JP4161131B2 - Method for forming light shielding pattern of microlens array sheet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of forming by utilizing the property of adhesion to a change in tack by sensitive is the altered substrate (support), the light-shielding layer made of a black photosensitive layer (light-shielding pattern), in particular a liquid crystal The present invention relates to a method for forming a light shielding pattern of a microlens array sheet on which a light shielding layer used for a rear projection screen used in a projector or the like is formed .
[0002]
[Prior art]
Conventionally, as a rear projection type screen used for a liquid crystal projector or the like, a convex cylindrical lens used in combination with a Fresnel lens sheet is mainly a lenticular sheet arranged in a one-dimensional manner, and a pattern for forming a light shielding layer is: This is a stripe pattern (referred to as a black stripe “BS”) corresponding to a non-condensing portion of the cylindrical lens.
[0003]
In order to view a high-definition image having a large number of pixels, the convex cylindrical lens pitch of the lenticular sheet is also refined, and accordingly, the light shielding pattern (BS) is also refined. In order to realize a high-definition light-shielding pattern, it is necessary to realize a transfer layer having a high resolution and transferable with a fine pattern.
That is, when forming a light-shielding layer on the flat surface opposite to the lens portion of the lenticular sheet, after forming a photosensitive layer (a known material whose adhesiveness disappears by exposure) on the entire flat surface By exposing from the lens side, the photosensitive layer in the part corresponding to the condensing part is denatured, and ink or toner is attached to the remaining sticky part corresponding to the non-condensing part, or the transfer layer is transferred. This method is preferably used to form a light shielding layer at an accurate position by a so-called self-alignment method called so-called self-alignment due to the condensing characteristic of the lens itself. In particular, the pattern for forming the light shielding layer by the transfer forming method is excellent in the sharpness of the light shielding layer and the pattern outline (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-120102
On the other hand, as a back-illuminated screen used in a liquid crystal projector or the like, when a microlens sheet having a configuration in which unit convex lenses are two-dimensionally arranged in a matrix instead of a lenticular sheet, the light-shielding pattern has a spot shape. The pattern excluding the condensing part of the unit convex lens.
[0006]
In order to improve the contrast of the displayed display image, a light shielding layer (black matrix “BM”) is formed on the flat portion on the side opposite to the lens array portion (observer side) and on the portion corresponding to the non-condensing portion by each unit lens. Is preferred and is practiced routinely.
[0007]
Even in a microlens sheet having a structure in which minute unit lenses are arranged in a two-dimensional matrix at a fine pitch, it is preferable to form a pattern with a high light shielding rate in order to view an image with high contrast. It is necessary to make the pattern excluding the condensing part of the unit convex lens that is a minute spot, but compared with the case of forming a stripe-shaped light shielding layer using a lenticular sheet, the resolution is higher and finer. There has been a demand for a technique capable of forming a light-shielding layer composed of a transfer layer that can be transferred in a pattern.
[0008]
As described above, a light-shielding pattern such as a black stripe (BS) or a black matrix (BM) is formed on a lens using a lenticular, but an ink using the adhesiveness of a photosensitive resin, which is a conventional forming method, is used. In the case of a fine pitch BS or a matrix like BM, especially in the transfer method, the ink layer of the transfer foil is poor in the direction of the peeling direction. There is a problem that a fine pattern cannot be formed due to the occurrence of tailing and a gritty phenomenon during peeling. In consideration of such foil breakage, the conventional method for forming a single ink layer is to increase the adhesion between the adhesive photosensitive resin on the substrate to be transferred and the ink layer and transfer the ink layer. The method of increasing the adhesion between the sheet support and the ink layer and reducing the cohesion of the ink layer has been used, but the problem of peeling unevenness called zipping caused by high peeling strength in continuous peeling operation was there. That is, when the transfer / non-transfer is faithfully performed on the surface of the stripe pattern in which the adhesive / non-adhesive portions defined by the exposure alternately appear on the photosensitive resin layer, the tailing and the jaggedness phenomenon at the time of peeling are avoided. Above, cohesive peeling (a technique of breaking and transferring inside the ink layer) was effective. However, this method has a problem in that it is difficult to control the destruction position, so that the thickness of the transfer layer is uneven and the black density is likely to vary. Also, according to the interface peeling method that peels at the interface between the ink layer and the transfer sheet substrate, the black density can be ensured, but the peeling strength is required compared to the cohesive peeling, which causes the problem of zipping. It was.
