JPH1090796A - Reflection type projection screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reflecting luminance and contrast from being lowered by using the surface of a light diffusion layer as a projection light incident surface and a picture observation surface on which projection light is made incident and a reflected picture is observed and including additive having lubricity in the light diffusion layer. SOLUTION: A light reflection layer 3 is formed on one surface of a base material 2. As the layer 3, the layer obtained by dispersing scale-like foil pieces 3a made of a light reflecting material in transparent resin 3b is used. Then, the light diffusion layer 4 is formed on the surface of the layer 3. By the layer 4, transmitted light is diffused while light is transmitted. The layer 4 is constituted of transparent resin 4C being binder, calcite microcrystal grains 4b being light diffusing agent and achromatic color dye or pigment 4a for enhancing the light and dark contrast of the picture. Besides, the surface of the layer 4 is the projection light incident surface and the picture observation surface 5 on which the projection light is made incident and the picture is observed. Then, the additive 6 having the lubricity is included in the layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reflection type projection screen for receiving an image projected from a projection device.

[0002]

2. Description of the Related Art With respect to a projection screen for receiving an image projected from a projection device, the following proposals have been made conventionally.

[0003] Japanese Utility Model Registration No. 30811 discloses that a coating film formed by dispersing aluminum powder in a resin binder is formed on the surface of a projection screen and used as a light diffusion surface and a light reflection surface of the projection screen. Proposed.

Japanese Utility Model Publication No. 11-1966, Japanese Utility Model Publication No. 3
JP-A-5-6346, JP-A-64-40835 and JP-A-5-88263 disclose a so-called pearl pigment in which a mica scale-like foil piece or a surface thereof is coated with a titanium dioxide coating film. To be used as a light reflecting surface and a light diffusing surface.

JP-A-4-53945 discloses that a light diffusion layer formed by dispersing calcite microcrystal particles acting as a light diffusing agent having a low light absorption property in a transparent resin layer is formed on a light reflecting layer. It has been proposed to use them in a stack.

US Pat. No. 1,610,423, JP-A-6
JP-A-2-266980 or JP-A-7-248536 proposes laminating a polarizing filter on a projection screen and polarizing and projecting projection light.

[0007]

However, each of these conventional techniques has the following problems.

In the projection screen according to Registered Utility Model No. 30811, when the brightness of the reflected light is increased, it approaches the specular reflection, and the diffusion angle becomes narrow. Conversely, if the diffusion angle is increased, the brightness of the reflected light will decrease. Further, the contrast of light and dark required as a projection screen is also insufficient.

Japanese Utility Model Publication No. 11-1966, Japanese Utility Model Publication No. 3
In the projection screen disclosed in Japanese Patent Application Laid-Open No. 5-6346, Japanese Utility Model Application Laid-Open No. 64-40835 or Japanese Patent Application Laid-Open No. 5-88263, the luminance (gain), diffusion angle (half-value angle), and image contrast of reflected light are all reduced. Better than the projection screen described above.

However, in recent years, it has been required to further improve the luminance and the image contrast while maintaining the diffusion angle, and the projection screen according to these proposals has been required to meet this requirement. I can't respond. In particular, such a demand is extremely strong in a projection television receiver for general home use, which has a relatively low projection light luminance and cannot completely block external light (sunlight, electric light, etc.).

In the projection screen disclosed in Japanese Patent Application Laid-Open No. 4-53945, the brightness (gain) is improved but the contrast is insufficient as compared with the above-described projection screen.

US Pat. No. 1,610,423, JP-A-6
In the projection screen disclosed in JP-A-2-266980 or JP-A-7-248536, it is necessary to form a material having a polarization characteristic or a layer having a special characteristic such as a square pyramid prism arrangement. Therefore, the manufacturing process becomes complicated, and the manufacturing cost increases.

Further, it is necessary to attach a polarizing filter to the projector itself, which leads to an increase in cost. Furthermore, the intensity of projection light is attenuated by providing a polarizing filter in the projector itself.

