JPH10312027A - Reflection type projection screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a wider visual field angle than that of a conventional reflection screen and bright images with a good contrast by widening the visual field angle, forming the reflection type projection screen in such a manner that a screen gain is lowered, the light diffusivity is improved by acrylic particles and the gain of front reflected light is lowered and effectively absorbing incoming light by a difference in the optical path lengths of the incident light beams in a light absorption layer. SOLUTION: This screen is formed by successively laminating a base sheet 1, a light reflection layer 2 which is formed by dispersing flaky leaves into a transparent resin, the light absorption layer 4 which consists of a colored or colorless transparent resin/and a light diffusion layer 3 which is formed by providing a light transparent film with a compsn. prepd. by dispersing and forming acrylic resin particles into a light transparent resin by coating and has a rugged shape. Otherwise, the screen is constituted by successively laminating the base material sheet 1, the light reflection layer 2 which consists of a metallic vapor deposited layer, the light absorption layer 4 which consists of the colored or colorless transparent resin and the light diffusion layer 3 which is formed by providing the transparent film with the compsn. prepd. by dispersing and forming the acrylic resin particles into the light transparent resin by coating and has the rugged shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type television and a projection screen, and more particularly to a reflection type screen for projecting an image from a projection device.

[0002]

2. Description of the Related Art A reflection type projection screen is known to be used as a light reflection surface of a projection screen by coating a projection surface of the projection screen with a paint in which aluminum powder is dispersed in a binder. It is also known that a mica scale-like flake or its surface is coated with a coating containing titanium dioxide, which is a coating containing a so-called pearl pigment, and used as a light diffusing surface or a light reflecting surface of a projection screen. Further, there is disclosed a technique of laminating a polarizing filter on a projection screen and polarizing and projecting projection light.

[0003] There is also known a light-reflective layer in which a light-diffusing layer in which microcrystalline particles of calcite, which act as a light-diffusing agent having low light-absorbing properties, are dispersed in a transparent resin is laminated on a light-reflective layer.

[0004] However, in the case where the aluminum powder is dispersed, when the brightness of the reflected light is increased, specular reflection approaches,
When the viewing angle is narrowed, and when the viewing angle is widened, the density of the reflected light is reduced, and there is a problem that the light-dark contrast required by the projection screen is insufficient.

Mica scale-like flakes or those coated with titanium dioxide on the surface, or screens having a light diffusion layer coated with calcite fine particles, have a screen gain,
The viewing angle and the contrast between light and dark are better than those using aluminum powder for the light diffusion layer.

However, in recent years, high-quality ones that maintain a viewing angle and have improved contrast between brightness and brightness of an image have been demanded, and in particular, projection brightness tends to be insufficient, and In addition, it is not possible to completely block extraneous light such as electric light and the like, and it has been required to solve the above-mentioned problems also in the use of a projection type television receiver which is required for general household use.

[0007] The screen using calcite microcrystalline particles can improve the brightness, but does not provide satisfactory viewing angle and contrast. Laminating a polarizing filter requires special materials and shapes, complicates the manufacturing process, and may not negate the effect on cost.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to maintain the brightness of a conventional reflection type projection screen using a light reflecting layer and calcite, and to obtain any of the brightness, viewing angle and contrast that cannot be obtained by the conventional method. It is an object of the present invention to provide a reflection type projection screen that can satisfy the above conditions.

[0009]

According to the present invention, there is provided a reflection type projection screen comprising: a base sheet; a light reflecting layer in which flaky flakes are dispersed in a transparent resin; a light absorbing layer made of a colored or achromatic transparent resin; And a light diffusion layer having an uneven shape formed by applying a composition in which acrylic resin-based particles are dispersed and formed in a light-transmitting resin to a transparent film by coating.
Further, the invention of claim 2 disperses and forms acrylic resin-based particles in a base sheet, a light reflection layer made of a metal deposition film, a light absorption layer made of a colored or achromatic transparent resin, and a light transmissive resin. And a light diffusion layer having a concavo-convex shape provided by coating the composition on a transparent film.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, a reflection type projection screen 10 of the present invention comprises
A light reflecting layer 2 in which flaky flakes are dispersed in a transparent resin, a light absorbing layer 4 made of a colored or achromatic transparent resin, and a composition in which acrylic resin-based particles are dispersed and formed in a light transmitting resin are formed into a transparent film. The light diffusion layer 3 having an uneven shape provided by coating is sequentially laminated. The use of a metal vapor-deposited film (layer) as the light reflection layer provides the second aspect of the present invention.

