JP2007187843A - Manufacturing method of microlens substrate, the microlens substrate, transmission screen and rear-type projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microlens substrate where bubbles are prevented from getting mixed therein, and irregularities in thickness are suppressed, and to provide a method for manufacturing the microlens substrate. <P>SOLUTION: The method includes a process of sticking a transfer sheet 13 composed of light-shielding material to a pressure sensitive adhesive layer 31 so that a light-shielding material layer 32' is brought into contact with the pressure-sensitive adhesive layer 31 is performed in a reduced pressure state by using a pressure-reducing vacuum device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a microlens substrate, a microlens substrate, a transmissive screen, and a rear projector.

In recent years, the demand for rear projectors is increasing as a display suitable for home theater monitors, large-screen televisions, and the like.
A transmission screen used for a rear projector generally includes a lens substrate (lenticular lens substrate) including a lenticular lens. The transmission screen provided with such a lenticular lens substrate has a problem that the left and right viewing angles are large but the vertical viewing angles are small (the viewing angles are biased).

As a solution to such a problem, there is a transmissive screen using a lens substrate (microlens substrate) provided with a microlens instead of a lenticular lens.
As a method of manufacturing such a lens substrate (lens array sheet, lens sheet), an uncured resin is supplied to the surface of the glass substrate provided with a large number of recesses, and the resin is cured. Thus, a method of forming a microlens with a resin filled in the recess is used (see, for example, Patent Document 1). In the lens substrate as described above, since the focal length of the microlens is as short as several tens of μm, in order to obtain a thinner microlens substrate, the lens shape is changed to a film material by, for example, the photopolymer method (2P method). It has been transferred to.

  However, when the resin is supplied and extended on the glass substrate, the recesses (microlens recesses) are two-dimensionally arranged, so that the resin flow is restricted. As a result, problems such as bubbles remain between the film material and the resin, and the resin does not extend evenly and become partially thick, etc. As a result, the optical position of the microlens substrate may be significantly deteriorated due to variations in the focal position of the microlens or the presence of bubbles in the microlens substrate.

JP-A-2005-37694 (paragraph numbers 0018 to 0022)

  An object of the present invention is to provide a microlens substrate in which bubbles are prevented from being mixed and unintentional thickness variation is suppressed, and to provide a manufacturing method capable of efficiently manufacturing the microlens substrate. Another object of the present invention is to provide a transmissive screen and a rear projector provided with the microlens substrate.

Such an object is achieved by the present invention described below.
A method of manufacturing a microlens substrate of the present invention is a method of manufacturing a microlens substrate including a substrate body having a large number of microlenses,
A composition applying step for applying a composition having fluidity on the surface of a mold having an inverted shape on the surface side where the microlenses of the substrate body to be manufactured are provided;
An adhesion step for closely adhering the sheet material to the composition;
A solidification step for solidifying the composition,
The adhesion step is performed in a reduced pressure state where the pressure between the composition and the sheet material is reduced.
Accordingly, it is possible to provide a method for manufacturing a microlens substrate that can efficiently manufacture a microlens substrate in which bubbles are prevented from being mixed and unintentional thickness variation is suppressed.

In the method for manufacturing a microlens substrate of the present invention, it is preferable that a vacuum chamber is used so that a space including the entire composition and the sheet material is brought into the reduced pressure state.
As a result, a reduced pressure state can be created more suitably, the composition applied on the mold can be more evenly spread, and unintentional thickness variations occur in the manufactured microlens substrate. Can be more effectively prevented, and air bubbles can be more effectively prevented from remaining between the composition and the sheet material.

In the method for manufacturing a microlens substrate of the present invention, it is preferable that only the space between the composition and the sheet material is selectively brought into the reduced pressure state by using a sealing material.
As a result, a reduced pressure state can be created more suitably, the composition applied on the mold can be more evenly spread, and unintentional thickness variations occur in the manufactured microlens substrate. Can be more effectively prevented, and air bubbles can be more effectively prevented from remaining between the composition and the sheet material. In addition, the contact process can be performed using a relatively simple and small apparatus.

In the method for producing a microlens substrate of the present invention, the surface of the substrate body manufactured through the composition application step, the adhesion step, and the solidification step is opposite to the surface side on which the microlens is provided. In addition, a pressure-sensitive adhesive layer forming step of forming a pressure-sensitive adhesive layer by applying a positive photosensitive pressure-sensitive adhesive,
A light irradiation step of applying light to the pressure-sensitive adhesive layer through the substrate body to reduce the adhesiveness of the photosensitive portion;
A sticking step of bonding a light-shielding material transfer sheet having a light-shielding material layer composed of a light-shielding layer forming material on the pressure-sensitive adhesive layer;
The light-shielding material transfer sheet bonded is peeled off from the pressure-sensitive adhesive layer, and the light-shielding layer forming material is selectively transferred to the non-photosensitive portion of the photosensitive pressure-sensitive adhesive, thereby forming a light-shielding film having an opening. A light shielding film forming step to be formed;
The adhering step is preferably performed in a reduced pressure state where the pressure between the pressure-sensitive adhesive layer and the light-shielding material transfer sheet is reduced.
As a result, it is possible to more effectively prevent the occurrence of inconvenience due to the unintentional thickness variation in the microlens substrate to be manufactured or the bubbles remaining in the microlens substrate. In the manufactured microlens substrate, an image with higher contrast can be displayed.

In the method for producing a microlens substrate of the present invention, the pressure-sensitive adhesive layer forming step is performed by laminating a pressure-sensitive adhesive sheet composed of a photosensitive pressure-sensitive adhesive on the substrate body,
The pressure-sensitive adhesive layer forming step is preferably performed in a reduced pressure state in which the space between the substrate body and the pressure-sensitive adhesive sheet is reduced.
As a result, it is possible to more effectively prevent the occurrence of inconvenience due to the unintentional thickness variation in the microlens substrate to be manufactured or the bubbles remaining in the microlens substrate. In the manufactured microlens substrate, an image with higher contrast can be displayed.