As described above, in the conventional reflection type projection screen, desired reflection luminance, viewing angle and contrast could not be obtained. In view of this, the present inventor has previously proposed a reflection type projection screen capable of obtaining desired reflection luminance, viewing angle and contrast at a low cost according to Japanese Patent Application No. 8-42449.

The reflection type projection screen 1 according to this proposal
Is, as shown in FIG. 4, a plate-shaped or sheet-shaped base material 2,
A light reflecting layer 3 made of a transparent resin 3b formed on the surface of the substrate 2 and having a scale-like foil piece 3a of a light reflecting substance dispersed therein; and a calcite microcrystal formed on the surface of the light reflecting layer 3 The light diffusion layer 4 is made of a transparent resin 4c in which particles 4b and an achromatic dye or pigment 4a are dispersed, and is transparent and has a light diffusion property. The surface of the light diffusion layer 4 receives projection light. A projection light incidence and image observation surface 5 for observing a reflection image. With such a configuration, the following effects can be obtained.

(I) The calcite microcrystalline particles 4b have low light absorption and moderate diffusion characteristics. Therefore, the transmittance of the light diffusion layer 4 in which the calcite microcrystalline particles 4b are dispersed in the transparent resin 4c is increased. Further, the reflectance of the light reflecting layer 3 having the scale-like foil pieces 3a made of a light reflecting substance in the resin 3b is also high.
Therefore, the reflection type projection screen 1 has extremely high reflection luminance (high gain) due to these synergistic effects.

(Ii) Incident light is diffused in two stages by the calcite microcrystalline particles 4b contained in the light diffusing layer 4 and the flaky foil pieces 3a of the light reflecting substance contained in the light reflecting layer 3. Has a sufficiently wide viewing angle, and a high contrast can be obtained even in a bright place.

(Iii) In the reflection type projection screen 1,
An achromatic pigment or dye 4a is added to the light diffusion layer 4.
Therefore, the contrast of the reflection image is improved to such an extent that there is no practical problem as a projection screen.

However, as a result of the inventor's intensive studies on the reflection type projection screen 1 in order to further improve the performance, it has been found that the following problems exist.

The surface is easily damaged during handling and the like, and the cellophane tape releasability on the surface of the light diffusion layer 4 after long use is apt to decrease (generally, the adhesion between the coating film and the substrate is When a cellophane tape is applied and peeled off, it is evaluated whether the coating film peels off together with the cellophane tape.It is required that only the cellophane tape be peeled off and the coating film does not peel off.),

When wound up in a roll and stored for a long period of time, the substrate 2 and the light diffusion layer 4 which are in contact with each other tend to adhere to each other (this phenomenon is called "blocking"), and the substrate is unwound and used. May not be possible.

Dirt easily adheres to the surface. These problems can be improved by carefully examining the materials of the base material 2, the light reflecting layer 3 and the light diffusing layer 4, but depending on the material, the optical characteristics (reflection luminance, contrast, etc.) which are further indispensable as a screen are required. ) May be reduced.

It is possible to solve the problem (1) by further applying a lubricant on the surface of the light diffusion layer 4, but this time, since strong water repellency is developed on the surface, the light diffusion layer 4 It is difficult to form a Waku print layer on the surface of.

In view of the above-mentioned problems of the reflection type projection screen 1 proposed in Japanese Patent Application No. 8-42449, the inventor of the present invention has made intensive studies, and as a result, has found that the light diffusing layer 4
(I) to (iii) due to the synergistic action of forming an uneven layer on the surface of the light diffusing layer 4 and forming a layer having lubricity by adding an additive having lubricity to the surface.
The inventors have found that the above-mentioned problems can be solved while maintaining the above, and completed the present invention.

According to the first aspect of the present invention, there is provided a light-reflecting material comprising a plate-like or sheet-like base material and a transparent resin formed on the surface of the base material and having a scale-like foil piece of a light-reflective substance dispersed therein. Layer, formed on the surface of the light reflection layer and made of a transparent resin in which calcite microcrystalline particles and an achromatic dye or pigment are dispersed, including a light diffusion layer having a transparent and light diffusing property, The surface of the light diffusion layer is a projection light incident and image observation surface for projecting projection light and observing a reflected image, and the light diffusion layer has an additive having lubricity (hereinafter, in this specification, " The present invention is a reflection type projection screen characterized by containing a lubricant.

