JPH086160A - Reflection type projection screen - Google Patents

Abstract

PURPOSE:To obtain a reflection type projection screen capable of preventing generation of a fire accident by using materials which decrease synthetic resin materials and less generate heat quantity at the time of combustion among screen constituting materials. CONSTITUTION:This reflection type projection screen consists, successively from an incident side, at least a light diffusion sheet layer 1, a polarizing sheet layer 3, a light diffusive or/and light absorptive ink layer 4 and a reflective base material layer 6. This reflective base material layer 6 consists of an incombustible material and the layer thickness of the base material layer 6 is >=2/3 total thickness of the screen. Since the plastic combustible parts are decreased, the combustibility of the screen is suppressed. Since the light diffusive ink layer 4 is disposed in contact with a light reflection treated surface 5, a good light reflection gain and light diffusivity are obtd. In addition, the darkness of shadow parts is enhanced and a good contrast is obtd. The good screen luminance and contrast as the reflection type projection screen are obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type projection screen used when an image is projected from an optical projector such as a slide projector or a video projector and the image is viewed from the same direction as the projector.

[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 screen and enjoy it. However, the reflection type projection screen is affected by the external light. In order not to use it, the room is often used in a darkened state, but recently, a screen that can be observed even in a relatively bright room has been developed, and has been used in various fields.

[0003]

Various materials are used for the reflection type projection screen, and generally, a synthetic resin film that is relatively inflammable or is not inflammable but is not nonflammable is used. Since many of the base materials are used, it is necessary to impart flame retardancy to prevent the occurrence of fire accidents. The flame retardancy of synthetic resins is based on the molecular structure of the polymer that is the material. It is preferable to use a material having a high heat resistance and a high heat decomposition resistance as the screen material. For example, among synthetic resins, cellulosic resins and the like are flammable resins, but fluorine-based resins and polyimide resins have high flame resistance, and polymers modified by introducing halogen, phosphorus, nitrogen, etc. into the molecule are It has high flame retardancy. In addition, there are flame-retardant synthetic resins obtained by adding or copolymerizing halogen-based flame retardants, phosphorus-based flame retardants, antimony trioxide, aluminum hydroxide, molybdenum compounds and other inorganic flame retardants in synthetic resins. .

The present invention provides a reflection type projection screen,
It is to prevent the occurrence of a fire accident by using a material that is flame-retardant, has high flame resistance, and generates a small amount of heat during combustion, and uses a small amount of synthetic resin material among the screen constituent materials.

[0005]

According to the present invention, at least a light diffusing sheet layer 1, a polarizing sheet layer 3, a light diffusing or / and light absorbing ink layer 4, and a reflective substrate layer 6 are arranged in this order from the incident side. In the reflective projection screen, the reflective substrate layer 6 is made of an incombustible material, and the thickness of the substrate layer 6 is 2/3 or more of the total thickness of the screen. Is.

[0006]

EXAMPLE A reflective projection screen of the present invention is described below.
A detailed description will be given according to examples. FIG. 1 is a partial side sectional view showing an embodiment of the reflection type projection screen of the present invention,
Light diffusion sheet layer 1, adhesive layer 2 (for example, pressure-sensitive adhesive layer), polarizing sheet layer 3, adhesive layer 2 (for example, pressure-sensitive adhesive layer), light-diffusing ink layer 4, mirror-finished surface 5, metal in this order from the incident side. It is a layered structure composed of the base material layer 6.

The light diffusion sheet layer 1 is a transparent stretched polypropylene film, a polyvinyl chloride film, a triacetyl cellulose (TAC) film, a polyethylene terephthalate (PET) film, the surface of which is matt-finished and embossed. , A polycarbonate film, a fluororesin film and the like can be used.

The thickness of the light diffusion sheet layer 1 is 20 to 50 μm.
The degree is appropriate, but more than 500 μm to 1000
It may be about μm.

For the adhesive layer 2, a transparent adhesive (pressure-sensitive adhesive or heat-sensitive adhesive) or solvent volatilizing adhesive (wet laminate type or dry laminate type) is used. In particular, an acrylic adhesive having a ΔYI value of 2 or less indicating the degree of yellowing due to heat or the like and a haze value (turbidity) indicating the ratio of scattered light to incident light of 10% or less (a layer thickness of about 10 to 30 μm is suitable. ), Or urethane-based adhesive, polyester-based adhesive (layer thickness 10 to 3)
0 μm is suitable).