In the method for manufacturing a microlens substrate of the present invention, the surface of the substrate body manufactured through the composition application step, the adhesion step, and the solidification step is opposite to the surface side on which the microlenses are provided. In addition, a diffusion part forming step of forming a diffusion part by bonding the diffusion plate,
It is preferable that the diffusion part forming step is performed in a reduced pressure state in which a space between the substrate body and the diffusion plate is reduced.
As a result, it is possible to more effectively prevent the occurrence of inconvenience due to unintentional thickness variation in the manufactured microlens substrate, or bubbles remaining in the microlens substrate. The viewing angle characteristics can be made particularly excellent.

In the method for manufacturing a microlens substrate of the present invention, the pressure in the reduced pressure state is preferably 1 × 10 ⁻² to 1 × 10 ⁵ Pa.
As a result, it is possible to more effectively prevent the occurrence of inconvenience due to unintentional thickness variation in the manufactured microlens substrate, or bubbles remaining in the microlens substrate. The viewing angle characteristics can be made particularly excellent.

In the method for manufacturing a microlens substrate of the present invention, the thickness of the sheet material is preferably 20 to 200 μm.
As a result, it is possible to more effectively prevent bubbles and the like from remaining in the microlens substrate, and it is possible to more effectively prevent wrinkles from occurring in the sheet material in the adhesion process, which is manufactured. It is possible to more effectively prevent unintentional thickness variations in the microlens substrate.

In the method for producing a microlens substrate of the present invention, the sheet material is preferably made of polyethylene terephthalate.
Polyethylene terephthalate has suitable optical properties and moderate flexibility, so that the adhesion process can be performed efficiently. Moreover, it is excellent also in affinity with various materials used as the composition, and the reliability of the manufactured microlens substrate can be made particularly excellent.

The microlens substrate of the present invention is manufactured by the method of the present invention.
Thereby, it is possible to provide a microlens substrate in which bubbles are prevented from being mixed and unintentional thickness variation is suppressed.
The transmission screen of the present invention is characterized by including the microlens substrate of the present invention.
Accordingly, it is possible to provide a transmission screen in which inconveniences such as color unevenness when displaying an image are sufficiently prevented.

In the transmissive screen of the present invention, a Fresnel lens portion provided with a Fresnel lens on the light exit side;
It is preferable that the microlens substrate is provided on the light emission side of the Fresnel lens portion.
Accordingly, it is possible to provide a transmission screen in which inconveniences such as color unevenness when displaying an image are sufficiently prevented.
A rear projector according to the present invention includes the transmission screen according to the present invention.
Accordingly, it is possible to provide a rear projector in which occurrence of inconvenience such as color unevenness when an image is displayed is sufficiently prevented.

Hereinafter, a method for manufacturing a microlens substrate, a microlens substrate, a transmissive screen, and a rear projector according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
In the present invention, the “substrate” refers to a concept that is substantially inflexible and includes a relatively large thickness, a sheet-like material, a film-like material, and the like. .

The use of the microlens substrate of the present invention is not particularly limited, but in the following description, the microlens substrate will be described as being mainly used as a member constituting a transmissive screen and a rear projector.
First, the configuration of the microlens substrate and the transmission screen of the present invention will be described.
1 is a schematic longitudinal sectional view showing a preferred embodiment of the microlens substrate of the present invention, FIG. 2 is a plan view of the microlens substrate shown in FIG. 1, and FIG. 3 is a microlens substrate shown in FIG. It is a typical longitudinal section showing a suitable embodiment of a transmission type screen of the present invention provided with. In the following description, the left side in FIGS. 1 and 3 is referred to as “(light) incident side”, and the right side is referred to as “(light) emission side”. In the present invention, unless otherwise specified, the “(light) incident side” and the “(light) output side” are the “incident side” of light for obtaining image light (video light), respectively. ”And“ outgoing side ”, not“ incident side ”or“ outgoing side ”of external light or the like.

The microlens substrate 1 is a member constituting a transmissive screen 10 described later. As shown in FIG. 1, the microlens substrate 1 includes a substrate body 2 having a plurality of microlenses 21 arranged in a predetermined pattern, a black matrix ( A light-shielding film) 3 and a diffusion portion 4 having a function of diffusing incident light by irregular reflection.
The substrate body 2 is usually composed mainly of a material having optical transparency.
As the constituent material of the substrate body 2, for example, various resin materials, various glass materials, and the like can be used. Is preferred.

  Examples of the resin material constituting the substrate body 2 include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), cyclic polyolefin, modified polyolefin, polyvinyl chloride, and polychlorinated. Vinylidene, polystyrene, polyamide (eg, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12, nylon 6-66), polyimide, polyamideimide, polycarbonate (PC), Poly- (4-methylpentene-1), ionomer, acrylic resin, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer Polyoxymethylene, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester such as polycyclohexane terephthalate (PCT), polyether, polyether ketone (PEK), polyether ether ketone (PEEK), polyether imide, polyacetal (POM), polyphenylene oxide, modified polyphenylene oxide, polysulfone, polyether sulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer), poly Tetrafluoroethylene, polyvinylidene fluoride, other fluororesins, styrene, polyolefin, polyvinyl chloride, polyurea Various polyesters, polyesters, polyamides, polybutadienes, transpolyisoprenes, fluororubbers, chlorinated polyethylenes, and other thermoplastic elastomers, epoxy resins, phenol resins, urea resins, melamine resins, unsaturated polyesters, silicones Resins, urethane-based resins, etc., or copolymers, blends, polymer alloys, etc. mainly composed of these, and combinations of one or more of these (for example, blend resins, polymer alloys, laminates) As body etc.).

  The constituent material (solidified material) of the substrate body 2 generally has an absolute refractive index greater than various gases (the atmosphere in which the microlens substrate 1 is used), but the specific value of the absolute refractive index is 1.35 to 1.9, and more preferably 1.40 to 1.75. When the absolute refractive index of the constituent material of the substrate body 2 is a value within the above range, the viewing angle characteristic can be made particularly excellent while making the utilization efficiency of light (incident light) particularly excellent.