In the reflection type projection screen of the first aspect, it is desirable to satisfy the following conditions. (1) The lubricant is localized on the surface of the light diffusion layer.

(2) The lubricant is a silicone compound. (3) 0.05% of lubricant with respect to 100 parts by weight of transparent resin
Not less than 1.0 parts by weight (4) The light diffusion layer containing a lubricant has a surface wetting index of 31 or more and 39 or less.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a base material, a light reflection layer and a light diffusion layer in a reflection type projection screen according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view schematically showing the structure of a reflection type projection screen 1 according to the present invention. FIG.
FIG. 1 is a perspective view showing a scale-like foil piece 3a made of a light-reflective substance contained in a light reflection layer 3 in the reflection type projection screen 1 according to the present invention.

[Substrate 2] As the substrate 2, a sheet or plate is used. Examples of the sheet-like substrate 2 include polyolefin resin, polyester resin, polyvinyl chloride resin (hard, semi-hard or soft), polystyrene resin, AB
Examples include a resin such as S resin, glass, and a woven or nonwoven fabric using resin fibers. These may be used as a single layer, or two or more different types may be laminated and used. From the viewpoints of flame retardancy, compatibility between strength and flexibility, and prevention of traces of bending, a laminate of a biaxially stretched polyethylene terephthalate sheet and soft or semi-rigid polyvinyl chloride is preferred. When used as a wind-up projection screen, from the viewpoint of strength and flexibility, usually 50 μm or more and 500 μm
Use a sheet with the following thickness.

As the plate-like substrate 2, a single layer of the above-mentioned resin plate, metal, wood, or the like, or a laminate of two or more different materials is used. When the base material 2 is made of a resin or the like having no concealing property, a concealing pigment such as titanium dioxide or carbon black is added to the base material 2 or a coating material containing the concealing pigment is coated on the surface. It is preferable to apply to the surface. The shape of the plate may be a curved plate other than a flat plate.

[Light Reflecting Layer 3] In the present embodiment, the light reflecting layer 3 is formed on one surface of the substrate 2. The light reflection layer 3
A material in which flaky foil pieces 3a of a light reflective substance are dispersed in a transparent resin 3b is used. Preferably, as shown in FIG.
The scaly foil piece 3a is oriented such that the flat plate surface 3c is substantially parallel to the projection light incidence and image observation surface 5 described later, which is the projection screen surface. With such orientation, both a better reflectivity and an appropriate diffusion angle can be obtained.

As shown in FIG. 2, in order to orient the scaly foil piece 3a so that the flat surface 3c is substantially parallel to the projection light incidence and the image observation surface 5, a roll coating method or a comma coating method is used. A coating method in which a shear stress acts in a direction parallel to the coating film at the time of coating is used. Then, the coating thickness is set to be equal to or less than the particle size of the flake-shaped foil 3a, and the coating method of orienting the flake-shaped foil 3a at the time of application is used, or the flake-shaped foil 3a is contained in a dispersed state. Use of a processing method of stretching a sheet material can be exemplified.

As the light reflecting material, aluminum,
Metals such as silver, chromium, nickel, etc., mica coated with titanium dioxide, and foil pieces obtained by cutting a resin sheet having a metal deposited on the surface can be used, but metal is used to increase the reflectance. Is most preferred.

The average particle size of the flaky foil piece 3a is 5 μm or more from the viewpoint of compatibility between high reflected light luminance and a wide diffusion angle.
A range of 0 μm or less is preferable. More preferably, 10μ
m or more and about 20 μm or less.

The amount of the scale-like foil piece 3a is preferably 5% by weight or more and 30% by weight or less. The resin (binder) 3b is selected from those having transparency. As such a resin, for example, an acrylic resin, a polyester resin, a polycarbonate resin, a vinyl chloride-vinyl acetate copolymer, a polyurethane resin and the like, or a mixture of two or more of them can be exemplified.

