JP2000292861A - Lenticular lens sheet and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a light absorbing layer capable of giving a high contrast image at an exact location in a short time with good productivity by forming the light absorbing layer by using an active energy line-cured resin in recesses between the adjacent lenticular lenses on the light emergent face of a substrate. SOLUTION: Light emergent lenticular lenses 1 comprising an active energy line-cured resin are formed on one face of a light transmissive substrate 5 and light incident lenticular lenses 2 comprising an active energy line-cured resin are formed on the other face. Black stripes 3 as a light absorbing layer are formed by using an active energy line-cured resin in recesses corresponding to non-condensing regions between the light emergent lenticular lenses 1. The active energy line-cured resin forming the black stripes 3 is, e.g. polyester resin or epoxy resin cured with UV or electron beams. An ionizing radiation-curable composition used for the cured resin contains a poly (meth)acrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lenticular lens sheet used for a projection screen suitable as a screen for a projection television or a microfilm reader, and more particularly to a lenticular lens having a fine pitch and a uniform lens thickness. The present invention relates to a double-sided lenticular lens sheet capable of easily forming a lens and providing a high-definition and high-quality image.

[0002]

2. Description of the Related Art A lenticular lens sheet is a CRT.
In order to form an image projected from a projection device such as a projector, an LCD projector, and a DMD (digital micromirror device) projector, and to diffuse an incident light beam to widen a viewing angle, a Fresnel lens sheet is usually used. Used in combination as a screen.

A lenticular lens sheet generally used as a screen, as shown in FIG.
An lenticular lens 1 having an elliptical cross section formed on the light incident surface side, a lenticular lens 2 formed on the light emitting surface side (observation side), and a light absorbing layer 3;
The light diffusing material 4 is dispersed in the sheet. Light absorbing layer 3
As shown in FIG. 3B, a ridge is formed in a non-light-condensing area between adjacent lenticular lenses on the exit surface, and a light absorbing layer 3 is formed on the ridge (top on the observation side). 3A, the light absorbing layer 3 is formed in a concave portion corresponding to a non-light-condensing region between the adjacent exit surface lenticular lenses as shown in FIG. 3A, and the latter has a wide viewing angle. It is suitable from the viewpoint of securing

The external light absorbing layer 3 formed on the exit surface lenticular lens of the lenticular lens sheet is for preventing the reflection of external light and improving the contrast of an image, and contains a black pigment or dye. A black ink is used, and a general printing technique is used as a forming method thereof. However, when such a black ink is used, it is necessary to perform a drying treatment of a solvent contained in the black ink, and it takes a long time for the drying, resulting in poor productivity and a complicated manufacturing apparatus. Had problems.

[0005]

On the other hand, in video display devices such as projection televisions, demands for higher image quality and higher definition have been increasing in recent years in order to cope with higher resolution of images. Under such circumstances, a lenticular lens sheet used as a screen of a projection television or the like is required to have high resolution, high contrast, and a wide viewing angle. In order to cope with such a high resolution, it is necessary to make the lens pitch very fine, 500 μm or less, but it is difficult to form a light absorbing layer accurately in the concave portion between the lenticular lenses having such a fine pitch. It was very difficult.

Accordingly, an object of the present invention is to provide a lenticular lens sheet capable of forming a light absorbing layer capable of providing a high-contrast image at an accurate position in a short time with high productivity, and a method of manufacturing the same.

[0007]

SUMMARY OF THE INVENTION In view of such circumstances, the present inventors have made it possible to form a light absorbing layer with a fine pitch lenticular lens sheet by forming the light absorbing layer with an active energy ray curable resin. The present inventors have found that they can be formed in a suitable position in a short time with high productivity, and have reached the present invention.

That is, the lenticular lens sheet of the present invention is a lenticular lens sheet in which a large number of lenticular lenses are formed in parallel at least on the exit surface, and a concave portion formed between adjacent lenticular lenses on the exit surface. The light absorption layer is formed of an active energy ray-curable resin.
In addition, the method of manufacturing a lenticular lens sheet according to the present invention may further include a method of manufacturing the lenticular lens sheet, wherein at least a plurality of lenticular lenses are formed in parallel on the output surface. And curing the active energy ray-curable composition by irradiating an active energy ray from one or both sides of the lenticular lens sheet.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

[0010] The lenticular lens sheet of the present invention comprises:
As shown in FIG. 1, a lenticular lens 1 made of an active energy ray-curable resin is formed on one surface of a translucent substrate 5, and an incident surface lenticular lens 2 made of an active energy ray-cured resin is formed on the other surface. Is formed. Further, an external light absorbing layer 3 is formed in a concave portion corresponding to a non-light-condensing region between the exit surface lenticular lenses 1. In the figure, reference numeral 4 denotes a light diffusing material contained in a lenticular lens, and inorganic fine particles made of glass, silica, talc, barium sulfate, etc., acrylic resin, styrene resin, polyethylene,
Organic fine particles such as nylon and polycarbonate can be used. The configuration of the lenticular lens sheet is not limited to this, and even if a lenticular lens is formed only on one surface of the translucent substrate 5,
The lenticular lens may be formed of a thermoplastic resin, or may not use a translucent substrate.

