JPH07128745A - Transmission type screen - Google Patents

Abstract

PURPOSE:To remarkably improve visibility and contrast against external light by laminating a diffusing material comprising spherical light-diffusing fine particles in a specified range of particle size and a light-diffusing antistatic layer formed by printing with an ink containing fine particles of an antistatic agent of specified size or smaller to form a Fresnel lens. CONSTITUTION:An antistatic layer 7 is formed on the surface of a transparent or semitransparent resin substrate where light exits by printing with a printing ink containing an antistatic agent. This ink is prepared by preliminarily mixing and dispersing the antistatic agent 9 comprising tin oxide of <0.5mum particle size. Then a diffusing layer 6 is formed by printing with a printing ink containing a diffusing material on the surface of the resin substrate where light enters to obtain a diffusing plate 5. This printing ink is prepared by preliminarily mixing and dispersing spherical light-diffusing material of 1-50mum particle size and is applied with using a screen printing plate of a mesh size proper to the particle size of the diffusing material 8 to form the diffusion layer 6 thicker by 10-20mum than the max. particle size of the diffusing material 8. Then the obtd. diffusing plate 5, a lenticular lens 3, and a Fresnel lens are laminated by an usual method to obtain the transmission type screen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmissive screen suitable for a projection television receiver and a method for manufacturing the same.

[0002]

2. Description of the Related Art Large-sized televisions having a large screen (hereinafter abbreviated as televisions) are becoming popular in the high-definition era. As a receiver for this large-sized television, a conventional cathode-ray tube type has a problem in weight, size, cost, and the like, and therefore a projection television (projection television) receiver is often used. However, conventional projection television receivers are inferior in brightness, viewing angle, contrast, sharpness and the like to those of cathode ray tube type, and improvements have been desired.

That is, a transmissive screen used in a projection television has a structure in which a lenticular lens is arranged on the light exit side of a Fresnel lens, which has been used in the past. In order to form an image and to expand the vertical viewing angle, a material containing light diffusing fine particles such as titanium or mica is often used. However, since the light-diffusing fine particles are dispersed throughout the lens, a considerable part of the incident light is repeatedly reflected by the light-diffusing material to become stray light, which lowers the resolution. However, there is a problem in that the light amount of the emitted light is lost, which causes a decrease in brightness.

Further, since a part of the light diffusing material is projected on the surface of the lenticular lens or the surface of the black stripe, when the projections and depressions on the outgoing light side are irradiated with external light, irregular reflection occurs and the screen surface. There was also a problem that the image became white and the contrast deteriorated. Therefore, in order to improve the above-mentioned vividness and the deterioration of the contrast due to external light, a method of arranging a glass or plastic transparent plate with a reduced light transmittance on the light-emission-side front surface of the screen was used, This method has another drawback that the screen becomes dark.

Therefore, the inventors of the present invention have solved the above-mentioned problems of the conventional transmissive screen, and improved the light utilization efficiency while forming an image, enlarging the viewing angle, and improving the vividness and contrast. As a result of repeated research on the structure of the screen and the light diffusing material in order to obtain a transmissive screen having a bright and good quality screen, specific light diffusing fine particles (particularly preferable are beads of acrylic resin having a diameter of 5 to 50 microns) are selected. The inventor has previously filed a patent application (Japanese Patent Application No. 5-115187) that the object can be achieved by disposing a diffusion plate composed of transparent plates laminated by a printing method on the light outgoing side of a transmission screen.

According to this prior invention, in a transmission screen having a Fresnel lens and a lenticular lens, a transparent plate on which a light diffusing fine particle layer is laminated is arranged such that the fine particle layer is located on the light outgoing side of the transmission screen. The present invention provides a transmissive screen characterized in that The present inventors succeeded in making the diffuser plate more excellent by continuing research after that.

That is, the inventors of the present invention have conducted extensive studies on the diffusion material, the antistatic agent, the method of supporting the same, and the structure of the diffusion plate in which they are laminated, and as a result, the diffusion material has a certain spherical diameter. Spherical fine particles are printed by a printing method so as to be arranged side by side in a row with a constant thickness, and SnO ₂ powder is used as an antistatic agent, and this is applied by a printing method, and the diffusion surface is made incident. By using it on the light side, the transmittance of light is improved, and by preventing irregular reflection of external light and preventing the surface from being charged, dust,
We have invented and filed a patent application (Japanese Patent Application No. 249688/1993) that a bright and clear feeling without dust, etc., and an unprecedented excellent diffuser plate can be obtained.

