KR100859365B1 - Transmitting screen-use light diffusing member - Google Patents

Abstract

Provided is a light diffusing member for use in a transmissive screen which also has an excellent surface protection effect while maintaining an antireflection effect. A light diffusing member for a transmissive screen in which a hard coat layer is provided on a surface of a substrate composed of at least one layer, wherein the substrate contains fine particles, and the surface glossiness of the hard coat layer is incident angle 60 ° / reflection angle 60 °. When the surface glossiness of a gloss standard plate is 100 on the measurement conditions of, it shall be 60-80.

Hard coat layer, light-diffusion member for transmissive screens, fine particles, surface glossiness, gloss standard plate

Description

Light diffusion member for transmissive screens {TRANSMITTING SCREEN-USE LIGHT DIFFUSING MEMBER}

The present invention relates to a light diffusing member for use in a transmissive screen for use in a transmissive projection TV and the like, an optical member and a transmissive screen using the light diffusing member.

The transmissive projection TV is a display device that enlarges and projects an image from a light source such as a CRT, a liquid crystal projector, or a DLP on a transmissive screen. In such a display device, a light diffusing plate or the like for diffusing outgoing light is provided on the screen surface in order to reduce glare when the screen is visually seen. In addition, in order to reduce the visibility deterioration of the projection image by the reflection of external light to the screen surface, an antireflection film may be provided on the screen surface. Such a light diffusion plate and an antireflection film are organic in the resin constituting the light diffusion plate or the like, as disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 11-295818 and Japanese Patent Application Laid-open No. Hei 7-28169. It is produced by containing transparent fine particles, such as a filler. Moreover, what has the antireflection effect also has been developed by making transparent microparticles | fine-particles protrude on the resin surface, and forming the surface of a light-diffusion plate into an uneven | corrugated shape.

However, when a protective layer (also referred to as a hard coat layer) is provided on the surface of the light diffusion plate to protect the screen surface, there is a problem in that the uneven shape of the surface of the light diffusion plate is lost, so that an antireflection effect cannot be obtained.

On the other hand, if the protective layer is to be provided to the extent of antireflection effect, there is a problem that a sufficient surface protection effect cannot be obtained because the thickness of the protective layer must be made thinner than the degree of irregularities on the surface of the light diffusion plate, that is, the particle diameter of the transparent fine particles. there was.

The present inventors can control the surface hardness and surface glossiness of the hard coat layer by adjusting the particle diameter and content of the fine particles contained in the substrate and the thickness of the resin forming the hard coat layer when the hard coat layer is provided on the light diffusion plate. It has been found that the light diffusing member having a sufficient surface protection effect can be realized while maintaining the antireflection effect. The present invention is based on this finding.

Accordingly, the present invention provides a light diffusing member for use in a transmissive screen which also has an excellent surface protection effect while maintaining an antireflection effect.

The light diffusing member for a transmissive screen according to the present invention is a light diffusing member for a transmissive screen in which a hard coat layer is provided on a surface of a substrate composed of at least one layer, wherein the substrate contains fine particles. The surface glossiness of the layer is 60 to 80 when the surface glossiness of the gloss standard plate is 100 under the measurement conditions of the incident angle of 60 ° / reflection angle of 60 °. Moreover, as a preferable aspect, the surface hardness of the said hard-coat layer is 3H or more in the pencil hardness test based on JISK5600-5-4. By providing the hard coat layer having the surface hardness as described above on the observer side (most surface), a sufficient surface protection effect can be realized while maintaining the antireflection effect.

[Detailed Description of the Invention]

Hereinafter, the light diffusing member according to the present invention will be described.

As shown in FIG. 1, the light-diffusion member according to the present invention has a structure in which a hard coat layer 3 is provided on the surface of the substrate 1 containing the fine particles 2, and the hard coat layer is disposed on the foremost surface of the observer side. It is installed. Here, the foremost surface on the observer's side means that the light diffusing member is located on the outermost surface on the side for viewing the transmitted light when the light diffusing member is incorporated into the transmissive screen.