The base sheet of the present invention comprises polyethylene, ethylene / vinyl acetate copolymer (EVA), ionomer, ethylene / ethyl acrylate copolymer (EEA),
Polyethylene resins such as ethylene-acrylic acid copolymer (EAA), methylpentene polymer and polybutene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyvinyl chloride (hard,
Semi-rigid or soft), polyamides such as nylon 6, nylon 66, cellulose triacetate, polystyrene, acrylonitrile / styrene / butadiene copolymer, saponified ethylene / vinyl acetate copolymer, polyarylate,
Synthetic paper made from stretched or non-stretched resin sheets such as polycarbonate, noryl (registered trademark of GE), polyethersulfon, polymethyl methacrylate, etc., and low-foam plastic sheets, and woven fabrics using glass or resin fibers Or a nonwoven fabric or the like. These are used as a single layer or as a laminate of two or more different layers.

The reflection type projection screen is made of glass fiber woven or non-woven fabric, soft or semi-rigid polyvinyl chloride sheet, from the viewpoint of compatibility with flame retardancy, rigidity and flexibility, and prevention of traces such as bending. Are preferred. Furthermore, in order to enhance the surface smoothness of the base sheet and stabilize the performance of the light reflection layer and the light diffusion layer by coating, a biaxially stretched polyethylene terephthalate sheet and a soft or semi-rigid polyvinyl chloride sheet are used. Or a laminate with a polybutylene terephthalate film. As the base sheet used for the structure, two or more layers of different kinds such as the above-mentioned resin sheet and the resin sheet and a metal plate or wood are laminated and used. If the base sheet does not have a masking property, a pigment having a large masking property such as titanium dioxide or carbon black may be added to the base material, or a paint containing the masking pigment may be applied to the back surface. Is preferred. As the plate-shaped base sheet, a curved plate having a concave or convex shape can be used in addition to a flat plate. The fixed type projection screen is not particularly limited in thickness as long as it has a strength as a structure.

When the reflection type projection screen is used in the form of a roll, the film can be wound in a cylindrical shape having a minimum diameter of 30 mm, and the tension at the time of winding / unwinding can be up to 20 kg.
/ M width tension, the most important factor is that there is no deformation such as slack, curl or wrinkle when repeatedly used for winding / unwinding, and the light reflection layer, light diffusion layer, etc. It is necessary that the outermost surface has smoothness to the extent that unnecessary irregularities such as texture and formation unevenness do not appear, and that heat and tension in a processing step of laminating and coating other materials are not affected. In the case of the winding type, it is preferable to use a substrate sheet having a thickness of 50 to 500 μm from the viewpoint of strength and flexibility. Dimensionally stable base sheets with these properties are required by a single plastic sheet or by lamination.These sheets must have the optical properties of the projection screen, such as light absorption, whiteness, and reflectivity. Is desirable.

The light reflecting layer is formed by applying a coating material in which flaky flakes as a light reflecting substance are dispersed using a transparent resin as a binder. The flakes included in the coating film are preferably arranged so as to be parallel to the surface of the screen, whereby a good screen gain and viewing angle can be obtained.
In order to orient the flake-like flakes such that the plane part of the flake-like flakes constituting the light reflection layer is substantially parallel to the projection light incidence and the image observation surface, a roll coating method, a comma coating method, etc. When the coating is performed as described above, it is preferable to apply the coating so that the shearing stress acts in the direction parallel to the traveling direction of the sheet. Further, the thickness of the coating and the scale-like flakes are set to be equal to or less than each other, and the coating is performed so as to be oriented at the time of coating.

When the light reflecting layer is composed of a sheet, the sheet in which the flake-like flakes are dispersed in a transparent resin is stretched, so that the plane portion of the flake-like flakes is substantially aligned with the projection light incidence and the image observation surface. It can be oriented to be horizontal.