The present invention is characterized in that the light absorption layer 3 is formed of an active energy ray-curable resin in a concave portion formed between the adjacent lenticular lenses 2 on the exit surface.
The active energy ray-curable resin forming the light absorbing layer 3 is not particularly limited as long as it is cured with an active energy ray such as an ultraviolet ray or an electron beam. For example, polyesters, epoxy resins, polyesters (Meta)
(Meth) acrylate resins such as acrylate, epoxy (meth) acrylate, and urethane (meth) acrylate are exemplified. Among them, (meth) acrylate resins are particularly preferable from the viewpoint of their optical characteristics and the like. Examples of the ionizing radiation-curable composition used for such a cured resin include polyvalent acrylate and / or polyvalent methacrylate (hereinafter, referred to as polyvalent (meth) acrylate) in terms of handleability and curability. It is preferable to use monoacrylate and / or monomethacrylate (hereinafter, referred to as mono (meth) acrylate) and a photopolymerization initiator using active energy rays as main components. Representative polyvalent (meth) acrylates include polyol poly (meth) acrylate, polyester poly (meth) acrylate, epoxy poly (meth) acrylate, urethane poly (meth) acrylate, and the like. These can be used alone or
Used as a mixture of more than one species. Also, thing (meta)
As the acrylate, mono-alcohol mono (meth)
Acrylic esters and mono (meth) acrylic esters of polyols are exemplified.

The light absorbing agent contained in the light absorbing layer 3 may be a dye-based one, a carbon black-based one, or a resin bead colored therewith. These light absorbers are preferably contained in the range of 0.5 to 15% by weight in the case of dyes or carbon black, and in the range of 5 to 40% by weight in the case of resin beads. In the present invention, additives such as a flame retardant and a matting agent may be further added to the light absorbing layer 3 as necessary.

The light-transmitting substrate 5 constituting the lenticular lens sheet of the present invention is not particularly limited as long as it is a material that transmits active energy rays such as ultraviolet rays and electron beams.
A flexible glass plate or the like can be used, but polyester resin, acrylic resin, polycarbonate resin,
A transparent resin sheet or film such as a vinyl chloride resin or a polymethacrylimide resin is preferable. In particular, those made of polymethyl methacrylate having a low surface reflectance, a mixture of polymethyl acrylate and polyvinylidene fluoride-based resin, polycarbonate-based resin, and polyester-based resin such as polyethylene terephthalate are preferable. The thickness of the light-transmitting substrate 5 varies depending on its use, but is 50 μm or more.
Those having a range of about 5 mm are used. In addition, in order to improve the adhesiveness with the lenticular lenses 1 and 2, it is preferable that the surface of the translucent substrate 5 be subjected to an adhesiveness improving treatment such as an anchor coat treatment.

The active energy ray-curable resin for forming the light incident surface lenticular lens 2 and the light emitting surface lenticular lens 1 is not particularly limited as long as it is cured with active energy rays such as ultraviolet rays and electron beams. Instead, a material similar to the active energy ray-curable resin used for the light absorbing layer 3 can be used.

Next, a method for manufacturing a lenticular lens sheet according to the present invention will be described with reference to FIG. Reference numerals 8 and 8 ′ in the figure denote lens molds having a lens pattern in which lenticular lens units are imprinted, such as aluminum, brass, metal molds made of metal such as steel, silicone resin, polyurethane resin, epoxy resin, ABS resin,
A resin mold made of a synthetic resin such as a fluororesin or polymethylpentene resin, an electroforming mold manufactured by Ni electroforming, or the like is used.
In particular, in the case of a roll type, it is desirable to use a metal type from the viewpoint of heat resistance and strength. In the present invention,
It is not limited to the roll type, but may be a flat type flat plate. In the case of a roll type, a thin plate lens type having a lens pattern formed thereon may be used by being wound around a cylindrical roll and fixed. Alternatively, a cylindrical stepped lens mold in which a thin plate stepped lens mold having a thick portion formed at an end portion is wound around a cylindrical roll and fixed may be used. It is preferable to apply plating such as copper or nickel to the surface of such a lens mold in order to prevent various types of corrosion. Further, in order to make the cutting material particles uniform and fine, it is also possible to form a thick plating of copper, nickel or the like and form a lens pattern on the plating layer portion.

