JP3636248B2 - Transmission type screen and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmissive screen used in a projection display device such as a liquid crystal projector, a projection television, a video projector, and a slide projector.
[0002]
[Prior art]
The projection 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 it on a screen. Depending on the type of screen used at this time, the transmission type (rear display) Type) and reflection type (front type).
FIG. 1 shows an example of a transmission type (rear type) liquid crystal projector. An image obtained by the light source 70 and the liquid crystal panel 60 is magnified by the projection lens 50, and projected onto the transmission screen 30 including the lenticular lens 10 and the Fresnel lens 20 through the mirror 40. At this time, the observer observes the image from the lenticular lens 10 side.
[0003]
An example of a transmission screen is shown in FIG. Reference numeral 20 denotes a Fresnel lens, which guides light incident from the light source side (right side of the drawing) vertically to the lenticular lens 10. The lenticular lens 10 disperses the light incident from the Fresnel lens 20 in a direction horizontal 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, for the purpose of suppressing reflection by external light and increasing contrast, a black stripe is formed on the surface of the lenticular lens on the outgoing light side (the side opposite to the Fresnel lens 20).
[0004]
[Problems to be solved by the invention]
The above-described transmission type screen using a lenticular lens and a Fresnel lens can obtain high brightness and high contrast, but has a drawback of being very expensive. In addition, with a lenticular lens, in principle, only one plane of diffusion can be obtained, and because the repeating unit of the lenticular lens is in the submillimeter order (ie, 0.1 mm), high-definition display cannot be obtained. There are drawbacks.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present inventors have intensively studied to diffuse light over the entire space on the outgoing light side without reducing the transmittance of the entire screen. In addition, as a result of studying the possibility of high-definition display using a micron-order fine structure, the resin layer contains particles with a specific value of the average particle diameter, and the film thickness specifies the average particle diameter of the particles. In a transmissive screen in which a light diffusion layer having a thickness equal to or less than the value and a transparent resin layer having a film thickness that is a specific multiple of the light diffusion layer are alternately formed on a transparent polymer film, the light diffusion layer has two or more layers. As a result, it was found that the above object could be achieved, and the present invention was completed.
[0006]
That is, the present invention includes (1) a light diffusion layer (A) formed by applying and drying a solution containing a resin in which particles are dispersed on a transparent polymer film, and applying and drying the solution containing the resin. A transparent resin layer (B) formed in the order of ABA in the order of three or more layers, or BAB in the order of four or more layers, (2) the light diffusion layer (A) is a particle (3) a transmissive screen according to (1), (3) a transmissive screen according to (2) wherein the average particle size of the particles is 1 μm to 15 μm, and (4) a light diffusing layer (A) The transmission type screen according to (2) or (3), wherein the average film thickness is not more than twice the average particle diameter of the particles contained in the light diffusion layer (A), (5) the light diffusion layer (A) (2) to (4), wherein the difference in refractive index between the particles used in the resin and the resin is 0.05 or more (6) The average thickness of the transparent resin layer (B) is 0.25 times or more and 10 times or less that of the light diffusion layer (A). (7) A method for producing a transmission screen, wherein the light diffusion layer (A) is formed by applying a solution containing a resin in which particles are dispersed and drying the solution, and transparent And a step of forming a resin layer (B) by applying a resin-containing solution and drying the resin layer (B). The method of manufacturing a transmission screen according to any one of (1) to (6).
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 shows an embodiment of the transmission screen of the present invention. From the right side of the drawing, it is a screen comprising a transparent polymer film 80, a light diffusion layer 90, a transparent resin layer 100, and a light diffusion layer 90. By using a single particle layer of particles having a particle size of 1 to 15 μm as the light diffusion layer. It becomes possible to diffuse light over the entire space on the outgoing light side without reducing the transmittance of the entire screen. FIG. 4 shows a transparent polymer film 80, a light diffusing layer 90, a transparent resin layer 100, a light diffusing layer 90, a transparent resin layer 100, and a transmissive screen of the present invention in which six layers of light diffusing layers 90 are laminated. An example is shown.