The materials constituting the light-reflective substance are as follows. A pearl pigment manufactured by baking titanium oxide or iron oxide on the inside of shells or crushed pearls, mica, or flaky fine particles of mica having an average particle size of 10 to 30 μm. Copper, aminium, brass, bronze, gold, silver, etc.
Metal powder processed into 30 μm flat fine particles. 4 deposited with the metal described above, usually aluminum
A fragment of a polyethylene terephthalate film having a thickness of ８8 μm. Among these light-reflective substances, in order to improve the screen gain, aluminum foil pieces, metal-deposited films (aluminum-deposited) or crushed pieces thereof are preferable, and the plane of the scale is parallel to the surface of the base reflection sheet. When arranged, the light reflectance can be improved.

The average particle size of the flaky flakes is 5 to 30 in order to achieve both high light reflectance and high screen gain.
μm, more preferably 10 μm
〜20 μm.

The transparent resin (binder) of the light reflection layer may be one or more of acrylic resin, polyester, polycarbonate, vinyl chloride / vinyl acetate copolymer, polyurethane, etc., and a leveling agent, a plasticizer, a surfactant. It is prepared by appropriately adding agents and the like. And it is preferable that the scale-like flake added to a binder is 5 to 30%.

The thickness of the light reflecting layer must cover the entire surface of the base sheet with the glitter pigment, and is preferably 5 to 10 μm from the viewpoint of high light reflectivity and economy. The formation is performed by a coating method such as a roll coating method, a gravure coating method, or a comma coating method. In addition, a coating liquid made of a material lacking in affinity with a binder, such as a brilliant pigment, is likely to cause unevenness during coating,
By performing overprinting several times, the amount of material used to cover the entire surface can be reduced, and the effect of light reflection can be obtained.
Therefore, it is preferable to perform the coating twice to cover the entire surface. In addition, a sheet containing a light-reflecting substance or a metal-deposited film formed in advance by a usual extrusion method or casting method can be laminated. In addition, the light reflection layer can be formed to be smooth. However, in order to increase the screen gain, it is also possible to form irregularities such as a grain, a satin finish, a lenticular lens, and a Fresnel lens. The light reflection layer according to the second aspect is a normal metal vapor-deposited layer, preferably an aluminum vapor-deposited layer, provided on the base sheet.

The light absorbing layer provided on the light reflecting layer of the present invention has a function of absorbing light while transmitting light. An achromatic dye or pigment is dispersed in a transparent resin to improve the contrast of an image. As the achromatic dye or pigment, carbon pigments such as carbon black and graphite, black pigments such as aniline black and cyanine black, and white pigments such as titanium foil and zinc white can be used. Further, the color may be adjusted to an achromatic color (white to gray to black) by mixing three primary color components such as phthalocyanine blue, quinacridone red, and isoindolinone (yellow) having excellent light resistance. Further, by dispersing and containing fine calcite powder, the contrast can be improved and the light diffusion effect can be further enhanced.

The transparent resin used for the light absorbing layer is made of polyester, acrylic resin, vinyl chloride / vinyl acetate copolymer, polyvinyl butyral, cellulose acetate, polyester / polyol, polyurethane / polyol, etc. using polyisocyanate. Aqueous varnish was prepared by adding the necessary leveling agent, heat stabilizer, ultraviolet absorber, plasticizer, surfactant, etc. to one or a mixture of two or more types of two-component reactive resins as a curing agent. A "light absorbing layer coating agent" in which 0.5 to 2% of a dye or pigment is dispersed is applied to the surface of the light diffusion layer to form a light absorbing layer.

As shown in FIG. 1, the light diffusion layer 3 of the present invention is formed by coating a transparent base film with a light diffusion film. Then, while transmitting the light beam once diffused and reflected by the light reflection layer 3, it further diffuses a part of the light beam, reduces the glare of the screen, and has a function of appropriately widening the viewing surface. Glitter pigment added to the light diffusion layer, generally, silica particles, mica scales, titanium dioxide-coated mica scales, fine powder of calcite, etc., acrylic resin beads in the present invention,
By using fine particles or scale-like flakes such as polycarbonate beads and polyester beads, the light transmittance is high, the viewing angle is widened, and sufficient contrast is achieved.