The thickness of the light reflecting layer 3 is preferably 5 μm or more and 10 μm or less from the viewpoint of high reflected light luminance and economy. The light reflecting layer 3 is formed on one surface of the substrate 2 by applying a coating method such as a roll coating method, a gravure roll coating method or a comma coating method, or by laminating a sheet formed in advance by an extrusion method or a casting method. Form.

[Light Diffusion Layer 4] In the reflection type projection screen 1 according to the present invention, the light diffusion layer 4 is formed on the surface of the light reflection layer 3.

The light diffusion layer 4 is a layer that transmits light and diffuses transmitted light. The light diffusing layer 4 is composed of a transparent resin 4c as a binder, calcite microcrystal particles 4b as a light diffusing agent, and an achromatic dye or pigment 4a for increasing the contrast between bright and dark images. Calcite microcrystalline particles 4
b is uniformly dispersed in the transparent resin 4c.

The thickness of the light diffusion layer 4 is 10 μm or more and 30 μm or more.
m or less is preferable. The light diffusion layer 4 includes calcite microcrystal particles 4b and an achromatic dye or pigment 4a in a transparent resin 4c.
A composition in which is dispersed by a roll coating method, a gravure roll coating method, a comma coating method, or the like;
It is formed on the surface of the light reflecting layer 3 by using a processing method of bonding sheets formed by an extrusion method, a casting method, or the like.

FIG. 3 is an explanatory view schematically showing the configuration of the reflection type projection screen according to the present invention. In particular, as shown in FIG. 3, when the calcite microcrystalline particles 4b are isotropically orientated randomly, in the case of a coating method in which shear stress acts in a direction parallel to the coating film surface such as roll coating, The thickness of the coating film is made larger than the particle size 4b of the calcite microcrystal particles 4b, or the coating is performed by suppressing shear stress in a direction parallel to the coating film such as spray coating. In addition, the paint before coating is sufficiently stirred.

The transparent resin 4c constituting the light diffusion layer 4 is composed of a single transparent resin such as an acrylic resin, a polyester resin, a polycarbonate resin, a vinyl chloride vinyl acetate copolymer, a polyurethane resin, or a mixture of two or more transparent resins. .

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

In this embodiment, the average particle size is 2 μm or more and 2 μm or more.
Calcite microcrystalline particles 4b of 0 μm or less are used. The particle size distribution of the calcite microcrystal particles 4b is preferably as narrow as possible from the viewpoint of optical characteristics. For example, when the average particle diameter is 5 μm, 80% by weight or more of all particles is 3 μm or more and 7 μm or less.
It is desirable to make the distribution so as to fall within the following range. Note that a preferable addition amount of the calcite microcrystal particles 4b is 10% by weight or more and 30% by weight or less.

The achromatic dye or pigment 4a is
Is added to the extent that the contrast of the reflected image can be improved without impairing the transparency of the reflected image or the luminance of the reflected image. Examples of the achromatic dye or pigment 4a include carbon black,
Carbon pigments such as graphite, and black pigments or dyes such as aniline black and cyanine black can be used. Alternatively, by mixing the three primary color components of a blue pigment or dye such as phthalocyanine blue, a red pigment or dye such as quinacridone red, and a yellow pigment or dye such as isoindolinone, an achromatic color (gray to black) is obtained. May be colored.

The preferable addition amount of the achromatic dye or pigment 4a depends on the kind thereof, but in the case of carbon black, it is about 0.01% by weight or more and 1% by weight or less, more preferably 0.1% by weight or more. It is about 1% by weight or less. In addition,
As a mode for increasing the image contrast in a bright place while maintaining the high reflected light luminance and the wide diffusion angle, as shown in FIG. 3, the orientation distribution of the calcite microcrystal particles 4b in the light diffusion layer 4 is determined by using a flat plate. The calcite microcrystal particles 4b whose surface is non-parallel to the projection light incidence and image observation surface 5 are made to exist at least partially (typically, when the flat plate surface is isotropically randomly oriented), and the light is reflected. The scale-like foil piece 3a of the layer 3 is
There is a mode in which the entire flat surface 3c is oriented substantially parallel to the image observation surface 5 (see FIG. 3).

