JPH03200949A - Screen for projection - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a projection screen.

<Prior Art> FIG. 2 is a diagram showing the configuration of a conventional projection screen, and this projection screen is composed of a Fresnel lens 4 and a lenticular lens 5. As shown in FIG. 2, the Fresnel lens 4 has the function of converting the light from the light source 1 into parallel light and making it almost perpendicular to the lenticular lens 5. On the other hand, the lenticular lens 5 converts the light incident from the Fresnel lens into parallel light. It has the function of scattering in a controlled manner. Conventional Fresnel lenses and lenticular lenses use transparent thermoplastic resins such as acrylic resin, polystyrene resin, polyvinyl chloride resin, polycarbonate resin, etc. Among them, acrylic resin has the highest transparency, hardness, and durability. It is widely used due to its processing suitability.

Lenticular lenses are widely used in which light-diffusing substances such as silica, alumina, viscosity, glass, and beads are mixed with the thermoplastic resin to impart light-diffusing properties.

<Problems to be Solved by the Invention> Both light diffusivity and light transmission performance are important for projection screens. Lenticular lenses made of conventional screen materials have good light diffusivity, but have a low total light transmittance, resulting in a dark screen.

If an attempt is made to increase the total light transmittance in order to make the screen brighter, the light diffusivity decreases and the resolution of the screen decreases, making it difficult to satisfy both requirements at the same time.

<Means for Solving the Problems> The present invention aims to solve the problems of the conventional projection screens described above.

That is, it has been found that by using the screen of the present invention which has high light diffusivity without reducing light transmittance (total light transmittance), it is possible to simultaneously satisfy both conditions and brighten both sides of the screen.

The present invention relates to a composition containing at least two types of monomers or oligomers each having a polymerizable carbon-carbon double bond and capable of producing a polymer having a different refractive index, and a composition having a polymerizable carbon-carbon double bond. at least one compound having a polymerizable carbon-carbon double bond and capable of producing a polymer having a refractive index different from that of the compound.
Compositions containing a variety of monomers or oligomers; Compositions containing at least one monomer or oligomer that has multiple polymerizable carbon-carbon double bonds in the molecule and have different refractive indexes before and after polymerization. Provided is a projection screen comprising a light control film whose haze value is angle-dependent and obtained by curing at least one selected composition by irradiating light from a rod-shaped light source or a linear light source. It is something.

The manufacturing method of this light control film is disclosed in the patent application filed by the applicant.
It is as described in Japanese Patent Application No. 1983-316460 (filed on December 14, 1988) entitled "Light Control Board and Method for Manufacturing the Same".

Examples of the production method include compositions containing at least two monomers or oligomers that have polymerizable carbon-carbon double bonds and can produce polymers with different refractive indexes, polymerizable carbon-carbon Contains a compound having no double bonds and at least one type of heptamer or oligomer having a polymerizable carbon-carbon double bond and capable of producing a polymer having a refractive index different from that of the compound. At least one composition selected from compositions containing at least one monomer or oligomer having multiple polymerizable carbon-carbon double bonds in the molecule and having different refractive indexes before and after polymerization. The material is coated on a substrate or encapsulated in a cell together with a photopolymerization initiator and irradiated with specific light.

