JPH06332074A - Projection screen - Google Patents

Abstract

PURPOSE:To reduce the influence of external light and to display bright image which is high in contrast by arranging many infinitesimal reflecting members on the screen surface of the projection screen on which an image is displayed by reflecting projection light from the forward direction. CONSTITUTION:Many corner cubic mirrors 1 having respective 1st, 2nd, and 3rd surfaces 5-7 formed of reflecting mirrors centering on a vertex of a transparent material 2 in a cubic shape more infinitesimal than a pixel of a projected image are arranged on the screen surface 9 without a gap. The corner cubic mirrors 1 installed on the projection screen surface 9 reflect light beams which are made incident by the corner cubic mirrors so that they return in nearly 180 deg. opposite directions. The corner cubic mirrors may use a smooth surface parallel to the surface of the projection screen as the transparent materials 2 or consist of only the three surfaces 5-7 centering on one vertex of a cube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection screen for reducing the influence of external light and displaying bright images with good contrast.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing a usage state of a conventional front projection type projector. The projection screen 10 displays a projected image by reflecting forward a light beam projected from the projector so as to form an image on the projection screen 10. Conventionally, in order to obtain a bright image on the projection screen 10, aluminum powder, glass beads, etc. have been applied so as to enhance the reflection efficiency of the screen.
Therefore, a bright image can be obtained under conditions where the influence of outside light is small, but under general use conditions where the influence of outside light is large, the reflected light 15 of outside light is similar to the reflected light 12 of the image.
Also reflects well. Therefore, the image on the projection screen is
There is a problem that the picture becomes difficult to see because the contrast is lowered due to the influence of outside light such as from a window.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a projection screen that reduces the influence of external light and displays a bright image with high contrast.

[0004]

In order to achieve the above object, in a projection screen for displaying an image by reflecting a light beam projected from the front and returning it to the front, a large number of minute reflecting members are arranged on the screen surface. I will do it.

[0005]

With the above construction, a large number of corner cubic mirrors installed on the surface of the projection screen reflect the incident light rays for each corner cubic mirror and return in the opposite direction by approximately 180 degrees. To proceed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The projection screen according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a view showing a corner cubic mirror installed on the surface of a projection screen according to the present invention. The figure (a) shows the arrangement of the corner cubic mirrors on the projection screen, and the figure (b) shows the structure of one corner cubic mirror.
In comparison with the pixels of the image to be projected, 1 is a transparent material 2 in the form of a minute cube, and the first, second, and third surfaces 5, 6 and 7 are formed by reflecting mirrors around one vertex A. It is a corner cubic mirror. A large number of the corner cubic mirrors 1 are arranged on the screen surface 9 without a gap to form a projection screen according to the present invention.

The operation of the projection screen according to the present invention will be described. FIG. 2 is a diagram showing a usage state of the projection screen according to the present invention. The projection screen 10 displays a projected image by reflecting light rays projected from the projector so as to form an image on the projection screen 10.
In this case, the reflected lights 11 and 13 of the external light A and the external light B are reflected.
Is almost returned to the incident direction, so that only the reflected light 12 of the image travels forward and to the front. In the corner cubic mirror, the transparent material 2 may be a smooth surface parallel to the surface of the projection screen 10, or the transparent material 2 may not be provided and three surfaces 5 centering on one vertex A of the cube may be used. It may be configured with only the reflecting mirrors 6 and 7.

[0008]

As described above, the present invention provides a projection screen that reduces the influence of external light and displays a bright image with high contrast. Therefore, the image projected in the environment affected by the external light can be displayed in a high quality state,
This contributes to higher performance of the front projection type projector device.

[Brief description of drawings]

FIG. 1 is a view showing a corner cubic mirror installed on the surface of a projection screen according to the present invention.

FIG. 2 is a diagram showing a usage state of a projection screen according to the present invention.

FIG. 3 is a diagram showing a usage state of a conventional front projection type projector.

[Explanation of symbols]

 1 corner cubic mirror 2 transparent material 5 first surface centering on vertex A 6 second surface centering on vertex A 7 third surface centering on vertex A 9 screen surface 10 projection screen 11 reflected light of outside light A 12 Reflected light of image 13 Reflected light of external light B 15 Reflected light of external light

Claims (4)

[Claims] 1. A reflection type projection screen for displaying an image by reflecting a light beam projected from the front and returning it to the front, wherein a large number of minute reflecting members are arranged on the screen surface to prevent the influence of external light. A projection screen characterized by suppressing and obtaining a large contrast ratio. 2. The projection screen according to claim 1, wherein the reflecting member is composed of a corner cubic mirror formed by reflecting mirrors with three faces centering on one vertex of a transparent material having a cubic shape. 3. The projection screen according to claim 1, wherein the corner cubic mirror forms three surfaces with one vertex of a cube as a center with reflecting mirrors. 4. The projection screen according to claim 3, wherein the surface of the corner cubic mirror is covered with a smooth flat transparent material.