JPH0570827B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an illumination device for a liquid crystal display element that can be used in a large screen display device comprising a plurality of transmissive liquid crystal display elements.

Conventional configurations and their problems In recent years, in addition to large-screen display devices that use three primary color fluorescent lamps or three primary color cathode tubes (CRT), liquid crystals are used as light switches to display three primary color displays. A method using color filters is being considered.

A conventional illumination system for a liquid crystal display element will be described below with reference to the drawings.

In FIG. 2, when the light emitted from the white fluorescent lamp 4 enters the liquid crystal section (LCD) 1,
The amount of light passing through the LCD is adjusted according to an external signal, and the light enters the color filter layer 3.

The filter consists of three color filters, B, G, and R (B, G, and R refer to color filters for converting white light into blue light, green light, and red light, respectively) corresponding to one picture element. The light that has passed through this is mixed again to form color picture elements, and a color image is displayed at position 7 on the front panel 5.

The size of a single liquid crystal display element that can currently be manufactured is from 6 inches to 12 inches square, and to construct a larger screen, it is necessary to arrange multiple panels. However, since the wiring portion 2 is generally located at the end of a liquid crystal display element, there is a problem in that the joint 6 appears as a black line (8 in FIG. 3) in a large screen configuration.

OBJECTS OF THE INVENTION The lighting device for a liquid crystal display device of the present invention relates to a lighting device for a liquid crystal display device that prevents the seams from being noticeable even when a plurality of liquid crystal displays are used.

Structure of the Invention The lighting device for a liquid crystal display element of the present invention has a bottom portion on the liquid crystal display side at a position corresponding to the joint in order to form a large screen liquid crystal display element by arranging a plurality of transmissive liquid crystal display elements. , a long triangular prism having a surface that slopes from the picture element on the outer edge of the adjacent liquid crystal part toward the apex located on the light source side, is placed along the joint, and the illumination light is directed to the edge of the liquid crystal display element. The light is incident in an oblique direction so that the joints are not noticeable on the front panel of the liquid crystal display element, so that the joints are not visible as black lines and are not conspicuous.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 illustrates the invention.

In addition to the basic components shown in FIG. 2, a prism 10 is added. The operation of the embodiment configured as above will be described below. The light beam 11 emitted from the illumination light source 4 is passed through the prism 10.
It is bent in the direction of the LCD seam, and the LCD picture element 1
2 and is irradiated to a position 13 on the front panel 5. On the other hand, the ray bundle 14 is transmitted through the prism 10.
It is bent in the direction of the LCD seam, and the LCD picture element 1
5 and reaches 16 above the front panel 5.
If 13 and 16 are placed adjacent to each other with a gap, the information of picture elements 12 and 15 on the outer edge of the LCD will be displayed on 13 and 16, which originally did not receive light.
If the front panel is configured to use it as a light source and emit light in all directions, a person viewing the display from the front will be able to see the image as if there were no LCD seams.

As described above, according to this embodiment, by adding an illumination light prism, it is possible to display a large screen with unnoticeable seams.

As shown in Figure 4, the length l of the bottom of the prism
is selected depending on how many picture elements are used for this joint. That is, if d is the length of the part without picture elements of each LCD, n is the required number of pixels, and d ₁ is the size of the pixel, then lnd ₁ +2d is obtained. The angle of inclination A becomes larger as the refractive index of the prism material becomes smaller, and becomes larger as the distance L between the LCD and the front panel becomes shorter.

In addition to a general light source, the lighting device of the present invention has prisms arranged along the rows of a plurality of LCD panels, so it is a prism net in which prisms are arranged in a mesh pattern as shown in Figure 5. Consists of work. The intersection between the prisms is shaped like a horizontal prism passing through a vertical prism.

In other embodiments, the shape of the prism in the above structure is such that the bending angle of the light beam is gradually increased toward the joint, as shown in FIG. A shape is taken.

Effects of the Invention As is clear from the above description, the present invention provides a prism with the liquid crystal section as the bottom surface on the illumination light side of the joint between the liquid crystal display elements.
A light beam obliquely enters the display portion near the outer edge of the liquid crystal display element, covering the seams through which no light normally passes, and providing an excellent effect of enabling display with no visible seams.

Furthermore, by dividing the inclined surface of the prism into several parts having different angles, it is possible to obtain the effect that the natural feeling of the connecting part can be further strengthened.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the basic components of the present invention, Figure 2 is a diagram showing the basic components of the present invention.
Figure 3 shows a conventional illumination system, Figure 3 shows a display image when using the conventional illumination system, Figure 4 shows the positional relationship between the prism and the liquid crystal front panel,
FIG. 5 is a diagram showing the arrangement of prisms that are components of the illumination device according to the present invention, and FIG. 6 is a diagram showing the improved shape of the prism. 1...Liquid crystal section, 2...Wiring section of liquid crystal section, 3...
Color filter, 4... light source, 5... front panel,
6... Joint, 7... Image display section, 8... Black line at the joint, 10... Prism, 11, 14...
...Light flux, 12,15...Pixel, 13,16...Position of adjacent picture elements on the front panel.

Claims (1)

[Claims] 1. When forming a large-screen liquid crystal display element by arranging a plurality of transmissive liquid crystal display elements, a liquid crystal display element is placed at the joint of the liquid crystal display elements, with the liquid crystal display side as the bottom and the light source side as the bottom. A liquid crystal display element characterized in that a triangular prism having a vertex is arranged, illumination light is incident on the outer edge of the liquid crystal display element in an oblique direction, and a joint is made inconspicuous on a front panel of the liquid crystal display element. lighting equipment. 2. The angle of inclination of the triangular prism is small near the bottom and increases toward the apex in several steps to make the joint on the front panel of the liquid crystal display element more natural and less noticeable. An illumination device for a liquid crystal display element according to claim 1.