The first lens mold 8 is supplied with a light-transmitting substrate 5 along the lens pattern forming surface.
The first active energy ray-curable composition 10 is continuously supplied from the resin tank 12 between the lens mold 8 and the translucent substrate 5. A nip roll 9 for uniforming the thickness of the supplied first active energy ray-curable composition 10 is provided outside the translucent substrate 5. As the nip roll 9, a metal roll, a rubber roll, or the like is used. In addition, in order to make the thickness of the first active energy ray-curable composition 10 uniform, the roundness of the nip roll 9 is determined by:
It is preferable that the surface is processed with high accuracy in terms of surface roughness and the like. In the case of a rubber roll, a rubber roll having a high hardness of 60 degrees or more is preferable. This nip roll 9 is
In order to enable accurate adjustment of the thickness of the active energy ray-curable composition 10 described above, the composition is operated by a pressure adjusting mechanism 11. As the pressure adjusting mechanism 11, a hydraulic cylinder, a pneumatic cylinder, various screw mechanisms and the like can be used, but a pneumatic cylinder is preferable from the viewpoint of simplicity of the mechanism. The air pressure is controlled by a pressure regulating valve or the like.

First active energy ray-curable composition 10
Is supplied between the first lens mold 8 and the translucent substrate 5,
In a state where the first active energy ray-curable composition 10 is sandwiched between the first lens mold 8 and the translucent substrate 5, the active energy ray is transmitted from the active energy ray irradiation device 12 to the translucent substrate. 5, the first active energy ray-curable composition 10 is polymerized and cured to transfer a lens pattern formed into a lens shape, and the first active energy ray-curable composition 10 is transferred onto one surface of the light-transmitting substrate 5.
To form a lenticular lens. As the active energy ray irradiation device 12, a chemical reaction chemical lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a visible light halogen lamp, or the like is used. It is preferable that the irradiation amount of the active energy ray is set so that the integrated energy at a wavelength of 200 to 600 nm becomes 0.1 to 50 J / cm ² . The active energy ray irradiation atmosphere may be air or an inert gas atmosphere such as nitrogen or argon.

Next, the light-transmitting substrate 5 having a lenticular lens formed on one surface is supplied so that the other surface thereof comes into contact with the lens pattern forming surface of the second lens mold 8 '. Similarly, the second active energy ray-curable composition 10 ′ is provided between the second lens mold 8 ′ and the translucent substrate 5.
Is continuously supplied from the resin tank 13 '. A nip roll 9 ′ operated by a pressure adjusting mechanism 11 ′ for equalizing the thickness of the supplied second active energy ray-curable composition 10 ′ is provided outside the translucent substrate 5. ing. Second active energy ray-curable composition 10 ′
Is supplied between the second lens mold 8 ′ and the translucent substrate 5, and then the second active energy ray-curable composition 10 ′ is
In the state of being sandwiched between the lens mold 8 ′ and the light-transmitting substrate 5,
The active energy ray irradiating device 12 ′ irradiates an active energy ray through the translucent substrate 5 to polymerize and cure the second active energy ray curable composition 10 ′ to transfer a lens pattern formed into a lens mold. Then, a second lenticular lens is formed on one surface of the translucent substrate 5.

The active energy ray-curable compositions 10 and 10 ′ supplied between the lens molds 8 and 8 ′ and the translucent substrate 5.
Is preferably maintained at a constant viscosity. The viscosity range is generally preferably in the range of 20 to 3000 mPa · S, more preferably 100 to 1 mPa · S.
000 mPa · S. In order to maintain the viscosity of the active energy ray-curable compositions 10, 10 'at a constant level, the temperature of the active energy ray-curable compositions 10, 10' can be controlled so that the outside of the resin tanks 13, 13 'can be controlled. Heat source equipment 1 such as sheathed heater and hot water jacket inside
It is preferable to install 4,14 '.

Active energy ray curing containing a light diffusing agent is carried out by a common injection method such as a nip roll method, a gravure roll method or a curtain coating method into a concave portion between the adjacent exit surface lenticular lenses of the obtained double-sided lenticular lens sheet. Infusible composition. In this case, the injection amount of the active energy ray-curable composition is not particularly limited, and is appropriately determined according to the shape and size of the lenticular lens. When the active energy ray-curable composition has spread over the entire exit surface of the lenticular lens sheet, excess resin is scraped off with a plastic squeegee knife such as silicone rubber. The amount of the active energy ray-curable composition injected into the recesses (the thickness of the light absorbing layer) can be controlled by adjusting the contact pressure of the squeegee. If the amount of injection into the concave portion is too large, the amount of energy required for curing increases, so that the thickness is preferably adjusted to 50 μm or less.

After the injection of the active energy ray-curable composition into the concave portion is completed, the active energy ray-curable composition is cured by irradiating active energy rays from one or both surfaces of the lenticular lens sheet, and the lenticular lens is cured. Alternatively, adhesion to a light-transmitting substrate is performed.

