provides a color light source type liquid crystal display provided with red, green, and blue light sources, and constitutes a large display of 21 type or more, and a plurality of pixels arranged in a grid pattern. impermeable due to lattice-shaped black matrix and the TN liquid crystal display device having no active elements, which is between adjacent pixels disposed around the plurality of pixels, less likely to blur the color light source type specific colors with Provided is a color light source type liquid crystal display characterized by comprising a light portion.
Furthermore, in order to achieve the above object, the present invention is a color light source type liquid crystal display provided with red, green, and blue light sources. A TN liquid crystal display element having no active element having pixels;
An opaque portion formed by a grid-like black matrix which is arranged around each of the plurality of pixels and adjacent to each other to prevent color peculiar color bleeding, and on the surface side of the TN liquid crystal display element A color light source type liquid crystal display, wherein the surface cover has fine irregularities on at least one of the front surface and the back surface.

  Moreover, this invention is good also as a structure which has a fine unevenness | corrugation in at least one of the surface or back surface of the surface cover of a liquid crystal display.

  Since the surface cover has fine irregularities, the light from each pixel diffuses when passing through the surface cover, so that the viewing angle is widened.

  In addition, by forming an opaque part around each pixel, light from each pixel is distinguished, and even if light diffuses when passing through the surface cover, the light from adjacent pixels mixes with each other. Colors are unlikely to bleed and the information on the screen can be read clearly.

  Furthermore, by disposing a prism sheet between the light guide plate and the liquid crystal display element, light travels perpendicularly from the light source to each pixel, so that the color of adjacent pixels is more difficult to spread.

According to the present invention, it is possible to obtain a clear display image because it is difficult for the color light source type color blur to occur between adjacent pixels. In addition, the structure itself of the color light source type liquid crystal display is not changed at all, and a liquid crystal display with a wide viewing angle can be realized only by providing fine irregularities on the surface cover. Accordingly, it is possible to provide a color light source type liquid crystal display having a wide viewing angle and having a stable performance at low cost by an easy process.

  Furthermore, by disposing a prism sheet between the light guide plate and the liquid crystal display element, even if a wide viewing angle is obtained, color bleeding between adjacent pixels is less likely to occur and luminance is also increased.

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

  FIG. 1 shows a liquid crystal display using an example of an embodiment of the present invention. The liquid crystal display includes a display unit 1, a backlight 2, and a prism sheet 3 disposed therebetween. It is made up of.

  The structure of the display unit 1 is the same as that of a conventionally manufactured TN liquid crystal display, and a surface cover 11, a liquid crystal display element 12, an electronic circuit 13, a glass substrate 14, and a polarizing plate 15 are laminated in order from the upper layer. Is.

  On the other hand, the backlight 2 includes a light guide plate 21 disposed on the lower surface of the polarizing plate 11 in the display unit 1 and light sources disposed on one side surface thereof, for example, an R (red) tube 22 and a G (green) tube 23. , B (blue) tube 24 and a light source comprising a three-color tube.

  The surface cover 11 is made of, for example, plate glass, and the surface thereof is subjected to a chemical method such as cleaning with hydrofluoric acid, or a mechanical method such as sand blasting using extremely fine powder. As shown in FIG. 1, fine concavo-convex portions are provided to form a frosted glass shape so that light reaching from the backlight 2 is diffused and emitted to the outside. As a result, light is emitted at a wider angle than when transparent glass is used as the surface cover, so that the display has a wide viewing angle. At this time, the size of the unevenness of the front cover 11 is set to, for example, about 1 μm to 100 μm, and is appropriately adjusted according to the relationship between the light amount of the backlight 2, the light diffusion degree, and the pixel size.

  Further, the periphery of each pixel is surrounded by a light-impermeable portion 16 of a grid-like black matrix formed of, for example, metallic chromium, and adjacent to each other even if light is diffused by providing a black partition between the pixels. The pixel colors are made difficult to mix with each other. Accordingly, a clear image with a wide viewing angle can be obtained.

  Further, the prism sheet 3 is the same as that conventionally used, and is for causing the light from the backlight 2 to travel vertically to each pixel. By arranging this, light can be prevented from accidentally reaching adjacent pixels, and color bleeding can be prevented even when the viewing angle is wide.

  For example, in addition to the use of the black matrix and the prism sheet, an increase in the amount of light of the backlight 2 is effective for reducing the visible light transmittance caused by making the front cover 11 ground glass. .

It is a schematic perspective view which shows embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display part 2 Backlight 3 Prism sheet 11 Surface cover 21 Light guide plate

Claims (5)

In a color light source type liquid crystal display with red, green and blue light sources,
A TN liquid crystal display element having a large display of 21 type or more and having no active element having a plurality of pixels arranged in a lattice;
A color light source comprising a non-translucent portion of a grid-like black matrix that is arranged around each of the plurality of pixels and is less likely to cause a color blur peculiar to the color light source type. Type LCD display. In a color light source type liquid crystal display with red, green and blue light sources,
A TN liquid crystal display element having a large display of 21 type or more and having no active element having a plurality of pixels arranged in a lattice;
A non-transparent portion of a grid-like black matrix that is arranged around each of the plurality of pixels and is less likely to cause color- specific blurring between adjacent pixels;
A surface cover disposed on the surface side of the TN liquid crystal display element,
The color light source type liquid crystal display, wherein the front cover has fine irregularities on at least one of a front surface and a back surface.   3. The color light source type according to claim 1, wherein the light source is disposed on a back side of the TN liquid crystal display element and is configured by a backlight composed of three color tubes of red, green, and blue. LCD display. Comprising a prism sheet disposed between the backlight and the TN liquid crystal display element;
The color light source type liquid crystal display according to any one of claims 1 to 3, wherein the prism sheet causes light from the light source to travel vertically to each of the plurality of pixels.   The color light source type liquid crystal display according to claim 2, wherein the surface cover has an unevenness of 1 to 100 μm.