[0009]
[Problems to be solved by the invention]
The present invention was made in view of the above technical background, shading of the microlens array sheet convex lens to form a high-concentration shielding layer without unevenness is arranged in a two-dimensional matrix It is an object to provide a pattern forming method .
[0010]
[Means for Solving the Invention]
In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that an ionizing radiation curable resin layer having a lens formed on one surface of a support that is allowed to transmit ionizing radiation and having adhesiveness on the opposite surface. The step of forming, irradiating ionizing radiation from the lens side, curing the portion condensed by the lens of the ionizing radiation curable resin layer to lose the adhesiveness, the adhesiveness of the non-condensing portion is A microlens array comprising: a step of maintaining, and a step of forming a light-shielding pattern by pressing and peeling a transfer sheet on which at least two colored layers are formed from the side of the ionizing radiation curable resin layer A method for forming a light shielding pattern on a sheet ,
At least two colored layers are in close contact with each other, and the colored layer closest to the base material of the transfer sheet is laminated so that the interfacial separation does not occur, and the subsequent layers and the subsequent layers are not coherently broken. The pigment content of the colored layer closest to is 60 to 90 parts by weight capable of cohesive peeling, and the pigment content of the subsequent layers is 10 to 59 parts by weight capable of interfacial peeling. .
[0011]
The invention according to claim 2 is characterized in that the thickness of the colored layer closest to the substrate of the transfer sheet is 0.1 μm to 3 μm, and the thickness of the subsequent layers is 1 μm to 10 μm. .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining an example of a method for forming a light-shielding layer (light-shielding pattern) according to the present invention. FIG. 1 (a) shows a microlens array (or lenticular sheet) 5 formed on one side of a substrate (support) 1. FIG. 5B is a diagram illustrating a process of forming the ionizing radiation curable resin layer 2 on the opposite surface. FIG. 5B is a diagram illustrating ionizing radiation (for example, ultraviolet rays = UV or electron beam) from the microlens array 5 side on the ionizing radiation curable resin layer 2. FIG. 6C is a diagram showing a process of forming a photosensitive pattern 8 and a non-photosensitive pattern 7 on the ionizing radiation curable resin layer 2, and FIG. It is a figure which shows the process to peel.
In FIG. 1 (c) and FIG. 2, reference numerals 3, 4 and 9 denote a substrate (or support), a first colored layer (aggregated release layer), and a second colored layer (interface release layer), respectively. ing.
FIG. 3 is a diagram showing the shapes of the photosensitive pattern 8 and the non-photosensitive pattern 7 as viewed from the microlens array 5 side.
[0015]
In order to form the light shielding layer, a microlens array is formed on one surface of the substrate 1. In manufacturing the microlens array, molding by a 2P method (Photo-Polymer method) is employed after a molding stamper is manufactured.
The stamper is a reverse type of a microlens sheet (that is, a surface shape in which a unit lens portion becomes a recess), and mechanically engraves the recess on the surface of the metal layer. Alternatively, a technique such as chemical corrosion or a technique such as carving the concave portion by laser processing is used.
In any method, it goes without saying that the shape of the curved surface of the unit lens needs to be accurately processed, and it is selected according to the definition.
[0016]
As the microlens array sheet 5 used in the present invention, the following can be used.
