JPH01189616A - Photoconductive type display device - Google Patents

Abstract

PURPOSE:To easily and surely attain the optical combination between a picture forming device and a photoconductor by carrying out the optical combination between the picture forming device and the photoconductor with an arranged lens group. CONSTITUTION:The optical combination between a picture forming device 101 of a liquid crystal electro-optical element, etc., and a photoconductor 104 using, for example, a plastic optical fiber is carried out by a lens group 103 arranged between them. A microlens array MLA is used for the lens group 103, and when the MLA is formed, by carrying out heating-pressing to for example, an acrylic resin, the MLA, whose diameter is the same as that of the optical fiber and whose array is the same as that of the optical fiber of the picture forming device, can be easily formed. As this result, the optical combination between the picture forming device 101 and the photoconductor 104 is easily and surely attained, and misregistration due to temperature change, etc., can be sufficiently coped with.

Description

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

[Prior Art] In conventional light guide type display devices, the image forming device and the light guide were usually coupled directly.

[Problems to be Solved by the Invention] At this time, the light emitted from the pixels of the image forming apparatus must be contained within the range of possible incident angles determined by N and A of the fiber. If the light emitted from the image forming apparatus has no spread at all, scattering from the image forming apparatus only becomes a problem. However, in reality, in most cases there is at least some spread, and there is a problem in that optical coupling becomes difficult, such as by extremely shortening the distance between the image forming device and the light guide.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for easily coupling an image forming apparatus and a light guide by optically coupling the image forming apparatus and the light guide using an array of lenses.

[Means for Solving the Problems] The light guide type display device of the present invention is characterized in that the image forming device and the light guide are optically coupled by an arranged lens group. .

[Example 1] In this example, a group of arranged lenses for optical coupling (hereinafter abbreviated as microlens array, MLA)
We will show you how to create it.

The simplest method is to use a molded resin lens.

For example, by hot-pressing acrylic resin, it is possible to easily create a lens whose diameter is the same as that of the optical fibers, and which is the same as the arrangement of the optical fibers in the image forming apparatus. In this example, lenses with a diameter of 800 μm are arranged in a square array of 440 in length and 960 in width, with a thickness of 100 μm.
It was formed on a micrometer acrylic film, and the surface was coated with anti-reflection coating with silicon oxide or magnesium fluoride according to a conventional method to obtain an MLA.

In addition, with a flat plate microlens that functions as a lens by imparting a refractive index distribution to a thin glass plate through ion exchange, it has been possible to construct an MLA relatively easily due to the pattern accuracy of the mask.

Furthermore, ions are implanted into elongated cylindrical glass to give it a refractive index distribution in the diametrical direction, and many short cylindrical gradient index lenses are cut in front to form a flat plate, and then thinly shaved to form an MLA. Created.

[Example 2] In this example, a light guide type display device in which an image forming device and a light guide were combined was created using the MLA created in Example 1.

As the image forming device, any self-luminous display device such as a CRT, EL, or plasma display, or a combination of a light source and a light shutter can be used, but in this example, a xenon lamp light source and a liquid crystal display are used. It consists of a light shutter using optical elements. Further, the light guide may be an optical fiber made of glass such as quartz glass or an optical fiber made of plastic such as Ac-1-Nor resin, but in this embodiment, a plastic optical fiber was used because it is inexpensive and lightweight.

FIG. 1 shows an enlarged cross-sectional view showing the concept of the connecting portion between the image forming device and the light guide. Although the lens in the figure is drawn in a biconvex shape to make the concept easier to understand, the MLA configured in Example 1 does not necessarily have this shape.

No matter which MLA is used, alignment between the image forming device and the light guide is much easier than with conventional image forming devices, but in particular, in the case of a flat MLA with no protrusions, the end of the light guide and the
It was possible to bring the LA, MLA and the end of the image forming apparatus into close contact with each other, making assembly easier.

We also confirmed the effect of increasing the margin against slight misalignment between the light guide and the image forming device due to temperature changes.

[Example 3] This example is an example in which the light guide has an MLA function at the end of the image forming device.

As for the construction method, in the case of glass optical fiber,
By implanting germanium, phosphorus, aluminum, and other ions to create a refractive index distribution, the end of the optical fiber was processed into a lens. In the case of plastic optical fibers, for example, the end of the light guide is softened by heating and processed into a convex shape to have a lens function.

It was confirmed that the light guide constructed in this manner also had the same effects as in Example 2.

[Effects of the Invention] As described above, according to the present invention, the image forming device and the light guide can be easily coupled by optically coupling the image forming device and the light guide by using the arrayed lens group. We will be able to provide ways to do this. Furthermore, there is also the effect of increasing the margin against subtle positional deviations between the light guide and the image forming apparatus due to temperature changes or the like.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view showing the concept of the optical coupling part between the image forming device of the light guide type display device and the light guide according to the present invention, and FIG. 2 shows the image forming device of the conventional light guide type display device and FIG. 2 is an enlarged cross-sectional view showing the concept of an optical coupling portion of a light guide. 101... Image forming device +02.
......Pixel 103... Lens 104...
・・・・・・・・・Light guide +05・・・・・・・・・・
...Optical path 201... Image forming device 202.
......Pixel 203......Light guide 204...
......Light path and above Applicant Seiko Epson Corporation Figure 1

Claims (1)

[Claims] In a light guide type display device consisting of at least an image forming device and a light guide, the optical coupling between the image forming device and the light guide is
A light-guiding type display device characterized by displaying using an array of lenses.