A two-component composition comprising a glitter pigment in a proportion of 20 to 80%, a polyester, an acrylic resin, a vinyl chloride / vinyl acetate copolymer, a polyester / polyol, a polyurethane / polyol, and a polyisocyanate as a curing agent. “Coating liquid for light diffusion layer” dispersed in a varnish obtained by adding necessary leveling agents, heat stabilizers, ultraviolet absorbers, plasticizers, surfactants, etc. to one or a mixture of two or more reactive resins. Is prepared.

The light diffusion layer 3 of the present invention has a thickness of 12 to 15
It is formed by coating a light diffusion film with a thickness of 5 to 30 μm on a substrate film of 0 μm. The coating is carried out by a usual roll coating method, a gravure coating method, a comma coating method, a bar coating method or the like according to the properties of the coating liquid and the amount of coating. In the drying step, an uneven shape is formed by a cooling roll or a shaping sheet.

In order to maintain a high screen gain and a high viewing angle while maintaining a high image contrast, it is preferable that the fine particles (beads) of the light diffusion layer are oriented and distributed in a random direction. The light diffusion layer is also a surface on which projection light enters and an image is observed. The shape of the surface on which the projection light is incident and the image is observed is formed into a concave and convex shape such as a grain, a matte surface, a lenticular lens, a Fresnel lens, etc., rather than a smooth surface, and the screen gain of the reflected light, the viewing angle. ,
Orientation characteristics such as contrast can also be adjusted.

In the present invention, the light reflecting layer, the light diffusing layer and the light absorbing layer formed by coating are formed on the basis of a general method in order to more firmly and stably adhere to the surface to be coated. A primer layer can also be provided. The primer layer is a two-component reaction using a conventionally used polyester, acrylic resin, vinyl chloride / vinyl acetate copolymer, epoxy, polyester polyol, polyurethane polyol, etc. with a polyisocyanate as a curing agent. The mold is coated and formed with a thickness of 0.5 to 3 μm.

[0027]

Hereinafter, the present invention will be described in more detail with reference to examples. (Example 1) As shown in FIG. 1, a base sheet 1 having a thickness of 300 μm containing 48 parts by weight of dioctyl adipate was used.
Soft polyvinyl chloride sheet (sheet material B) and thickness 1
A 25 μm biaxially stretched polyethylene terephthalate sheet (sheet material A) is laminated by ordinary dry lamination using a polyester-isocyanate adhesive,
The base sheet 1 of Example 1 was formed.

On the other hand, a coating liquid for a light reflecting layer was prepared which contained 20% by weight of a scale-like aluminum foil piece as a light reflecting substance in a transparent polyurethane varnish. Then, the flat surface of the scale-like aluminum flake is applied to the surface of the soft polyvinyl chloride sheet (sheet material B) of the base sheet 1 by the gravure coating method with respect to the projected incident light and the image observation surface. 5μ thick so as to be almost parallel (to the base sheet)
The coating was performed in two separate steps of m each to provide a light reflecting layer 2 having a total thickness of 10 μm.

Then, a light absorbing layer 4 was formed on the surface of the light reflecting layer 2. This light absorbing layer was an achromatic light absorbing layer composed of carbon black and transparent polyurethane, and was formed by gravure coating to have a thickness of 10 μm.

On the other hand, as a substrate film, a thickness of 100 μm
[Light-diffusing layer coating solution] having the following composition on one surface of a biaxially stretched polyethylene terephthalate film of
The light-diffusing layer 3 provided with the light-diffusing film is formed by coating, and the light-absorbing layer 4 and the surface (non-coated surface) of the biaxially stretched polyethylene terephthalate are brought into contact with each other and usually using the above-mentioned adhesive. The light diffusion layer 3 was formed on the surface of the light absorption layer 4 by dry lamination to form the reflection type projection screen 10 of the present invention. [Composition of Light Diffusion Layer Coating Solution] Acrylic resin particles (P) 120 parts by weight Polyester resin (V) 100 parts by weight Antistatic agent 10 parts by weight Toluene 130 parts by weight Methyl ethyl ketone 100 parts by weight The ratio between P) and the polyester resin (V) is described as P: V = 5.3: 4.7.

