JP2984801B2 - 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 drawbacks, but a technique for imparting directivity to the reflective surface of these screens has not yet been developed. In other words, a technique has been developed to form an omnidirectional flaw on the reflecting surface that makes the diffusivity in the horizontal and vertical directions almost equal, Scratch technology has not 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 necessary to form fine scratches for imparting the different diffusivities to the mold surface and to transfer and form the fine scratches on the screen. Means for forming a flaw for imparting different diffusivity to the mold surface (a flaw for exhibiting directivity) has not been proposed.

According to the present invention, a flaw formed on the surface of a mold for mass production, which exerts both horizontal and vertical diffusivity equally, that is, a flaw for imparting directivity, is transferred to a reflecting surface, It is a technical problem to provide a Fresnel reflective screen that can be mass-produced with good directivity by using in combination with unevenness formed on the screen surface that imparts directional diffusivity.

[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
And a fine asperity 18 for imparting diffusivity in a substantially equal state in both the horizontal and vertical directions is formed on the inclined surface 6 of the Fresnel-shaped member 2. is there.

[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. Meanwhile, outside light
19 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 transparent film 4 on which the unevenness 4 'for imparting the horizontal diffusivity is formed and the inclined surface 6 for imparting the horizontal and vertical diffusivities in substantially the same state.
Due to the fine irregularities 18, the screen according to the present invention is most desirable as a screen, that is, it can exhibit good directivity with wide horizontal diffusion and narrow 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.

The Fresnel shaped member 2 has a thickness of 0.2
mm-0.3mm thermoplastic pigmented thermoplastic film
(Urethane film, PVC film, etc.). 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) is performed on the inclined surface 6 of the Fresnel surface 2 'to form the inclined surface 6 on the reflecting surface and to form fine unevenness 18 (scratch) on the inclined surface 6.

The fine unevenness 18 (scratch) is formed by roughening the mold surface of the Fresnel-shaped member 2 into a mat shape by etching, blasting or the like, and transferring the roughened surface to the inclined surface 6. The degree of roughening is determined in consideration of the degree of the unevenness 4 ′ of the transparent film 4.

Next, a specific screen manufacturing method will be described.

As shown in FIG. 3, a raw material 8 formed of a urethane film containing a black pigment with a predetermined thickness is formed on a heated metal roll 9 (heated to 100.degree. C. to 150.degree. C.) and an inclined surface 6 of the Fresnel surface 2 '. Mold roll 10 with fine irregularities
(Heated to 50 ° C. to 100 ° C.), and the Fresnel-shaped member 2 is continuously formed by the cooling metal roll 17 (cooled to 50 ° C. or less). Reference numeral 1 denotes a holding roller, and 5 denotes a winding roller.

The Fresnel shaped member 2 having the fine irregularities 18 formed as described above is subjected to metal vapor deposition (Al vapor deposition) on the inclined surface 6 of the Fresnel surface 2 'in the vapor deposition section 11 as shown in FIGS.

Subsequently, as shown in FIG.
Is subjected to a primer treatment in a primer treatment section 12 and heated in a heating section 13 so that the metal-deposited surface and an ultraviolet-curable resin to be a transparent resin layer 3 to be described later are bonded well.

Finally, as shown in FIG. 7, the transparent film 4 is adhered to the Fresnel-shaped member 2 while applying the ultraviolet-curable resin to the Fresnel-shaped member 2 in the ultraviolet-curable resin coating portion 14. The resin is cured by irradiating ultraviolet rays, cut into a predetermined width by the slitter 16, and the screen according to the present embodiment is formed.

Since this embodiment is manufactured by the above-described 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 naturally impart these characteristics. 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 section of the prior art, means for forming such fine scratches on the mold surface has not yet been established.

According to the screen according to the embodiment, it is only necessary to form scratches in the mold (roll mold) which are technically simple and exhibit substantially the same diffusivity in both the horizontal and vertical directions. The formation is very simple, and the combination of the fine irregularities 18 (scratch) transferred and formed by the fine irregularities on the mold surface thus easily formed and the irregularities 4 ′ of the transparent film 4 is better. Because it is possible to obtain directivity, the screen becomes excellent in mass production.

[0026]

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 is washable on the surface, so that maintenance is 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.

FIG. 3 is an explanatory view of a manufacturing process of the present invention.

FIG. 4 is an explanatory view of a manufacturing process of the present invention.

FIG. 5 is an explanatory view of a manufacturing process of the present invention.

FIG. 6 is an explanatory view of a manufacturing process of the present invention.

FIG. 7 is an explanatory view of a manufacturing process of the present invention.

[Explanation of symbols]

 2 Fresnel shaped member 2 'Fresnel surface 3 Transparent resin layer 4 Transparent film 4' Unevenness 6 Inclined surface 6 'Shelf surface 18 Fine unevenness

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-131741 (JP, U) JP-A 50-130940 (JP, U) (58) Fields investigated (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 characterized by forming irregularities to be imparted, and forming fine irregularities on the inclined surface of the Fresnel-shaped member so as to impart diffusivity in substantially the same state in both the horizontal and vertical directions.