[0008]
The transparent polymer film in the present invention includes polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyethersulfone (PES), polyetheretherketone (PEEK), and polycarbonate (PC). Polyimide (PI), acrylic resin, cellulose triacetate resin (TAC), polyarylate resin, polysulfone resin, fluorine resin, etc. can be used, but are not necessarily limited to these, and are transparent, Any can be used as long as the heat resistance temperature is high to some extent.
[0009]
The thickness of the transparent polymer film is not limited, but when it is laminated with another member to form a screen, it is preferably about 10 to 1000 μm, more preferably about 10 to 500 μm, and still more preferably. Is about 25 to 200 μm. Moreover, when it is set as a screen independently, Preferably, about 0.1 mm-5 mm are used, More preferably, about 0.2 mm-2 mm are used, More preferably, about 0.3 mm-1 mm are used.
[0010]
As for the optical characteristics of the transparent polymer film to be used, the light transmittance at a wavelength of 550 nm is preferably 80% or more. More preferably, the light transmittance is 80% or more for light in the wavelength range of 500 to 600 nm, and still more preferably 80% or more for light in the wavelength range of 400 to 800 nm. If the light transmittance is lower than 80%, the transmittance of the screen is lowered, and the luminance of the screen is lowered.
[0011]
In addition, 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.
[0012]
Transparent resin layers include, for example, acrylic resins such as polymethyl methacrylate, polyacrylonitrile resins, polymethacrylonitrile resins, silicon resins such as polymers obtained from ethyl silicate, polyester resins, fluorine resins, polystyrene resins Or a mixture thereof.
[0013]
The average film thickness of the transparent resin layer is 0.25 times to 10 times, preferably 5 times or less the average film thickness of the light diffusion layer. More preferably, they are 0.5 times or more and 4 times or less, More preferably, they are 1 time or more and 3 times or less. If the average film thickness of the transparent resin layer is too thin, the effect of stacking with the light diffusion layer, the transparent resin layer, and the light diffusion layer is reduced. If it is too thick, it becomes difficult to form a layer.
[0014]
As the light diffusion layer, a layer in which particles are dispersed in a resin is used. Particularly preferred is a light diffusion layer comprising a single particle layer, and more preferred is a light diffusion layer comprising a single particle layer having a uniform particle size. The average film thickness of the light diffusion layer is preferably not more than twice the average particle size of the particles contained in the light diffusion layer. More preferably, it is 1.5 times or less, still more preferably 1.2 times or less, and preferably 1.0 times. If it is too thick, particles are randomly present in the light diffusion layer, and the return light increases.
[0015]
Examples of the particles used for the light diffusion layer include organic particles such as acrylic, polystyrene, and divinylbenzene, and inorganic particles such as glass and titania. The average particle diameter of preferable particles is 1 μm to 15 μm, more preferably 2 μm to 12 μm, and still 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 particle arrangement is random in the light diffusion layer, so that the return light increases. If the average particle size is too large, it is difficult to form a diffusion layer. Also, transparent particles are desirably used in order to obtain high luminance when used as a screen.
As the resin used for the light diffusion layer, the same resin as the transparent resin layer is used.
[0016]
It is preferable that the difference in refractive index between the particles used in the light diffusion layer and the resin is large. Preferably it is 0.05 or more, More preferably, it is 0.1 or more, More preferably, it is 0.15 or more. 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 or the like, and means a measured value at 25 ° C. using a sodium D line (wavelength 589 nm).
[0017]
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 diffusion layer, a solution containing a resin in which particles are dispersed is applied and dried. When forming a transparent resin layer, a solution containing a resin is applied and dried. From the viewpoint of performance, it is preferable that a hard coat layer and an antireflection layer are further used for these transmissive screens formed by the above method. The performance of the transmission screen can be easily confirmed visually.
[0018]
【Example】
Embodiments of the present invention will be described below with reference to [FIG. 3] and [FIG. 4].