The polarizing sheet layer 3 has a polarization degree of 70 to 10
It is preferable to use a 0% uniaxially stretched polyester film 13 (polyethylene terephthalate film, see FIG. 2) having a transmittance of 35 to 70%. For example, on a polyethylene terephthalate (PET) film surface,
For example, a dye 14 of a dark color system (black system, dark blue system, dark red system, gray system, or a mixed dark system in which any of these is mixed, a mixed color system in which other colors are mixed, etc.) is adsorbed or coated. A processed product or a film obtained by mixing a dye 14 in a polyethylene terephthalate (PET) resin is formed into a film, which is uniaxially stretched to molecularly orient the dye 14 in a predetermined direction. , Polarization axis of the polarizing sheet layer 3 (orientation direction of dye molecules)
Is matched with the polarization axis of the projection light of the projector.

Further, the polarizing sheet layer 3 is provided with dimensional stability due to temperature change during normal use,
Annealing treatment (resin stabilization treatment by heating) is performed. In order to reduce the resin portion of the material used for the screen, it is preferable that the three layers of the polarizing sheet have a thickness in the range of about 20 to 150 μm.

The light diffusing ink layer 4 is made of an ink in which a light diffusing agent is mixed in a transparent resin, or an ink in which a light reflecting agent and a light reflecting agent are mixed at the same time.
It is suitable to mix 1 to 50 parts by weight of the light diffusing agent and 1 to 50 parts by weight of the light reflecting agent with respect to parts by weight. The thickness of the light diffusing ink layer 4 is 5 to 1
0 μm, or 10 to 20 μm, or 20 to 40
A range of about μm is suitable.

The light-diffusing ink layer 4 may have a two-layered structure, if necessary. For example, an ink in which a light-diffusing agent is mixed with a transparent resin, or a light-reflecting agent and a light-reflecting agent are used. The first light-diffusing ink layer using the above ink mixed at the same time, and 100 parts by weight of the transparent resin, the light-reflecting agents 1 to 1
A second light-diffusing ink layer using an ink containing 100 parts by weight may be used.

Further, in the present invention, the light absorbing ink layer 4 may be used in order to increase the contrast of the projected image on the screen. The light absorbing ink layer 4
Is a transparent or semi-transparent ink in which a transparent resin is mixed with a pigment or dye having a light-absorbing color tone (dark color tone such as black, dark blue, or gray) as a light absorber, and 100 parts by weight of the transparent resin is used. On the other hand, it is suitable to mix pigments of dark color tone in the range of 1 to 30 parts by weight. Further, the thickness of the light absorbing ink layer 4 is 5 to 10
μm, or 10 to 20 μm, or 20 to 40 μm
A suitable range is about m, and it is suitable to coat the surface of the base material layer 6 so as not to cover it.

Further, the light absorbing ink layer 4 may have a two-layered structure, for example, a transparent resin 100.
With respect to 100 parts by weight of the transparent resin, the first light-absorbing ink layer in which a pigment or dye (light absorber) having a dark color tone is mixed in an amount of 1 to 30 parts by weight, and 1 to 30 parts by weight of a pigment having a color tone and 1 to 50 parts by weight of a light diffusing agent, or 1 to 30 parts by weight of a pigment having a dark color tone, 1 to 50 parts by weight of a light diffusing agent, and 1 to 1 part of a light reflecting agent. You may comprise by the 2nd light absorptive ink layer mixed in the range of 50 weight part.

The ink layer 4 may be an ink layer having both light diffusing property and light absorbing property, and has a light diffusing property and a light absorbing property in which a light diffusing agent and a light absorbing agent are mixed. You may comprise with the ink layer which has it together.

As the light diffusing agent which can be used, for example, silica, granular particles of titanium dioxide or the like, or acrylic,
Examples thereof include white or transparent plastic beads such as urethane (average particle diameter of about 1 to 50 μm), and the refractive index of the transparent plastic beads is appropriately in the range of n = 1.0 to 1.5, Examples of the light reflecting agent include aluminum paste, aluminum powder, and pearl pigment.

As the light absorbing agent, a pigment or dye having a light absorbing color tone (dark color tone such as black, dark blue or gray) or a mixture thereof can be used.

As the transparent resin, cellulose derivative, styrene resin, styrene copolymer, acrylic resin, methacrylic resin, rosin ester resin, polyvinyl acetate resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer. One or a mixture of two or more of polyester resin (polyethylene terephthalate resin), polyurethane resin, butyral resin, polyamide resin, EB curable resin, UV curable resin and the like can be used.

The reflective base material layer 6 is made of a metal plate, and a light metal such as aluminum is suitable for maintaining the lightness, but a copper plate or the like may be used. The surface of the reflective substrate layer 6 in contact with the ink layer 4 is a smooth mirror-finished highly reflective surface, or a light diffusive fine concave-convex reflective surface, and the fine concave and convex surfaces are, respectively, Suitably, the treated surface 5 has a high diffusivity and a high reflectivity, which has been treated so as to have specular reflectivity.

