JPH10274812A - Reflection type projection screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the luminance of a conventional reflection type projection screen and to obtain the satisfactory angle of visibility and especially contrast by providing an achromatic mesh-like light absorbing layer on the surface of a light diffusing layer. SOLUTION: The achromatic layer being the light absorbing layer 4 is farmed to a netlike shape on the light diffusing layer 3. Thus, projection light perpendicularly entering in the layer 4 is absorbed by only the part of the layer 4 where the achromatic mesh is formed, the projection light other than that is directly introduced in the layer 3. Light reflected by a light reflection layer 2 is diffused and emitted while being reflected and diffused by the crystallite particle of the calcite of the layer 3. Obliquely entering external light directly enters the layer 4, is reduced and absorbed; moreover, the part of the reflected light is absorbed by the layer 4 on the layer 3, so that the contrast can be improved. Besides, the layer 3 is obtained by forming the light diffusing film 3 having a recessed part on the layer 2 by painting work.

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 projection 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 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.

A screen having a light diffusing layer coated with a paint containing pigment or calcite microcrystalline particles coated with titanium dioxide on the surface of mica scale-like flakes has a screen gain, a viewing angle, and a contrast of light and dark. It is better than one 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. In particular, projection brightness tends to be insufficient, and sunlight, electric lights, etc. A device that cannot completely block extraneous light such as light has been required to solve the above-mentioned problems in the use of a projection television receiver which is needed for general home use.

Screens using calcite microcrystalline particles have improved brightness but not satisfactory 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 reflection type projection screen using a conventional light reflecting layer and calcite microcrystalline particles, and to obtain a viewing angle, In particular, it is an object of the present invention to provide a reflection type projection screen capable of satisfying contrast.

[0009]

The reflection type projection screen of the present invention comprises a base sheet, a light reflecting layer in which scaly flakes are dispersed in a transparent resin, and calcite microcrystalline particles dispersed in a light transmitting resin. A reflection type projection screen having a light diffusion layer having a concave-convex shape, comprising a light absorption layer having an achromatic mesh shape on the surface of the light diffusion layer. The light absorbing layer is made of a transparent resin containing a black fibrous material.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A reflection type projection screen 1 according to the present invention.
0, as shown in FIG. 1 and FIG. 2, a base sheet 1, a light reflecting layer 2 in which scale-like flakes are dispersedly formed in a transparent resin, and irregularities in which calcite microcrystalline particles are dispersed in a light transmitting resin. The reflection type projection screen 10 includes a light diffusion layer 3 having a shape and a light absorption layer 4 having an achromatic mesh shape on the surface of the light diffusion layer 3.

The reflection type projection screen 10 of the present invention, as shown in FIGS. 1 and 2, forms an achromatic layer, which is a light absorbing layer 4, on a light diffusing layer 3 in a mesh-like manner. Projection light that enters the layer at right angles is absorbed only by the achromatic network forming portion of the light absorption layer 4, and the other projection light is directly introduced into the light diffusion layer 3. The light reflected by the light reflecting layer 2 diffuses and emits light while being reflected and diffused by the calcite microcrystal particles in the light diffusing layer. In addition, the extraneous light that enters obliquely directly enters the light absorbing layer 4 and is not only dimmed or absorbed, but also a part of the reflected light in the light diffusing layer 3 is absorbed by the light absorbing layer. The contrast can be improved. In addition, the extraneous light is also reduced by various conventional techniques, but at the same time, the projection light is also reduced over the entire surface of the light diffusion layer, so that the screen gain is reduced as a whole.

