JPH06167746A - Reflective projection screen - Google Patents

Abstract

PURPOSE:To provide large-sized projected images which are high in contrast even in a bright room, not darker in the peripheral part than in the central part and uniformly bright over the entire part of the screen by providing a polarizing layer and transparent bead layer (or transparent bead layer and polarizing layer on the surface of a light reflection layer in this order. CONSTITUTION:This screen 10 is produced by coating the surface of a base 1 consisting of a flexible resin film with ink contg. aluminum pigments as fillers to provide the light reflection layer 2 thereon, then sticking a polarizing film which is flexible and is formed by subjecting the surface to a non-glare treatment thereon to provide the polarizing layer 3 and further densely arraying transparent beads thereon to provide the transparent bead layer 4. The transmission axis of the polarizing film aligns to the polarized waves projected from a liquid crystal video projector 5. The projected light passes the bead layer 3 and the polarizing layer 4 and is emitted by being reflected in the light reflection layer 2. On the other hand, disturbance light (illuminating light) is absorbed and shut off by the polarizing layer 3 and the quantity of the light emitted hardly affects the observation.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an image projector (slide projector, video projector, etc.).
The present invention relates to a reflective projection screen that is used when projecting images from the same direction and observing the image from the same direction as the projector. Also referred to as), a reflection type projection screen capable of clearly observing a projected image.

[0002]

2. Description of the Related Art A liquid crystal type video projector has been developed, and it has become possible to easily project a television image on a large screen and enjoy it. However, because this type of image is difficult to see in a bright room due to low light intensity, the room was normally darkened for observation.

As the screen, there are various types as shown below. White screen made of white PVC sheet. A screen with a high reflectance by coating and forming a reflective layer with a pearl pigment or aluminum pigment on the surface of the sheet. Furthermore, a bead screen in which transparent beads are closely arranged on the surface of these screens to form a transparent bead layer. A metal screen with a hairline finish on the surface of a metal plate such as an aluminum plate.

The screen of the type (1) controls the reflected light in a specific direction (generally, the direction of the projector) in order to maximize the contribution of the light projected from the projector having a small light amount to the observation.

When a projected image is observed in a bright room using these screens, the projected image has a low contrast due to the influence of illumination or light coming from a window (hereinafter, these are collectively referred to as ambient light). Was becoming.

As a screen for viewing a projected image in a bright room, a so-called polarizing screen of a type in which a polarizing film is attached to the surface of a light reflecting layer has been proposed. This type of screen reflects only the light projected from the projector through the polarizing filter,
It suppresses the reflection of ambient light. That is, the polarizing film provided on the surface of the light reflecting layer has the same transmission axis as the polarization direction of the polarizing filter, and incident light rays having different transmission axes do not pass through the polarizing film, and the light reflecting layer This is because it does not contribute to the reflection on the surface of.

When this polarizing screen has a large size (for example, 80 inches or more), when an observer observes from the front of the center of the screen, the illuminance of the projection light from the projector decreases in the peripheral part of the screen. Also, due to the characteristics of the reflective surface (a light ray having a large incident angle is reflected to the outside of the screen due to specular reflection), the reflective brightness is reduced, and the reflective brightness is uneven over the entire screen.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned drawbacks. A large-sized projected image of 80 inches or more has a high contrast even in a bright room, and a peripheral portion is a central portion. It is intended to obtain a bright projected image that is not darker than that of, and is uniform over the entire screen.

[0009]

The present invention has both properties of a bead screen and a polarizing screen having a retroreflective property (the property that reflected light is directed to a light source). That is, the reflective projection screen has a structure in which the polarizing layer and the transparent bead layer (or the transparent bead layer and the polarizing layer) are provided in this order on the surface of the light reflecting layer.

[0010]

Example A surface of a support 1 made of a flexible resin film is coated with an ink containing an aluminum pigment as a filler, a light reflection layer 2 is provided, and a flexible surface is subjected to a non-glare treatment. The polarizing film thus obtained was laminated to provide the polarizing layer 3, and the transparent beads were closely arranged on the polarizing layer 3 to provide the transparent bead layer 4, thereby producing the screen 10.

The polarizing film has a transmission axis that matches the polarized wave projected from the liquid crystal video projector 5.

The projected light A passes through the bead layer 4 and the polarizing layer 3, is reflected by the light reflection layer 2, and is emitted in the range of an angle θ toward the projector. The intensity of the reflected light is highest at A _{1, and} as the angle to the incident light increases,
Although it is as low as A ₂ and A ₃ , it has a sufficient intensity of light for viewing the projected image. (Figure 3)

On the other hand, the ambient light (illumination light) 6 is absorbed / blocked by the polarizing layer 3, the amount of light reaching the reflecting surface is reduced to about half, and the amount of light emitted is further reduced to half, so that the projected image is projected. It has almost no effect on observation (viewer's eyes 7).

In this embodiment, the structure in which the light reflecting layer, the polarizing layer and the transparent bead layer are laminated in this order has been described, but the structure in which the light reflecting layer, the transparent bead layer and the polarizing layer are laminated in this order is also the same. Is.

In this embodiment, aluminum ink is used as the light reflecting layer and a flexible resin film is used as the support, but the present invention is not limited to these, and various ones are applied according to the application. Needless to say.

[0016]

EFFECTS OF THE INVENTION A large-sized projected image can be observed with high contrast even in a bright room, and the peripheral portion is not darker than the central portion, and a uniform bright projected image can be observed over the entire screen. Due to this, the advantages exemplified below can be expected. You can take notes and read materials while watching the video. In a two-way communication such as a video conference, it is not necessary to increase the sensitivity of the TV camera and it is not necessary to use a special TV camera.

[0017]

[Brief description of drawings]

FIG. 1 is an explanatory sectional view showing the structure of a reflection type projection screen of the present invention.

FIG. 2 is an explanatory cross-sectional view showing the configuration of a reflective projection screen according to another embodiment.

FIG. 3 is an explanatory view showing a usage state of the reflection type projection screen of the present invention.

[Explanation of symbols]

 1 ... Support 2 ... Light reflection layer 3 ... Polarization layer 4 ... Transparent bead layer 10 ... Reflective projection screen

Claims (4)

[Claims] 1. A reflective projection screen having a structure in which a polarizing layer and a transparent bead layer are provided in this order on the surface of a light reflecting layer. 2. A reflection type projection screen having a structure in which a transparent bead layer and a polarizing layer are provided in this order on the surface of the light reflecting layer. 3. The reflection type projection screen according to claim 1, wherein an aluminum foil or an aluminum ink is formed on the surface of a support made of a flexible resin film as the light reflection layer. . 4. The reflection type projection according to claim 1, wherein a polarizing film which is flexible and has a non-glare surface is used as the polarizing layer. screen.