The double-sided lenticular lens sheet of the present invention thus obtained has a lenticular lens thickness of about 50 to 1000 μm and a lens unit pitch of 5 μm.
The thickness is preferably about 0 to 1000 μm. In particular, when forming a lenticular lens with an active energy ray-curable resin, it is suitable for a fine-pitch double-sided lenticular lens sheet, and the lens unit pitch is 50 to
It is preferably in the range of 500 μm, more preferably in the range of 50 to 400 μm.

[0023]

The present invention will be specifically described below with reference to examples. The sectional shapes of the entrance surface lenticular lens and the exit surface lenticular lens are represented by the following equation (1). Where:
C is the curvature, and K is the conic constant.

[0024]

(Equation 1) K = -0.43, C =
−1.16, and K = −0.8 and C = −1.37 in the exit surface lenticular lens,
A metal matrix for manufacturing a double-sided lenticular lens sheet was prepared with a pitch of 0.38 mm for both the light incident surface lenticular lens and the light emitting surface lenticular lens.

As the active energy ray-curable composition constituting the incident surface lenticular lens 2 and the exit surface lenticular lens 1, 45 parts by weight of phenoxy acrylate (Biscoat # 192 manufactured by Osaka Organic Chemical Industry Co., Ltd.) and bisphenol A-epoxy acrylate (Kyoeisha) 55 parts by weight of epoxy ester 3000A manufactured by Yushi Kagaku Kogyo KK, 2
-Hydroxy-2-methyl-1-phenyl-propane-
1-one (Darocur 1173 manufactured by Ciba-Geigy)
An acrylic monomer mixture to which 5 parts by weight and 5 parts by weight of crosslinked methacrylic resin fine particles (MBX-5, manufactured by Sekisui Chemical Co., Ltd.) having a weight average particle diameter of 8 μm was prepared was prepared.

Next, as the translucent substrate 5, a thickness of 188 μm
m, a polyethylene terephthalate resin film having a refractive index of 1.60, and a distance between the lenticular lens on the light incident surface and the lenticular lens on the light emitting surface of 0.4.
Using the above-described metal matrix, a double-sided lenticular lens sheet as shown in FIG. 1 was produced using the production apparatus shown in FIG.

On the exit surface of the obtained double-sided lenticular lens sheet, an ultraviolet curable composition (XV manufactured by Kyoritsu Chemical Sangyo Co., Ltd.)
L-90) 100 parts by weight of black crosslinked methacrylic resin fine particles having a weight average particle diameter of 8 μm (MB manufactured by Sekisui Plastics Co., Ltd.)
XR-8 black) 15 parts by weight of an ultraviolet-curable mixture was added, and the excess mixture was scraped off with a squeegee knife made of silicone rubber. Next, an ultraviolet ray was irradiated from the exit surface lenticular lens side to cure the ultraviolet curable mixture, and was adhered to the lenticular lens.

When the obtained double-sided lenticular lens sheet was used in combination with a Fresnel lens sheet as a projection screen of a projection television, it was possible to provide a very high-definition, high-contrast, high-quality image.

[0029]

According to the present invention, a light capable of providing a high-resolution and high-contrast image can be provided by forming a light-absorbing layer made of an active energy ray-curable resin in a concave portion formed between adjacent lenticular lenses on the exit surface. An object of the present invention is to provide a lenticular lens sheet capable of forming an absorbing layer at an accurate position in a short time with high productivity, and a method for manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a schematic partial sectional view of a double-sided lenticular lens sheet of the present invention.

FIG. 2 is a schematic view illustrating a method for manufacturing a double-sided lenticular lens sheet of the present invention.

FIG. 3 is a schematic partial sectional view showing a conventional double-sided lenticular lens sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lenticular lens of light emission surface 2 Lenticular lens of light incidence surface 3 Black stripe 4 Light diffusing material 5 Translucent base material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B29L 11:00

Claims (3)

[Claims] 1. A lenticular lens sheet in which a large number of lenticular lenses are formed in parallel on at least an exit surface, and a concave portion formed between adjacent lenticular lenses on the exit surface absorbs light with an active energy ray-curable resin. A lenticular lens sheet having a layer formed thereon. 2. The lenticular lens sheet according to claim 1, wherein the lenticular lens is formed of an active energy ray-curable resin on a surface of a translucent substrate. 3. An active energy ray-curable material containing a light absorbing material in a concave portion formed between adjacent lenticular lenses on an emission surface of a lenticular lens sheet having a plurality of lenticular lenses formed in parallel on at least an emission surface. A method for producing a lenticular lens sheet, comprising injecting a composition and irradiating an active energy ray from one or both sides of the lenticular lens sheet to cure the active energy ray-curable composition.