The surface of the light diffusion layer 4 is a projection light incidence and image observation surface 5 on which projection light enters and an image is observed. The projection light incidence and image observation surface 5 can be made flat and smooth as shown in FIG. 1 or, if necessary, formed into a concave and convex shape such as a grain, a matte surface, a lenticular lens, a Fresnel lens, etc. It is also possible to adjust the angular distribution (light distribution characteristics) of the luminance of the reflected light.

The lubricant 6 has lubricity by lowering the surface energy or reducing the contact area of the surface and the like, and is a component contained in the light diffusion layer 4 (achromatic dye or pigment 4a). And any other additive that is compatible with the calcite microcrystal particles 4b), and is not limited to a particular additive.

However, in the case of an additive that does not exhibit lubricity unless added in a large amount, the above-mentioned compatibility is adversely affected, the adhesion between the light diffusion layers 4 is reduced, and the production cost is increased. . Therefore, lubricity is exhibited by a small amount of addition, and unintended irregularities are formed on the surface of the light diffusion layer 4,
It is desirable to use a lubricant that does not cause fluctuations in the reflection / diffusion characteristics of the light diffusion layer 4 and deteriorate the characteristics of the reflection screen.

From these viewpoints, the lubricant used in the present invention is preferably an organosilicon compound such as silicone oil, modified series corn oil, silicone acrylate monomer, or prepolymer.

When these additives are used, the compatibility with the constituents of the light diffusion layer 4 is good, and the additives are localized and fixed on the surface of the light diffusion layer 4 in a small amount, so that the additives such as slip beads The above-mentioned problems (1) to (4) can be solved without impairing the characteristics of the reflection screen by forming surface irregularities or changing the refractive index of the light diffusion layer 4 like a fluorine-based polymer.

When an organosilicon compound is used as the lubricant, the amount ranges from 0.05 to 1.0 part by weight, based on 100 parts by weight of the transparent resin, depending on the type of the silicone compound. It is desirable to ensure that the above-mentioned effects are achieved.

The compounding amount is set by the wetting index on the surface of the light diffusion layer 4. The wetting index on the surface of the light diffusion layer 4 is in the range of 31 or more and 39 or less.
desirable.

If the blending amount is small and the wetting index exceeds 39, the desired lubricity cannot be obtained. Conversely, if the blending amount is large and the wetting index is less than 31, if necessary,
When performing normal printing, logo printing, or other printing (usually screen printing), the adhesion to the printing layer is reduced. In this case,
It is also conceivable to improve adhesion by adding the same additive to the ink for wax printing. However, it is not practical because there are problems such as a decrease in suitability for silk printing and a problem that repelling occurs when a normal silk ink is used next time.

Other usable lubricants include waxes such as wax, montan wax and paraffin wax, powders of fluororesins such as polytetrafluoroethylene and polyvinylidene fluoride, and polyolefins such as polyethylene and polypropylene. Examples thereof include resin powder.

When the light diffusing layer 4 is formed by a coating method, the light diffusing layer 4 helps to distribute the calcite microcrystalline particles 4b in a uniform layer in addition to the above-mentioned components. In order to improve aptitude, preferably, fine particles such as fine (micro) silica and organic bentonite are used.
About 5 to 10 parts by weight is added to 100 parts by weight of the resin.

The reflection type projection screen 1 according to the present invention
Comprises a light reflecting layer 3 and a light diffusing layer 4 on the surface of a substrate 2 in this order in a laminated state. Therefore, the following effects are obtained.

