JPH09114002A - Reflection type projection screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain such a screen that a projected enlarged image can be observed as a bright and high-contrast image with a wide angle of visual field even in a bright environment by forming a light-diffusing reflection plane having a fine rough surface on the surface of a reflection layer. SOLUTION: This reflection type projection screen consists of a screen base body 2 and a reflecting layer 3 formed by printing the one surface of the base body 2 with a silver printing ink (toned by aluminum powder) or a reflection layer 3 formed by vapor deposition of aluminum or by laminating an aluminum foil. The surface of the reflecting layer 3 is made as a light-diffusing reflection plane 3a having a fine rough state. The light-diffusing reflection plane 3a of the reflection layer 3 is formed by using a material having a matted surface as the base body to constitute the reflection layer 3 or as the base body to constitute the screen base body 2 and by using the random micro-ruggedness of the matted surface.

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 a projection device such as a video projector, which is capable of displaying a magnified image with a wide viewing angle in a bright and high contrast when projected under a particularly bright viewing environment. The present invention relates to a reflective projection screen having characteristics.

[0002]

2. Description of the Related Art In recent years, various video projectors have been developed, and it has become possible to easily project a television image on a large reflective projection screen, but it should not be affected by outside light. In many cases, it is used in a darkened room, but recently, a screen that can be observed even in a relatively bright room has been developed, and it has been used in various fields.

A conventional reflective projection screen has a screen substrate 2, a reflective layer 3, a polarizing layer 4 having a transmission polarization axis coaxial with the polarization axis of polarized incident light of a projected image, and a light-transmissive layer. A screen in which the light diffusion layer 5 and the light diffusion layer 5 are sequentially stacked,
It is desirable that the contrast (the density difference between the highlight part and the shadow part of the projected image) has an easy-to-see brightness, and the image projected on the projection screen is easy for many people to see. Therefore, it is desired that the screen surface has a good viewing angle due to an appropriate light diffusion characteristic so that the screen can be viewed.

The light diffusion characteristic of the reflection type projection screen is that it is incident on the screen with its optical axis vertical (front),
The brightness (diffuse brightness) of the image light reflected by the reflection surface of the screen and emitted in a diffused state is 1/2 (half value) with respect to the brightness (front brightness) of the image light emitted directly in front (optical axis direction). It is obtained by the angle (half-value angle) formed with the optical axis.

In general, by widening this half-value angle, it is possible to make a screen having a wide viewing angle so that many people can view an image from both sides of the screen.

[0006]

However, if the illuminance of the projection light (light source) on the screen surface is constant, the relationship between the half-value angle and the front luminance is generally inversely proportional. By widening, the front brightness (the overall brightness of the screen) would be reduced, and thus it was very difficult to balance both of them in a high dimension.

An object of the present invention is to improve the reflection characteristics of the image light on the reflection layer surface of the screen in order to balance the relationship between the half-value angle of the reflection type projection screen and the front luminance together in a high dimension, and it is particularly bright. Even in a visual environment, it is intended to allow a magnified image to be projected with a wide viewing angle to be viewed brightly and in high contrast.

[0008]

According to the present invention, a reflective layer 3 is provided on a screen substrate 2, a polarizing layer 4 having a transmission polarization axis coaxial with the polarization axis of polarized incident light of a projected image, and a light transmitting layer. A reflective projection screen in which a light-diffusing layer 5 having a light-transmitting property is laminated in this order, wherein the surface of the reflective layer 3 has a light-diffusing reflective surface 3a having fine irregularities.

Further, according to the present invention, in the above reflection type projection screen, the relation between the uneven pitch p1 of the reflecting surface 3a and the uneven pitch p2 of the light diffusing surface 6a of the light diffusing layer 5 is as follows:
A reflective projection screen with p1 ≤ p2.

Further, according to the present invention, in the reflection type projection screen described above, the relation between the uneven height h1 of the reflecting surface 3a and the uneven height h2 of the light diffusing surface 6a of the light diffusing layer 5 is h1.
A reflective projection screen with ≤h2.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The reflection type projection screen of the present invention will be described below in detail according to the embodiment shown in the partial side sectional view of FIG.

