JPS60202422A - Large size display device - Google Patents

Abstract

PURPOSE:To give an appropriate distribution of light beam to a large size display device comprising a transparent panel by spreading display units displaying on a transparent panel all over in the direction of the surface of the panel, interposing light conducting tubes in the space between the display units, and arranging a linear light source provided to the rear side of the display units vertically and transversally with an approximately parallel arrangement. CONSTITUTION:A light conducting element 12 is interposed in a space between a display unit 11 and another display unit 11. Plastic fiber or glass fiber, or an integrally molded plastic such as polyester, polystyrene, phenoxy resin, polyethylene terephthalate, acrylic resin, etc. may be preferred as the material for the light conducting element 12. When light flux uniformly distributed to the display unit 11 is incident, the luminance of a picture image displayed on the display surface 14 through the light conducting element 12 is distributed to be lighter in the central part and darker in the periphery in a row of the display units as shown by a dotted line 19, and a fluorescent display tube 15 is provided to the rear side of the periphery of the display unit 11 so as to result distribution of light beam as expressed by a continuous line 20. By this constitution, the luminance on the surface of a display surface 14 becomes almost uniform, and a large size display surface contg. no difference of luminance is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for attaching a light source to a large-sized display device that combines a display unit that performs display using a plurality of transmissive panels and a light guide element. In addition, in the present invention, large size means 14
A theater is a theater that has a display screen larger than an inch CRT display screen.

This refers to something that can be viewed by multiple people at the same time, such as inside a station or department store.

[Prior art]

As a means for displaying images in place of a cathode ray tube, a display device using a fluorescent display tube or the like has been proposed.

These display devices usually employ a so-called dot matrix method in which a large number of column electrodes and row electrodes are arranged on a substrate, and signals are selectively applied to each of these electrodes to display the image to be displayed as dots. Therefore, for display panels used for these, there is a fee for space on the periphery to connect each column and row electrode to an external circuit, and for those that use a liquid crystal display method, there is a fee. In addition to the above-mentioned space, a space is required to seal the liquid crystal, and in addition, in this type of display device, in order to reduce the voltage difference and maintain constant brightness, it is necessary to lower the drive date. Although it simplifies the circuit configuration, there is also a design problem in that it is better not to make the display size too large.

Therefore, in order to obtain, for example, a meter-sized art dealer using this type of display means, it becomes necessary to arrange many display units in a tiled manner as shown in FIG. A problem arises in that the non-display portion α, which is a connection portion with an external circuit provided at the periphery of the display panel, appears on the display panel like an eye on the board.

Of course, in order to eliminate this inconvenience, for example,
As shown in Figure 2, the connection terminal 2.4 for connecting the column electrode 11 and the row electrode 3 to the external electrode is connected to the glass substrate 5.6 at 111!1l.
At the same time, make the sealing part 7 of the liquid crystal 8 as narrow as possible so that the distance between the outermost electrode 1.3 and the O edge of the panel is 1/2 of the gap between each electrode tube. However, this is difficult in practice; for example, advanced technology is required to draw out the Nesa film onto the substrate fil! This may also lead to other troublesome problems such as deterioration of the characteristics.

〔the purpose〕

The present invention has been made in view of these problems, and its purpose is to provide a large display device that is composed of a display unit and a light guide element that interpolates the gap between the display units, and that displays images in a transmissive manner. This provides a light source with an appropriate luminous flux distribution.

〔composition〕

The large display device of the present invention is a liquid crystal panel, EOD.

Display units that display on transparent panels such as KL are laid out side by side, and a light guide tube made of plastic type, plastic fiber, glass fiber, etc. is used to interpolate the gaps between the display units and display the display at the rear of the display unit. The arranged linear light sources are arranged substantially parallel to each other in a striped or horizontal manner, and the luminous flux distribution is such that the central part has a low luminous flux and the peripheral part has a high luminous flux with respect to the display unit row, thereby obtaining an appropriate luminous flux distribution.

〔Example〕

The details of the present invention will be explained below based on illustrated embodiments.