<Microlens array sheet>
FIG. 4 is a view showing an example of the microlens array sheet of the present invention, and (a) is a cross-sectional view of the microlens array sheet. (B) is a plan view of a microlens array sheet in which a region (unit lens region) in which irregularities constituting a unit lens are formed has a rectangular shape and the unit lens region has a grid-like matrix arrangement. is there. (C) is a plan view when the shape of the unit lens region is a triangle and the unit lens region is a delta arrangement in the microlens array sheet. (D) is a plan view of a microlens array sheet in which the shape of a unit lens region is a hexagon and the unit lens region is a honeycomb array.
[0017]
A microlens array portion made of a reaction cured product of ultraviolet or ionizing radiation curable resin, in which unit lenses 5 are two-dimensionally arranged in a matrix on at least one surface of the transparent resin film substrate 1. It is a lens array sheet. The microlens array unit includes unit lenses having an aspherical shape or a spherical curved surface, and the arrangement pitch of the unit lenses is 100 μm or less.
[0018]
The arrangement of the unit lenses is a grid arrangement, a delta arrangement, or a matrix arrangement of a honeycomb arrangement.
The microlens array part may contain a filler having a refractive index close to that of the reaction cured product, a release agent, an antistatic agent, and the like.
[0019]
<Formation of light shielding pattern>
As a method for forming the light-shielding layer of the present invention, the ionizing radiation curable resin 2 having a transparent adhesive property is applied or laminated on the substrate 1 (FIG. 1A). By exposing to light from the surface of the lens 5, a pattern is formed such that the condensing portion 8 of the ionizing radiation curable resin 2 is cured and the non-condensing portion 7 is uncured (FIGS. 1B and 3). " The ink layer surface of the transfer sheet of FIG. 2 according to the present invention is overlapped and pressure-bonded and peeled at this portion to form a light shielding layer as shown in FIG. 1 (c).
[0020]
Specific examples of the film used for the microlens lens sheet of the present invention include plastic films such as polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, and ionomer. Can be mentioned. Moreover, in order to adjust the adhesiveness of the photosensitive resin, it is desirable that corona treatment and easy adhesion treatment are performed on one or both surfaces of the base material.
[0021]
The material to be coated or laminated on the microlens array sheet is an ultraviolet photosensitive resin material having a transparent adhesive property, but is not particularly limited. For example,
(1) Photopolymerizable compound of monomer, oligomer and / or prepolymer (2) Thermoplastic resin having no photopolymerization if necessary (3) Photopolymerization initiator activated by actinic rays, if necessary Contains a thermal polymerization inhibitor.
[0022]
Examples of the black colored ink layer binder resin according to the present invention include polyvinyl chloride, poly (meth) acrylic acid, poly (meth) acrylic acid ester, polyvinyl ether, polyvinyl acetal, urethane resin, epoxy resin, and poamide resin. , Diacryl phthalate, ethylene vinyl acetate, styrene resin, epoxy acrylic resin, ethylene vinyl acetate resin and the like.
[0023]
Examples of the black colorant include inorganic pigments, organic pigments, carbon, and the like, but carbon is preferable in terms of dispersibility and black density.
[0024]
Examples of the substrate 3 of the transfer sheet 10 include plastic films such as polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, and ionomer.
[0025]
In the first aspect of the present invention, it is preferable that the transfer sheet has two or more colored layers. In the case of a single layer, when the cohesive force of the ink layer is improved in consideration of the ability to cut the foil, interfacial peeling occurs at the time of pressure peeling and zipping unevenness occurs. In addition, if the cohesive force of the ink layer is reduced, cohesive failure occurs at the time of pressure-bonding peeling, and at this time it is difficult to control the location of the breakage, and the black density decreases. A good light-shielding pattern can be formed by controlling the black density in the second and subsequent layers.
[0026]
In the present invention, as a method for adjusting the cohesive strength of the ink, 60 to 90 parts by weight of the pigment in the layer is preferable in the case of a composition that performs cohesive separation, and 10 to 59 parts by weight is preferable in the case of interfacial peeling. If this range is exceeded, different peeled states will occur and a good light shielding layer cannot be formed.