In particular, since the substrate body 2 is manufactured by a method that will be described in detail later, mixing of bubbles is prevented, and unintentional thickness variations are suppressed. Thereby, the optical characteristics of the microlens substrate 1 are excellent, and it is possible to sufficiently prevent the occurrence of inconveniences such as color unevenness when an image is displayed.
In addition, since the unintentional variation in thickness of the substrate body 2 is suppressed, the focal length of each microlens 21 provided in the substrate body 2 can be made uniform by a method described later. Further, variation in the size of the opening 33 of the black matrix 3 can be prevented, and color unevenness or the like when an image is displayed can be more reliably prevented.
Moreover, since the board | substrate body 2 is manufactured using the sheet | seat material 24, generation | occurrence | production of the unintentional unevenness | corrugation in the surface (surface of the light emission side) of the board | substrate body 2 is prevented effectively. This makes it easy to control the optical characteristics of the microlens substrate 1 as designed.

The microlens substrate 1 includes a plurality of microlenses 21 as convex lenses having a convex surface on the light incident surface side.
In the present embodiment, the microlens 21 has a flat shape (substantially elliptical, substantially bowl-shaped) in which the vertical width (vertical width) when the microlens substrate 1 is viewed in plan is smaller than the horizontal width (horizontal width). have. When the microlens 21 has such a shape, it is possible to make the viewing angle characteristics particularly excellent while effectively preventing the occurrence of inconvenience such as moire. In particular, both the horizontal and vertical viewing angle characteristics can be improved.

When the length in the minor axis direction (longitudinal direction) of the microlens 21 in plan view is L ₁ [μm] and the length in the major axis direction (lateral direction) is L ₂ [μm], 0.10 ≦ The relationship of L ₁ / L ₂ ≦ 0.99 is preferably satisfied, the relationship of 0.50 ≦ L ₁ / L ₂ ≦ 0.95 is more preferably satisfied, and 0.60 ≦ L ₁ / L ₂ More preferably, the relationship of ≦ 0.80 is satisfied. By satisfying the relationship as described above, the effects as described above become more remarkable.

  The length of the microlens 21 in the short axis direction (vertical width of the microlens 21) when viewed in plan is preferably 10 to 500 μm, more preferably 30 to 300 μm, and 50 to 100 μm. Is more preferable. When the length of the microlens 21 in the short axis direction is a value within the above range, it is possible to obtain sufficient resolution in the image projected on the screen while effectively preventing the occurrence of inconvenience such as moire. The productivity of the microlens substrate 1 (transmission type screen 10) can be further increased.

  Further, the length of the microlens 21 in the major axis direction (horizontal width of the microlens 21) in plan view is preferably 15 to 750 μm, more preferably 45 to 450 μm, and 70 to 150 μm. Is more preferable. When the length of the microlens 21 in the short axis direction is a value within the above range, it is possible to obtain sufficient resolution in the image projected on the screen while effectively preventing the occurrence of inconvenience such as moire. The productivity of the microlens substrate 1 (transmission type screen 10) can be further increased.

  The radius of curvature of the microlens 21 is preferably 7.5 to 375 μm, more preferably 22.5 to 225 μm, and still more preferably 35 to 75 μm. When the radius of curvature of the microlens 21 is a value within the above range, the viewing angle characteristics can be made particularly excellent. In particular, both the horizontal and vertical viewing angle characteristics can be improved. The microlens 21 may have a different radius of curvature in the minor axis direction and a radius of curvature in the major axis direction. In such a case, the radius of curvature in the major axis direction is a value within the above range. Is preferred.

The height of the microlens 21 is preferably 7.5 to 375 μm, more preferably 22.5 to 225 μm, and further preferably 35 to 75 μm. When the height of the microlens 21 is within the above range, the light utilization efficiency and viewing angle characteristics can be made particularly excellent.
The plurality of microlenses 21 are arranged in a staggered pattern (in a staggered pattern). By arranging the microlenses 21 in this way, it is possible to effectively prevent inconveniences such as moire. On the other hand, for example, if the microlenses are arranged in a square lattice shape or the like, it may be difficult to sufficiently prevent the occurrence of inconvenience such as moire depending on the size of the microlenses 21 and the like. . In addition, when the microlenses are randomly arranged, depending on the size of the microlens 21 or the like, it becomes difficult to sufficiently increase the occupation ratio of the microlens in the effective region where the microlenses are provided. It is difficult to sufficiently increase the transmittance (light utilization efficiency), and the obtained image may be dark.

  As described above, in the present embodiment, the microlenses 21 are arranged in a staggered pattern when the microlens substrate 1 is viewed in plan view. However, the first row includes a plurality of microlenses 21. 25 and the adjacent second row 26 are preferably offset by a half pitch in the vertical direction. As a result, it is possible to more effectively prevent the occurrence of moire due to light interference and to make the viewing angle characteristics particularly excellent.

The arrangement method of the microlenses 21 is not limited to the one described above. For example, even if the arrangement is a square lattice, the arrangement is optically random (from the main surface side of the microlens substrate 1 in plan view). In this case, the microlenses 21 may be arranged in a random positional relationship with each other.
Further, when the microlens substrate 1 is viewed in plan from the light incident surface side (direction shown in FIG. 2), the occupation ratio of the microlens 21 is 90 to 100 in the effective region where the microlens 21 is provided. % Is preferred. When the occupation ratio of the microlens 21 is a value within the above range, the light use efficiency can be further improved, and the brightness and contrast of the projected image can be made particularly excellent. The occupation ratio of the microlens 21 is a line segment connecting the center 211 of the microlens 21 when viewed in plan and the central portion of the portion adjacent to the microlens 21 where the microlens 21 is not formed. It can be determined as a ratio (L ₃ / L ₄ × 100 [%]) between the length L ₃ [μm] of the portion where the microlens 21 is formed and the length L ₄ [μm] of the line segment. (See FIG. 2).

  As described above, by strictly defining the shape and arrangement method of the microlenses, the viewing angle characteristics and the like can be made particularly excellent while effectively preventing the occurrence of moire due to light interference. . In particular, by strictly defining the shape and arrangement method of the microlens as described above, the microlens is formed by the effect of having the microlens having the shape and arrangement method as described above and the method described in detail later. The effects of having the black matrix 3 act synergistically, and particularly excellent effects (for example, particularly excellent viewing angle characteristics, light utilization efficiency, etc.) can be obtained.

