JP2976148B2 - Fresnel reflective screen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Fresnel reflection screen used for a liquid crystal projector or the like.

[0002]

2. Description of the Related Art In recent years, with the advent of liquid crystal projectors, demand for reflective screens has been increasing.

[0003] These conventional reflective screens include:
There is a flat screen such as a reflective surface with glass beads, a reflective surface in a white mat shape, or a reflective surface with an aluminum foil, or a cylindrical or spherical reflective surface. .

[0004]

However, glass beads and white mat screens have the drawbacks that they have low luminance gain, sharply reduce contrast due to external light, and can be used only in a dark room. Although screens and spherical screens are excellent in characteristics, these screens cannot be rolled up, are inconvenient to transport, and are in contrast to portable projectors. Circular or linear Fresnel-shaped screens have been proposed as ideas to solve the above two drawbacks.However, a technique for imparting directivity to the reflective surface of these screens, that is, the diffusivity in the horizontal and vertical directions However, a technique for applying a fine flaw to the reflecting surface such that the surface is in a different state has not yet been established, and practical products are not yet on the market.

By the way, if it is attempted to mass-produce the reflective surface of a screen having such directivity with a synthetic resin,
Of course, a mold is required. Therefore, it is an essential condition of the screen to form fine scratches for imparting the different diffusivity to the mold surface and transfer and form the fine scratches to the screen. Means for forming a flaw for imparting different diffusivity (directivity) to the mold surface (a flaw for exhibiting directivity) has not been proposed.

[0006] The present invention is based on the conventional idea that a flaw having a different diffusivity between the horizontal direction and the vertical direction, that is, a flaw for imparting directivity must be formed on a mold surface for mass production. Switching, a member that imparts substantially equal diffusivity in both the horizontal and vertical directions, that is, a member that imparts omnidirectionality, is disposed in front of the reflecting surface, and directing is performed by combining this member with unevenness that imparts horizontal diffusivity. It is a technical problem to provide a Fresnel reflection screen that can be mass-produced with good performance.

[0007]

The gist of the present invention will be described with reference to the accompanying drawings.

A transparent film 4 is provided on the Fresnel surface 2 'of the Fresnel-shaped member 2 having the inclined surface 6 as a reflection surface and the shelf surface 6' as an absorption surface via a transparent resin layer 3. Unevenness 4 'that gives horizontal diffusion to the surface
Is formed in the vertical direction of the screen, and a light diffusing agent 5 that imparts diffusivity in substantially the same state in both the horizontal direction and the vertical direction is disposed in the transparent resin layer 3. is.

[0009]

The light from the projector 7 is transmitted to the Fresnel surface 2 '.
Is reflected by the inclined surface 6 and is focused on the observer. On the other hand, the external light 8 is absorbed by the shelf surface 6 'of the Fresnel-shaped member 2 or travels downward, and does not reach the observer (see FIG. 2).

At this time, the present invention comprises the transparent film 4 having the unevenness 4 'for imparting the horizontal diffusivity and the light diffusing agent 5 for imparting the horizontal and vertical diffusivities in substantially the same state. Such a screen is most desirable as a screen, that is, it can exhibit a good directivity with a wide horizontal diffusion and a small vertical diffusion.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate one embodiment of the present invention. This will be described below.

As the transparent film 4 for imparting horizontal diffusivity, a high transmission film (for example, PET, PP, PVC, TAC, AC, etc.) having a thickness of 5 μm to 100 μm is used.

The surface condition of the film is a lenticular shape in which fine pitches are arranged in the vertical direction of the screen or a shape in which irregularities are cut in the form of scratches in the vertical direction. Is 20 ° to 40 ° (H / 3 =
(20 ° to 40 °).

As the transparent resin layer 3, an ultraviolet-curable resin (for example, an acrylate such as urethane, epoxy, or polyester) having a high transmittance is used.

As the light diffusing agent 5, spherical SiO ₂ .TiO _{2 of} several μm or glass beads is used. The amount of the light diffusing agent 5 is determined in consideration of the degree of the unevenness 4 ′ of the transparent film 4.

The Fresnel shaped member 2 is made of an ultraviolet curable resin containing a black pigment. The linear Fresnel surface 2 ′ on the front surface is formed such that the angle θ of the peak is gradually reduced from the top to the bottom. The angle θ of this mountain is calculated by calculation in consideration of gain, screen size, service area, and the like. Metal evaporation (Al evaporation) on the inclined surface 6 of the Fresnel surface 2 '
To form the inclined surface 6 on the reflecting surface. The Fresnel-shaped member 2 is made of a substrate 1 (PET having a thickness of 50 μm to 250 μm).
UV-transmitting film such as a film).

Next, a specific manufacturing method of the screen will be described.

First, a Fresnel-shaped member 2 is formed on a substrate 1 (an ultraviolet transmitting film such as a PET film) using a mold and an ultraviolet curing resin containing a black pigment.

Metal evaporation (Al evaporation) is performed on the inclined surface 6 of the Fresnel-shaped member 2 thus molded.

Subsequently, a light diffusing agent 5 is applied to the Fresnel-shaped member 2.
The transparent film 4 is adhered to the Fresnel-shaped member 2 by applying an ultraviolet curable resin mixed with the resin, and the resin is cured by irradiating ultraviolet rays to form the screen according to the present embodiment.

Since the present embodiment is manufactured by the above steps, continuous molding is possible, and therefore, excellent mass productivity is achieved.

Conventionally, in order to impart directivity to a Fresnel screen, fine irregularities (scratches) must be formed on the Fresnel surface 2 'to give these characteristics as a matter of course. Therefore, in order to continuously mass-produce Fresnel screens having such good characteristics, it is necessary to form fine irregularities on the surface of the mold so that the diffusivity in the horizontal direction and the diffusivity in the vertical direction are different. There must be.

However, as described in the above-mentioned conventional example, means for making such fine scratches on the mold surface has not yet been established.

In the screen according to the embodiment, since the light diffusing agent 5 is used, there is no need for any means for forming fine irregularities on the surface of the mold. With this, good directivity is exhibited, and mass production is extremely excellent.

[0025]

Since the present invention is configured as described above, the following effects are exhibited.

A screen having high contrast (high contrast screen) even under external light is obtained.

A high gain screen (high gain screen) is obtained.

The screen can be wound up.

Since both surfaces are flat, the screen becomes a washable surface, so that maintenance becomes easy.

Reflection surface (Fresnel surface of Fresnel shaped member)
Is protected by the resin layer, so that it has excellent durability.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of the present invention.

FIG. 2 is an explanatory diagram of optical characteristics of the present invention.

[Explanation of symbols]

 2 Fresnel-shaped member 2 'Fresnel surface 3 Transparent resin layer 4 Transparent film 4' Unevenness 5 Light diffusing agent 6 Inclined surface 6 'Shelf surface

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-306822 (JP, A) JP-A-4-56837 (JP, A) JP-A-59-131741 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) G03B 21/60

Claims (1)

(57) [Claims] 1. A transparent film is provided on a Fresnel surface of a Fresnel-shaped member having an inclined surface as a reflection surface and a shelf surface as an absorption surface via a transparent resin layer, and the surface of the transparent film has horizontal diffusivity. A Fresnel reflection screen, wherein irregularities to be imparted are formed in the longitudinal direction of the screen, and a light diffusing agent which imparts diffusivity in substantially the same state in both the horizontal and vertical directions is disposed in the transparent resin layer.