This prior invention is a diffusing material containing a printing ink containing a transparent or semi-transparent resin substrate and a diffusing material composed of spherical light diffusing fine particles having a particle size of 1 to 50 microns provided on the plane on the light incident side. Printing ink containing a diffusion layer formed by printing to a thickness of 10 to 20 microns thicker than the maximum particle size of the above, and a fine-grained antistatic agent having a particle size of 0.5 microns or less provided on the plane on the light emitting side of the resin substrate. The present invention provides a diffusion plate comprising an antistatic layer formed by printing.

[0009]

According to the inventions of the inventors of the present invention described above, the transmission screen of the projection television receiver has been greatly improved and improved, but the innermost portion (inner side) of the screen is improved.
If dust adheres to the Fresnel lens located at the position, the image is affected, but the problem remains that the dust is extremely difficult to remove. The present invention aims at solving the problem of dust adhesion to the Fresnel lens and expanding the viewing angle (particularly the vertical viewing field) for which further improvement is desired.

[0010]

As a result of repeated studies to solve the above-mentioned problems, the present inventors have found that the light-diffusing fine particles (diffusing particles) made of the specific resin beads in the above-mentioned invention previously developed by the present inventors. Material) and an ink containing a heat-resistant agent is applied to the Fresnel lens to solve the problem, and since the diffusing material of the diffusion plate can be reduced, the brightness and contrast can be improved. Heading The present invention has been completed.

That is, according to the present invention, in a transmission type screen having a diffusion plate, a Fresnel lens and a lenticular lens as main constituent elements, the Fresnel lens has spherical light diffusing fine particles having a particle size of 1 to 50 microns on a plane on the light incident side. A light-diffusing antistatic layer formed by printing a printing ink containing a finely divided antistatic agent having a particle size of 0.5 micron or less It provides a mold screen.

The present invention will be described in detail below. First, the structure of the transmissive screen of the present invention will be described with reference to the drawings.
FIG. 1 is a partial sectional view showing a transmissive screen according to an embodiment of the present invention, and FIG. 2 is a partially cutaway perspective view thereof.

In the figure, reference numeral 1 denotes a Fresnel lens, and a light diffusing antistatic layer 2 containing a diffusing material and an antistatic agent is laminated on the light incident side, that is, the back surface of the lens, and the lenticular lens is on the light emitting side. 3 are provided. Black stripes 4 are projection surfaces present at the boundaries between the semi-cylinders on the light output side of the lenticular lens 3. A diffusion plate 5 provided with a diffusion layer 6 and an antistatic layer 7 is laminated so as to adhere to the black stripe 4.

As described above, the transmission screen of the present invention has a Fresnel lens 1 having a photonucleic acid antistatic layer, a lenticular lens 3 (black stripe 4).
1), the light diffusing layer 6 and the diffusing plate 5 having the antistatic layer are laminated in the order shown on the left to have the sectional structure shown in FIG.

As the Fresnel lens and the lenticular lens used in the present invention, any of well-known ones conventionally used can be used for their shape, structure and material. Usually, as the material, acrylic resin, polycarbonate resin, styrene resin and the like having excellent light transmission are often used. Depending on the purpose, colored semi-transparent ones (eg dark smoked) are also used.

In the constitution of the present invention, what is important is a Fresnel lens in which a light diffusive antistatic layer is laminated, and the diffusion layer and the antistatic layer are particularly advantageous. The light diffusion antistatic layer 2 is uniformly and diffused on the surface of the resin substrate 1 using an ink prepared by dispersing and mixing a diffusion material 8 made of light diffusing fine particles and an antistatic agent 9 in a plastic printing ink. The material 4 is formed by printing so that the material 4 is juxtaposed in a substantially horizontal row as shown in FIG. As described above, the diffusing materials are arranged in a horizontal row in the diffusing layer, and are arranged side by side in a single layer.Therefore, incident light is stray light due to undesired reflection that occurs in the conventional case where the diffusing material is multiplexed. Since no loss of transmitted light occurs, good light transmittance can be obtained.