  Each microlens 21 is provided as a convex lens protruding toward the incident side, and the focal point f is located near the surface on the emission side of the substrate body 2 and near the opening 33 of the black matrix (light-shielding film) 3. Designed to be That is, parallel light La (parallel light La from a Fresnel lens unit 5 described later) incident on the microlens substrate 1 from a substantially vertical direction is condensed by each microlens 21 of the microlens substrate 1 and A focal point f is formed in the vicinity of the surface on the emission side of the main body 2 and in the vicinity of the opening 33 of the black matrix 3. As described above, the microlens 21 is focused near the surface on the emission side of the substrate body 2 and near the opening 33 of the black matrix 3, so that the light utilization efficiency can be made particularly excellent. As a result, the contrast of the image formed by the light transmitted through the microlens substrate 1 can be made particularly excellent.

A black matrix (light-shielding film) 3 is provided on the light emission side surface of the substrate body 2.
The black matrix 3 includes an adhesive layer 31 and a light shielding layer 32.
Such a black matrix 3 has an opening 33 on the optical path of the light transmitted through each microlens 21. Thereby, unnecessary light can be blocked while sufficiently transmitting the light for image formation. As a result, the black matrix 3 can absorb external light (external light that is not preferable in forming a projection image), and the image projected on the screen can have excellent contrast.

4-30 micrometers is preferable and, as for the thickness of the adhesive layer 31, 5-25 micrometers is more preferable. When the thickness of the pressure-sensitive adhesive layer 31 is a value within the above range, the viewing angle characteristics and the contrast of the displayed image can be made particularly excellent.
As a constituent material of the pressure-sensitive adhesive layer 31, for example, various resin materials can be used.
Examples of the resin material constituting the pressure-sensitive adhesive layer 31 include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), cyclic polyolefin, modified polyolefin, polyvinyl chloride, poly Vinylidene chloride, polystyrene, polyamide (eg, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12, nylon 6-66), polyimide, polyamideimide, polycarbonate (PC) , Poly- (4-methylpentene-1), ionomer, acrylic resin (including acrylic adhesive), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), Polyesters such as tadiene-styrene copolymer, polyoxymethylene, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PCT) Resin, polyether, polyetherketone (PEK), polyetheretherketone (PEEK), polyetherimide, polyacetal (POM), polyphenylene oxide, modified polyphenylene oxide, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, Aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, polyvinylidene fluoride, other fluororesins, styrene, polyolefin , Polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluoro rubber, chlorinated polyethylene, and other thermoplastic elastomers, epoxy resins, phenol resins, urea resins, melamines Resins, unsaturated polyesters, silicone resins, urethane resins, and the like, or copolymers, blends, polymer alloys, etc. mainly composed of these, and combinations of one or more of these (for example, , Blend resins, polymer alloys, laminates, etc.).

  The constituent material (solidified material) of the pressure-sensitive adhesive layer 31 generally has an absolute refractive index larger than various gases (the atmosphere in which the microlens substrate 1 is used), but a specific value of the absolute refractive index. Is preferably 1.15 to 2.1, more preferably 1.30 to 1.85. When the absolute refractive index of the constituent material of the pressure-sensitive adhesive layer 31 is a value within the above range, the viewing angle characteristics can be made particularly excellent while making the utilization efficiency of light (incident light) particularly excellent. .

Further, when the refractive index (absolute refractive index) of the constituent material of the substrate body 2 is n ₁ and the refractive index (absolute refractive index) of the constituent material of the pressure-sensitive adhesive layer 31 is n ₂ , −0.20 ≦ n ₁ − It is preferable to satisfy the relationship of n ₂ ≦ 0.20, and it is more preferable to satisfy the relationship of −0.10 ≦ n ₁ −n ₂ ≦ 0.10. By satisfying such a relationship, even if light for image formation is incident on the pressure-sensitive adhesive layer 31, the light incident on the pressure-sensitive adhesive layer 31 can be suitably emitted to the emission side. It is possible to form a suitable image with high contrast. Further, the viewing angle characteristics can be made particularly excellent.

  Moreover, it is preferable that the thickness of the light shielding layer 32 is 0.3-8 micrometers, It is more preferable that it is 0.8-7 micrometers, It is further more preferable that it is 1.4-6 micrometers. When the thickness of the light shielding layer 32 is a value within the above range, it is more effective to cause a problem that light for image formation is blocked by the light shielding layer 32 (so-called “vignetting” occurs). While preventing, the light-shielding property as the whole black matrix 3 can be made especially excellent. As a result, the viewing angle characteristics and the contrast of the displayed image can be made particularly excellent.

The light shielding layer 32 is made of a material having a light shielding property.
Although the material which comprises the light shielding layer 32 is not specifically limited, Coloring agents (for example, ink etc.), such as various pigments and various dyes, can be used.
The light shielding layer 32 may include a resin material or the like as a constituent component. Thereby, the adhesiveness with the adhesive layer 31 can be made especially excellent.

As will be described later in detail (by a method described in detail later), the opening 33 effectively prevents reflection of external light at a portion other than the opening 33 of the black matrix 3 and provides light for image formation. Is sufficiently sized to be prevented from being absorbed and reflected by the black matrix 3.
The opening 33 of the black matrix 3 may have any shape, but it is preferable that the shape when viewed in plan is substantially circular. When the opening 33 is substantially circular, the size of the opening 33 is not particularly limited, but the diameter is preferably 5 to 100 μm, more preferably 15 to 90 μm, and 20 to 70 μm. More preferably. Thereby, the image projected on a screen can be made more excellent in contrast.

  Further, the area ratio (opening ratio) of the opening 33 to the black matrix 3 in plan view is preferably 5 to 50%, more preferably 10 to 35%, and 15 to 25%. Is more preferable. If the aperture ratio is a value within the above range, external light (for example, external light incidentally incident from the side opposite to the light incident side) is sufficiently suppressed from reflecting to the output side. In addition to making the light utilization efficiency particularly excellent, it is possible to prevent the reflection and make the contrast of the obtained image particularly excellent, and the viewing angle characteristics of the microlens substrate 1 are particularly excellent. Can be. On the other hand, if the aperture ratio is less than the lower limit, it may be difficult to make the light utilization efficiency and viewing angle characteristics sufficiently excellent. Also, if the aperture ratio exceeds the upper limit, it becomes difficult to keep external light reflection sufficiently low, and it becomes difficult to prevent reflection and make the contrast of the obtained image sufficiently excellent. there is a possibility.