The light-diffusion member by this invention is 60-80 in the measurement conditions of the surface glossiness of the hard-coat layer provided on the base material at the incident angle of 60 degrees / reflection angle of 60 degrees. Here, surface glossiness means the relative value at the time of making the glass plate of refractive index 1.567 based on JISK5600-4-7 a standard gloss plate, and making the surface glossiness of a standard gloss plate 100. If the surface glossiness of the hard-coat layer which comprises the light-diffusion member of this invention is 60-80, the anti-reflective effect excellent as a transmissive screen use will be obtained. When the surface glossiness is less than 60, the light diffusion on the surface of the hard coat layer becomes remarkable, so that the haze value increases and the light transmittance as a screen decreases. On the other hand, if it exceeds 80, since the regular reflection of light on the surface of the hard coat layer becomes dominant, the reflection of external light of the screen occurs. In addition, surface glossiness can be measured using a general glossmeter (for example, a handy glossmeter: GLOSS CHECKER IG-330, an acid and abrasive). In order for the hard coat layer to have the above-mentioned surface hardness and surface glossiness, the particle size and content of the fine particles contained in the substrate and the thickness of the resin forming the hard coat layer must be in the ranges described below.

It is preferable that the hard-coat layer 3 is 3-15 micrometers in thickness. If the thickness of a hard-coat layer is about this, the surface hardness of a hard-coat layer can be made into 3H or more by the pencil hardness test based on JISK5600-5-4 regardless of the material of a base material. If the thickness of the hard coat layer is less than 3 µm, the hardness of the material of the base material on the lower surface is affected, and sufficient surface hardness cannot be realized, and the damage preventing effect of the screen is not obtained. On the other hand, when it exceeds 15 micrometers, the thickness of a hard-coat layer will become thick too much, and the uneven | corrugated shape formed by the microparticles | fine-particles of a base material surface will not be projected on the hard-coat layer surface, and as a result, an antireflection effect cannot be expected. As for the thickness of a hard-coat layer, it is more preferable that it is 5-10 micrometers.

Moreover, it is preferable that the average particle diameters of the microparticles | fine-particles 2 contained in the base material 1 are 5-15 micrometers. If it is less than 5 micrometers, when a hard-coat layer is provided, the surface of a hard-coat layer will become too smooth and an antireflection effect will not be acquired. On the other hand, when the average particle diameter of microparticles | fine-particles exceeds 15 micrometers, the surface of a hard-coat layer will be rough, and an antireflection effect will reduce.

Moreover, it is preferable that the said microparticles | fine-particles are contained 10-20 weight% with respect to a base material. If it exceeds 20% by weight, the light diffusing effect by the fine particles becomes too large, so that the haze value as the transmissive screen increases, and a sufficient transmittance cannot be obtained. On the other hand, when it is less than 10 weight%, the light-diffusion effect is not fully acquired and the surface glossiness of a hard-coat layer will exceed 80.

As a base material used for this invention, a transparent resin film, a transparent resin plate, a transparent resin sheet, and transparent glass can be used. As a transparent resin film, a triacetate cellulose (TAC) film, a polyethylene terephthalate (PET) film, a diacetyl cellulose film, an acetate butyrate cellulose film, a polyether sulfone film, a polyacrylic resin film, a polyurethane resin film, a polyester film , Polycarbonate film, polysulfone film, polyether film, polymethylpentene film, polyether ketone film, (meth) acrylonitrile film and the like can be used most suitably. The thickness of a base material is about 0.025-2 mm normally.

As the microparticles | fine-particles 2 contained in the base material 1 used for this invention, organic fillers, such as a plastic bead, are the most suitable, It is especially preferable that transparency is high and refractive index difference with the hard-coat layer mentioned later is about 0.05.

Examples of the plastic beads include beads made of copolymer resins such as melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49), polycarbonate beads, polyethylene beads, polystyrene beads (1.60), vinyl chloride beads, and acrylic-styrene beads. It can use suitably. The beads made of these copolymer resins can change the refractive index by the content of each monomer. Among these, acrylic beads or methacryl-styrene copolymer (MS) beads are preferable. As for the particle diameter of a plastic bead, the thing of 5-15 micrometers is used as mentioned above.

In this invention, as shown in FIG. 1, you may provide the hard-coat layer 3 using the base material 1 as one layer, but as shown in FIG. 2, two layers of the base material 1a and the base material 1b. It is good also as a structure. Although content of the microparticles | fine-particles contained in the base material 1a needs to be made into the range demonstrated above, it is preferable to make content of microparticles | fine-particles contained in the base material 1b less than content of the microparticles | fine-particles in the base material 1a. When the optical member, such as the horizontal viewing angle expansion member mentioned later, is combined by reducing the content of the fine particles in the base material 1b, the bonding surface becomes smooth, and the adhesiveness of the light-diffusion member 4 and an optical member becomes high.

The hard coat layer constituting the light diffusion member according to the present invention may be a resin which is cured by ultraviolet rays or electron beams, that is, a mixture of a thermoplastic resin and a solvent in an ionizing radiation curable resin, an ionizing radiation curable resin, and a thermosetting resin. Among these, ionizing radiation curable resins are particularly preferable.

The film-forming component of the ionizing radiation curable resin composition preferably has an acrylate-based functional group, for example, a relatively low molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, alkyd resin, spiro Oligomers or prepolymers, such as (meth) acrylates which are polyfunctional compounds, such as acetal resin, polybutadiene resin, polythiolpolyene resin, and polyhydric alcohol, and ethyl (meth) acrylate, ethylhexyl (meth) acrylate, Monofunctional monomers and polyfunctional monomers, such as styrene, methyl styrene, and N-vinylpyrrolidone, for example, polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, and tripropylene glycol di (meth) Acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaeryth The thing which contains a relatively large amount of lititol hexa (meth) acrylate, 1, 6- hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. can be used.

In order to make the said ionizing radiation curable resin composition into an ultraviolet curable resin composition, there are acetophenones, benzophenones, Michler's benzoyl benzoate, α-amyl oxime ester, tetramethyl thiuram monosulfide, and thioxanthone as photopolymerization initiators. N-butylamine, triethylamine, poly-n-butylphosphine, etc. can be mixed and used as a type and a photosensitizer. In particular, in this invention, it is preferable to mix urethane acrylate as an oligomer, dipentaerythritol hexa (meth) acrylate, etc. as a monomer.

The hardening method of the said ionizing radiation curable resin composition can be hardened by a normal hardening method, ie, irradiation of an electron beam or an ultraviolet-ray.

For example, in the case of electron beam curing, 50 to 1000 keV emitted from various electron beam accelerators such as cockcroft Walton type, van degraf type, resonant transformer type, insulated core transformer type, linear type, dynamtron type, and high frequency type, are preferable. Preferably, an electron beam or the like having an energy of 100 to 300 keV is used, and in the case of ultraviolet curing, ultra-high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, ultraviolet light emitted from light rays such as carbon arc, xenon arc, metal halide lamp and the like can be used.

The hard coat layer constituting the light diffusing member according to the present invention is coated with a coating liquid of the ionizing radiation (ultraviolet) ray curable resin composition on a substrate by spin coating, die coating, dip coating, bar coating, flow coating, roll coating, and gravure. It can apply | coat to the surface of a base material by methods, such as a coat, and can form by hardening a coating liquid by the above means.

Next, a transmissive screen using the light diffusing member according to the present invention will be described.

The light diffusing member 4 according to the present invention can be used in combination with the horizontal viewing angle expanding member 8 as shown in FIG. 3. In this invention, the light-diffusion member is arrange | positioned at the foremost surface of a light transmission direction. In the optical member 9 of FIG. 3, the light-diffusion member 4 is provided in the foremost surface of a light transmission direction. The horizontal viewing angle expanding member 8 generally has a structure in which the lens 6 is provided on the lens base material 7. In the present invention, as shown in Fig. 3, a lens function is expressed by combining a boundary surface of the transparent resin portion 6 and the light absorbing portion (light shielding portion) 5 as a reflecting surface. The light absorbing portion may be provided on the lens substrate 7 to form the horizontal viewing angle expanding member 8. In the present invention, by combining the horizontal viewing angle expanding member 8 and the light diffusing member 4 in this manner, external light does not shine on the screen, so the visibility is excellent, the contrast is good, and a clear image can be realized.

In addition, in this invention, as shown in FIG. 4, a light-diffusion member may be combined with the cylindrical lens member 11, and an optical member may be comprised. The cylindrical lens member 11 is provided on one surface of the lens base material 10, and has a structure in which the light absorption part (shielding part) 12 is provided in the other surface. As the horizontal viewing angle expanding member combining the cylindrical lens member and the light absorbing portion, the lenticular lens member 13 may be used as shown in FIG. 5.

In the optical member using the light diffusing member, the light diffusing member and the lens member may be adhered to each other through an adhesive layer (not shown), and as shown in FIGS. 6 to 8, the light diffusing member and the horizontal viewing angle are shown. The magnification member or the lens member may be combined in a state where they are not bonded.

As shown in Figs. 9 to 11, the transmissive screen according to the present invention has a structure in which the optical member and the Fresnel lens member 14 are combined. In the present invention, since the light diffusing member 4 provided with the hard coat layer having a surface hardness of 3H or more is disposed on the outermost surface (viewer side) of the transmissive screen, external light or the like does not shine on the screen, A transmissive screen hard to be damaged can be realized.

1 shows a schematic cross-sectional view of a light diffusing member according to the present invention.

2 shows a cross-sectional schematic diagram of another type of light diffusing member according to the present invention.

It is a schematic cross section which shows an example of the optical member using the light-diffusion member which concerns on this invention.

It is a schematic cross section which shows an example of the optical member using the light-diffusion member which concerns on this invention.

It is a schematic cross section which shows an example of the optical member using the light-diffusion member which concerns on this invention.

It is a schematic cross section which shows an example of the optical member using the light-diffusion member which concerns on this invention.

It is a schematic cross section which shows an example of the optical member using the light-diffusion member which concerns on this invention.

It is a schematic cross section which shows an example of the optical member using the light-diffusion member which concerns on this invention.

It is a schematic cross section which shows an example of the transmissive screen by this invention.

It is a schematic cross section which shows an example of the transmissive screen by this invention.

It is a schematic cross section which shows an example of the transmissive screen by this invention.

Although an Example demonstrates this invention further in detail below, this invention is not limited to these Examples.

MS (methacryl-styrene copolymer) resin (refractive index 1.53) was used as resin used for the base material of a light-diffusion member. The fine particles added to the substrate were added so that the amount of fine particles added to the substrate was 15% by weight using MS beads (refractive index: 1.49, average particle diameter: 10 mu m). These mixtures were extrusion-molded by the melt extruder, and the base material of the light-diffusion member was produced.

Next, the surface of this base material is coated with a UV curable resin composition containing urethane acrylate as a main component by a dip coating method, and irradiated with ultraviolet rays to cure the resin composition to form a hard coat layer on the base material to form a light diffusion member. Got it. The thickness of the hard coat layer was adjusted by adjusting the speed of raising the substrate from the coating liquid layer when the hard coat layer was formed by the dip coating method. In the same way, the light-diffusion member which changed the thickness of the hard-coat layer was produced. Each film thickness of the hard coat layer was as shown in Table 1.

Next, about the obtained light-diffusion member, the surface gloss of the surface by which the hard-coat layer was provided in the measurement conditions of incident angle 60 degrees / reflection angle 60 degrees using the surface glossmeter (handy glossmeter GLOSS CHECKER 1G-330: Sanwa abrasive). Degrees were measured.

In addition, the pencil hardness test was implemented by the method based on JISK5600-5-4 about the surface of the side in which the hard-coat layer of the light-diffusion member was provided.

Moreover, the lenticular lens sheet and the Fresnel lens sheet were combined, and the obtained light-diffusion member was incorporated in the said lenticular lens side, and the transmissive screen was produced. The sensory evaluation of the image quality of the produced screen was performed. Moreover, the external light was exposed to the screen surface (light-diffusion member side) in the state which projected the image on the obtained transmissive screen, and the evaluation which reflected external light on the screen surface was evaluated.

Evaluation criteria were as follows.

1. Quality Evaluation

(Circle): The screen of a screen is bright, and the outline of an image was clear.

(Triangle | delta): The screen of the screen was slightly white, and the outline of an image was slightly blurred.

×: Screen of screen was light gray, and outline of image was blurry

2. Evaluation of external light on the screen surface

(Circle): It was weak, and the visibility of the image was favorable.

(Triangle | delta): Although there was an invisibility, visibility of the image was normal

×: The reflection was very strong and the visibility of the image was bad

Measurement results and evaluation results are shown in Table 1.

TABLE 1

Hard coat layer film thickness (㎛)  Surface glossiness  Surface hardness  Quality  Shine Example 1 3 62 3H △ ○ Example 2 5 66 3H ○ ○ Example 3 10 71 3H ○ ○ Example 4 15 79 4H ○ △ Comparative Example 1 0 26 H × ○ Comparative Example 2 1.5 47 2H × ○ Comparative Example 3 20 89 4H ○ × Comparative Example 4 30 110 4H ○ ×

According to the present invention, it is possible to provide a light diffusing member for use in a transmissive screen which also has an excellent surface protection effect while maintaining an antireflection effect. The present invention provides a light diffusing member for a transmissive screen having a hard coat layer provided on a surface of a substrate having at least one layer, wherein the substrate contains fine particles, and the surface glossiness of the hard coat layer has an incident angle of 60 °. When the surface glossiness of a gloss standard plate is 100 under the measurement conditions of 60 degree of reflection angle, it shall be 60-80.

Claims (12)

As a light-diffusion member for transmissive screens in which a hard coat layer is provided on the surface of a base material consisting of one layer or two or more layers, The light-diffusion member which microparticles | fine-particles are contained in the said base material, and the surface glossiness of the said hard-coat layer is 60-80, when the surface glossiness of a gloss standard plate is 100 under the measurement conditions of an incident angle of 60 degrees / reflection angle of 60 degrees. The method of claim 1, The surface hardness of the hard coat layer is 3H or more in a pencil hardness test according to JIS K5600-5-4. No light diffusion. The method of claim 1, The hard coat layer is provided on the foremost surface on the observer's side. No light diffusion. The method according to any one of claims 1 to 3, The hard coat layer has a thickness of 3 to 15 µm. No light diffusion. The method of claim 1, The average particle diameter of the said fine particles is 5-15 micrometers No light diffusion. The method of claim 1, 10 to 20% by weight of the fine particles contained in the substrate No light diffusion. The method of claim 1, The hard coat layer is made of an ionizing radiation curable resin No light diffusion. The method of claim 1, Said microparticles | fine-particles consist of an acryl-styrene copolymer resin No light diffusion. An optical member combining the light diffusing member according to claim 1 and a horizontal viewing angle expanding member, An optical member for a transmissive screen in which the light diffusing member is disposed at the foremost surface in the light transmission direction. As an optical member which combined the light-diffusion member and lens member of Claim 1, An optical member for a transmissive screen in which the light diffusing member is disposed at the foremost surface in the light transmission direction. As an optical member which combined the light-diffusion member and lenticular lens member of Claim 1, The light diffusing member is disposed on the foremost surface in the light transmission direction Optical member for transmissive screen. The transmissive screen which combined the optical member and Fresnel lens member of any one of Claims 9-11.

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