The display unit constituting the large-sized display device of the present invention is constructed as shown in FIG. 3, for example. That is, one display unit 11 and another display unit 11 are displayed using the light guide element 12.
Interpolate the gap between. The light guide element 12 may be made of a fiber made of plastic, glass, or the like, or an integrally molded product made of a plastic resin such as polyester, polystyrene, phenoxy, polyethylene terephthalate, or acrylic resin. Note that the display panel α is provided so as to face the viewing direction. Further, as shown in the figure, each display unit 11 may include a drive 101 (IC, etc.) b for the display panel.

In FIG. 3, the viewing direction is the left, and the displayed image is viewed from the left side.

FIG. 4 shows an embodiment in which a rod-shaped fluorescent tube is used as a linear light source, in which reference numeral 11 is a display unit, 12 is a light guide element,
13 is a structure, 14 is a display surface, 15 is a fluorescent tube, 16 is a reflector, 17 is a back plate of the structure, 1
8 is a ventilation hole for cooling, and there is a similar ventilation hole on the bottom of the structure. This embodiment [Accordingly, the luminous flux irradiated from the fluorescent tube 15 fixed to the back plate of the structure 17 is directly or reflected by the reflector 160 to the drive circuit in the display unit 11. This leads to a transmissive panel that performs display, and the luminous flux is controlled to be transparent, opaque, or semi-transmissive by the transmissive panel, enters the light guide element 12, and passes through the light guide element through iM contact. Or repeat the reflection and sign 1
4. Display on the display screen. Ventilation holes 18 provided at the top and bottom of the structure 13 radiate heat generated from the fluorescent tube by natural convection or forced air cooling.

FIG. 5 shows the arrangement and effect of the light sources according to this embodiment. It is a top view explaining in detail. When a uniformly distributed light beam enters the display unit 11, the luminance distribution of the image displayed on the display surface 14 after passing through the light guide element 12 is as shown by the dotted line 19 with respect to the row of display units. The center is bright and the periphery is dark, the seams of the display units are emphasized, and the display is not uniform. Therefore, the fluorescent tube 15 is arranged at the rear of the periphery of the display unit 11 so as to have a light east distribution as shown by the solid line 20. Due to the above arrangement, in the brightness distribution shown by code 19, a large amount of light flux enters the dark areas, and a small amount of light flux enters the bright areas, so that the front brightness on the display surface shown by code 14 becomes almost uniform, and the brightness A large display surface with no difference can be obtained.

Figure 6 is an upper iRt diagram showing the light source arrangement according to another embodiment, and in Figure 6 (a) the number of light sources 15 is reduced,
This is an example in which a ridge-shaped reflector is used, and if the surface has sufficient brightness, such a configuration may be used.

Figure 6 (b) shows an example in which the number of light sources numbered 15 is increased, and one reflector plate numbered 16 is used in each unit row to effectively utilize the luminous flux, and the luminous flux escaping into the gap between the display units is reflected. It is restricted. Figure 6 (C) shows a case where the display unit is larger than the diameter of the light source 15, and the light sources are arranged so that the center of the display unit row is coarse and the display unit row is dense at the periphery to obtain a predetermined luminous flux distribution. It is configured like this. The reflector plate 16 in the above embodiment may be formed into one piece or into a plurality of pieces.

FIG. 7 shows another embodiment in which a heat shield plate 21 is disposed between the display unit 11 and the light source 15, and the heat generated from the light source is harmful to the display unit and display panel. It is effective if it has a strong effect. Furthermore, by making the heat shielding plate 21 a milky-white or semicylindrical diffusion plate, it becomes possible to correct or optimize the luminous flux distribution of the light source.