The reflection type projection screen 1 has a reflection layer 3 formed by printing a silver printing ink (ink toned with aluminum powder) on one surface of a screen substrate 2 or by aluminum vapor deposition or aluminum foil attachment. A reflective layer 3 is provided, and the surface of the reflective layer 3 is provided with a light-diffusing reflective surface 3a having fine irregularities.

The above-mentioned one surface of the screen substrate 2 may be either glossy (smooth) or matte (fine concavo-convex). Further, the base material 2 and the reflective layer 3 may be an integrated sheet.

The light diffusive reflecting surface 3a of the reflecting layer 3 is
As a base material forming the main body of the reflective layer 3 or as a base material forming the screen base material 2, a surface mat-like base material is used, and the mat-like surface of the base material is random (fine unevenness of the matte surface). The reflecting surface 3a is formed by utilizing fine unevenness in which the distribution state is uniform throughout but the unevenness itself is indefinite.

As the surface mat-like base material, a base material made of a foamed resin or a base material having a foamed resin layer, a base material whose surface is sandblasted or embossed, or a matting agent (for example, pearlescent agent, silica, etc.) Examples include base materials coated with and printed with a printing ink (matting ink) containing

The reflective layer 3 is formed on such a surface-matte base material by a metal vapor deposition method such as aluminum or a printing method using silver ink.

A light diffusing layer 5 is formed by laminating a polarizing layer 4 on the reflecting layer 3 if necessary, and then applying or laminating a transparent synthetic resin 6 (paint, ink or film). Prepare

As shown in FIG. 1, the light diffusing layer 5 has a fine unevenness formed on its surface to form a light diffusing surface 6a. In the transparent synthetic resin 6 of the light diffusing layer 5, a light diffusing material (fine powder of kaolin, silica, etc.) may be added if necessary.
May be mixed. In addition, L indicates the incident / exit direction of the image projection light.

The light diffusion layer 5 may be colored with a chromatic or achromatic transparent coloring material 7 (a dye or a pigment, or a coloring material in which these are mixed).

The polarizing layer 4, which is laminated as necessary, has a uniaxial structure that serves as a support (base layer) for the polarizer, with adhesive layers on both sides of the polarizer made of a polyvinyl alcohol film on which iodine is adsorbed. It is a laminate of stretched polyethylene terephthalate film and the like.
The polarization axis direction (stretching axis direction) of the polarizer is set to the same direction as the polarization axis orthogonal to the incident optical axis of the projected image.

Further, as shown in FIG. 1, the unevenness height h1 of the uneven reflecting surface 3a formed on the surface of the reflecting layer 3 is as follows.
, And the uneven height h2 of the uneven light diffusing surface 6a formed on the surface of the light diffusing layer 5 is 3 to 50 μm.
It is suitable to set it in the range of 10 μm or less, and it is suitable to set the uneven pitches p1 and p2 respectively.
Is set in the range of 30 to 200 μm, preferably 1
It is suitable to set the thickness to 00 μm or less.

The uneven height h1 and the uneven pitch p1 of the reflecting surface 3a, and the uneven height h2 and the uneven pitch p2 of the light diffusing surface 6a are expressed by the following relational expression: (1/10) p1≤h1 By setting the range such that ≤ (5/3) p1 (1/10) p2 ≤h2 ≤ (5/3) p2 is satisfied, the half value angle can be increased while maintaining the front luminance properly. it can.

It should be noted that the unevenness height h1 of the reflecting surface 3a is extremely large with respect to the unevenness pitch p1, and the unevenness height h2 of the light diffusing surface 6a is extremely large with respect to the unevenness pitch p2. Surface, h1 and p1, h2 and p
When the relationship with 2 is (5/3) p1 <h1 (5/3) p2 <h2, the light diffusion effect becomes excessive and a large half-value angle is obtained, but the front brightness is reduced. .