  Further, a diffusing portion 4 is provided on the light emitting side surface of the microlens substrate 1. The diffusion unit 4 has a function of diffusing incident light (incident light) by irregular reflection. By having such a diffusing portion 4, the viewing angle characteristics can be made excellent. The diffusing portion 4 has a region formed on the light emission side from the black matrix 3. With such a configuration, the light incident on the diffusing unit 4 can be efficiently directed to the emission side (the direction opposite to the light incident side), and the viewing angle characteristics of the transmissive screen 10 can be improved. It can be made particularly excellent (the viewing angle at which an image projected on the screen can be suitably viewed can be made particularly large). In the present embodiment, the diffusing section 4 has a configuration in which a diffusing material is dispersed in a substantially transparent material (for example, an acrylic resin, a polycarbonate resin, or the like) excellent in light transmittance. As the diffusing material, for example, particulate (bead-shaped) silica, glass, resin, or the like can be used. The average particle size of the diffusing material is not particularly limited, but is preferably 1 to 50 μm, and more preferably 2 to 10 μm.

  Moreover, although the thickness of the spreading | diffusion part 4 is not specifically limited, It is preferable that it is 0.05-5 mm, It is more preferable that it is 0.7-4 mm, It is further more preferable that it is 1.0-3 mm. When the thickness of the diffusing portion 4 is a value within the above range, the viewing angle characteristics can be made particularly excellent while sufficiently improving the light utilization efficiency. On the other hand, if the thickness of the diffusing portion 4 is less than the lower limit, the effect of providing the diffusing portion 4 may not be sufficiently exhibited. Further, when the thickness of the diffusing portion 4 exceeds the upper limit value, the probability (frequency) that the light (photon) and the diffusing material collide with each other tends to increase rapidly, and quenching easily occurs. There is a high possibility that light (photons) incident on will return to the incident side again. As a result, it may be difficult to sufficiently increase the light use efficiency.

  Since the microlens substrate of the present invention is manufactured by a method described in detail later, defects due to mixing of bubbles and the like are effectively prevented, and light utilization efficiency is excellent. The light utilization efficiency of the microlens substrate 1 (ratio of the amount of light emitted from the exit surface to the amount of light incident from the entrance surface of the microlens substrate 1) is preferably 65% or more, and 75 % Or more is more preferable, and it is further more preferable that it is 85% or more.

Next, the transmission screen 10 including the microlens substrate 1 as described above will be described.
As shown in FIG. 3, the transmission screen 10 includes a Fresnel lens portion 5 and the microlens substrate 1 described above. The Fresnel lens unit 5 is installed on the light (image light) incident side, and the light transmitted through the Fresnel lens unit 5 is incident on the microlens substrate 1.

The Fresnel lens unit 5 has a prism-shaped Fresnel lens 51 formed in a substantially concentric shape on the exit side surface. The Fresnel lens unit 5 refracts image light from a projection lens (not shown) to produce parallel light La parallel to the vertical direction of the main surface of the microlens substrate 1.
In the transmissive screen 10 configured as described above, the image light from the projection lens is refracted by the Fresnel lens unit 5 and becomes parallel light La. The parallel light La is incident from the side of the microlens substrate 1 on which the microlenses 21 are provided, is condensed by each microlens 21, is diffused after being focused. The light that has passed through the opening 33 diffuses and is observed as a planar image by the observer.

Next, a method for manufacturing the microlens substrate 1 described above will be described.
4 is a schematic longitudinal sectional view showing a member with a recess (molding die) used for manufacturing a microlens substrate, and FIG. 5 is a schematic longitudinal sectional view showing a method for manufacturing the member with a recess shown in FIG. is there. 6 to 8 are schematic longitudinal sectional views showing an example (first embodiment) of the manufacturing method of the microlens substrate shown in FIG. 1, and FIGS. It is a typical longitudinal cross-sectional view which shows another example (2nd Embodiment) of the method. In the following description, the lower side in FIGS. 5 to 11 is referred to as “(light) incident side”, and the upper side in FIGS. 5 to 11 is referred to as “(light) emission side”. Further, in the manufacture of the member with concave portions, a large number of concave portions (recesses for microlenses) are actually formed on the substrate, and in the manufacture of the microlens substrate (substrate body), actually a large number of convex portions (convex lenses). However, in order to make the explanation easier to understand, a part thereof is highlighted.

First, prior to the description of the manufacturing method of the microlens substrate, the configuration of the member with a recess (molding die) used for manufacturing the microlens substrate and the manufacturing method thereof will be described.
The member with a recess (molding die) 6 may be made of any material, but is preferably made of a material that is difficult to bend and is not easily damaged. As a constituent material of the member 6 with a recessed part, various glass materials, various resin materials, etc. are mentioned, for example. Examples of the glass material include soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass. Examples of the resin material include polyethylene, polypropylene, and ethylene- Polyolefin such as propylene copolymer, ethylene-vinyl acetate copolymer (EVA), cyclic polyolefin, modified polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide (eg, nylon 6, nylon 46, nylon 66, nylon 610) , Nylon 612, nylon 11, nylon 12, nylon 6-12, nylon 6-66), polyimide, polyamideimide, polycarbonate (PC), poly- (4-methylpentene-1), ionomer, acrylic resin, acryloni Ryl-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer, polyoxymethylene, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH) ), Polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PCT), polyether, polyetherketone (PEK), polyetheretherketone (PEEK), polyetherimide, polyacetal (POM) ), Polyphenylene oxide, modified polyphenylene oxide, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer) Polytetrafluoroethylene, polyvinylidene fluoride, other fluororesins, styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluoro rubber, chlorinated polyethylene Various thermoplastic elastomers such as epoxy resins, phenol resins, urea resins, melamine resins, unsaturated polyesters, silicone resins, urethane resins, etc., or copolymers, blends, polymer alloys, etc. mainly comprising these A resin material etc. are mentioned, Among these, it can use combining 1 type (s) or 2 or more types. Among these, as a constituent material of the member 6 with a recessed part, a glass material is preferable and soda glass, crystalline glass (for example, neo-ceram etc.), and an alkali free glass are more preferable. Such a material is generally excellent in shape stability. Therefore, the stability (reliability) of the shape of the recess 61 included in the member 6 with a recess, the dimensional accuracy of the microlens 21 formed using the recess 61, and the like can be made particularly excellent. The optical characteristics of the lens substrate can be made particularly reliable. In addition, since the glass material is generally excellent in shape stability, in the method for manufacturing the microlens substrate 1 described in detail later, the handleability of the manufactured substrate body 2 is improved. Further, soda glass, crystalline glass, and non-alkali glass are easy to process, are relatively inexpensive, and are advantageous from the viewpoint of manufacturing cost.