FIG. 8 is a side view of an embodiment in which a liquid crystal panel is used as a transmissive panel, and is an example of effectively utilizing the optical characteristics of the liquid crystal panel. When displaying on a liquid crystal panel, there are positions 1b' where the display is easy to view and positions where it is difficult to see, and the range of positions where it is easy to see is called the clear viewing angle. The clear viewing angle of the liquid crystal panel of this example is in the downward direction. The light beam directly from the light source 15 or reflected by the reflector 16 is marked @21.
The light beam passes through the diffusion plate 22 and reaches the serrated refraction plate 22, where the light beam is refracted in the direction of approximately the center of the clear viewing angle, and controlled by the liquid crystal panel to be transparent, opaque, or semi-transparent. Code 12 having an angle in the direction of approximately the center of the clear vision angle
The light enters the light guide element 14 and reaches the display surface 14 for display. In this type of (A-4), the light beam passing through the liquid crystal panel is refracted toward the center of the clear viewing angle by the sawtooth refracting plate 22 before entering the liquid crystal panel, so it can easily pass through the liquid crystal molecules. Attenuation of the luminous flux is small.Also, since the direction of the light guiding element 12 is almost the same as that of the luminous flux transmitted through the liquid crystal panel, it guides the luminous flux efficiently, resulting in a bright display surface with little difference in brightness in the vertical direction. The light sources are arranged as shown in FIG. 7 from FIG. 184.

In the present invention, an example in which the linear light sources are arranged in a vertical direction is shown as an example, but it goes without saying that the linear light sources may be arranged in a horizontal direction or an oblique direction. Even in such a case, ventilation holes may be provided at least in the upper part (only the upper part, the upper part and the lower part, or the upper part and the side parts). Alternatively, ventilation holes may be provided on the sides and forced cooling may be performed using a blower or the like.

Furthermore, it goes without saying that the display panel may not be a rectangle long in the horizontal direction, but may be square or long in the vertical Q direction. In these cases, it is preferable to arrange the linear light sources along the arrangement direction of the plurality of display panels.

Furthermore, it goes without saying that the display device' of the embodiment may be placed horizontally or diagonally.

Transmissive display panels include, for example, nematic liquid crystal panels with a 90° twisted orientation and two polarizers on top and bottom, with the clear viewing direction aligned upward, horizontally, downward, etc., white tiller type GH panels, and polarized display panels. Of course, a liquid crystal panel placed on the child viewing side or the opposite side may also be used.

Further, the display unit may be a display panel.

Furthermore, in the large display device of the present invention, the light can be varied by increasing or decreasing the number of light sources, and considering that the screen of a normal display device is horizontally long, the light sources can be arranged in a striped pattern. This means that there is a large degree of freedom in increasing and decreasing the light cover, allowing for fine adjustments.

Furthermore, if linear light sources are arranged in a striped pattern, the heat generated by the light source will be dissipated smoothly.For example, if a fluorescent tube is used as the light source, opening ventilation holes on the top and bottom of the structure will allow natural convection. Furthermore, since the rod-shaped light sources are arranged in a twill pattern, the flow of air cannot be prevented even when heat is dissipated by convection, and a special space for heat dissipation is not required.

In addition, in FIG. 6, the diameter of the light guide element 12 farther from the light source is made thicker, or the diameter of the elements arranged in a direction intersecting the direction of light travel is made larger than the diameter of the elements in the direction parallel to the direction of light travel. You can make it thicker.

〔effect〕

As explained above, the large display device of the present invention has 'FM number of display units arranged in the plane direction, but the distribution of the luminous flux of the linear light source is at the center of the display unit (or display panel) with respect to the row or column. Because the area has low luminous flux and the surrounding area has high luminous flux, there is no sudden change in brightness between display units (display panels), even when multiple display units (display panels) are used. , we were able to obtain a display image with uniform brightness distribution across the screen and no display unevenness.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are explanatory views of the prior art, respectively. FIG. 3 shows an embodiment of a display unit used in the apparatus of the present invention. Figures 4 and 5 are a perspective view and a top view, respectively, of an embodiment of the display device of the present invention. 6N is a block diagram of another embodiment of the present invention, and FIGS. 7 and 8 are block diagrams of still other embodiments. Applicant Epson Corporation Agent Patent Attorney Mogami Figure 1 (a) (b) Figure 3 Figure 5 (b) Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] A plurality of display units that perform display using a transmissive panel are arranged side by side in a plane direction, and a light guide element interpolates the gap between the display units, and linear light sources arranged at the rear of the display units are arranged almost in parallel, The distribution of the luminous flux of the linear light source is
1. A large-sized display device characterized by having a low luminous flux at the center and a high luminous flux at the periphery for each front display unit or column.