JPH01189613A - Photoconductive type display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a light guiding type display device.

[Prior Art] In a conventional light guide type display device consisting of at least an image forming device and a light guide, patents and literature have been investigated regarding a method of processing the end face of the light guide, which corresponds to the display surface enlarged by cutting. I couldn't find anything specifically mentioned in the scope of what I did.

[Problems to be Solved by the Invention] However, the treatment of the display surface of the light guide in a light guide type display device is very important and is one of the major factors that determines the quality of image display.

Therefore, an object of the present invention is to obtain a light guide type display device with excellent display quality by performing a light diffusion process on the output surface.

[Means for Solving the Problems] The light guide type display device of the present invention is characterized in that a light diffusion process is performed on the display surface of the light guide.

[Example 1] A light guide type display device consisting of an image forming device and a light guide was manufactured as a prototype. The image display device used was a combination of a liquid crystal electro-optical device with a light shutter and a light source, and a plastic optical fiber was used as the light guide. As a method for enlarging the display surface, a cutting method was used for vertical enlargement, and a spacer method was used for horizontal enlargement.

In this embodiment, as a light diffusion treatment method for the display surface that has been subjected to the enlargement treatment, the optical fiber was ground with something like a grinder, and a line thinner than the diameter of the optical fiber was carved. FIG. 1 is an enlarged sectional view showing the concept of the exit surface according to this embodiment. If the direction of this carved fine line is set to match the direction of enlargement by the cutting method (vertical direction in this example), the direction of diffusion of the emitted light on the display surface will match the direction of enlargement by the cutting method. It got better in the right angle direction. For this reason, the light was excellently diffused into areas from which light was not emitted due to the expansion by the spacer, and was useful for improving the uniformity of the display surface.

With this method, the brightness unevenness on the display surface is reduced to about 1/2 at a viewing distance of 1,000 times the diameter of the optical fiber used.
It declined to .

In addition, for color-compatible light-guiding display devices that mix colors on the display surface, those that do not undergo light diffusion treatment on the display surface may be viewed at a distance of 3°,000 times or more the optical fiber diameter. However, the light diffusion process according to the present example resulted in a sufficiently natural color mixture even at a viewing distance of about 273 cm.

[Example 2] In this example as well, a light guide type display device was prototyped as in Example 1, but as a light diffusion treatment method for the display surface, the end face of the light guide was sandblasted all at once. This method also improved the uniformity of the display surface as in Example 1. It was confirmed that the brightness unevenness on the display surface decreased from a maximum of about 24% before the light diffusion treatment to 13% or less at a viewing distance of about 1,000 times the diameter of the optical fiber used.

We also tried other light diffusion treatments on the display surface, such as sawtooth processing and satin finish, but both were able to improve display uniformity and reduce brightness unevenness compared to before the diffusion processing. We confirmed that it can be improved by 30% or more.

[Example 3] In this example, a light diffusion plate made of a thin transparent acrylic resin plate that has been surface-treated in advance to diffuse light is attached to the end face of the light guide, which serves as the display surface, to diffuse light. Processed.

The surface treatment of the diffuser plate can be carried out in the same way as the surface treatment in Example 1 by rubbing it in one direction with a file, by sandblasting, or by injection molding to make one side uneven. Both methods were effective in improving the uniformity of the display surface.

In addition, uniformity and workability were better when this surface treatment was performed before pasting to the display surface, but there was no particular difference in effectiveness regarding the uniformity of the display surface even if the surface treatment was performed after pasting. .

According to the method of this example, there is some diffuse reflection from the interface of the pasted thin plates, so the intensity of the emitted light decreases slightly (approximately 5% in this example), but the uniformity of the display surface is improved.
After all, brightness unevenness can be improved by 30% or more.

Although the embodiments have been described above, the present invention is not limited only to the above embodiments. □For example, C as an image forming device
The display quality is the same even when using a light-emitting type display device such as RT, EL, or plasma display, or one using a reflective type display device and a light source, or when using a quartz glass optical fiber as a light guide. improvement is possible.

[Effects of the Invention] As described above, according to the present invention, by performing light diffusion treatment on the display surface, uneven brightness on the display surface can be improved, and a light guiding type display device with excellent display quality can be obtained. It has the effect of being able to

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view showing the concept of diffusion processing on the display surface according to the first embodiment. FIG. 2 is a diagram showing the concept of diffusion processing of a display surface using a light diffusing plate according to a third embodiment. 101・・・・・・・・・・・・Fiber bundle 10
2...Display surface 201...
......Fiber bundle 202...
......Light diffusion plate 203...
・・・Display screen 2nd figure

Claims (1)

[Claims] A light guide type display device characterized in that a light guide body of the light guide type display device is subjected to a light diffusion treatment on a display surface.