JPH09114001A - Projection screen - Google Patents

Abstract

(57) Abstract: In order to balance the relationship between the half-value angle of the screen and the front luminance together in a high dimension, the light diffusion characteristics of the light diffusion layer in which the projection image light that constitutes the projection screen advances are improved. Therefore, even in a particularly bright viewing environment, the enlarged image to be projected can be viewed brightly and with high contrast due to the wide viewing angle. SOLUTION: In a projection screen having a light diffusion layer 5 having an uneven light diffusing surface 6a on one outermost surface of the screen, the uneven height of the light diffusing surface 6a is 3 to 50 μm, and the uneven pitch is 10. It is set to ˜200 μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can display a magnified image with a wide viewing angle and a high contrast in a projection screen for a projection device such as a video projector, especially when projected in a bright viewing environment. The present invention relates to a projection screen having screen 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 projection screen, and enjoy it in a room so as not to be affected by outside light. Often used in a darkened state, but recently, a screen has been developed that can be observed even in a relatively bright room.
It is being used in various fields.

As the screen, it is desired that the screen has a contrast (a density difference between a highlight portion and a shadow portion of a projected image) and has a brightness that is easier to see, and an image projected on a projection screen is desired. It is desired that the screen surface has a good viewing angle due to an appropriate light diffusion property so that many people can view it with easy-to-see contrast and brightness.

The light diffusing characteristic of the screen surface of the projection screen is the brightness of the image light (diffuse brightness) which is incident on the optical axis perpendicular to the screen surface (front) and diffuses and exits on the light diffusing surface of the screen. Is determined by the angle (half-value angle) formed with the optical axis that is 1/2 (half value) the luminance (front luminance) of the image light emitted to the front (optical axis direction).

By widening this half-value angle, it is possible to provide 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 balance the relationship between the half-value angle of the screen and the front luminance in a high dimension.
By improving the light-diffusing characteristics of the light-diffusing layer in which the projection image light that constitutes the projection screen travels, it is possible to view the projected magnified image with a wide viewing angle in a bright and high-contrast manner even under a particularly bright viewing environment. To do.

[0008]

The present invention provides a projection screen having a light diffusing layer 5 having an uneven light diffusing surface 6a on one outermost surface of the screen. The projection screen is characterized in that the pitch is set to 3 to 50 μm and the pitch of the uneven shape is set to 10 to 200 μm.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The projection screen of the present invention will be described below in detail according to the embodiments.

FIG. 1 is a side sectional view of a reflection type projection screen 1 according to the first embodiment. The screen 1 has one surface of a base material 2 and a silver printing ink (ink toned with aluminum powder). ) Is formed by printing (or by aluminum vapor deposition or aluminum foil attachment).

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 fine unevenness formed on its surface to form a light diffusing surface 6a, or does not have the light diffusing surface 6a, and the light diffusing layer 6a has no light diffusing surface 6a. A light diffusing property is imparted by mixing a diffusing material (fine powder such as kaolin). In addition, L indicates the incident direction and the emission direction of the image projection light.

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

The polarizing layer 4, which is laminated if necessary, is a uniaxial material 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 having adsorbed iodine. 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.

FIG. 2 is a side sectional view of the transmission type projection screen 11 according to the second embodiment.

The screen 11 is formed by laminating a polarizing layer 4 on one surface of a transparent base material 12 if necessary, and then coating or laminating a transparent synthetic resin 6 (paint, ink, or film) on the one surface. The diffusion layer 5 is provided.

As shown in FIG. 2, the light diffusing layer 5 has fine unevenness formed on its surface to form a light diffusing surface 6a, or does not have the light diffusing surface 6a, and the light diffusing layer 6a has no light diffusing surface 6a. A light diffusing property is imparted by mixing a diffusing material (fine powder such as kaolin). It should be noted that one surface of the base material 12 may be either glossy (smooth) or matte (fine concavo-convex).

The light diffusing layer 5 may be colored with a chromatic transparent coloring material 7, or the substrate 12 may be colored.
Also, it may be colored with a chromatic transparent coloring material 7 as necessary.