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 unstretched resin sheets such as polycarbonate, noryl (registered trademark of GE), polyethersulfon, polymethyl methacrylate, etc., low-foam plastic sheets, and woven fabric 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 a glass fiber woven or nonwoven fabric, a 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, the base sheet has a surface smoothness, and in order to further 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 the above-mentioned resin sheet and a different kind of sheet such as a metal plate or wood are laminated. 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-like base sheet, a curved plate curved in 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 while being moved in a roll shape, it is flexible so that it can be wound into a column having a minimum diameter of 30 mm, and has a maximum tension of 20K which is a tension at the time of winding / unwinding.
g / m width of tension, the most important factors are sagging, curling,
There is no deformation such as wrinkles, and on this surface, smoothness such that unnecessary irregularities such as texture and formation unevenness do not appear on the outermost surface through the light reflection layer, light diffusion layer, etc., and further laminated with other materials In addition, it is necessary that heat and tension in the processing step of coating be not hindered. 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 paint in which flaky flakes of a light reflecting substance are dispersed using a transparent resin as a binder. The flakes contained in the coating film are preferably arranged so as to be parallel to the surface of the screen, whereby good screen gain and viewing angle can be obtained. In order to orient the flake-like flakes so that the plane part of the flake-like flakes constituting the light reflection layer is substantially parallel to the projection light incident surface and the image observation surface, a roll coating method or a comma coating method is used. When the coating is performed as described above, it is preferable that the coating be applied so that shearing stress acts in a 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 in contact with the projection light incidence and the image observation surface. It can be oriented to be horizontal.

The glitter pigments 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 materials, in order to improve the screen gain, aluminum foil pieces or crushed pieces of a metal-deposited film (aluminum-deposited) are preferable, and the plane of the scale is parallel to the reflection surface of the base material 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, and a surfactant. And the like are added as appropriate. And it is preferable that the scale-like flake added to a binder is 5 to 30%.

The thickness of the light reflecting layer is required to cover the entire surface of the base sheet with the brilliant 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.

As shown in FIG. 1, the light diffusion layer 3 of the present invention is formed by coating a light diffusion film 3 having a concave portion on a light reflection layer 2 by coating. Then, while transmitting the light beam once diffused and reflected by the light reflection layer 2, it absorbs extraneous light coming from the side surface,
Further, the light diffuses a part of the light rays, reduces glare of the screen, and has an effect of appropriately widening the viewing surface. As the transparent resin (binder) of the light diffusion layer, an acrylic resin, polyester, polycarbonate, vinyl chloride / vinyl acetate copolymer, polyurethane or the like alone or in combination of two or more, and a leveling agent, a plasticizer, a surfactant and the like are appropriately used. In addition, it is produced. The glitter pigment added to the light diffusion layer generally includes silica particles, mica scales, mica scales coated with titanium dioxide, microcrystalline particles of calcite, synthetic resin beads such as acrylic resin and polycarbonate. Particularly preferred are calcite microcrystal grains, which widen the viewing angle and exhibit sufficient contrast.

Calcite is a hexagonal transparent crystal having a chemical composition of CaCO ₃ , and can be any of single crystal or polycrystal, self-crystal or other crystal, fully cleaved crystal or incompletely cleaved crystal. . Preferably, it is a single crystal exhibiting an automorph or a completely cleaved one thereof.

In the present invention, it is preferable that the average particle size of the calcite microcrystal particles is 2 μm to 20 μm and the crystal particle size distribution is as narrow as possible from the viewpoint of optical characteristics. For example, when the average particle size is 5 μm, it is preferable that 80% by weight or more of all particles are distributed so as to fall within the range of 3 to 7 μm. And the addition amount of the calcite microcrystal particles is 10 to
30% by weight.

Note that high reflection luminance (screen gain)
In order to maintain a wide diffusion angle (viewing angle), the orientation distribution of the calcite microcrystal particles contained in the light diffusion layer 3 is determined by changing the flat surface of the calcite microcrystal to be non-parallel to the projection light incidence surface and the image observation surface. In order for the particles 31 to be present in at least a part (preferably, the flat surfaces of the particles are randomly and randomly oriented).
I do.

