JPH06230477A - Screen for rear type liquid crystal projector - Google Patents

Abstract

PURPOSE:To obtain a screen for the rear type liquid crystal projector having excellent optical properties by using as its constituents, a surface polarizing plate, an intermediate lenticular lens and a rear Fresnel lens, all of which are forlmed by the casting. CONSTITUTION:The screen (a) for the rear type liquid crystal projector receives the light which is radiated through a reflection plate. The screen is formed by concurrently and integrally casting the polarizing plate 1 and the lenticular lens 2 by using a UV-curable resin, and then bonding Fresnel lens 3 which is also molded by casting, to the resulting integrally-molded part through the adhesive layer 6. This screen formation enables the mass-projection of the most preferable screen for the liquid crystal projector not having anisotropy to be mass-produced since the lenses are formed by the casting not by the conventional extrusion. In addition, in order to reduce the surface reflection, the polarizing plate 1 is preferably provided with black stripes or a non- reflective coating layer on its surface and further a diffusing agent is preferably added to the lenticular lens 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen for a rear type liquid crystal projector.

[0002]

2. Description of the Related Art CRT projectors (hereinafter referred to as CR
T. There are two types of screens for), and there are a front type screen and a rear type screen (the former is a large screen).

The former is a screen for directly projecting the light from the CRT and is formed of only a reflecting material, and the latter is for indirectly expanding and irradiating the light from the CRT through a reflecting plate. The screen is a lenticular lens 11 formed by extrusion molding for diffusing light as shown in FIG. 1, and a Fresnel lens 12 formed by extrusion molding for converging light on the back surface of the lenticular lens 11 through an adhesive layer 13. It is a structure which is pasted together (light is irradiated from the right side in FIG. 1).

By the way, in recent years, a liquid crystal projector (hereinafter referred to as LCD) using a front type screen has been proposed. The LCD has the advantages of being thin, lightweight, and usable outdoors, and has made remarkable progress in recent years.

According to various studies by the applicant, the extrusion molding exerts an extruding force on the resin used, so that the molded resin is distorted, and this distortion causes the lens to have anisotropy (birefringence). This occurs (a lens having the same refractive index in the x, y, and z directions is called a non-anisotropic lens).

It is well known that in the case of LCD, it is not preferable that the screen used has anisotropy.

Therefore, a polarizing plate is attached to the screen (in the case of a screen for LCD, a polarizing plate is essential in order to obtain a good contrast since the liquid crystal member makes the vibration direction of light in one direction. ), Even when used as a screen for a rear type LCD, it turned out to be a very poor screen as a result.
It is a technical object of the present invention to provide a rear type liquid crystal projector screen that solves such drawbacks.

[0008]

The gist of the present invention will be described with reference to the accompanying drawings.

A rear type liquid crystal projector screen a for receiving the light emitted through the reflector 4,
The present invention relates to a screen for a rear type liquid crystal projector having a structure of a front polarizing plate 1, an intermediate lenticular lens 2 and a back Fresnel lens 3 formed by casting.

[0010]

Since the screen is made of a member integrally formed by casting, the screen has no anisotropy.

[0011]

2 and 3 show one embodiment of the present invention, which will be described below.

The screen a according to the present embodiment uses a UV resin, the polarizing plate 1 and the lenticular lens 2 are integrally molded at the same time by casting (molding), and the Fresnel lens 3 similarly molded by casting is an adhesive layer. It is formed by combining through 6 and has no anisotropy (birefringence) (a lens having the same refractive index in the x, y and z directions is called a lens having no anisotropy) and has mass productivity. It will be an excellent screen.

Since the present embodiment is formed by casting instead of the lens formed by extrusion molding as described above, it is an optimum screen for an LCD having no anisotropy.

Since the present embodiment is not a three-tube type CRT screen but an LCD screen, the lenticular lens does not cause any trouble due to unevenness on one side surface.

In order to reduce the surface reflection, the surface of the polarizing plate according to the present embodiment may be provided with a black stripe or a non-reflective coating. A diffusing agent may be mixed to provide directivity (horizontal and vertical directivity).

The screen a according to this embodiment as described above
Is used as shown in FIG. 3 (the screen a according to the present embodiment is arranged in a state where the Fresnel lens 3 is located on the reflection plate 4 side). Reference numeral 5 in FIG. 3 is an LCD.

[0017]

As described above, the present invention provides a screen for a rear type liquid crystal projector having a very good contrast and excellent optical characteristics because it is constructed as described above.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a screen according to a conventional example.

FIG. 2 is an explanatory diagram of a screen according to this embodiment.

FIG. 3 is an explanatory diagram showing a usage state of the present embodiment.

[Explanation of symbols]

 a screen 1 polarizing plate 2 lenticular lens 3 Fresnel lens 4 reflector

Claims (1)

[Claims] 1. A screen for a rear type liquid crystal projector which receives light emitted through a reflection plate, the rear type liquid crystal having a structure of a surface polarizing plate, an intermediate lenticular lens and a back surface Fresnel lens formed by casting. Screen for projector.