(Embodiment 2) In Embodiment 1, P: V =
The reflection projection screen 10 of the second embodiment is the same as that of the first embodiment except that the light diffusion layer 3 is set to 3.0: 7.0.
Was configured.

(Embodiment 3) In Embodiment 1, P: V =
The reflection type projection screen 10 of the third embodiment is the same as that of the first embodiment except that the light diffusion layer 3 is set to 4.0: 6.0.
Was configured.

Example 4 A reflection type projection screen 10 of Example 4 was constructed in the same manner as in Example 1, except that the light reflection layer 2 was changed to an aluminum vapor-deposited layer.

Example 5 A reflection type projection screen 10 of Example 5 was constructed in the same manner as in Example 2, except that the light reflecting layer 2 was changed to an aluminum vapor-deposited layer.

Example 6 A reflective projection screen 10 of Example 6 was constructed in the same manner as in Example 3, except that the light reflecting layer 2 was changed to an aluminum vapor-deposited layer.

(Comparative Example) In Example 1, the light absorbing layer 4
A reflection type projection screen of a comparative example was constructed in the same manner as in Example 1 except that the light diffusion layer 3 was provided directly. That is, a biaxially stretched polyethylene terephthalate film having a thickness of 100 μm as a base film, a transparent polyurethane varnish, and calcite fine particles having an average particle diameter of 4 μm and 70% of all particles contained in 3 to 7 μm. Applying a coating liquid containing 20% by weight with a thickness of 10 μm,
A light diffusion layer provided with a light diffusion film was formed. Then, the surface of the light reflecting layer produced in Example 1 and the surface of the biaxially stretched polyethylene terephthalate film were dry-laminated in the same manner as in Example 1 to form a reflection type projection screen of Comparative Example.

Table 1 shows the screen gain (reflection luminance) and the viewing angle of the reflection type projection screens constructed in the examples and the comparative examples. The projector projects an all-white image from the projector onto the projection surface of the reflective projection screen, and the brightness (c
d / m ² ) and the illuminance (1 ×) are measured, and the screen gain is calculated according to Equation 1.

[0038]

## EQU1 ## Screen gain = π × (luminance / illuminance)...

As in the measurement of the screen gain, a white image is projected on the entire surface, and the luminance meter is set to have a luminance in the horizontal direction within an angle range of -60 ° to + 60 ° with respect to a normal set from the center of the screen. Is measured as an angle request property (orientation characteristic). Then, an angle range having half or more of the luminance in the normal direction, that is, a half-value angle is defined as a viewing angle. (Below)

[0040]

[Table 1] However, the base sheet is a laminated sheet of polyvinyl chloride and biaxially oriented polyethylene terephthalate.

[0041]

According to the reflection type projection screen of the present invention, when the ratio of acrylic particles in the light diffusion film provided on the transparent base film is high, the viewing angle is wide and the screen gain is reduced. When the light diffusion property of the acrylic particles is improved, the gain of the front reflected light is reduced. Furthermore, due to the difference in the optical path length of the incident light in the light absorbing layer, external light is effectively absorbed,
As compared with the conventional reflection type screen, there is an effect that the viewing angle is widened and the contrast is good.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration of a reflection type projection screen of the present invention.

[Description of Signs] 1 Base sheet 2 Light reflecting layer 3 Light diffusing layer 4 Light absorbing layer 10 Reflection type projection screen

Claims (2)

[Claims] 1. A base sheet, a light reflecting layer in which flaky flakes are dispersed in a transparent resin, a light absorbing layer made of a colored or achromatic transparent resin, and acrylic resin particles dispersed in a light transmitting resin. A reflection type projection screen, wherein a light diffusing layer having a concavo-convex shape provided by applying the formed composition to a transparent film is sequentially laminated. 2. A composition comprising a base sheet, a light-reflective layer made of a metal-deposited film, a light-absorbing layer made of a colored or achromatic transparent resin, and a composition in which acrylic resin-based particles are dispersed and formed in a light-transmitting resin. A reflection type projection screen comprising a transparent film and a light diffusion layer having an uneven shape provided by coating are sequentially laminated.