JPH05273655A - Bead screen - Google Patents

Abstract

PURPOSE:To provide the bead screen which projects the image to be projected from a video projector, etc., drastically decreases the reflection of incoming light by absorbing the wavelength of a higher specific visual sensitivity among the wavelength spectra of the incoming light and forms the bright projected image having a contrast even in a relatively bright place. CONSTITUTION:Any of the beads 1, base material 3 or a protective film 6 provided on the surface of the bead 1 at need of the bead screen formed by fixing the beads 1 by the adhesive 2 to the surface of the base material 3 is subjected to coloration to absorb the wavelength of the light between about 530 to about 640nm. Consequently, the wavelength near 550nm of the high specific visual sensitivity among the wavelength spectra of the incoming light is absorbed and the reflection of the incoming light is drastically decreased. The bright projected image having the contrast is thus obtd. even in the relatively bright place.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bead screen for displaying a projected image of a video projector, a film projector, an overhead projector or the like.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a conventional bead screen. Reference numeral 1 is a bead (spherical lens) made of uncolored transparent glass, which has a diameter of 0.2 mm or less. The beads 1 are uniformly adhered to the surface of a base material (screen base material) 3 with an uncolored transparent adhesive 2. The base material 3 is made of an opaque white polyvinyl chloride resin (PVC) that diffuses and reflects light. The glass fiber 4 reinforces the base material 3, and the black back coating 5 prevents external light from the back surface of the screen from passing through to the front surface.

FIG. 5 is an enlarged view of FIG. Diffuse reflection of the projection light from the bead screen will be described with reference to FIG. The light ray L is incident on the beads 1, passes through the adhesive 2, and reaches the surface of the substrate 3. In general, the base material 3 is made of a white vinyl chloride resin sheet mixed with a white pigment, solid fine powder or the like. Fine irregularities are formed on this surface,
The incident light L is diffused and reflected, spreads in a wide angle range as indicated by L1 to L5, and passes through the beads 1 twice. It is well known that the reflective directional characteristic of a bead screen is suitable for a reflective screen, and it has a feature that the brightness of an image appears to be substantially constant when viewed from any of the left, right, top and bottom.

[0004]

However, in the conventional bead screen, both projection light and external light are reflected in the same manner, so there is no problem when used in a dark room.
When the room is made slightly brighter, the screen surface becomes whitish due to the extraneous light, and the contrast of the projected image is lost, resulting in a blurred image.

[0005]

In order to solve the above-mentioned problems of the prior art, the present invention provides (1) a bead screen for projecting an image projected from a video projector or the like, which comprises a screen substrate and Adhesive on the surface of the substrate, consisting of a plurality of beads that are uniformly fixed,
Any of the plurality of beads, the adhesive, the base material, or a protective film provided on the surface of the plurality of beads as necessary, has a thickness of approximately 530 nm to approximately 640 n.
A bead screen characterized by being colored to absorb a wavelength of light between m and (2) a bead screen for projecting an image projected from a video projector or the like, comprising: a screen substrate; A plurality of beads uniformly adhered to the surface of the base material by an adhesive, and the plurality of beads, the adhesive, the base material, or the surface of the plurality of beads as necessary. It is intended to provide a bead screen characterized in that any one of the protective films provided is colored with a light-transmitting gray color.

[0006]

EXAMPLES The bead screen of the present invention will be described below.
Description will be given with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an embodiment of the bead screen of the present invention, FIG. 2 is a cross-sectional view showing another embodiment of the bead screen of the present invention, and FIG. 3 is a transmittance characteristic of wavelength selective absorption coloring and a phosphor. It is the figure which showed the emission spectrum. 1 and 2, the same parts as those in FIGS. 4 and 5 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 3, the horizontal axis represents the wavelength of light and the vertical axis represents the light transmittance and relative energy. Reference numeral 20 is a characteristic curve showing the light transmittance characteristic of the coloring of the present invention. The characteristic curve 20 absorbs a wavelength of about 530 nm to about 640 nm and a wavelength of visible light of about 430 nm or less. 21B, 2
1G and 21R show the characteristics of the relative energy of each color phosphor of the projection device using the cathode ray tube (CRT).
21B shows the emission spectrum characteristics of a blue phosphor, 21G a green phosphor, and 21R a red phosphor.