The diffusing material 4 used in the present invention is a fine spherical particle having a sharp particle size distribution such as an acrylic resin such as a methylmethacrylate resin or a copolymer thereof, a styrene resin, a polyester resin, a polycarbonate resin or a fluorine resin. Resin beads are used. Although these resin beads are transparent. The diffuser plate may be colored. Inorganic beads such as glass beads can also be used.

Since this diffusing material has a great influence on the uniformity of the light diffusing antistatic layer, it is necessary to use the following specific shape and size. Further, the blending amount thereof may be 10 to 20% by weight in the printing ink. First, a spherical shape is used, and the average particle size is 1 to
The range of 50 microns and its variation is preferably selected from the range of 5 ± 4 microns to 25 ± 25 microns. That is, it is necessary that the range of variation in the particle size is 30 microns or less, preferably 25 microns or less.

When this diffusing material is used, for example, when the thickness of the light-spreading diffused antistatic layer is set to about 15 μm, spherical particles having an average particle size within 15 μm with a variation within 1 to 10 μm. Fine particles (resin beads) are preferably used, and when the layer thickness is set to about 50 microns, the average particle size is selected from the range of 25 to 50 microns with variation within 25 microns. It is good to keep it.

As the printing ink 4 in which the diffusing material described above and the antistatic agent to be described later are dispersed and mixed, a printing ink for plastics having an acrylic resin, polyester resin, urethane resin or the like as a binder is used.
Among these, acrylic printing ink is particularly preferable.
When used for a diffusion plate, it is also possible to add a light absorbing substance such as a dye, a pigment, carbon or a metal salt to the ink to color it.

The printing ink containing the diffusing material and the antistatic agent described above must be printed uniformly on the resin substrate so that the diffusing material forms one horizontal line. A printing method, particularly preferably a screen printing method, is used to obtain such a diffusion layer. In the screen printing method, by adjusting the mesh to the particle size of the diffusing material, the diffusing material can be regularly arranged in one layer by the mesh of the screen, and a uniform layer can be formed.

The light diffusing antistatic layer of the present invention is formed by uniformly printing an ink 7 in which an antistatic agent 6 is mixed and dispersed in addition to the above-mentioned diffusing material. Without the antistatic agent, the surface resistance value is 10 ^{16 to 18} because the diffusion plate is made of resin.
Becomes Ω, and static electricity is generated due to friction, discharge, and the like, and dust and dirt are attached, and as a result, there arises a problem that the image becomes difficult to see and the appearance of the screen is impaired. In the present invention, the light-diffusing antistatic layer can be formed by using a suitable antistatic agent, and the surface resistance value can be set to 10 ¹¹ Ω or less, so that the above static electricity problem does not occur.

The antistatic agent used in the present invention may be appropriately selected from known antistatic agents and used, but most preferably, tin oxide (SnO ₂ ) having a particle size of 0.5 micron or less is used. Is. The SnO ₂ is dispersed and mixed with a plastic printing ink, for example, an acrylic printing ink together with the above-mentioned diffusing material, and uniformly printed by a printing method, for example, screen printing. In this way, a transparent light diffusive antistatic layer is formed on the Fresnel lens of the present invention having a surface resistance value of 10 ¹¹ Ω or less.

Next, a method of forming the light diffusing antistatic layer of the Fresnel lens of the present invention will be described. The Fresnel lens is formed by molding the above-mentioned resin, but it is convenient to use a commercially available product that meets the standards of the present invention. These Fresnel lenses are thoroughly washed with ultrasonic waves before printing. In addition, a printing ink containing a diffusing material and an antistatic agent is added to the above-mentioned diffusing material and antistatic agent in the plastic printing ink and well dispersed and mixed to prepare. In addition,
A method that destroys the shape of the diffusing material, such as a ball mixer or a roll mixer, should not be used for the dispersion mixing.