The member with a recess (molding die) 6 includes a plurality of recesses 61 arranged in a system (transferred positional relationship) corresponding to the array system of the microlenses 21. These recesses 61 have a shape corresponding to the microlens 21 (substantially the same shape except for the transferred shape) and dimensions, except that the microlens 21 is a recess while the microlens 21 is a protrusion. have.
More specifically, in the present embodiment, the concave portion 61 has a flat shape (substantially oval) in which the vertical width (width in the vertical direction) when viewed in plan is smaller than the horizontal width (width in the horizontal direction). (Substantially bowl-shaped). The concave portion 61 having such a shape is preferably used for manufacturing the microlens substrate 1 capable of effectively preventing the occurrence of inconvenience such as moire and having particularly excellent viewing angle characteristics. Can do.

Further, when the length in the minor axis direction (vertical direction) of the concave portion 61 in plan view is L ₁ [μm] and the length in the major axis direction (lateral direction) is L ₂ [μm], 0.10 ≦ L ₁ / L ₂ ≦ 0.99 is preferably satisfied, more preferably 0.50 ≦ L ₁ / L ₂ ≦ 0.95 is satisfied, and 0.60 ≦ L ₁ / L _It is more preferable to satisfy the relationship of ₂ ≦ 0.80. By satisfying the relationship as described above, the effects as described above become more remarkable.

  Further, the length in the minor axis direction of the recess 61 when viewed in plan is preferably 10 to 500 μm, more preferably 30 to 300 μm, and further preferably 50 to 100 μm. When the length of the concave portion 61 in the minor axis direction is a value within the above range, the viewing angle characteristics of the manufactured microlens substrate 1 and the contrast and brightness of the image projected by the microlens substrate 1 are particularly excellent. However, sufficient resolution can be obtained in the projected image. Further, when the length of the concave portion 61 in the short axis direction is a value within the above range, it is possible to effectively prevent the occurrence of inconvenience such as moire when the manufactured microlens substrate 1 is used. The productivity of the microlens substrate 1 (member 6 with a recess) can be further increased.

  Further, the length in the major axis direction of the concave portion 61 when viewed in plan is preferably 15 to 750 μm, more preferably 45 to 450 μm, and further preferably 70 to 150 μm. When the length of the concave portion 61 in the major axis direction is a value within the above range, the viewing angle characteristics of the manufactured microlens substrate 1 and the contrast and brightness of the image projected by the microlens substrate 1 are particularly excellent. However, sufficient resolution can be obtained in the projected image. Further, when the length of the concave portion 61 in the major axis direction is a value within the above range, it is possible to effectively prevent the occurrence of inconvenience such as moire when the manufactured microlens substrate 1 is used. The productivity of the microlens substrate 1 (member 6 with a recess) can be further increased.

  Moreover, it is preferable that the curvature radius of the recessed part 61 is 7.5-375 micrometers, It is more preferable that it is 22.5-225 micrometers, It is further more preferable that it is 35-75 micrometers. When the radius of curvature of the recess 61 is a value within the above range, the viewing angle characteristics of the manufactured microlens substrate 1 can be made particularly excellent. In particular, both the horizontal and vertical viewing angle characteristics can be improved. The concave portion 61 may have a different radius of curvature in the minor axis direction and a radius of curvature in the major axis direction. In such a case, the radius of curvature in the major axis direction is a value within the above range. Preferably there is.

Moreover, it is preferable that the depth of the recessed part 61 is 7.5-375 micrometers, It is more preferable that it is 22.5-225 micrometers, It is further more preferable that it is 35-75 micrometers. When the depth of the recess 61 is a value within the above range, the viewing angle characteristics of the manufactured microlens substrate 1 can be made particularly excellent.
The plurality of recesses 61 are arranged in a staggered pattern (in a staggered pattern). By arranging the recesses 61 in this way, it is possible to effectively prevent inconveniences such as moire when the manufactured microlens substrate 1 is used. On the other hand, for example, if the concave portions are arranged in a square lattice shape or the like, it is difficult to sufficiently prevent the occurrence of inconvenience such as moire depending on the size of the concave portions (microlenses). In addition, when the concave portions are randomly arranged, depending on the size of the concave portion (microlens) or the like, it becomes difficult to sufficiently increase the occupancy ratio of the concave portions in the effective area where the concave portions are provided. It is difficult to sufficiently increase the transmittance (light utilization efficiency), and the obtained image may be dark.

  Further, as described above, the recesses 61 are arranged in a staggered pattern when the member 6 with recesses is viewed in plan view, but are adjacent to the first row composed of the plurality of recesses 61. The second row is preferably shifted by a half pitch in the vertical direction. As a result, when the manufactured microlens substrate 1 is used, it is possible to more effectively prevent the occurrence of moiré due to light interference and to make the viewing angle characteristics particularly excellent. it can.

  In the above description, the concave portion 61 is described as having substantially the same shape (dimension) and arrangement method as the microlens 21 except that the concave portion 61 has a concave-convex relationship. In the case where the constituent material of the substrate main body 2 is easily contracted (when the composition constituting the substrate main body 2 contracts due to solidification or the like), the microlens 21 and the recess 61 are considered in consideration of the contraction rate and the like. You may make it a shape (dimension), an occupation rate, etc. differ among these.

