JPH0667306A - Reflection type screen - Google Patents

Abstract

(57) [Abstract] [Purpose] Disclosure of a reflection type screen having a bright image quality and a wide observation range [Configuration] A diffuse reflection surface having fine irregularities is formed on the surface of a spherical bead 3 having translucency, and the bead 3 is formed. The metal film 5 is formed on one of the hemispheres, the other hemisphere of the bead 3 is used as a light incident portion, and the beads 3 with the incident portion side facing the light source side are arranged in the closest packed state on the fixed base material 1. It is characterized by having done.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective screen for projecting light to display an image, such as an overhead projector, a 16 mm movie or a video projector.

[0002]

2. Description of the Related Art Recently, overhead projectors and
There is known a reflection type screen which projects an image by projecting light such as a 6 mm movie or a video projector.

As the reflective screen, a white screen, a metal screen, a bead screen, etc. are known.

The white screen is made of soft white vinyl chloride resin and is either plain or embossed.

The metal screen uses an aluminum plate as a reflecting member, and the surface of the aluminum plate is grained or a plurality of films are laminated.

Further, in the case of a bead screen, 0.05 to 0.1 mm is placed on a soft white polyvinyl chloride sheet material.
A large number of glass beads having a certain diameter are attached.

[0007]

However, the white screen or the metal screen has a specular reflection characteristic and the image quality of the screen is not bright, but it has an advantage that the viewing side can be observed. On the other hand, the bead screen has a retroreflective property and is bright when viewed near the projection position, but has a problem that the viewing side on the viewing side is narrow.

The present invention focuses on such a problem, and an object thereof is to provide a reflection type screen having a bright image quality and a wide viewing range on the viewing side.

[0009]

In order to solve the above-mentioned problems, the reflection type screen according to the present invention forms a diffuse reflection surface having fine irregularities on the surface of translucent spherical beads, and the beads are formed. One of the features is that a metal film is formed on one of the hemispheres, the other hemisphere of the bead is used as the light incident site, and the beads with the incident site side facing the light source side are arranged in the closest packed state on the fixed base material. And

[0010]

According to the reflection type screen of the present invention, since the fine irregularities are formed on the surface of the beads and the irregularities corresponding to the fine irregularities are formed on the surface of the metal film, the closest density on the fixed base material is obtained. When the image forming light is incident on the incident portion of the arranged beads, the incident light incident on the beads is irregularly reflected on the surface of the metal film. For this reason, the light emitted from the bead's incident part to the outside of the bead is diffused in various directions. Therefore, when viewing from the screen side, the image viewing range is expanded and the incident light inside the bead is reflected by the metal film. Therefore, the image quality becomes brighter.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cross-sectional structure which is a main structure of a reflective screen according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cross-sectional structure of the reflection type screen of this embodiment. Reference numeral 1 is a soft vinyl chloride resin sheet as a base material. On the surface of the vinyl chloride resin sheet 1, a large number of small-diameter glass beads 3 are fixed via an adhesive layer 2 in the most densely packed state. The beads 3 have a particle size of 30 μm to 100 μm and a refractive index of 1.
90 granular spheres made of glass. A large number of fine concave portions 4 are formed on the surface of the bead 3, so that it looks as if a large number of irregularities were formed on the surface of the bead 3. An aluminum vapor deposition layer 5 as a metal film is formed on the hemisphere portion of the beads 3 on the side fixed to the vinyl chloride resin sheet 1, and the aluminum vapor deposition layer 5 is sufficiently vapor deposited to the bottom of the recesses 4 ... There is.
A portion of the bead 3 facing the aluminum vapor deposition layer 5 is a light-transmitting portion so that the light can enter the inside of the bead 3 and the light entering the inside can be emitted.
The aluminum metal film is not limited to the vapor deposition film and may be a film formed by plating.