Further, the uneven pitch p1 of the reflecting surface 3a,
The relationship with the uneven pitch p2 of the light diffusing surface 6a is p1 ≤
Suitably p2.

The relation between the height h1 of the unevenness of the reflecting surface 3a and the height h2 of the unevenness of the light diffusing surface 6a is h1≤h2
It is appropriate that

In the reflection type projection screen of the present invention,
The image light L entering and exiting the screen surface is reflected by the reflecting surface 3a.
Also, the image can be viewed from the front side of the screen and the left-right direction directly facing the screen surface by diffusing by the respective convex portions (or concave portions) of the light diffusion surface 6a.

Further, the convex (or concave) surface of each of the reflecting surface 3a and the light diffusing surface 6a also presents a fine rough surface, and the image light L entering and exiting by this surface is the front and The half-value angle of the screen is increased by spreading in the left and right diagonal directions.

[0028]

EXAMPLES Specific examples of the reflection type projection screen of the present invention will be described in detail below.

<Example 1> As a screen substrate, a sheet made of polyethylene terephthalate having a matte surface (fine irregularities) (thickness: 25 μm, or 25 to 35 μm)
m, or 35 μm or more and 200 to 300 μm or less).

First, on the entire mat-like surface of the base material,
A silver-colored ink mixed with aluminum powder is used to print by a gravure printing method and dried to form a light-reflecting layer (ink coating thickness: 10 to 30 μm) having a light-diffusing reflecting surface with fine irregularities on the surface. did.

Subsequently, a glossy (smooth) biaxially stretched polypropylene film (thickness: 15 to 25 μm) is heat-laminated or a transparent pressure-sensitive adhesive or adhesive (thickness: 15 μm or less) on the reflective layer. While laminating via, the film surface is heated and pressed by an embossing roll and a press roll having a light-diffusing surface-shaped uneven pattern, and the uneven height is 5 to 8 μm or 10 to 20 μm, and the uneven pitch is 5 to 8 μm or A light diffusing layer having a light diffusing surface embossed into a fine uneven shape of 10 to 20 μm (for example, uneven height of 5 to 8 μm and uneven pitch of 10 to 20 μm) was formed to prepare a reflection type projection screen of the present invention. In addition,
As the adhesive material and the adhesive material used for the laminate, those mainly composed of a resin having a light refractive index similar to that of the light diffusion layer were used.

Example 2 As the glossy (smooth) biaxially oriented polypropylene film in the above example,
A reflective projection screen of the present invention was prepared in the same manner as in Example 1 except that a light diffusing material (fine powder of silica, kaolin, etc.) was mixed.

<Example 3> Example 1 or Example 2 described above except that a polarizing layer was formed between the reflective layer and the light diffusion layer.
A reflection type projection screen of the present invention was prepared in the same manner as in.

The polarizing layer is a polarizing layer in which a base layer made of a uniaxially stretched polyethylene terephthalate film is bonded to both sides of a polarizer made of a polyvinyl alcohol film having adsorbed iodine via adhesive layers (total thickness). 50 to 70 μm or more), and the polarizing layer was laminated on the reflective layer after coating a thin film-shaped (film thickness; 15 μm or less) translucent adhesive layer.

Example 4 As the screen substrate, a sheet (thickness: 25 μm or 25 to 35 μm, or 35 μm or more and 200 to 300 μm or less) made of polyethylene terephthalate having a glossy (smooth) surface is used. ,
A surface mat-shaped base material layer for forming a reflection layer (thickness: 20 to 50 μm) is laminated on the sheet, and then a matte surface of the base material layer is gravure-printed by using a silver ink mixed with aluminum powder. A reflective projection screen of the present invention was prepared in the same manner as in Examples 1 to 3 except that the surface was printed and dried to form a light-reflecting layer having a light-diffusive reflecting surface having fine irregularities. Created.

Example 5 A polarizing layer made of a polyethylene terephthalate film (thickness: 25 μm, or 25 to 35 μm, or 35 to 120 μm) which was uniaxially stretched after mixing a black dye as a polarizing layer was used.
A reflection type projection screen of the present invention was prepared in the same manner as in Example 3 above.