One of the compositions of the light control film constituting the projection screen of the present invention includes at least two monomers each having a polymerizable carbon-carbon double bond and capable of producing a polymer having a different refractive index. Alternatively, compositions containing oligomers may be mentioned. The monomer or oligomer used here is a compound having at least one carbon-carbon double bond in the molecule, for example, a polymerizable group such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group, etc. It is a monomer or oligomer containing one or more. Any combination can be used as long as it can be polymerized by light, such as ultraviolet light, can produce polymers with different refractive indexes, and has different reactivity ratios and appropriate compatibility. However, the chemical and physical properties of the resin are determined as necessary. Suitable examples include polyester acrylate, polyol polyacrylate, modified polyol polyacrylate, isocyanuric acid skeleton polyacrylate, doramin acrylate, hydantoin skeleton polyacrylate, polybutadiene acrylate, epoxy acrylate, polyfunctional acrylate such as urethane acrylate. Acrylates and methacrylates corresponding to these acrylates, or tetrahydrofurfuryl acrylate, ethylcarpitol acrylate, dicyclopentenyloxyethyl acrylate, phenylcarbitol acrylate, nonylphenoxyethyl acrylate, 2-hydroxy-3-phenoxy Propyl acrylate, ω-hydroxyhexanoyloxyethyl acrylate, acryloyloxyethyl succinate, acryloyloxyethyl phthalate, phenyl acrylate, tribromophenyl acrylate, phenoxyethyl acrylate, tribromophenoxyethyl acrylate, benzyl acrylate, p-bromobenzyl acrylate, Bisphenol A diacrylate, 2,2-bis(4-methacryloxyethoxy-3,5-dibromophenyl)propane, isobornyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, 2
, 2゜3.3-tetrafluoropropyl acrylate,
and methacrylates corresponding to these monofunctional acrylates, and styrene, p-chlorostyrene, divinylbenzene, vinyl acetate, acrylonitrile,
Examples include vinyl compounds such as N-vinylpyrrolidone and vinylnaphthalene, and allyl compounds such as diethylene glycol bis(allyl carbonate), triallylisocyanurate, diallylidenepentaerythritol, diallylphthalate, and diallylisophthalate.

The light control film used in the present invention uses a mixture of at least two types selected from these photopolymerizable monomers or oligomers, but the refractive indexes of these two types of homopolymers must be different from each other. at least 2
Seeds or oligomers of at least 0.01.
When using three or more types of photopolymerizable monomers or oligomers, preferably having a refractive index difference (in the homopolymer) of at least 0.05, the It is sufficient that the difference between the refractive indexes of any two of them satisfies the above conditions. At least 0.
The mixing ratio of two types of photopolymerizable monomers or oligomers having a refractive index difference of 0.01 is 10:90 to 90:1 by weight.
It is preferably in the range of 0.

A preferred example of a composition containing at least two monomers or oligomers that have polymerizable carbon-carbon double bonds and can produce polymers with different refractive indexes is polyether urethane acrylate and ethylene oxide modified A homogeneous mixture in combination with tribromophenol acrylate (difference in refractive index of polymers of about 0.14) can be mentioned. These monomers or oligomers not only have different refractive indices from each other, but also have different reactivity (reaction rate) to form a phase-separated structure that exhibits light control functions.
must also be different from each other.

Another composition of the light control film constituting the projection screen of the present invention is a compound having no polymerizable carbon-carbon double bond and a compound having a polymerizable carbon-carbon double bond,
Also included are compositions containing at least one heptamer or oligomer capable of producing a polymer having a refractive index different from the refractive index of the compound. This compound that does not have a polymerizable carbon-carbon double bond in its molecule is a compound that does not contain a polymerizable group such as an acryloyl group, a mekacryloyl group, a vinyl group, or an allyl group in its molecule. For example, polymers such as polystyrene, polymethyl methacrylate, polyethylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, nylon, toluene, n-hexane, cyclohexane, methyl alcohol, ethyl alcohol, acetone, methyl ethyl ketone, tetrahydrofuran, ethyl acetate, dimethyl formamide, Examples include organic compounds such as dimethylacetamide and acetonitrile, halogen compounds of these organic compounds, and plastic additives such as plasticizers and stabilizers.

In addition, the above-mentioned compounds can be used as at least one heptadmer or oligomer capable of producing a polymer having a polymerizable carbon-carbon double bond and having a refractive index different from the refractive index of the compound. The refractive index of the compound and the polymer refractive index of the monomer or oligomer must be different. The difference in refractive index is at least 0.
01, more preferably at least 0.05. The mixing ratio of the compound and the monomer or oligomer is preferably in the range of 10:90 to 90:10 in terms of weight ratio.

Compositions containing the compound and at least one monomer or oligomer capable of forming a polymer having a refractive index different from that of the compound are preferred. For example, a homogeneous mixture of polystyrene (refractive index of about 1.59) and polyether urethane acrylate (refractive index of the polymer about 1.49) can be mentioned.

Other compositions of the light control film constituting the projection screen of the present invention include at least one monomer or oligomer having a plurality of polymerizable carbon-carbon double bonds in the molecule and having different refractive indexes before and after polymerization. Examples include compositions containing.