FIG. 3 is an enlarged side sectional view showing an uneven light diffusing surface 6a formed on the surface of the light diffusing layer 5 of the projection screen according to the first or second embodiment of the present invention. The height h is set in the range of 3 to 50 μm, preferably 10 μm or less, and the uneven pitch p is in the range of 10 to 200 μm, preferably 10 to 100 μm, or 10
It is suitable to set it to ˜20 μm.

The image light entering and exiting the screen surface is
An image can be viewed from the front side of the screen and the left-right direction directly facing the screen surface by being diffused by each convex portion (or concave portion) of the light diffusion surface 6a.

Further, as shown in FIG. 3, each convex (or concave) surface of the light diffusing surface 6a also presents a fine rough surface so that the incident / exiting image light can be projected to the front and left and right. It diffuses in the direction.

FIGS. 4 (a) to 4 (c) schematically show various concave and convex side shapes of the light diffusing surface 6a of the projection screen.

(A) schematically shows the uneven shape of the light diffusing surface 6a of the projection screen of the present invention, and the relationship between the uneven height h and the uneven pitch p is (1/10) p≤ By setting h ≦ (5/3) p approximately, the half-value angle can be increased while maintaining the front brightness appropriately.

Further, (b) is a light diffusing surface having a shape in which the height h of the unevenness is extremely large with respect to the pitch p of the unevenness,
The relationship between the height h of the unevenness and the pitch p of the unevenness is (5/3) p <h 2, and the light diffusion effect becomes excessive and a large half-value angle is obtained, but the front luminance is reduced.

Further, (c) shows that between the uneven pitches p, p,
It is a light diffusing surface having a flat shape surface with a small diffusing effect, and although the front brightness is obtained, the light diffusing effect is not sufficiently obtained, and therefore an appropriate half-value angle cannot be obtained.

[0026]

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

Example 1 A sheet of polyethylene terephthalate having a glossy (smooth) surface is used as a reflection type projection screen substrate (thickness: 25 μm).
m, or 25 to 35 μm, or 35 μm or more, 200 to
300 μm or less) was used.

First, a light reflection layer (thickness: 15 to 15) is printed on the entire gloss surface of the base material by a gravure printing method using a silver ink mixed with aluminum powder and dried.
30 μm) was formed.

Subsequently, a glossy (smooth) biaxially stretched polypropylene film (thickness: 15 to 25 μm) is heat-laminated on the above-mentioned reflection layer or an adhesive material or an adhesive material (thickness: 15 μm or less) is interposed. While laminating, the film surface is heated and pressed by an embossing roll and a press roll having a light-diffusing surface-shaped concavo-convex pattern to have a concavo-convex height of 5 to 8 μm or 10 to 20 μm and a concavo-convex pitch of 5 μm.
m to 8 μm or 10 to 20 μm (for example, uneven height 5 to
Forming a light diffusing layer having a light diffusing surface embossed into a fine uneven shape having an uneven pitch of 8 μm and an uneven pitch of 10 to 20 μm;
A reflective projection screen of the present invention was created.

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 kaolin) was mixed.

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

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> The same procedure as in Examples 1 to 3 was repeated except that a polypropylene sheet having a matte surface (fine unevenness) was used as the reflective projection screen substrate. A reflective projection screen of the present invention was 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.

<Embodiment 6> As a light diffusion layer, the surface of the film was previously provided with an uneven height of 5 to 8 μm or 10 to 20 μm.
A biaxially stretched polyethylene terephthalate film matted (having or not containing a light diffusing material) into a fine uneven shape having an uneven pitch of 5 to 8 μm or 10 to 20 μm (for example, an uneven height of 5 to 8 μm and an uneven pitch of 10 to 20 μm). A reflective projection screen of the present invention was prepared in the same manner as in Examples 1 to 5 except that the above was used.

<Example 7> 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 reflective projection screen substrate.

<Example 8> A reflective projection screen of the present invention was prepared in the same manner as in Examples 1 to 7 except that an aluminum vapor deposition layer (vapor deposition film thickness: about 3000Å) was formed as the reflection layer. Created.

<Example 9> A reflective projection screen of the present invention was prepared in the same manner as in Examples 1 to 7 except that an aluminum foil (about 25 μm) was used as the reflective layer.

<Example 10> The reflective projection of the present invention was carried out in the same manner as in Examples 1 to 9 except that a polyvinyl chloride film or a fluororesin film was used as the constituent resin of the light diffusion layer. Created a screen.