(1) The calcite microcrystalline particles 4b have low light absorption and moderate diffusion characteristics. Therefore, the transmittance of the light diffusion layer 4 in which the calcite microcrystalline particles 4b are dispersed in the transparent resin 4c increases. In addition, the reflectance of the light reflecting layer 3 having the scale-like foil pieces 3a made of a light reflecting substance in the resin 3b is high. Therefore, the reflection type projection screen 1 according to the present invention has extremely high reflection luminance (high gain) due to these synergistic effects.

(2) Incident light is diffused in two stages by the calcite microcrystalline particles 4b contained in the light diffusion layer 4 and the scale-like foil pieces 3a of the light reflective substance contained in the light reflection layer 3. Have a sufficiently wide viewing angle due to the synergistic effect of

The orientation distribution of the calcite microcrystal particles 4b in the light diffusion layer 4 is set so that at least a part of the calcite microcrystal particles 4b whose flat surface is not parallel to the projection light incidence and image observation surface 5 is present. At the same time, when the scale-like foil pieces 3a in the light reflection layer 3 have the entire flat surface 3c oriented substantially parallel to the projection light incidence and the image observation surface 5, the projection light incidence and the normal N of the image observation surface 5 Most of the projection light incident from the direction in which the angle formed is small, the gap between the calcite microcrystalline particles 4b (especially when the flat surface is oriented at an angle close to or orthogonal to the image observation surface) is increased. The light is transmitted while being diffused moderately with little attenuation, reflected by the light reflection layer 3 at a high reflectance, and again diffused moderately into the light diffusion layer 4 while being projected from the projection light incident and output from the image observation surface 5 to become an image. .

On the other hand, noise (external) light having a large angle between the incident light of the projection light and the normal line N of the image observation surface 5 is reflected in a direction almost parallel to the incidence of the projection light and the image observation surface 5. Therefore, the light is attenuated by multiple reflection between the calcite microcrystal particles 4b, or deviates out of the field of view (the horizontal direction in FIG. 3). Therefore, higher contrast can be obtained even in a bright place.

(3) The calcite microcrystal particles 4b are
, The contrast of the reflection image generally decreases, which is disadvantageous as a projection screen. However, in the reflection type projection screen 1 according to the present invention, the light diffusion layer 4
Since the achromatic pigment or dye 4a is added to the above, noise light having a long traveling optical path length due to multiple reflection is strongly attenuated.
On the other hand, projection light having a short optical path length is less attenuated (the amount of attenuation is proportional to the exponential function of the optical path length), so that the SN ratio between the projection (signal) light and the noise light is improved. As a result, the contrast of the reflected image in the bright room can be improved to such an extent that there is no problem as a projection screen.

(4) Since the light diffusing layer 4 contains the lubricant 6, the surface of the screen can be scratched or stained at the time of product processing and product use without impairing the effects (1) to (3) described above. Is reduced or eliminated.

(5) Since the light diffusing layer 4 contains the lubricant 6, the surface after the durability test (heat resistance, moisture resistance, cold resistance, light resistance test) can be performed without impairing the effects (1) to (3) described above. The adhesiveness of cellophane tape and the like, that is, the peelability is improved. This is because even if the adhesive strength between the layers (or each layer) between the light diffusion layer 4 and the light reflection layer 3 is reduced by the durability test,
This is because the effect that the lubricant 6 makes the cellophane tape easily peel off prevents the cellophane tape from transmitting a force for peeling the light diffusion layer 4 and the light reflection layer 3.

(6) Since the light diffusing layer 4 contains the lubricant 6, the booking phenomenon during storage does not occur without impairing the effects (1) to (3) described above. (7) Since the lubricant 6 is appropriately diluted and dispersed in the light diffusion layer 4, water repellency is also suppressed. Thereby, the blank printing can be performed without a printing defect due to ink repelling.

[0066]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a reflection type projection screen according to the present invention will be described with reference to FIGS.