This 7-mer or oligomer is a monomer or oligomer containing at least two polymerizable groups such as acryloyl group, methacryloyl group, vinyl group, or allyl group in the molecule, and the refractive index before and after polymerization is different. , preferably having a refractive index difference of at least 0.01. Specifically, for example, triethylene glycol acrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, 1.
6-hexanediol acrylate, hydrogenated dicyclopentadienyl diacrylate, ethylene oxide modified bisphenol A diacrylate, trimethylolpropane triacrylate, pentaerythritol hexaacrylate, tris(acryloxy)isocyanurate,
Examples include polyfunctional urethane epoxy acrylate, polyfunctional urethane acrylate, methacrylates corresponding to these acrylates, divinylbenzene, triallylisocyanurate, diethylene glycol bis(allyl carbonate), and the like.

The photopolymerization initiator is not particularly limited, and includes those used in ordinary photopolymerization.

For example, benzophenone, benzyl Michler, zuketone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, benzoin ethyl ether, jetoxyacetophenone, benzyl dimethyl ketal, 2-hydroxy-2-methylpropiophenone, ■-hydroxycyclo Examples include xylphenyl ketone.

The substrate used for photopolymerization may be any substrate that can provide a smooth surface of the coated film, and examples thereof include flat plates or templates made of glass, plastic, metal, and the like.

In addition, during photopolymerization, a linear or rod-shaped light source is used as the light source for irradiation, and when the irradiation conditions are adjusted, the cured sheet-like material exhibits anisotropy in the long and short axis directions of the light source. , when the light source is rotated around the long axis direction, light at a specific angle is significantly scattered. As the linear or rod-shaped light source, an ultraviolet light source is suitable in consideration of productivity and the like. Ultraviolet rays are usually produced using mercury lamps or metal halide lamps. A light source with another wavelength may be used as long as the composition is modified so that it is sensitive to the wavelength of the light source, and the wavelength of the light source is not particularly limited.

That is, according to the present invention, a linear or rod-shaped light source, ie a linear light source viewed from the film to be irradiated, preferably a light source whose viewing angle A in the long direction is at least 8°, preferably at least 12°; Light is irradiated at a predetermined angle of incidence from such that the viewing angle B in the minor axis direction of the target is at most A/4, more preferably A/10 or less.

When the composition is irradiated with light, it polymerizes and hardens, but on the inner surface of the cured film, there are many strips that extend approximately parallel to the long axis of the linear light source when viewed in parallel, and that are approximately parallel to each other. A microstructure is formed in which layers with alternating refractive indexes are arranged periodically, and when viewed in cross section of the film, each strip is a microstructure in which the irradiation light from the irradiation light source enters the film. is formed almost parallel to the angle at which it travels. It is thought that these layers having different refractive indexes are generated due to differences in the reactivity of photopolymerization materials during photopolymerization, which causes diffusion movement and phase separation, resulting in differences in composition and concentration. When light is incident on this polymerized and cured film from a certain angle range centered on an angle parallel to the strip-shaped structure, the light passing through the microstructures within the film is scattered.

FIG. 1 is a drawing showing an example of the configuration of a projection screen according to the present invention.

As shown in FIG. 1, the projection screen of the present invention is constructed by adhering pre-emptive ff1llll13 to the surface of a transparent base material 2 such as transparent glass or transparent plastic, or by laminating it between multiple base materials. It can be configured as a body. As shown in FIG. 1, when light from the light source 1 is incident on the projection screen of the present invention, the light passing through the light control film 3 is scattered as described above.

The aforementioned transparent substrate is not particularly limited as long as it is transparent, and examples thereof include polycarbonate resin plates, methacrylic resin plates, polystyrene resin plates, glass plates, and the like.

The method of attaching the transparent substrate and the light control film is not particularly limited, and any known method can be used.

The transparent substrate used for lamination is preferably subjected to an abrasion-resistant coating and/or a non-glare treatment on its outer surface.

In the projection screen of the present invention, the substrate used when manufacturing the light control film can also be a transparent base material.

In addition, the present invention has excellent light diffusivity by laminating and using a light control film and a light diffusing plate that reduces the amount of ground glass or filler added to reduce light diffusivity and increase total light transmittance. In addition, a projection screen with high total light transmittance can be obtained.