Next, the manufacturing method of a member with a recessed part is demonstrated, referring FIG. In practice, a large number of recesses (microlens formation recesses) are formed on the substrate. Here, in order to make the description easy to understand, a part of them is shown highlighted.
First, when manufacturing the member 6 with a recessed part, the board | substrate 7 is prepared.
The substrate 7 having a uniform thickness and having no deflection or scratches is preferably used. The substrate 7 is preferably one whose surface is cleaned by washing or the like.

<A1> A mask 8 having a large number of initial holes (openings) 82 is formed on the surface of the prepared substrate 7, and the back surface of the substrate 7 (the surface opposite to the surface on which the mask 8 is formed) A protective film 89 is formed (see a masking process, FIGS. 5A and 5B).
In particular, in this embodiment, first, as shown in FIG. 5A, a back surface protective film 89 is formed on the back surface of the prepared substrate 7 and a mask forming film 81 is formed on the surface of the substrate 7 (mask). (Formation film forming step) Then, as shown in FIG. 5B, the mask 8 is obtained by forming the initial hole 82 in the mask formation film 81 (initial hole formation step). The mask forming film 81 and the back surface protective film 89 can be formed simultaneously.

  It is preferable that the mask forming film 81 can form an initial hole 82 described later by laser light irradiation or the like and has resistance to etching in an etching process described later. In other words, the mask forming film 81 (mask 8) is preferably configured so that the etching rate is substantially equal to or lower than that of the substrate 7.

From this point of view, the material forming the mask forming film 81 (mask 8) is, for example, a metal such as Cr, Au, Ni, Ti, Pt, an alloy containing two or more selected from these, Examples thereof include oxides (metal oxides), silicon, and resins.
Further, the mask forming film 81 (mask 8) may have, for example, a substantially uniform composition, or a laminated body having a plurality of different layers.

  As described above, the configuration of the mask forming film 81 (mask 8) is not particularly limited. However, the mask forming film 81 (mask 8) is a laminate including a layer mainly composed of chromium and a layer mainly composed of chromium oxide. Preferably there is. The mask forming film 81 having such a configuration can easily and surely form an opening having a desired shape by irradiation with laser light as described later. The mask 8 obtained by using the mask forming film 81 has excellent stability against etching liquids having various compositions (the substrate 7 can be more reliably protected in an etching process described later). . Further, if the substrate 7 is made of glass and the mask forming film 81 (mask 8) has the above-described structure, for example, in an etching process described later, two hydrogen atoms are used as an etchant. A liquid containing ammonium fluoride can be suitably used. Since ammonium monohydrogen difluoride is not a poisonous deleterious substance, it is possible to prevent the human body and the environment during work more reliably. Further, the mask forming film 81 (mask 8) having the above-described configuration can relieve the internal stress of the mask efficiently, and is particularly excellent in adhesion with the substrate 7 (particularly, adhesion in the etching process). ing. For this reason, by using the mask forming film 81 (mask 8) having the above-described configuration, the concave portion 61 having a desired shape can be easily and reliably formed.

  A method for forming the mask forming film 81 is not particularly limited, but the mask forming film 81 (mask 8) is made of a metal material (including an alloy) such as chromium (Cr) or gold (Au) or a metal oxide (for example, chromium oxide). ), Or a composite material thereof (for example, a laminated body having a metal layer made of a metal material and a metal oxide layer made of a metal oxide, etc.) The film 81 can be suitably formed by, for example, a vapor deposition method or a sputtering method. When the mask forming film 81 (mask 8) is made of silicon, the mask forming film 81 can be suitably formed by, for example, a sputtering method or a CVD method.

  The thickness of the mask forming film 81 (mask 8) varies depending on the material constituting the mask forming film 81 (mask 8), but is preferably about 0.01 to 2.0 μm, preferably 0.01 to 0.3 μm. The degree is more preferable. If the thickness is less than the lower limit, the shape of the initial hole 82 formed in the initial hole forming step (opening forming step) described later may be distorted depending on the constituent material of the mask forming film 81 and the like. There is. In addition, when wet etching is performed in an etching process described later, the masked portion of the substrate 7 may not be sufficiently protected. On the other hand, if the upper limit is exceeded, depending on the constituent material of the mask forming film 81 and the like, it becomes difficult to form the initial hole 82 that penetrates in the initial hole forming step described later, and the mask forming film 81 (mask The mask forming film 81 (mask 8) may be easily peeled off by the internal stress of 8).

  The back surface protective film 89 is for protecting the back surface of the substrate 7 in the subsequent steps. By this back surface protective film 89, erosion, deterioration, etc. of the back surface of the substrate 7 are preferably prevented. This back surface protective film 89 has the same configuration as the mask forming film 81 (mask 8), for example. Therefore, the back surface protective film 89 can be provided in the same manner as the mask forming film 81 simultaneously with the formation of the mask forming film 81.

Next, as shown in FIG. 5B, a plurality of initial holes (openings) 82 are formed in the mask forming film 81 to obtain a mask 8 (initial hole forming step). The initial hole 82 formed in this step functions as a mask opening in the later-described etching.
A method for forming the initial hole 82 is not particularly limited, but a method using laser light irradiation is preferable. Thereby, the initial holes 82 having a desired shape arranged in a desired pattern can be easily and accurately formed. As a result, the shape, arrangement method, and the like of the recesses 61 can be controlled more reliably. In addition, by forming the initial hole 82 by laser irradiation, a member with a recess can be manufactured with high productivity. In particular, the concave portion can be easily formed even on a large-area substrate. In addition, by forming the initial hole 82 in the mask forming film 81 by laser light irradiation, the opening ( An initial hole 82) can be formed.

In addition, when the initial hole 82 is formed by laser light irradiation, the type of laser light to be used is not particularly limited, but a ruby laser, a semiconductor laser, a YAG laser, a femtosecond laser, a glass laser, a YVO ₄ laser, a Ne- Examples include He laser, Ar laser, CO ₂ laser, and excimer laser. Moreover, you may use wavelengths, such as SHG of each laser, THG, and FHG.