In FIG. 1, reference numeral 11 is a colored bead made of glass or resin, which is colored to have a light transmittance characteristic as shown by 20 in FIG. When an image of a three-tube type projector, which is currently the mainstream, is projected on the colored beads 11, the blue, green, and red light is transmitted and reflected without being reduced. At this time, in the wavelength spectrum of the external light, the wavelength near 550 nm, which has a high relative luminous efficiency, and the wavelength of visible light of 430 nm or less are absorbed, so that the reflection of the external light is greatly reduced. Therefore, it is possible to prevent the projected image from becoming a blurred image without white contrast due to the extraneous light.

In FIG. 1, all of the colored beads 11 are colored so as to absorb a visible light wavelength of about 530 to 640 nm and 430 nm or less. The beads 1 may be mixed, and in this case, the effect is exhibited when the colored beads 11 are mixed in an amount of 5% or more. Also, colored beads 11
The above-mentioned coloring is preferably provided with the above-mentioned wavelength selective absorption, but it may be colored in a light-transmitting gray color. When it is colored gray, the reflection of extraneous light can be reduced depending on the degree of gray, but the brightness of the projected image is also reduced.
However, since the black color of the image is prevented from becoming white and the image is blurred, the image looks relatively clear.

FIG. 2 shows a conventional bead screen having a bead surface provided with a protective film 6. The protective film 6 is formed by spraying a solution of a thin resin film and then drying and solidifying. By treating the protective film 6, the screen surface can be wiped clean with a wet cloth or the like. The same effect can be obtained by coloring the protective film 6 in the same manner as the colored beads 11 shown in FIG. Of course, even if the protective film 6 is transparent and non-colored, if the colored beads 11 are colored as described above, the effect of improving the contrast with respect to external light is produced.

As described above, the colored beads 11 and the protective film 6 have about 5
The coloring that absorbs the wavelength of visible light between 30 and 640 nm and 430 nm or less, or the light-transmitting gray coloring has been described, but even if the above-described coloring is applied to the adhesive 2 or the base material 3, Similar effects are obtained. That is, the beads, or the adhesive, or the base material, or the protective film provided on the surface of the beads as necessary has a thickness of about 530.
It suffices to perform coloring that absorbs the wavelength of light between nm and approximately 640 nm. The screen of the present invention has flexibility,
It has the feature that it can be wound up and sufficient flatness can be obtained without wrinkling due to the rigidity of the glass fiber.

[0012]

As described in detail above, the bead screen of the present invention is designed to absorb the wavelength of approximately 530 nm to 640 nm, which has a high relative luminous efficiency, in the wavelength spectrum of the external light. Significantly reduce reflection, project a clear projected image with contrast even in a relatively bright place, and reduce the reflection of extraneous light according to the degree of gray even when colored in light-transmitting gray. Since it is possible to prevent the image from being blurred due to the black color of the image becoming white, it is possible to obtain a relatively clear image, which is a very excellent practical effect.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a bead screen of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the bead screen of the present invention.

FIG. 3 is a diagram showing a transmittance characteristic of wavelength selective absorption coloring and an emission spectrum of a phosphor.

FIG. 4 is a cross-sectional view showing a conventional bead screen.

FIG. 5 is an enlarged view of FIG. 4.

[Explanation of symbols]

 2 Adhesive 3 Base material (screen base material) 4 Glass fiber 5 Back coating 6 Protective film 11 Colored beads

Claims (2)

[Claims] 1. A bead screen for displaying an image projected from a video projector or the like, which comprises a screen base material and a plurality of beads which are uniformly adhered to the surface of the base material by an adhesive. Any of the plurality of beads, the adhesive, the base material, or a protective film provided on the surface of the plurality of beads as necessary, has a thickness of approximately 530 nm to approximately 640 n.
A bead screen, which is colored to absorb a wavelength of light between m. 2. A bead screen for projecting an image projected from a video projector or the like, which comprises a screen base material and a plurality of beads which are uniformly adhered to the surface of the base material by an adhesive. The plurality of beads, or the adhesive, or the base material, or any of the protective film provided on the surface of the plurality of beads as required, is colored with a gray color having a light-transmitting property. Characterized bead screen.