On a surface of a black polyvinyl chloride sheet having a thickness of 300 μm and containing 48 parts by weight of dioctel adipate as a plasticizer and 5 parts by weight of carbon black as a black pigment, 5 parts by weight of titanium white as a white pigment A sheet composite obtained by dry laminating white biaxially stretched polyethylene terephthalate having a thickness of 125 μm and containing the same was used as a substrate 2, and a light reflection layer 3 was formed on the surface of the substrate 2 on the polyethylene terephthalate side. The light reflecting layer 3 is a transparent layer made of a polyurethane resin 3b containing 20% by weight of a scale-like foil piece 3a (average particle size: 10 μm) of aluminum as a light reflecting substance.

The light reflecting layer 3 is formed by coating the polyurethane resin 3b containing the flaky foil 3a with the flat surface 3c of the flaky foil 3a with respect to the projection light incidence and the image observation surface 5 by a gravure roll coating method. The coating was performed in two coating steps of 5 μm in thickness (when dried) so that the coating was parallel, and the total film thickness was 10 μm.
m was formed. As shown in FIG. 3, the flaky foil pieces 3a in the light reflection layer 3 were arranged such that the flat plate surface 3c (the surface having the largest surface area) was substantially parallel to the coating film surface.

Next, the thus formed light reflecting layer 3
The light diffusion layer 4 was formed on the surface of. This light diffusion layer 4
0.7% by weight of achromatic pigment 4a composed of a transparent layer of polyurethane resin 3b and composed of carbon black
It contains 20% by weight of calcite microcrystal particles 4b having an average particle diameter of 4 μm and 70% of all particles being in a range of 3 μm to 7 μm.

Further, in this embodiment, 0.3 parts by weight of amino-modified silicone oil as a lubricant 6 is added to 100 parts by weight of the polyurethane resin in the light diffusion layer 4. In this case, the wetting index of the light diffusion layer 4 was 35. 8.3 parts by weight of microsilica was added.

The light diffusion layer 4 is formed to a thickness of 10 μm by a gravure roll coating method. As shown in FIG. 3, the calcite microcrystal particles 4b in the light diffusion layer 4 were oriented substantially randomly.

Thus, the reflection type projection screen 1 of this embodiment was formed. On the other hand, as a conventional example, a reflection type projection screen proposed in JP-A-4-53945 out of the above-mentioned conventional technology was formed. That is, in Example, the reflection type projection screen was prepared by replacing the scale-like foil pieces 3a as the aluminum pigment of the light reflection layer 3 with titanium dioxide (titanium white) powder and excluding the achromatic pigment 4a of the light diffusion layer 4. Was formed.

When the lubricant 6 was not added (Comparative Example 1), the wetting index was 41. In addition, as Comparative Example 2, a material to which 1.5 parts by weight of the lubricant 6 was added was manufactured. The wetting index in this case was 29 or less.

For these, under the test conditions listed below, the screen gain (reflection luminance), the viewing angle, and the contrast of the reflection image were measured.

(Screen Gain) An all white solid image is projected from the projector onto the projection surface of the reflection type projection screen.
The luminance (cd / m ² ) at the center of the projection plane and the illuminance (1x) are measured, and the screen gain is calculated by the formula; screen gain = π × (luminance / illuminance). The distance between the projector and the screen was 2 m, and the divergence angle of the projection light was 30 ° in the vertical and horizontal directions with respect to the horizontal direction.

(Viewing Angle) A solid white image is projected on the screen under the same conditions as in the screen gain measurement, and the luminance meter is set to −60 ° to + 60 ° with respect to a normal line from the center of the screen.
Scanning is performed in the horizontal direction within an angle range of 60 ° to measure the angle dependence (orientation characteristics) of luminance. Then, evaluation is made as an angle range having (１ ／) or more of the luminance in the normal direction, that is, a half value angle.

(Contrast of Reflected Image) Two types of images, a solid black image and a white solid image, were projected from a projector onto a screen under the same conditions as in the case of the screen gain described above. Then, the ratio of “(screen luminance at the time of a black signal) / (screen luminance at the time of a white signal)” is changed to 1 for the numerator, and is set as the contrast. The results are summarized in Table 1.

[0078]

[Table 1]

As can be seen from Table 1, the reflection type projection screen of the embodiment has a high reflection luminance, a large viewing angle, a high contrast of light and dark, and has extremely desirable characteristics as a reflection type projection screen. I understand.