Furthermore, the projection screen of the present invention can be combined with a conventional lenticular lens or Fresnel lens.

The projection screen of the present invention has the preemptive function '4'.
'A single B film may be used, but it is preferable to use a laminated light control film obtained by laminating two light control films so that the directions of angle dependence are perpendicular to each other in both the horizontal and vertical directions. This is preferable because the viewing angle is wide and a bright image can be obtained.

<Effects of the Invention> Since the projection screen of the present invention exhibits good light diffusivity without reducing total light transmittance, a bright image can be obtained.

<Examples> Example 1 Tribromophenoxyethyl acrylate ( Refractive index 1.56
7) A resin composition prepared by adding and mixing 100 parts of hihenzyl dimethyl kecour and 6 parts of hihenzyl dimethyl kecour was coated on a glass plate to a thickness of about 300ξcm. After D, ultraviolet rays were irradiated for 60 seconds from a distance of 100 cm above using a bar-shaped high-pressure mercury lamp of 80 W/cm and a length of TO cm to form a light control film.

The obtained light control film is approximately 15° in front and on the left and right sides.
It was opaque when viewed from a range of angles. This light control film was peeled off from the glass plate and laminated between two methyl methacrylate resin plates using an adhesive to obtain a video projection screen.

The evaluation method was to project an image onto a screen and visually judge the brightness of the screen and the image. Also, the total light transmittance is JIS
It was measured using an integrating sphere type light transmittance measuring device according to K 6714, and the results are shown in Table 1.

Example 2 Two light control films were produced in the same manner as in Example 1, and the same as in Example 1 except that the light control films were laminated so that the directions of the angle dependence of the haze value were orthogonal to each other. A video projection screen was fabricated and evaluated. The results are shown in Table 1.

Example 3 After dissolving 33 parts of polymethyl methacrylate (refractive index 1.490) in 67 parts N-vinylpyrrolidone (refractive index 1.511), 3 parts of 2-hydroxy-2-methyl-propiophenone was dissolved. The added and mixed resin composition is placed on a glass plate for 3 minutes.
It was applied to a thickness of 0.00 ttm. 30W/cm, 5
Using a rod-shaped mercury lamp with a length of 0 cm, at a distance of 50C11,
A light control film was obtained by irradiating ultraviolet rays for minutes.

I got a projection screen.

The evaluation results are shown in Table 1.

Comparative Example 1 The same evaluation as in Example 1 was conducted using a conventional screen that is a combination of a Fresnel lens and a lenticular lens.

The evaluation results are shown in Table 1.

The obtained light control film was peeled from the glass plate and laminated between two acrylic plates (2 m+thickness) using an adhesive to obtain a projection screen.

The evaluation results are shown in Table 1.

Example 4 100 parts of trimethylolpropane triacrylate (refractive index before polymerization 1.47?, refractive index before polymerization 1.520
2-hydroxy-2-
The same procedure as in Example 3 was carried out except that a resin composition containing 3 parts of methyl-propiophenone was used.

[Brief explanation of drawings]

FIG. 1 is a drawing showing an example of the structure of a projection screen according to the present invention, and FIG. 2 is a drawing showing the structure of a conventional projection screen. Light source Transparent base material Light control film Fresnel lens Light diffusing material Substance-filled lenticular lens Figure 1 Figure 112

Claims (2)

[Claims] (1) A composition containing at least two types of monomers or oligomers having polymerizable carbon-carbon double bonds and capable of producing polymers each having a different refractive index; at least one compound having a polymerizable carbon-carbon double bond and capable of producing a polymer having a refractive index different from that of the compound.
Compositions containing a variety of monomers or oligomers; Compositions containing at least one monomer or oligomer that has multiple polymerizable carbon-carbon double bonds in the molecule and have different refractive indexes before and after polymerization. A projection screen comprising a light control film whose haze value is angularly dependent, obtained by curing at least one selected composition by irradiating light from a rod-shaped light source or a linear light source. (2) The projection screen according to claim 1, which is comprised of a laminated light control film obtained by laminating the light control films so that the directions of angular dependence of the light control films are orthogonal to each other.