[Example 1]
Divinylbenzene particles having an average particle size of 10 μm (manufactured by Sekisui Fine Chemical Co., Ltd., product name Micropearl SP-200, refractive index 1.57), silicone resin (manufactured by Daihachi Chemical Industry Co., Ltd., product name silicone coat 2, refractive index 1) .42) was used to prepare a particle dispersion of 21 parts of particles, 9 parts of silicone resin, and 70 parts of isopropyl alcohol. This particle dispersion was applied to a PET film having a film 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 silicone resin was applied so that the film thickness after drying was 10 μm, and dried at 100 ° C. for 10 minutes to form a resin layer. Subsequently, a light diffusion layer was formed in the same manner, and a transmission type screen (see FIG. 3) composed of PET film / light diffusion layer / transparent resin layer / light diffusion layer could be produced.
[0019]
[Example 2]
Acrylic particles having an average particle size of 7 μm (manufactured by Negami Kogyo Co., Ltd., product name Art Pearl G-7P, refractive index 1.49), latex mainly composed of acrylic and styrene (manufactured by Mitsui Toatsu Chemicals Co., Ltd., product name ALMA) A particle dispersion consisting of 21 parts of particles, 9 parts of latex and 70 parts of distilled water was prepared using Tex E-175, refractive index 1.54). This particle dispersion was applied to a TAC film having a thickness of 100 μm with a bar coater so that the thickness after drying was 7 μm and dried at 100 ° C. for 5 minutes to form a light diffusion layer. Subsequently, the latex was applied so that the film thickness after drying was 7 μm, and dried at 100 ° C. for 5 minutes to form a transparent resin layer. Subsequently, the same method is repeated to produce a transmission type screen (see FIG. 4) composed of PET film / light diffusion layer / transparent resin layer / light diffusion layer / transparent resin layer / light diffusion layer. I was able to.
[0020]
【The invention's effect】
In the transmission type screen of the present invention, a light diffusion layer comprising a resin containing particles having an average particle size of preferably 1 to 15 μm and having a film thickness of preferably not more than twice the average particle size of the particles, and a film A transparent resin layer having a thickness of preferably 0.25 to 10 times that of the light diffusion layer is alternately formed on the transparent polymer film, and the light diffusion layer has two or more layers. In addition to being able to three-dimensionally diffuse the image projected on the entire space as well as on a single plane, the present application uses particles of the order of 1 to 15 μm compared to submillimeter order lenticular lenses. High-definition display with more than digits is possible.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a transmissive (rear type) liquid crystal projector. FIG. 2 is a schematic diagram of a transmissive screen. FIG. 3 is an explanatory diagram showing an embodiment of the transmissive screen of the present invention. Explanatory drawing which shows one Example of a transmission type screen [Explanation of numerals]
DESCRIPTION OF SYMBOLS 10 Lenticular lens 20 Fresnel lens 30 Transmission type 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)

A light diffusion layer (A) formed by applying and drying a solution containing a resin in which particles are dispersed on a transparent polymer film, and a transparent resin layer (B) formed by applying and drying a solution containing a resin 3) in the order of ABA, or four or more layers in the order of BAB. The transmission screen according to claim 1, wherein the light diffusion layer (A) is a resin layer containing particles. The transmission screen according to claim 2, wherein the average particle diameter of the particles is 1 to 15 µm. The transmission type screen according to claim 2 or 3, 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). The transmission screen according to any one of claims 2 to 4, wherein a difference in refractive index between the particles used in the light diffusion layer (A) and the resin is 0.05 or more. The transmissive screen according to any one of claims 1 to 5, wherein an average film thickness of the transparent resin layer (B) is 0.25 to 10 times that of the light diffusion layer (A). A method of manufacturing a transmission screen, wherein a light diffusion layer (A) is formed by applying a solution containing a resin in which particles are dispersed and drying, and a transparent resin layer (B) A method for producing a transmission screen according to any one of claims 1 to 6, further comprising a step of forming the substrate by applying and drying a solution containing a liquid.

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