Explaining one of the methods for manufacturing this reflection type screen, first, the beads 3 are stirred with an abrasive having a high hardness such as gold sand and alundum to form irregularities on the surface of the beads 3. Next, the beads 3 are temporarily fixed and adhered to the polyester film having an adhesive layer to expose the upper hemisphere portion of the beads 3 on the polyester film and hide the lower hemisphere portion of the beads 3 in the adhesive layer. Further, aluminum is vapor-deposited on the polyester film on which the beads 3 are closely adhered, and aluminum is vapor-deposited on the exposed portion A of the beads 3. After that, when the soft vinyl chloride 1 having the adhesive layer 2 having a larger adhesive force than the adhesive layer of the polyester film is adhered to the surface of the polo ester film on which the aluminum vapor deposition layer is formed, the beads 3
Move to the soft vinyl chloride 1, and by fixing this, a reflection type screen is created. In the above embodiment, the vapor deposition method was used to form the aluminum thin film on the hemispherical portion of the bead 3, but a chemical thin film treatment may be used.

According to the reflective screen of this embodiment, when light including an image is projected onto the reflective screen,
This light enters the inside through the transparent portion B of the beads 3,
The light is reflected by the hemisphere portion where the metal film is formed. In this case, the reflected light amount of the incident light is larger than that in the case where the metal film is not formed on the beads 3, so that the reflected light amount emitted from the light transmitting portion B of the beads 3 to the space is large, and the image quality of the screen is bright and easy to see. Becomes In addition, since the surface of the aluminum metal film is uneven due to the recesses 4 formed on the surface of the beads 3, the light that has entered inside is scattered when reflected on the surface of the aluminum vapor deposition film. Therefore, when the scattered light is emitted from the light transmitting portion B of the bead 3 to the outer space, the scattered light is emitted at a wide angle, and the observation range on the screen viewing side is widened.

That is, if unevenness is provided on the surface of the metal film in FIG. 2, most of the light is retroreflected as shown by the thick lines in the figure, but the light rays disturbed at each point are centered around the thick line. The strength is distributed. FIG. 2 illustrates the reflection characteristics of a screen having such a fine shape, and the vertical axis represents the amount of light reflected from the screen (screen gain = S
In G), the horizontal axis indicates the angle spread to the left and right with the line extending at a right angle from the screen as the reference line (0 °). The numerical value 1 of the screen gain is a value when the reflection brightness of the standard white plate is 1, and the numerical value 6 of SG is the reflection brightness of 6 times the reflection brightness of the standard white plate. It is assumed that the overhead projector that projects the light including the image is located on this reference line, and the light including the image emitted from the overhead projector is projected at the right and left symmetric angles with the reference line as the center.

In this example, when the beads 3 are not provided with irregularities, the numerical value of SG shows 6, and the observation angle at which the SG is halved is about 10 ° to the left and right with reference to the intersection of the reference line and the screen. However, when irregularities are formed on the reflecting surface of the beads 3 as in this embodiment, SG is slightly reduced, but the observation range is widened and a large number of people can observe the screen image.

By adjusting the depth and / or the amount of the fine irregularities, it is possible to provide a screen suitable for the projection conditions such as the observation range.

[0018]

[Effect] According to the reflection type screen of the present invention, since the fine irregularities are formed on the surface of the beads and the irregularities corresponding to the fine irregularities are formed on the surface of the metal film, the close-packed on the fixed substrate. When the image forming light is incident on the incident portion of the arranged beads, the incident light incident on the beads is irregularly reflected on the surface of the metal film. For this reason, the light emitted from the bead's incident part to the outside of the bead is diffused in various directions. Therefore, when viewing from the screen side, the image viewing range is expanded and the incident light inside the bead is reflected by the metal film. Therefore, the image quality is brightened. Furthermore, by adjusting the depth and / or the amount of the fine irregularities, it is possible to provide a screen adapted to the projection conditions such as the observation range.

[Brief description of drawings]

FIG. 1 is an explanatory view of reflection characteristics when minute unevenness and a metal film are formed on beads.

FIG. 2 is a table showing the correlation between the amount of light reflected by the screen and the observation angle.

[Explanation of symbols]

 1 ... Soft vinyl chloride 2 ... Adhesive layer 3 ... Beads 4 ... Recess 5 ... Aluminum vapor deposition film

Continued Front Page (72) Inventor Akira Yoshikawa 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (1)

[Claims] 1. A light-transmitting spherical bead is provided with a diffused reflection surface consisting of fine irregularities on the surface, a metal film is formed on one hemisphere of the bead, and the other hemisphere of the bead is transmitted. A reflective screen in which beads having a transparent portion side facing the light source side are arranged in a close-packed state on a fixed base material.