[0027]
The invention described in claim 2 shows a thickness indispensable for maintaining the peeled state specified in the invention described in claim 1 , and in the case of cohesive failure, 0.1 μm to 3 μm is good, In the case, 1 μm to 10 μm is good. If this range is exceeded, different peeled states will occur and a good light shielding layer cannot be formed.
[0028]
【The invention's effect】
The present invention can provide a method for forming a light shielding layer having a high resolution and a fine pattern.
According to the light shielding pattern forming method of the present invention, there is provided a microlens array sheet in which unit convex lenses having a high light shielding rate and a high transmission density and having a light shielding layer formed at a predetermined position with high accuracy are arranged in a two-dimensional matrix. By combining this with a Fresnel lens sheet, it is possible to provide a high-resolution rear projection screen that has a wide horizontal viewing angle and a wide vertical viewing angle.
[Brief description of the drawings]
1A and 1B are diagrams illustrating a method for forming a light-shielding property according to the present invention. FIG. 1A is a diagram illustrating a process of forming a microlens array on one surface and an ultraviolet photosensitive resin layer on the opposite surface; ) Is a diagram showing a process of irradiating the ultraviolet photosensitive resin layer with UV from the microlens array side, and forming a photosensitive pattern and a non-photosensitive pattern on the ultraviolet photosensitive resin layer, and (c) is a black transfer sheet according to the present invention. It is a figure which shows the process of overlapping pressure bonding peeling.
FIG. 2 is a schematic cross-sectional view of a transfer sheet according to the present invention.
FIG. 3 is a schematic exploded perspective view showing the shapes of a photosensitive pattern 8 and a non-photosensitive pattern 7 as viewed from the microlens array 5 side.
4A and 4B are explanatory views showing a configuration of a microlens array sheet used in the present invention, wherein FIG. 4A is a cross-sectional view of the microlens array sheet, and FIG. 4B is a microlens array sheet having a grid arrangement. (C) is a plan view of a microlens array sheet with a lens arrangement of delta arrangement, and (d) is a plan view of a microlens array sheet with a lens arrangement of honeycomb arrangement.
[Explanation of symbols]
1 Microlens substrate (support)
2 Ionizing radiation curable resin layer 3 Transfer sheet substrate 4 First colored layer (aggregated release layer)
5 Microphone lens array 6 Ionizing radiation 7 Non-photosensitive pattern 8 Photosensitive pattern 9 Second colored layer (interface peeling layer)
10 Transfer sheet

Claims (2)

Forming a lens on one surface of a support that is capable of transmitting ionizing radiation, and forming an ionizing radiation curable resin layer having adhesiveness on the opposite surface;
Irradiating with ionizing radiation from the lens side, curing the portion condensed by the lens of the ionizing radiation curable resin layer to lose the adhesive property, and maintaining the adhesive property of the non-condensing portion;
From the side of the ionizing radiation curable resin layer, a step of forming a light shielding pattern by pressure-bonding and peeling a transfer sheet on which a colored layer consisting of at least two layers is formed; and
A light-shielding pattern forming method for a microlens array sheet comprising :
At least two colored layers are in close contact with each other, and the colored layer closest to the base material of the transfer sheet is laminated so that the interfacial separation does not occur, and the subsequent layers and the subsequent layers are not coherently broken. The pigment content of the colored layer closest to is 60 to 90 parts by weight capable of cohesive peeling, and the pigment content of the subsequent layers is 10 to 59 parts by weight capable of interfacial peeling. A method for forming a light shielding pattern on a microlens array sheet. 2. The microlens according to claim 1, wherein the thickness of the colored layer closest to the substrate of the transfer sheet is 0.1 μm to 3 μm, and the thickness of the subsequent layers is 1 μm to 10 μm. A method for forming a light shielding pattern on an array sheet .

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