JPH1048751A - Transmission screen and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stereoscopically diffuse an image projected on a transmission screen over the whole space and to enable high definition display by depositing plural light diffusing layers and transparent resin layers in a specified order on a transparent polymer film. SOLUTION: Light-diffusing layers 90 and transparent resin layers 100 comprising an acryl resin such as polymethyl methacrylate are deposited on a transparent polymer film 80 to obtain three or more layers in the order of light-diffusing layer 90, resin layer 100 and light-diffusing layer 90, or four or more layers in the order of resin layer 100, light-diffusing layer 90 and resin layer 100. The light-diffusing layer 90 is preferably a resin layer containing org. particles such as acryl and polystyrene or inorg. particles such as glass and titania, and the average particle size of the particles is preferably controlled to 1 to 15μm. Moreover, the average film thickness of the light-diffusing layer 90 is preferably made twice or less the average particle size of the particles included in the layer 90. The difference in the refractive index between the particles and the resin used for the light-diffusing layer 90 is preferably controlled to >0.05.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal projector, a projection television, a video projector,
The present invention relates to a transmission screen used for a projection display device such as a slide projector.

[0002]

2. Description of the Related Art A projection type display device enlarges an image displayed on an image display device such as a cathode ray tube or a liquid crystal display device with a lens and projects the image on a screen. There are two types, transmission type (rear type) and reflection type (front type).
FIG. 1 shows an example of a transmission type (rear type) liquid crystal projector. The image obtained by the light source 70 and the liquid crystal panel 60 is enlarged by the projection lens 50, and is projected via the mirror 40 onto the transmission type screen 30 including the lenticular lens 10 and the Fresnel lens 20. At this time, the observer observes the image from the lenticular lens 10 side.

FIG. 2 shows an example of a transmission screen. Reference numeral 20 denotes a Fresnel lens, which is on the light source side (right side in the drawing).
The more incident light is guided vertically to the lenticular lens 10. The lenticular lens 10 disperses the light incident from the Fresnel lens 20 in a direction parallel to the paper surface.
A diffusion sheet or the like may be used between the lenticular lens 10 and the Fresnel lens 20 for the purpose of increasing diffusion in the direction perpendicular to the paper surface. Further, in order to suppress the reflection by external light and increase the contrast, a black stripe is formed on the surface of the lenticular lens on the emission light side (the side opposite to the Fresnel lens 20).

[0004]

The above-mentioned transmission screen using a lenticular lens and a Fresnel lens can provide high brightness and high contrast, but has a disadvantage that the cost is very high. In addition, with lenticular lenses, in principle, only diffusion in one plane can be obtained,
Further, there is a drawback that high-definition display cannot be obtained because the repeating unit of the lenticular lens is of a sub-millimeter order (that is, 0.1 mm).

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies on diffusing light over the entire space on the emission light side without lowering the transmittance of the entire screen. . In addition, as a result of examining the possibility of high-definition display using a microstructure on the order of microns, the resin layer containing particles with a specific value of average particle size, the thickness of which is determined by the average particle size of the particles In a transmission screen in which a light diffusion layer having a value of not more than and a transparent resin layer having a film thickness that is a specific multiple of the light diffusion layer is alternately formed on a transparent polymer film, the light diffusion layer has two or more layers. As a result, it has been found that the above object can be achieved, and the present invention has been completed.

That is, the present invention provides: (1) a light diffusion layer (A) and a transparent resin layer (B) on a transparent polymer film;
(2) The transmissive screen characterized in that three or more layers in the order of ABA or four or more layers in the order of BAB are laminated, and (2) the light diffusion layer (A) is a resin layer containing particles. (3) The transmission screen according to (2), wherein the particles have an average particle diameter of 1 μm to 15 μm.
(4) The average film thickness of the light diffusion layer (A) is
(2) or (3), wherein the difference in the refractive index between the particles used in the light diffusion layer (A) and the resin is not more than twice the average particle size of the particles contained therein. 0.05
The above-mentioned transmission screen according to any one of (2) to (4), (6) the transparent resin layer (B) has an average film thickness of:
The transmission screen according to any one of (1) to (5), which is 0.25 to 10 times the light diffusion layer (A), and (7) the method for producing a transmission screen, wherein the light diffusion layer is (A) a step of applying a solution containing a resin in which particles are dispersed and then drying the same; and forming a transparent resin layer (B) by applying a solution containing a resin and drying. The method according to any one of (1) to (6), comprising:

[0007]

FIG. 3 shows an embodiment of the transmission screen of the present invention. The screen is composed of a transparent polymer film 80, a light diffusion layer 90, a transparent resin layer 100, and a light diffusion layer 90 from the right side of the drawing. By using one particle layer having a particle diameter of 1 to 15 μm as the light diffusion layer. In addition, light can be diffused in the entire space on the emission light side without lowering the transmittance of the entire screen. FIG. 4 shows a transparent polymer film 80, a light diffusion layer 90, a transparent resin layer 100, a light diffusion layer 90, a transparent resin layer 100, and a light transmission layer 90 of the present invention in which six layers are laminated. An example is shown.