On the back surface of the Fresnel lens, a printing ink containing a diffusing material and an antistatic agent is printed by a printing method such as a screen printing method, or by dipping, a light diffusing antistatic layer is formed. For this printing, it is important to print using a mesh screen suitable for the particle size of the diffusing material.

As described above, it is important to select the grain size of the diffusing material according to the intended thickness of the diffusing layer and keep the variation of the grain size of the diffusing material within a certain range (maximum 30 μm). is there. By carrying out screen printing while suppressing these points, it is possible to obtain a uniform light diffusing antistatic layer in which spherical diffusing fine particles are arranged side by side in a row.

The lenticular lens used in the transmissive screen of the present invention has a conventionally used structure and material, but it is not necessary to mix a diffusing material into the lenticular lens as in the prior art. The diffusing plate disposed on the forefront was previously invented by the present inventor (Japanese Patent Application No. 5-249688).
No.) A diffusion plate is used.

That is, a printing ink containing an antistatic agent prepared by mixing and dispersing an antistatic agent made of tin oxide having a particle size of 0.5 μm or less in advance on the plane on the light emitting side of a transparent or semitransparent resin substrate is printed. To form an antistatic layer, and then a diffusing material-containing printing ink prepared by previously mixing and dispersing a spherical light diffusing diffusing material having a particle size of 1 to 50 microns on the light incident side plane of the resin substrate is diffused. A diffusion plate is used in which a diffusion layer is formed by printing with a screen printing plate having a mesh suitable for the particle size of the material to a thickness of 10 to 20 microns thicker than the maximum particle size of the diffusing material.

In the above diffusion plate used in the present invention,
The amount of the diffusing material can be reduced as compared with the diffusing plate of the present invention of the present inventors, and can be eliminated depending on the performance of the diffusing layer laminated on the Fresnel lens. If the amount of the diffusing material of the diffusing plate can be reduced, the brightness is improved and the contrast becomes clear. The transmissive screen of the present invention can be obtained by stacking and assembling the diffuser plate, the lenticular lens, and the Fresnel lens described above by a conventional method.

[0030]

In the transmissive screen of the present invention, the light diffusive antistatic layer of the Fresnel lens has a structure in which spherical fine particle diffusing materials (resin beads) having a constant particle diameter are arranged side by side. Compared with a screen having a lenticular lens in which conventional diffusing materials are randomly overlapped and embedded with each other, incident light rays are reflected by these diffusing materials and are not lost as stray light, and the light transmittance is improved, In addition, it was possible to prevent reflection due to the unevenness of the screen surface and irregular reflection of outside light.

Further, since the antistatic layer of the light diffusive antistatic layer of the Fresnel lens in the screen of the present invention uses SnO _{2 of} 0.5 micron or less, it is obtained when fine particles of 1 micron or less are dispersed. Since a transparent film was obtained, the light transmittance of the entire layer was improved, and the light transmittance of this layer itself could be increased. Moreover, since the diffuser plate of the screen of the present invention can reduce the amount of the diffusing material, it has the effect of improving the brightness and the contrast as a whole.

[0032]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 Spherical acrylic resin beads having an average particle size of 5 μm (Technopolymer (trade name) manufactured by Sekisui Plastics Co., Ltd.) 20% by weight and SnO ₂ having a particle size of 0.1 to 0.5 μm. [Antistatic agent, Catalyst Chemical Industry Co., Ltd., ELCOM P3561
(Trade name)] An ink prepared by uniformly mixing and dispersing 0.5% by weight of a transparent acrylic printing ink (medium ink manufactured by Tojo Kako Co., Ltd.) into a 350 mesh plate is preformed by screen printing. Print on the back of the Fresnel lens made of polycarbonate. Then, this is dried at 80 ° C. for 20 minutes to manufacture a Fresnel lens having a light diffusing antistatic layer laminated on the back surface. When the surface resistance value of this Fresnel lens was measured by a conventional method, it was 10 ¹⁶ Ω before printing, but was lowered to 10 ⁸ Ω.