The thickness of the base material layer 6 needs to be such that it has a function as a support for holding the projection surface as a screen, and is 100 μm to 200 μm, or 200 to 300 μm, or that. The above thickness is suitable, but it is suitable that the thickness is at least ⅔ of the total thickness of the reflection type projection screen.

In the metallic reflective substrate layer 6 described above,
If necessary, a film having a thickness of 1000 to 30 is formed on the surface in contact with the ink layer 4 by a metal vapor deposition method, a metal plating method, or the like.
To form a mirror-reflected smooth surface by laminating a mirror-finished surface 5 of a metal-deposited film having a thickness of about 00 Å or more and about 5000 Å or a metal film having a thickness of about 50 to 100 μm. You may

Specific examples of the reflection type projection screen of the present invention will be shown below.

Example 1 A reflection type projection screen of the present invention was prepared with the following layer structure. Layer structure of the product of the present invention; light diffusion sheet layer / adhesive layer (using pressure sensitive adhesive) / polarizing sheet layer / adhesive layer (using pressure sensitive adhesive) / light absorbing and light diffusing ink layer / mirror surface treatment layer (aluminum metal vapor deposition film) (Use) / Metal base material layer-Light diffusion sheet layer; Transparent stretched polypropylene film with a satin-like embossed surface (thickness 20μ
m) -Adhesive layer; Acrylic adhesive (film thickness 20 μm) -Polarizing sheet layer; Uniaxially stretched polyester (P) which is uniaxially stretched after black dye is mixed and annealed
ET) film (30 μm) -Light absorbing and light diffusing ink layer; Polyester (PE
T) Light diffusion ink (film thickness 20 μm) in which 1 part by weight of black pigment and 3.5 parts by weight of polymer beads are mixed in 100 parts by weight of resin binder. Mirror surface treatment layer; aluminum metal vapor deposition film (3000Å = 0.3).
μm) ・ Metal base material layer; Aluminum plate (250 μm)

In addition, in order to compare with the product of the present invention obtained in the above Example 1, screens having the following layer constitutions were prepared as comparative products.

<Comparative Example 1> Layer structure: light diffusion sheet layer / adhesive layer (using pressure sensitive adhesive) / polarizing sheet layer / adhesive layer (using pressure sensitive adhesive) / light absorbing and light diffusing ink layer / mirror surface treatment layer ( Aluminum metal vapor deposition film) / Metal base material layer-Light diffusion sheet layer; Transparent stretched polypropylene film (thickness 20μ) with satin embossed surface
m) -Adhesive layer: Acrylic pressure-sensitive adhesive (film thickness 20 μm) -Polarizing sheet layer: A film in which both sides of a polyvinyl alcohol film uniaxially stretched after mixing an iodine dye with a triacetyl cellulose film (180 μm)
m) ・ Light absorbing and light diffusing ink layer; polyester (PE
T) Light diffusion ink (film thickness 20 μm) in which 1 part by weight of black pigment and 3.5 parts by weight of polymer beads are mixed in 100 parts by weight of resin binder. Mirror surface treatment layer; aluminum metal vapor deposition film (3000Å = 0.3).
μm) ・ Metal base material layer; Aluminum plate (250 μm)

<Comparative Example 2> Layer structure: light diffusion sheet layer / adhesive layer (using pressure sensitive adhesive) / polarizing sheet layer / adhesive layer (using pressure sensitive adhesive) / light absorbing and light diffusing ink layer / mirror surface treatment layer ( Aluminum metal vapor deposition film) / resin base material layer / light diffusion sheet layer; transparent stretched polypropylene film with a satin finish embossing treatment (thickness 20μ)
m) -Adhesive layer: Acrylic pressure-sensitive adhesive (film thickness 20 μm) -Polarizing sheet layer: A film in which both sides of a polyvinyl alcohol film uniaxially stretched after mixing an iodine dye with a triacetyl cellulose film (180 μm)
m) ・ Light absorbing and light diffusing ink layer; polyester (PE
T) Light diffusion ink (film thickness 20 μm) in which 1 part by weight of black pigment and 3.5 parts by weight of polymer beads are mixed in 100 parts by weight of resin binder. Mirror surface treatment layer; aluminum metal vapor deposition film (3000Å = 0.3).
resin base layer; polyester (PET) film (film thickness 125 μm)

<Comparison Results> The liquid crystal projector VX-A1Z (Sharp Co., Ltd.) was used for the reflection type projection screen of the present invention according to Example 1 and the reflection type projection screen of each comparative example according to Comparative Examples 1 and 2. ) Is used to project projection light in a predetermined bright room with a predetermined illuminance, and screen characteristics (screen gain, viewing angle, flexibility, contrast (measured in a room with a brightness of 100 lux)) ) Was obtained, the results shown in Table 1 were obtained, and the product of the present invention had good results as a comprehensive evaluation.