The transparent polymer film of the present invention includes:
Polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PE
T), polyethersulfone (PES), polyetheretherketone (PEEK), polycarbonate (P
C), polyimide (PI), acrylic resin, cellulose triacetate-based resin (TAC), polyarylate-based resin, polysulfone-based resin, fluorine-based resin, and the like can be used, but are not necessarily limited to these and are transparent. Yes, any material having a high heat-resistant temperature to some extent can be used.

The thickness of the transparent polymer film is not limited, but when it is laminated with another member to form a screen, the thickness is preferably about 10 to 1000 μm, more preferably about 10 to 500 μm. Still more preferably, about 25 to 200 μm is used. When the screen is used alone, preferably, the screen is 0.1 mm to 5 mm.
mm, more preferably about 0.2 mm to 2 mm, and still more preferably about 0.3 mm to 1 mm.

The optical characteristics of the transparent polymer film used are preferably such that the light transmittance at a wavelength of 550 nm is 80% or more. More preferably, wavelength 500-600n
m has a light transmittance of 80% or more for light in the range of m
More preferably, the light transmittance is 80% or more for light having a wavelength of 400 to 800 nm. Light transmittance is 80
%, The transmittance of the screen decreases, and the luminance of the screen decreases, which is not preferable in terms of screen performance.

It is preferable to use various fillers for the purpose of improving the heat resistance, weather resistance and ultraviolet resistance of the transparent polymer film.

As the transparent resin layer, for example, an acrylic resin such as polymethyl methacrylate, a polyacrylonitrile resin, a polymethacrylonitrile resin, a silicon resin such as a polymer obtained from ethyl silicate, a polyester resin, a fluorine resin, A polystyrene-based resin or a mixture thereof is used.

The average thickness of the transparent resin layer is preferably 0.25 to 10 times, more preferably 5 times or less the average thickness of the light diffusion layer. It is more preferably 0.5 times or more and 4 times or less, and still more preferably 1 time or more and 3 times or less. If the average thickness of the transparent resin layer is too small, the effect of laminating the light diffusion layer, the transparent resin layer, and the light diffusion layer is reduced. If it is too thick, it will be difficult to form a layer.

As the light diffusion layer, a layer in which particles are dispersed in a resin is used. Particularly preferred is a light diffusion layer composed of a single particle layer, and more preferred is a light diffusion layer composed of a single particle layer having a uniform particle size. The average thickness of the light diffusion layer is preferably not more than twice the average particle diameter of the particles contained in the light diffusion layer. It is still more preferably 1.5 times or less, still more preferably 1.2 times or less, and preferably 1.0 time. If the thickness is too large, particles are randomly present in the light diffusion layer, and return light increases.

The particles used in the light diffusion layer include, for example, organic particles such as acryl, polystyrene and divinylbenzene, as well as inorganic particles such as glass and titania. The preferred average particle size of the particles is 1 μm to 15 μm, more preferably 2 μm to 12 μm, and even more preferably 3 μm to 10 μm. If the average particle size is too small, it is difficult to form a single particle layer, and the arrangement of particles becomes random in the light diffusion layer, so that returning light increases. If the average particle size is too large, it becomes difficult to form a diffusion layer. Further, in order to obtain high brightness when the screen is formed, transparent particles are desirably used.
As a resin used for the light diffusion layer, a resin similar to the transparent resin layer is used.

It is preferable that the difference in the refractive index between the particles used in the light diffusion layer and the resin is large. It is preferably at least 0.05, more preferably at least 0.1, and even more preferably at least 0.15. If the refractive index difference is too small, a sufficient diffusion effect cannot be obtained. Here, the refractive index is a refractive index measured by a refractometer, etc.
It refers to the value measured at 25 ° C. using a line (wavelength 589 nm).

As a method for producing the light diffusion layer and the transparent resin layer, a coating method is preferable, and a three-reverse coating method, a gravure coating method, a bar coating method, or the like is used. When forming a light-diffusing layer, a solution containing a resin in which particles are dispersed is applied and dried, and when forming a transparent resin layer, a solution containing a resin is applied and dried. It is preferable in practical use and performance that a hard coat layer and an antireflection layer are further used in these transmission screens formed by the above method. In addition, the performance of the transmission screen can be easily confirmed visually.