<Embodiment 11> As a transmission type projection screen substrate, the surface thereof is glossy (smooth).
Polyvinyl chloride sheet (thickness: 100-300μ
m) was used.

Subsequently, a glossy (smooth) biaxially oriented polypropylene film (thickness: 15 to 25 μm) is heat-laminated on the above-mentioned reflection layer or an adhesive material or an adhesive material (thickness: 15 μm or less) is interposed. While laminating the film, the film surface is heated and pressed by an embossing roll and a press roll having a light-diffusing surface-shaped concavo-convex pattern to obtain a concavo-convex height of 5 to 8 μm or 10 to 20 μm and a concavo-convex pitch of 5 to 5.
8 μm or 10 to 20 μm (for example, uneven height 5 to 8 μm
Then, a light diffusing layer having a light diffusing surface embossed into a fine uneven shape having an uneven pitch of 10 to 20 μm) was formed, and the transmission type projection screen of the present invention was prepared.

<Example 12> The same as Example 11 except that the light-diffusing material (fine kaolin powder) was mixed in the glossy (smooth) biaxially stretched polyvinyl chloride film in Example 11 above. Then, a transmissive projection screen of the present invention was prepared.

<Example 13> The above Example 11 or Example 12 except that a polarizing layer was formed between the substrate and the light diffusion layer.
A transmissive 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 14 A polyethylene terephthalate film (thickness: 25 μm, or 25 to 35 μm, uniaxially stretched after mixing a black dye as a polarizing layer)
Alternatively, a transmission type projection screen of the present invention was prepared in the same manner as in Example 13 except that the polarizing layer of 35 to 120 μm) was used.

<Embodiment 15> As a light diffusing layer, the surface of the film is preliminarily provided with an uneven height of 5 to 8 μm or 10 to 20 μm.
m, uneven pitch 5 μm to 8 μm or 10 to 20 μm (for example, uneven height 5 to 8 μm, uneven pitch 10 to 20 μm)
The transmissive projection of the present invention was carried out in the same manner as in Examples 11 to 14 except that the biaxially stretched polypropylene film having a matt shape (having or not containing a light diffusing material) in the fine concavo-convex shape was used. Created a screen.

[0047]

EFFECT OF THE INVENTION The projection screen of the present invention suppresses a decrease in front luminance by setting the uneven height and uneven pitch of the light diffusing surface in the light diffusing layer of the screen within the predetermined ranges as described above. The half-value angle can be increased, so that 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 with 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 a spectral absorption performance for, there is an effect that can be solved the drawback that the image on the screen is tinged with white overall, the projection screen of the present invention, when using the screen in a bright room In particular, noise light such as room illumination light and outside light becomes inconspicuous, which is a remarkable effect in improving the brightness and contrast of the image.

[Brief description of the drawings]

FIG. 1 is a partial enlarged side sectional view showing a laminated structure of a reflection type projection screen according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged side sectional view showing a laminated structure of a transmission type projection screen according to a second embodiment of the present invention.

FIG. 3 is a partial enlarged side cross-sectional view illustrating an example of the uneven shape of the light diffusion layer and the light diffusion surface of the projection screen according to the first or second embodiment of the present invention.

FIG. 4 is a partially enlarged schematic view illustrating various shapes of the light diffusing layer and the uneven shape of the light diffusing surface of the projection screen.

[Explanation of Codes] 1 ... Reflective projection screen 2 ... Substrate
3 ... Reflective layer 4 ... Polarizing layer 5 ... Light diffusing layer 6 ... Transparent synthetic resin 6a ... Light diffusing surface 11 ... Transmissive projection screen 12 ... Transparent base material L ... Incident / emitted light of projected image h ... Height of irregularities p ... uneven pitch

Claims (3)

[Claims] 1. A projection screen having a light diffusing layer 5 having an uneven light diffusing surface 6a on one outermost surface of the screen, wherein the light diffusing surface 6a has an uneven shape height of 3 to 50 μm and an uneven shape pitch. A projection screen having a thickness of 10 to 200 μm. 2. The projection screen according to claim 1, wherein the light diffusion layer 5 is colored with an achromatic color material. 3. The projection screen according to claim 1, wherein the light diffusion layer 5 is colored with a chromatic color material.