The binder of the coating solution containing 10-30% of calcite microcrystal particles is polyester, acrylic resin, vinyl chloride / vinyl acetate copolymer, polyester / polyol, polyurethane / polyol and the like. Such as two-component reactive resins using isocyanate as a curing agent, and ionizing radiation-curable resins having thermoplasticity in an uncured state.
There are species or mixtures of two or more. Fine particles such as microsilica and organic bentonite are used in an amount of 3 to 10 parts by weight per 100 parts by weight of the binder resin for the purpose of assisting the uniform dispersion of the calcite microcrystal particles and improving the coating suitability (fluidity with thixotropic properties). Add by weight. In addition, if necessary, additives such as an antistatic agent, a heat stabilizer, and an ultraviolet absorber are added to the light diffusion layer 3 in addition to a lubricant such as silicone and wax to prepare a “light diffusion layer coating liquid”. .

The light diffusion layer 3 of the present invention can be provided directly on the light reflection layer 2. 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. An uneven shape is formed by a cooling roll, a shaping sheet or a shaping roll in the drying step. Moreover, thickness is 12-80.
A light diffusion layer made of an uncured curable resin or a thermoplastic resin having a thickness of 5 to 30 μm is provided on a transparent film of μm by coating, and a concave-convex shape is formed by a cooling roll, a molding sheet or a molding roll in a drying process. I do. These shaping can be performed by any method in the same step as the coating or in a separate step.

The light diffusion layer is also a surface on which projection light is incident 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 an uneven shape such as a grain, a matte surface, a lenticular lens, a Fresnel lens, etc.
It adjusts the orientation characteristics such as viewing angle and contrast.

After shaping the concavo-convex shape, a black fibrous material having a network structure is laminated on the surface of the light diffusion layer, or an excess light absorbing layer coating solution (a black fiber material having a network structure) is coated on the entire surface of the light diffusion layer. The light-absorbing layer 4 of the present invention is formed by applying an ordinary method such as bar coating, reverse coating, and commercial coating. Further, when the resin (binder) of the light reflecting layer and / or the light absorbing layer needs to be cured, the curing is completed by heating or ionizing radiation. The above-described shaping of the uneven shape can be formed immediately before the light absorbing layer is applied, in addition to the step of forming the light diffusion layer and the special shaping step of the uneven shape.

The light absorbing layer provided on the upper surface (surface) of the light diffusing layer of the present invention has a function of effectively absorbing external light and obtaining contrast while transmitting image light. The light-absorbing layer has a network structure of a black fibrous material or the like, and preferably has a thickness of 100 μm or more, and a film in which the black fibrous material is contained in a transparent resin.
Further, a material obtained by dispersing a black fibrous material in a transparent resin may be applied. Further, the form of the network structure may be formed by a silk printing method using silk ink.

Examples of the black fibrous material having an achromatic mesh form include a twisted yarn having a hole diameter of 0.8 mm to 2.0 mm and a yarn diameter of 0.03 to 0.06 mm or 3 to 3 mm. An octagonal black net layer can be used. For example, a net made of ordinary fibers such as cotton, nylon, silk, carbon fiber, polyester fiber, polyurethane fiber, aramid fiber, polyacetal fiber, acrylic fiber, polyethylene fiber and polypropylene fiber can be used.

The light absorbing layer is a layer for controlling absorption and reflection depending on the incident angle of light in order to obtain good contrast. Due to the correlation between the black area occupied area per unit area and the thickness of the black fiber, etc., when observed from the top surface of the light absorbing layer,
It is possible to adjust the light absorption performance depending on the incident angle of light, reflect image light, and efficiently absorb external light. 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 (binder) used for the light absorbing layer is polyester, acrylic resin, vinyl chloride.
Necessary for one or a mixture of two or more two-component reactive resins to be used as a curing agent by using a polyisocyanate in a vinyl acetate copolymer, polyvinyl butyral, cellulose acetate, polyester polyol, polyurethane polyol, or the like. Leveling agent, heat stabilizer, UV absorber,
A varnish to which a plasticizer, a surfactant and the like are added, and which has a network structure such as an achromatic (black or the like) fibrous material.
The light absorbing layer coating agent dispersed in 5 to 2% is applied to the surface of the light diffusing layer to form a light absorbing layer.

In the present invention, the light-reflecting layer and the light-diffusing layer formed by coating are provided with a primer layer based on an ordinary method in order to more firmly and stably adhere to the surface to be coated. You can also. 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.