However, the screen gain G in Table 1 is
G = (luminance / illuminance) × π (π; a numerical value indicating the free position of the measurement point in the luminance measurement of the screen, for example, a horizontal measurement angle (0 ° to
180 °), measurement distance, etc.). The screen gain value is 2.5 to 6.0, or 3.0 to 6.0.
In the range of 1, a sufficiently bright image can be obtained, but 2.
When it is less than 5 or less than 3.0, the brightness is low and the image becomes dark.

The viewing angle was set to an angle (half-value angle) at which the reflection brightness at the center of the screen was 1/2, that is, half value.
If this viewing angle (half-value angle) is not more than 30 ° (angle formed by the vertical line standing on the screen surface is ± 15 °), it is not practical.

The contrast is defined by the contrast value = white image brightness / black image brightness obtained by measuring white image brightness and black image brightness on the screen under the same conditions. If the contrast value is 8.0 or more, a high-contrast, easy-to-see image can be obtained even in a bright room of 100 lux, but if it is less than 8.0, 1
In a bright room of 00 lux, the contrast is low and it is difficult to see.

Further, the reflection type projection screens obtained in Example 1 and Comparative Examples 1 and 2 were heated at the same time with a gas burner to conduct a combustion test. As a result, the reflective projection screen of Example 1 (product of the present invention) in which 2/3 or more of the screen thickness is the metal substrate layer (total thickness of resin layer 90.3
The thickness of the metal base material layer was 250 μm, and the resin layer finished burning in a short time while leaving the metal base material layer, but the reflective projection screen of Comparative Example 1 (total thickness of the resin layer 240.3 μm).
m, the thickness of the metal substrate layer is 250 μm), and the reflective projection screen of Comparative Example 2 (the thickness of the resin layer is 365.3 μm)
Even after the reflection type projection screen according to Example 1 finished burning, the burning continued for a long time, and the amount of heat generated by the burning was larger than that in Example 1.

[0033]

[Table 1]

[0034]

The reflective projection screen of the present invention comprises at least the light diffusion sheet layer 1, the polarizing sheet layer 3,
A reflective projection screen comprising a light-diffusing or / and light-absorbing ink layer 4 and a metallic reflective substrate layer 6,
2/3 or more of the total thickness of the screen is a metallic reflective substrate layer 6
Therefore, the combustibility of the screen can be suppressed because the combustible portion made of resin is small.

Since the light-diffusing ink layer 4 is provided in contact with the light-reflecting treated surface 5, good light-reflecting gain and light-diffusing property can be obtained.
The darkness of the shadow portion in the image projected on the projection screen is increased to obtain a good contrast, and the good screen brightness and contrast as a reflection type projection screen can be obtained.

Further, the reflection type projection screen of the present invention is
Since the thin film-shaped polarizing sheet layer 3 having a film thickness of 20 to 150 μm, which has enhanced tear resistance by annealing and has reduced room temperature deformation by using a polyester film having moisture resistance, is used, the temperature of the screen surface in normal use is reduced. There is no deformation and the strength of the screen surface can be obtained.

[0037]

The reflection type projection screen of the present invention can obtain a screen brightness which is brighter than the conventional one as a reflection type projection screen while maintaining a wide screen viewing angle, and a flame-retardant screen can be obtained. is there.

[Brief description of drawings]

FIG. 1 is a partial side sectional view of an embodiment of a reflective projection screen of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Diffusion sheet layer 2 ... Adhesive layer 3 ... Polarizing sheet layer 4 ... Light-diffusing or / and light-absorbing ink layer 5 ... Light-reflecting treated surface 6 ... Reflective substrate layer

Claims (4)

[Claims] 1. A reflective projection screen comprising at least a light diffusion sheet layer 1, a polarizing sheet layer 3, a light diffusing or / and light absorbing ink layer 4, and a reflective base material layer 6 in this order from the incident side. The reflective projection screen is characterized in that the reflective base material layer 6 is made of a non-combustible material, and the thickness of the base material layer 6 is 2/3 or more of the screen thickness. 2. The reflective projection screen according to claim 1, wherein the reflective base material layer 6 is a metal layer such as aluminum or copper having high thermal conductivity. 3. The light-diffusing or / and light-absorbing ink layer 4 is formed of a light-diffusing printing ink or / and a light-absorbing printing ink. Reflective projection screen. 4. The polarizing sheet layer 3 is obtained by uniaxially stretching a dye-adsorbed or dye-mixed polyester film,
The reflection type projection screen according to claim 1, which is a film having a film thickness of 20 to 150 μm which is annealed.