<Example 6> A reflective projection screen of the present invention was prepared in the same manner as in Examples 1 to 5 except that polyvinyl chloride was used as the screen substrate.

<Example 7> A reflective projection screen of the present invention was prepared in the same manner as in Examples 1 to 6 except that an aluminum vapor deposition layer (vapor deposition film thickness: about 3000Å) was formed as the reflection layer. did.

Example 8 A reflective projection screen of the present invention was prepared in the same manner as in Examples 1 to 6 except that an aluminum foil (about 25 μm) was used as the reflective layer.

<Example 9> As a constituent resin of the light diffusion layer,
The reflective projection screen of the present invention was prepared in the same manner as in Examples 1 to 8 except that polyvinyl chloride was used.

[0041]

The reflection type projection screen of the present invention is provided with a light-diffusing reflective surface having a fine unevenness on the surface of the screen reflecting layer, and a light-diffusing light having a fine unevenness is provided on the reflective layer. A screen with a light diffusion layer having a diffusion surface,
By setting the uneven height and the uneven pitch of the reflecting surface of the reflecting layer and the diffusing surface of the light diffusing layer, respectively, within the predetermined range as described above, it is possible to increase the half-value angle while suppressing the decrease in the front luminance. As a result, the viewing angle is widened while maintaining the overall bright brightness of the screen, and a bright image can be observed even when viewing the image from the left and right directions of the screen.

Further, by coloring the light diffusing layer of the screen in a chromatic color such as black achromatic color or blue, unlike the conventional projection screen having a white color achromatic color tone, visible light in a specific wavelength range is provided. There is an effect of eliminating the drawback that the image on the screen is entirely white and observed.

As described above, the projection screen of the present invention can be used even when the screen is used in a bright room.
Noise light such as room illumination light and outside light becomes inconspicuous,
It has a remarkable effect on improving the brightness and contrast of the image.

[Brief description of the drawings]

FIG. 1 is a partial side sectional view showing a laminated structure of a reflective projection screen according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Reflective projection screen 2 ... Base material 3 ... Reflective layer 3
a ... Light diffusing reflective surface 4 ... Polarizing layer 5 ... Light diffusing layer 6 ... Transparent synthetic resin 6a
... Light diffusing surface L ... Incident / emitted light of projected image h1 ... Reflection surface irregularity height h2 ... Light diffusion surface irregularity height p1 ... Reflection surface irregularity pitch p2 ... Light diffusion surface irregularity pitch

Claims (6)

[Claims] 1. A screen substrate 2 is provided with a reflective layer 3, a polarizing layer 4 having a transmission polarization axis that is coaxial with the polarization axis of polarized incident light of a projected image, and a translucent light diffusion layer 5. A reflection type projection screen comprising a reflective layer 3 and a light diffusive reflection surface 3a having fine irregularities formed on the surface of the reflection layer 3. 2. The reflection type projection screen according to claim 1, wherein the relation between the unevenness pitch p1 of the reflecting surface 3a and the unevenness pitch p2 of the light diffusing surface 6a of the light diffusing layer 5 is p1 ≤p2. 3. The relationship between the height of unevenness h1 of the reflecting surface 3a and the height of unevenness h2 of the light diffusing surface 6a of the light diffusing layer 5 is h
The reflective projection screen according to claim 1, wherein 1 ≤ h2. 4. The relationship between the uneven height h1 and the uneven pitch p1 of the reflecting surface 3a, and the uneven height h2 and the uneven pitch p2 of the light diffusing surface 6a is (1/10) p1 ≦ h1 ≦ 4. The reflection type projection screen according to claim 1, wherein (5/3) p1 (1/10) p2 .ltoreq.h2 .ltoreq. (5/3) p2. 5. The reflection type projection screen according to claim 1, wherein the light diffusion layer 5 is colored with an achromatic color material. 6. The reflection type projection screen according to claim 1, wherein the light diffusion layer 5 is colored with a chromatic color material.