As described above, in the reflection type projection screen 10 of the present invention, the light reflecting layer 2 and the light diffusing layer 3 are provided on the surface of the substrate 1, and the entire surface of the uneven portion formed on the light diffusing layer 3 is formed. Provided with a light absorbing layer 4. Thus, the calcite microcrystal particles do not absorb light and have moderate light diffusion characteristics. Therefore, the light diffusion layer 3 in which the calcite microcrystal particles are dispersed in the transparent resin has a high light transmittance. And the light reflection layer 2 in which the scale-like flakes are dispersed in the transparent resin has a high reflectance. Therefore, the reflection type projection screen 10 of the present invention
Has an extremely high reflection luminance (screen gain) due to a synergistic effect of the light reflection layer and the light diffusion layer.

The projection light has brightness due to the synergistic effect of reflection and diffusion in two stages of the calcite microcrystal particles contained in the light diffusion layer 3 and the scale-like flakes of the light reflective substance contained in the light reflection layer 2. It has a wide viewing angle.

[0036]

Hereinafter, the present invention will be described in more detail with reference to examples. (Example 1) As a base sheet 1, a soft polyvinyl chloride sheet (sheet material B) having a thickness of 300 µm containing 48 parts by weight of dioctyl adipate and a biaxially stretched polyethylene terephthalate sheet (sheet material A) having a thickness of 125 µm were used. The substrate sheet 1 of Example 1 was formed by laminating with normal dry lamination using a polyester-isocyanate-based adhesive.

On the other hand, a scaly aluminum foil piece as a light-reflective substance was added to a polyurethane-based varnish as a transparent resin.
A coating liquid for a light reflection layer containing 0% by weight was prepared. Then, the flat surface of the flake-like aluminum flakes is applied to the surface of the flexible polyvinyl chloride sheet (sheet material B) of the base sheet 1 by the gravure coating method with the projection liquid incident surface and the image observation surface (substrate). The light-reflecting layer 2 having a total thickness of 10 μm was provided by applying the coating in two steps of 5 μm each so as to be substantially parallel to the sheet).

Further, the light-diffusing layer 3 was formed on the surface of the light-reflective layer 2 by applying a 20 μm-thick [light-diffusing layer coating solution] having the following composition. [Composition of light diffusion layer coating liquid] Calcite microcrystal particles 20 parts by weight Polyurethane resin 80 parts by weight Antistatic agent 5 parts by weight Toluene 130 parts by weight Methyl ethyl ketone 100 parts by weight

Then, the surface on which the light diffusion layer 3 was provided was heated and melted, shaped by a cooling roll having an uneven shape, and a light absorbing layer was formed on the cooled and solidified surface. The light absorbing layer was formed of a black fibrous material having an achromatic mesh shape, a mesh structure having a square structure with one side of 1 mm, and a thickness of 190 μm. Thus, the reflection type projection screen 10 of the present invention was configured. When using this reflective projection screen, the contrast can be improved compared to conventional products without impairing the screen gain and viewing angle,
A clear image could be obtained.

[0040]

The reflection type projection screen of the present invention has the effect of improving the contrast and obtaining a clear image without impairing the screen gain and the viewing angle.

[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.

FIG. 2 is a schematic plan view showing a state in which the reflection type projection screen of FIG. 1 is viewed from directly above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base sheet 2 Light reflection layer 3 Light diffusion layer 4 Light absorption layer (black mesh material) 10 Reflection type projection screen

Claims (2)

[Claims] 1. A reflection type projection having a base sheet, a light reflecting layer in which flake-like flakes are dispersed in a transparent resin, and a light diffusing layer having a concave-convex shape in which fine crystal particles of calcite are dispersed in a light transmitting resin. A reflection type projection screen, comprising: a screen; and a light absorption layer having an achromatic mesh structure on a surface of the light diffusion layer. 2. The reflection type projection screen according to claim 1, wherein the light absorbing layer is made of a transparent resin containing a black fibrous material.