Further, according to the reflection type projection screen 1 of this embodiment, there is no need to use a special device or member such as a polarizing filter or a polarizing type projector, and the projection system is simplified.

On the other hand, in the conventional example, it can be seen that the reflection luminance is lower, the viewing angle is smaller, and the performance as a reflection type projection screen is inferior to the embodiment. Regarding the reflective projection screens of these Examples, Comparative Examples 1 and 2, the surface was coated with an ink using a black two-component curable polyurethane resin as a binder, and a black frame pattern was formed on the outer peripheral edges of four sides of the screen. Was silk screen printed.

With respect to these reflection type projection screens,
The screen gain, viewing angle and contrast of the reflected image were measured. These all show good values,
Good screen characteristics were obtained.

Further, the anti-durability and the adhesive strength of the frame printing ink were measured on these reflective projection screens under the test conditions listed below. Where F
OM means irradiation by a sunshine carbon arc lamp type fade meter (light fastness tester).

(Durable Adhesion Prevention) 11 cuts perpendicular to the coating film surface and 11 cuts (1 mm pitch) were made.
Cut 100 grids. Then, after adhering on a grid having cellophane tape (Nichiban No. 405 cellophane tape) formed thereon and peeling it off, the number N of remaining coating films in 100 grids (0 ≦ N ≦ 100) was measured 10 times. I do. This is indicated as N / 100 for each number of times, and it is determined that the closer the N is to 100, the better the durability of the surface of the light diffusion layer 4 is.

(Adhesive Strength of Frame Printing Ink) A test method similar to the above-described durable adhesion preventing property is applied to the ink coating film. However, in the evaluation, the closer the number N of the remaining coating films is to 100, the better the adhesive strength between the ink and the light diffusion layer 4 is determined. The results are summarized in Table 2.

[0086]

[Table 2]

As shown in Table 2, it can be seen that the reflection type projection screen 1 of the example is excellent in both the durability against cellophane tape adhesion and the adhesive force of the frame printing ink, and has a sufficient adhesive force. It is considered that the reason why the adhesive strength of the ink is good even after the durability test is that the lubricant gushed out on the ink surface and the cellophane tape was easily peeled off.

On the other hand, in Comparative Example 1, since the lubricant 6 was not added, both the durability and the adhesion of the frame printing ink were reduced, and the adhesion was insufficient. Furthermore, in Comparative Example 2, since the amount of the lubricant 6 added exceeds the suitable range, the adhesion between the frame printing ink and the light diffusion layer 4 is reduced, although the durability and adhesion prevention properties are excellent.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a configuration of a reflection type projection screen according to the present invention.

FIG. 2 is a perspective view showing a scale-like foil piece made of a light-reflective substance contained in a light reflection layer in the reflection type projection screen according to the present invention.

FIG. 3 is an explanatory diagram schematically showing a configuration of a reflection type projection screen according to the present invention.

FIG. 4 is a cross-sectional view schematically showing a configuration of a reflection type projection screen proposed in Japanese Patent Application No. 8-42449.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reflective projection screen according to the present invention 2 Substrate 3 Light reflecting layer 3a Scale-like foil piece made of light reflecting material 3b Transparent resin 3c Flat surface 3d Side surface 4 Light diffusing layer 4a Achromatic pigment or dye 4b Calcite microcrystal particles 4c Transparent resin 5 Projection light incidence and image observation surface 6 Lubricant

Claims (1)

[Claims] 1. A plate- or sheet-shaped base material, a light-reflective layer formed of a transparent resin formed on a surface of the base material and having a scale-like foil piece of a light-reflective substance dispersed therein; A transparent light diffusion layer formed on the surface of the reflection layer and having calcite microcrystal particles and an achromatic dye or pigment dispersed therein, and having a transparent and light diffusion property. A reflective projection screen, wherein the surface is a projection light incidence and image observation surface for projecting projection light and observing a reflected image, and wherein the light diffusion layer contains an additive having lubricity. .