[0018]

Embodiments of the present invention will now be described with reference to FIGS. 3 and 4.
This will be described with reference to FIG. Example 1 Divinylbenzene particles having an average particle size of 10 μm (Micropearl S, manufactured by Sekisui Fine Chemical Co., Ltd.)
P-200, refractive index 1.57), silicone resin (product name: silicone coat 2, manufactured by Daihachi Chemical Industry Co., Ltd., refractive index 1.42), 21 parts of particles, silicone resin 9
And 70 parts of isopropyl alcohol. This particle dispersion was applied on a PET film having a thickness of 100 μm with a bar coater so that the film thickness after drying was 10 μm, and dried at 100 ° C. for 5 minutes to form a light diffusion layer. Subsequently, the above-mentioned silicone resin has a thickness of 10 after drying.
It was applied to a thickness of μm and dried at 100 ° C. for 10 minutes to form a resin layer. Subsequently, a light diffusion layer is formed in the same manner, and P
A transmissive screen (see FIG. 3) consisting of an ET film / light diffusion layer / transparent resin layer / light diffusion layer was produced.

Example 2 Acrylic particles having an average particle diameter of 7 μm (manufactured by Negami Kogyo Co., Ltd., Art Pearl G-7P, refractive index: 1.49), a latex containing acrylic and styrene as main components (Mitsui Toatsu) Particles 21 were obtained using a trade name of ALMA-TEX E-175, manufactured by Chemical Co., Ltd., with a refractive index of 1.54.
Was prepared in the form of a particle dispersion composed of 1 part, 9 parts of latex and 70 parts of distilled water. This particle dispersion is applied to a TAC having a thickness of 100 μm.
The film was coated with a bar coater so that the film thickness after drying was 7 μm, and dried at 100 ° C. for 5 minutes to form a light diffusion layer. Subsequently, the dried latex has a thickness of 7 μm.
And dried at 100 ° C. for 5 minutes to form a transparent resin layer. Subsequently, the same method is repeated, and PET
A transmissive screen (see FIG. 4) consisting of a film / light diffusion layer / transparent resin layer / light diffusion layer / transparent resin layer / light diffusion layer could be produced.

[0020]

According to the transmission screen of the present invention, a light having a resin having an average particle diameter of preferably 1 to 15 .mu.m and having a film thickness of preferably twice or less the average particle diameter of the particles. By alternately forming a diffusion layer and a transparent resin layer having a thickness of preferably 0.25 to 10 times the light diffusion layer on the transparent polymer film, and forming the light diffusion layer into two or more layers. In addition to allowing the image projected on the transmission screen to be three-dimensionally diffused not only in one plane but also in the entire space, the present application uses particles of 1 to 15 μm order as compared with a lenticular lens of sub-millimeter order. As a result, high-definition display of two digits or more was made possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a transmission (rear) liquid crystal projector.

FIG. 2 is a schematic diagram of a transmission screen.

FIG. 3 is an explanatory view showing one embodiment of a transmission screen of the present invention.

FIG. 4 is an explanatory view showing an embodiment of the transmission screen of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lenticular lens 20 Fresnel lens 30 Transmissive screen 40 Mirror 50 Projection lens 60 Liquid crystal panel 70 Light source 80 Transparent polymer film 90 Light diffusion layer 100 Transparent resin layer

Claims (7)

[Claims] 1. A light diffusion layer (A) on a transparent polymer film
And three or more transparent resin layers (B) in the order of ABA or four or more layers in the order of BAB. 2. The transmission screen according to claim 1, wherein the light diffusion layer (A) is a resin layer containing particles. 3. The transmission screen according to claim 2, wherein the particles have an average particle size of 1 μm to 15 μm. 4. The transmission screen according to claim 2, wherein the average film thickness of the light diffusion layer (A) is not more than twice the average particle diameter of the particles contained in the light diffusion layer (A). . 5. The transmissive screen according to claim 2, wherein the difference in the refractive index between the particles used in the light diffusion layer (A) and the resin is 0.05 or more. 6. The transparent resin layer (B) has an average thickness of 0.25 to 10 times the light diffusion layer (A).
6. The transmission screen according to any one of claims 1 to 5. 7. A method for producing a transmission screen, comprising:
Forming a light diffusion layer (A) by applying a solution containing a resin in which particles are dispersed and drying the solution, and applying a solution containing a resin to the transparent resin layer (B) and drying the transparent resin layer (B) The method for producing a transmission screen according to claim 1, further comprising the step of: