JP2008032979A - Film lenticular lens support plate and manufacturing method thereof - Google Patents

Abstract

To provide a support plate for a film lenticular lens that can prevent glare of a screen on a projection screen and can secure a sufficient field of view range.
A support plate for a film lenticular lens having an anisotropic light scattering layer whose light diffusion direction is perpendicular to the light diffusion direction of the film lenticular lens is used. The anisotropic light scattering layer irradiates a film-like composition containing at least two kinds of compounds each having a polymerizable carbon-carbon bond in the molecule and different refractive indexes from a rod-like light source. It is formed by curing the composition.
[Selection] Figure 1

Description

  The present invention relates to a support plate for a film lenticular lens, and more particularly to a support plate used for bonding and supporting a film lenticular lens on one side.

  As a projection screen incorporated in a projection display, a screen having a lenticular lens and a Fresnel lens is usually used. Recently, a screen using a film-like lenticular lens is also known. (For example, refer to Patent Document 1). For example, as shown in FIG. 1, the projection screen 4 using the film lenticular lens 2 is provided with light diffusion performance by a diffusing agent in order to secure a visual field range in a direction perpendicular to the light diffusion direction of the film lenticular lens 2. A support plate 1, a film lenticular lens 2 bonded to the support plate 1, and a Fresnel lens 3 disposed at a distance from the film lenticular lens 2. The image light L is projected from the projector 5 and viewed from the support plate 1 side.

JP 2002-122715 A

  However, the above conventional projection screen has a problem that screen glare is likely to occur because the light diffusing performance is imparted to the support plate by the diffusing agent in order to ensure the field of view. Therefore, as a result of intensive studies to develop a support plate that can prevent glare on the screen and sufficiently secure the field of view range, the present inventors have used the support plate having a predetermined anisotropic light scattering layer as described above. The inventors have found that desired performance can be obtained and have reached the present invention.

  That is, the present invention is a support plate for laminating and supporting a film lenticular lens, having an anisotropic light scattering layer whose light diffusion direction is in a direction perpendicular to the light diffusion direction of the film lenticular lens, The anisotropic light scattering layer irradiates light from a rod-shaped light source onto a film-like composition containing at least two kinds of compounds each having a polymerizable carbon-carbon bond in the molecule and having a different refractive index. A support plate for a film lenticular lens, which is obtained by curing the composition, is provided.

  Further, according to the present invention, there is provided a suitable method for producing the support plate, wherein the surface of the light-transmitting substrate has a polymerizable carbon-carbon bond in each molecule and has a refractive index different from each other. There is provided a method for producing a support plate for a film lenticular lens, which comprises applying a composition containing two kinds of compounds and curing the composition by irradiating light from a rod-shaped light source.

  By using the support plate of the present invention, it is possible to prevent glare of the screen and to ensure a sufficient field of view range.

  The support plate of this invention is a support plate for bonding and supporting a film lenticular lens, Comprising: It has an anisotropic light-scattering layer. Typically, an anisotropic light scattering layer is provided on the surface of the light transmissive substrate.

  As a material constituting the light-transmitting substrate, a thermoplastic resin is usually used, and methyl methacrylate-styrene copolymer resin (MS resin), polystyrene resin (PS resin) is less warped due to moisture absorption during use. ), Polycarbonate resin (PC resin), cyclic polyolefin resin and the like are preferably used. MS resin is a resin obtained by copolymerizing methyl methacrylate and styrene, and the mass ratio of methyl methacrylate units to styrene units is usually 20:80 to 80:20, preferably 40:60 to 70. : About 30. The MS resin may contain monomer units other than methyl methacrylate and styrene.

  The thickness of the light-transmitting substrate is usually about 0.05 to 2 cm, preferably about 0.1 to 0.5 cm in terms of practicality that can support a film lenticular lens and the mass is not excessive. As the light-transmitting substrate, a straight-transmitting substrate that does not contain a diffusing agent is usually used. However, within the range that does not impair the effects of the present invention, a diffusing agent may be included to impart diffuse permeability. Good.

  An anisotropic light scattering layer is provided on the surface of the light transmissive substrate, and the support plate of the present invention is configured. This anisotropic light scattering layer has an anisotropic diffusion transmission performance that transmits incident light while diffusing in a specific direction, and the light diffusion direction is orthogonal to the light diffusion direction of the film lenticular lens to be bonded. Set to direction. Thereby, the visual field range of the direction orthogonal to the light-diffusion direction of a film lenticular lens is securable.

  Each of the anisotropic light scattering layers irradiates light from a rod-shaped light source onto a film-like composition containing at least two kinds of compounds each having a polymerizable carbon-carbon bond in the molecule and different refractive indexes. Thus, the composition is preferably formed by curing.

Specifically, a compound having a polymerizable carbon-carbon bond in the molecule (hereinafter sometimes simply referred to as a polymerizable compound) has a polymerizable carbon-carbon bond in the molecule and an acryloyl group [CH ₂ = CHCO-], a methacryloyl group _{[CH 2 = C (CH 3)} CO- ], a vinyl group [CH ₂ = CH-], allyl [CH ₂ = CHCH ₂ -] are those having the like, various monomers or oligomers Can be used.

  Examples of the monomer include tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, dicyclopentenyloxyethyl acrylate, phenyl carbitol acrylate, nonylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and ω-hydroxyhexanoyloxyethyl. Acrylate, acryloyloxyethyl succinate, acryloyloxyethyl phthalate, 2,4,6-tribromophenyl acrylate, 2,4,6-tribromophenoxyethyl acrylate, isobornyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, 2 , 2,3,3-tetrafluoropropyl acrylate, phenyl carbitol acrylate, nonylphenoxye Acrylate, cumylphenyl acrylate, methacrylates corresponding to these monofunctional acrylates, N-vinyl pyrrolidone, triallyl isocyanurate, diethylene glycol diallyl carbonate, diarylidene pentaerythritol and alkylene glycol adducts thereof Can be mentioned.

  Examples of the oligomer include polyester acrylate, polyol polyacrylate, modified polyol polyacrylate, isocyanuric acid skeleton polyacrylate, melamine acrylate, hydantoin skeleton polyacrylate, polybutadiene acrylate, epoxy acrylate, urethane acrylate, and their multifunctional products. And methacrylates corresponding to the functional acrylate.

  These polymerizable compounds are used as a composition comprising at least two kinds of mixtures. At this time, one having a difference in refractive index is selected. By irradiating light from a predetermined direction and curing the composition in which at least two polymerizable compounds having different refractive indexes are mixed, a light scattering region, that is, a light scattering angle region is formed. This composition expresses the angle dependence of light scattering due to the mutual solubility of each of a plurality of composing compounds and the difference in refractive index, and the difference in refractive index is large due to a combination with poor compatibility. When the reaction rate is different, the degree of light scattering increases. This refractive index difference is preferably 0.01 or more.

  In order to improve curability, this composition is usually mixed with a photopolymerization initiator and subjected to photopolymerization. Examples of the photopolymerization initiator include benzophenone, benzyl, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzoin methyl ether, benzoin ethyl ether, diethoxyacetophenone, benzyldimethyl ketal, and 2-hydroxy-2-methyl. Examples include propiophenone and 1-hydroxycyclohexyl phenyl ketone.

  The support plate of the present invention can be produced by applying the composition directly on the surface of the light-transmitting substrate and gradually curing the composition while irradiating light from a rod-shaped light source. Moreover, the anisotropic light-scattering film obtained by applying the composition to the surface of a peelable substrate once, gradually curing it while irradiating light from a rod-shaped light source, and then peeling it off from the substrate is used as a light-transmitting film. Although it can manufacture also by bonding to a board | substrate, when the contrast fall by the reflection of a bonding interface and the bonding cost are considered, it is more preferable to apply | coat and harden the said composition directly to a transparent substrate.

  The method for applying the photocurable composition to the substrate surface is not particularly limited, and the photocurable composition may be applied by an ordinary method such as a bar coating method, a roll coating method, a die coating method, or a dipping method. it can.

  The light used for curing may have any wavelength as long as it cures the composition, and for example, visible light, ultraviolet light, and the like are often used. Ultraviolet rays are emitted from mercury lamps, metal halide lamps, etc., but by using a rod-shaped lamp and adjusting the irradiation conditions, the generated photocured film is anisotropic with respect to the major axis and minor axis direction of the light source. Only when the light source is rotated about the major axis direction of the light source, an anisotropic light scattering layer that scatters light at a specific angle is obtained.

  The degree of scattering and the angle of selectively scattered incident light can be adjusted depending on the composition used and the irradiation conditions, and in particular, by changing the incident angle of the irradiated light on the film-like composition sample surface during curing, When the light incident on the cured film is emitted from the film, the angle range with respect to the sheet film surface that is scattered or transmitted straight can be controlled.

  At the time of photocuring, a light scattering angle region is developed around the light irradiation direction. For example, if light is irradiated almost perpendicularly to the film surface formed from the photocurable composition, a light scattering angle region appears around the normal direction, that is, the normal direction, and the normal direction is When light is irradiated from an oblique direction inclined by a predetermined angle, a light scattering angle region is developed around the inclined direction.

  An example in the case of irradiating light from the perpendicular direction to the photocurable composition film will be described based on FIG. (A) of FIG. 2 is a side view schematically showing an example of an apparatus that can be used when light is irradiated from the vertical direction to the photocurable composition film, and (B) shows the apparatus. FIG. This apparatus includes a conveyor 10 that moves in the direction of a hollow arrow, a light shielding plate 12 that is disposed above the conveyor 10 and has slits 13 formed in the width direction of the conveyor, and a bar-like shape that is further spaced apart by a predetermined distance. It comprises a light source lamp 15. The slit 13 is formed so as to coincide with the length direction of the light source lamp 15. Then, the substrate 20 on which the photocurable composition film is formed is placed on the conveyor 10, and the light from the light source lamp 15 is applied to the composition film through the slits 13 of the light shielding plate 12 while moving at a constant speed. When irradiated, the composition film is centered on light in the vertical direction, and thus phases having different refractive indexes are alternately formed in the vertical direction (normal direction), and the light scattering angle region is centered on that direction. Will be expressed. By controlling the width of the slit 13, the distance from the rod-shaped light source lamp 15 to the photocurable composition film, the thickness of the photocurable composition film, the amount of irradiation light, the wavelength of the irradiation light, etc. Large and small can be controlled.

  The support plate of the present invention thus obtained has a light scattering angle region width of 30 ° or more showing a haze value of 60% or more when light is incident on the surface at an angle of 0 to 180 °. And more preferably 40 ° or more. However, if the width of this light scattering angle region is too large, the whole becomes dark and difficult to use, so it is usually within 100 °. Moreover, it is preferable that the center of the light scattering angle region showing a haze value of 60% or more substantially coincides with the normal direction.

  In addition, the support plate of the present invention has an angle distribution of light transmission intensity of light incident at an angle of 90 ° with respect to the surface in the vertical direction of the screen, that is, the direction perpendicular to the direction in which light is diffused by the film lenticular lens. The transmission direction in the front direction (the same direction as the incident angle) of the screen is the strongest, and the angle direction (half-value angle) at which the transmission intensity is half of the front direction is 10 to 40 ° with respect to the front direction. Preferably, the angle is 15 to 40 °. When the half-value angle is less than 10 °, the end portion becomes dark and the visual field range becomes narrow. If the half-value angle exceeds 40 °, the entire screen becomes dark.

  A film lenticular lens is bonded to the side surface of the anisotropic scattering layer of the support plate of the present invention or the opposite surface. Since the surface opposite to the bonding surface is an observer side, various surface treatments may be performed for surface protection and image quality improvement. Examples of the surface treatment include a hard coat, an antireflection treatment, an antiglare treatment, and an antistatic treatment, and the surface treatment may be performed directly on the support plate, or a surface treated film may be bonded.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by this Example. The evaluation method is as follows.

[Cloudiness value]
In accordance with JIS K7136, using a haze / transmittance / reflectometer ("HR-100" manufactured by Murakami Color Research Laboratory Co., Ltd.), light is incident from the normal direction to measure total light transmittance and diffuse transmittance. Haze value (%) = diffuse transmittance (τ _d ) / total light transmittance (τ _t ) × 100.

(Light scattering angle range)
The angle dependency of the haze was measured as follows. That is, when the angle θ of the incident light to the test piece is changed between 0 to 180 ° and the haze value is measured for each angle, the incident light is scattered in a specific angle range and shows a high haze value. In other angle ranges, incident light basically travels straight and exhibits a low haze value. And the angle range which shows the haze of 60 degrees or more was made into the light scattering angle area. The angle θ is a value in which the direction parallel to the surface of the test piece is 0 ° and the normal direction of the test piece is 90 °, and the rotation of the test piece maximizes the angle dependency of the haze value. Went in the direction. The haze value is determined by measuring the total light transmittance and diffuse transmittance using an integrating sphere light transmittance measuring device, and the haze value (%) = diffuse transmittance (τ _d ) / total light transmittance (τ _t ) x100.

[Scintillation evaluation (glare evaluation)]
For a film lenticular lens in which a cylindrical lens having a lens pitch of about 0.15 mm was formed on one side of the film, and a black stripe was formed in addition to the light condensing portion on the surface opposite to the lens, the film lenticular lens obtained in Example 1 The light control plate and the light diffusing plate of Comparative Examples 1 and 2 were bonded together, and the DLP light source was set at the center of the screen set position of the projection television so that the lenticular lens was on the light source side, and evaluated in a white screen state. Here, the light control plate of Example 1 is set so that the photocuring film is on the lenticular lens side, and the diffusion direction according to the lens shape of the lenticular and the light scattering angle region shown in Example 1 of the light control plate Was set so that the direction indicating (= light diffusion anisotropy direction) was orthogonal. In this state, the glare state (scintillation state) was visually evaluated.

Example 1
Polypropylene glycol having an average molecular weight of about 3,000 and a poly (polyethylene glycol) obtained by reacting 0.3 mol of toluene diisocyanate, 2.7 mol of hexamethylene diisocyanate and 2 mol of 2-hydroxyethyl acrylate per 2 mol of the polypropylene glycol. 40 parts by mass of ether urethane acrylate (refractive index 1.460), 30 parts by mass of 2,4,6-tribromophenyl acrylate (refractive index 1.6 or more), 2-hydroxy-3-phenoxypropyl acrylate (refractive 1.526) A photocurable composition prepared by adding 30 parts by mass and 1.5 parts by mass of 2-hydroxy-2-methylpropiophenone is composed of 60% by mass of methyl methacrylate units and 40% by mass of styrene units. Methyl methacrylate-styrene copolymer resin (MS resin) It was coated to a thickness of about 220μm to the extrusion-obtained 2mm thick sheet. A 80 W / cm rod-shaped high-pressure mercury lamp is fixed at a position 80 cm above the coating film, and the coating film is coated at a speed of 1 m / min through a light-shielding plate with a slit so that light is perpendicular to the entire coating film. The attached MS resin substrate is irradiated with light while moving in the lateral direction by the method as shown in FIG. 2 to obtain a light control plate, and the photocurable composition is applied to the control plate at a thickness of about 220 μm. It was applied and cured in the same way. The haze was 91.1%. Further, the light scattering angle region showing a haze value of 60% or more was in the range of 65.6 to 108.2 ° (center 86.9 °, width 42.6 °). As a result of evaluating the scintillation by bonding the light control plate to a film lenticular lens, the evaluation result was satisfactory with little glare.

Comparative Examples 1-2
Generally used as a film wrench support plate, a haze value of 81.4% and 87.9%, a two-type three-layer diffusion plate (transparent layer / light diffusion layer / transparent layer with a thickness of about 0.1 mm / about 1.65 mm) / About 0.1 mm). MS resin is used for the transparent layer, and the light diffusion layer is a layer containing organic crosslinked particles having a refractive index of 1.55 and an average particle diameter of 12 μm with respect to the MS resin (refractive index of 1.53). The two-type three-layer diffusion plate is isotropic diffusion without anisotropy in diffusion. As a result of scintillation evaluation by bonding the light diffusing plate with a film lenticular lens, all of the evaluation results were not good because of a lot of glare.

It is sectional drawing which shows typically the structure of the support plate for film lenticular lenses, and the projection screen using the same. It is the side view (A) and perspective view (B) which show the example of the apparatus in the case of irradiating light from a perpendicular direction with respect to a photocurable composition coating film.

Explanation of symbols

1 ... Support plate for film lenticular lens, 2 ... Film lenticular lens,
3 ... Fresnel lens, 4 ... Projection screen, 5 ... Projector, 10 ... Conveyor,
12 ... Light-shielding plate, 13 ... Slit provided in the light-shielding plate, 15 ... Bar-shaped light source lamp,
20: A substrate on which a photocurable composition film is formed.

Claims (2)

  A support plate for laminating and supporting a film lenticular lens having an anisotropic light scattering layer whose light diffusion direction is perpendicular to the light diffusion direction of the film lenticular lens, The film-like composition containing at least two kinds of compounds each having a polymerizable carbon-carbon bond in the molecule and having a different refractive index is irradiated with light from a rod-shaped light source to cure the composition. A support plate for a film lenticular lens, characterized by being made. A composition containing at least two kinds of compounds each having a polymerizable carbon-carbon bond in the molecule and having a different refractive index is applied to the surface of the light-transmitting substrate and irradiated with light from a rod-shaped light source. And a method for producing a support plate for a film lenticular lens, wherein the composition is cured.

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