Next, a transparent acrylic plate [Asahi Kasei Co., Ltd.
Made by Delaglass A (trade name)]
Acrylic printing ink containing 0.5% by weight of nO ₂ was printed by 350 mesh screen printing at 80 ° C. for 2
Dry for 0 minutes. Acrylic printing ink containing 10% by weight of the same spherical acrylic resin beads as described above was printed on the back side thereof by 350 mesh plate screen printing,
A diffusion plate is manufactured by drying for 20 minutes.

The Fresnel lens 1 and the diffusing plate 5 manufactured as described above, and the lenticular lens 3 manufactured by a conventional method.
As shown in FIG. 2, a diffusion screen, a lenticular lens, and a Fresnel lens are arranged in this order from the side of the emitted light closest to the observer to manufacture a transmission screen. When this screen was attached to a projection television and used, the stray light caused by reflection disappeared compared to the conventional screen in which a diffusing material was mixed in the lenticular lens, and as a result, color shift, reduction in resolution and viewing angle The problem of narrowing was solved all at once, and an image with excellent contrast was obtained without irregular reflection by external light.

Example 2 A Fresnel lens in which a light diffusive antistatic layer is laminated is manufactured in the same manner as in Example 1 except that the Fresnel lens body is made of acrylic resin. Next, a dark smoked semi-transparent acrylic plate [Delaglass A9 manufactured by Asahi Kasei Kogyo Co., Ltd.
No. 23 (trade name)] was printed with the SnO ₂ containing ink used in Example 1 in the same manner as in Example 1 and then dried to form an antistatic layer on both sides. The surface resistance value was 10 ⁸ Ω. A diffusing material-containing printing ink having the following composition, which was prepared so that the ink and the diffusing material had substantially the same light transmittance, was printed on one surface of the diffusing material by screen printing with a 350 mesh plate to form a diffusing layer.

(Compounding) Diffusion material: Acrylic resin beads made by Sekisui Plastics Co., Ltd. Average particle size 5 microns (Brand name: Technopolymer MBX) ... 10% by weight Coloring agent: Black acrylic type made by Jujo Kako Co., Ltd. Ink (# 6
90) 5% by weight Base ink: transparent acrylic ink (medium ink) manufactured by Jujo Kako Co., Ltd. 85% by weight After printing, a diffusion plate was obtained by drying at 80 ° C. for 20 minutes. The Fresnel lens and the diffusing plate obtained above were used in Example 1.
When used for a screen of a projection television in the same manner as in Example 1, the same effects as in Example 1 were obtained, and the front screen after the power was turned off appeared to have a more subdued color tone and a more textured appearance.

[0038]

INDUSTRIAL APPLICABILITY The transmission screen of the present invention is a screen suitable for a projection type television receiver, and it forms an image and enlarges the viewing angle, and has a clear feeling as compared with the conventional screen.
It has an excellent effect that the outside light contrast is greatly improved, the light utilization efficiency is high, and that the diffusion plate and the Fresnel lens are free from dust and dust.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a transmissive screen of the present invention.

FIG. 2 is a partially cutaway perspective view of the transmissive screen of the present invention.

FIG. 3 is a partial sectional view of a Fresnel lens used in the present invention.

FIG. 4 is a partial sectional view of a diffusion plate used in the present invention.

[Explanation of symbols]

 1 Fresnel Lens 2 Light-Diffusing Antistatic Layer 3 Lenticular Lens 4 Black Stripe 5 Diffusing Plate 6 Diffusing Layer 7 Antistatic Layer 8 Light Diffusing Material 9 Antistatic Agent 10 Incident Light 11 Outgoing Light

Claims (4)

[Claims] 1. A transmission screen mainly comprising a diffuser plate, a Fresnel lens and a lenticular lens, wherein the Fresnel lens has a grain size of 1 on a plane on the light incident side.
Fresnel laminated with a light diffusing antistatic layer formed by printing a printing ink containing a diffusing material composed of spherical light diffusing fine particles of ˜50 μm and a fine particle antistatic agent having a particle size of 0.5 μm or less A transmissive screen that is a lens. 2. The transmission screen according to claim 1, wherein the diffusing material is spherical transparent resin beads and the antistatic agent is tin oxide. 3. The transmissive screen according to claim 1, wherein the printing method is a screen printing method. 4. A projection type television receiver using the transmissive screen according to claim 1.