  The shape and size of the initial hole 82 formed in this step is not particularly limited, but it is substantially circular and its diameter is preferably 0.5 to 30 μm, more preferably 1.0 to 10 μm. Preferably, it is 1.5-5 micrometers. When the diameter of the initial hole 82 is a value within the above range, the concave portion 61 having the above-described shape can be reliably formed in the etching process described later. However, when the initial hole 82 has a flat shape such as a substantially elliptical shape, the length in the minor axis direction can be substituted for the value of the diameter. That is, when the initial hole 82 formed in this step has a flat shape, the width of the initial hole 82 (length in the minor axis direction) is not particularly limited, but is preferably 0.8 to 30 μm, More preferably, it is 1.0-10 micrometers, and it is still more preferable that it is 1.5-5 micrometers. When the width of the initial hole 82 is a value within the above range, the concave portion 61 having the above-described shape can be reliably formed in the etching process described later.

  Moreover, when the initial hole 82 formed in this process is a flat thing, it is preferable that the length (length of a major axis direction) of the initial hole 82 is 0.5-30 micrometers, 1.0- More preferably, it is 15 micrometers, and it is still more preferable that it is 1.5-10 micrometers. When the length of the initial hole 82 is a value within the above range, the concave portion 61 having the shape as described above can be more reliably formed in the etching process described later.

<A2> Next, as shown in FIG. 5C, the substrate 7 is etched using the mask 8 provided with the initial holes 82 to form a large number of recesses 61 on the substrate 7 (etching step). .
The etching method is not particularly limited, and examples thereof include wet etching and dry etching. In the following description, a case where wet etching is used will be described as an example.

  Etching (wet etching) is performed on the substrate 7 covered with the mask 8 provided with the initial holes 82, so that the substrate 7 has a portion where the mask 8 does not exist (see FIG. 5C). A large number of recesses 61 are formed on the substrate 7 by etching from a portion corresponding to the initial hole 82 of the mask 8. As described above, since the initial holes 82 provided in the mask 8 are arranged in a staggered pattern (in a staggered pattern), the formed recesses 61 are formed in a staggered pattern (in a staggered pattern) on the surface of the substrate 7. It will be arranged.

Further, when the wet etching method is used, the concave portion 61 can be suitably formed. If, for example, an etching solution containing ammonium monohydrogen difluoride is used as the etching solution, the substrate 7 can be etched more selectively, and the recess 61 can be suitably formed.
When the mask 8 (mask forming film 81) is mainly composed of chromium or chromium oxide, the hydrofluoric acid-based etchant is particularly preferably a liquid containing ammonium monohydrogen difluoride. Since the ammonium hydrogen difluoride solution is not a poisonous and deleterious substance, it can prevent the influence on the human body and the environment during work. When ammonium monohydrogen difluoride is used as the etching solution, the etching solution may contain, for example, hydrogen peroxide and / or sulfuric acid. Thereby, an etching speed can be made faster.
Further, according to wet etching, it is possible to perform processing with a simpler apparatus than dry etching, and it is possible to perform processing on many substrates at once. Thereby, productivity improves and the member 6 with a recessed part can be provided cheaply.

<A3> Next, as shown in FIG. 5D, the mask 8 is removed (mask removal step). At this time, by removing the back surface protective film 89 along with the removal of the mask 8, the member 6 with a recess is obtained.
When the mask 8 is a laminated body having a layer mainly composed of chromium and a layer mainly composed of chromium oxide as described above, the removal of the mask 8 is, for example, ceric ammonium nitrate and perchlorine. It can carry out suitably by etching using a mixture containing an acid.

For example, you may perform a mold release process to the surface side in which the recessed part 61 of the member 6 with a recessed part is provided. Thereby, in the manufacturing method of the microlens substrate 1 described in detail later, the member 6 with the recesses can be easily removed while sufficiently preventing defects such as chipping from occurring on the microlens 21 of the substrate body 2. As a result, defects in the microlens 21 can be prevented in the final microlens substrate 1. Examples of the mold release treatment include formation of a film composed of a material having releasability such as silicone resin such as alkylpolysiloxane, fluorine resin such as polytetrafluoroethylene, and hexamethyldisilazane ([(CH ₃ ) Surface treatment with a silylating agent such as ₃ Si] ₂ NH), surface treatment with a fluorine-based gas, and the like.

By the above, as shown in FIG.5 (d) and FIG. 4, the member 6 with a recessed part in which many recessed parts 61 were provided on the board | substrate 7 in zigzag form is obtained.
The method for forming the plurality of recesses 61 arranged in a staggered pattern on the substrate 7 is not particularly limited, but the method as described above (the initial holes 82 in the mask forming film 81 by laser irradiation). To obtain a mask 8, and then etching using the mask 8 to form the recess 61 on the substrate 7), the following effects are obtained.

That is, by forming the initial holes 82 in the mask forming film 81 by laser light irradiation, the openings (with a predetermined pattern) can be easily and inexpensively compared with the case where the openings are formed by a conventional photolithography method. A mask having initial holes 82) can be obtained. Thereby, productivity improves and the member 6 with a recessed part can be provided cheaply.
Further, according to the method as described above, it is possible to easily perform processing on a large substrate. When manufacturing a large substrate (a member with a recess, a microlens substrate), it is not necessary to bond a plurality of substrates as in the conventional case, and the seam of the bonding can be eliminated. Thereby, a high-quality large-sized substrate (a member with a recess, a microlens substrate) can be manufactured at a low cost by a simple method.
In addition, when the initial holes 82 are formed by laser irradiation, the shape, size, arrangement, and the like of the formed initial holes 82 can be easily and reliably managed.

Next, a method of manufacturing the microlens substrate 1 using the above-described member 6 with a recess will be described.
[First Embodiment of Microlens Substrate Manufacturing Method]
<B1> First, the composition 23 having fluidity (for example, a softened resin material, an unpolymerized (uncured) resin material) is applied to the surface of the member 6 with concave portions on which the concave portion 61 is provided. Apply (composition applying step, see FIG. 6A).

<B2> Next, a sheet material (base film) 24 is placed on the composition 23 provided on the member 6 with concave portions, and the sheet material 24 and the composition 23 are brought into close contact with each other (contact process; FIG. 6). (B), see FIG. 6 (c)).
The contact process may be performed using, for example, a flat plate (pressing member) on the sheet material 24 and using this flat plate, or using a pressure roller.

Here, the adhesion process is performed in a reduced pressure state in which the space between the composition 23 and the sheet material 24 is reduced.
In particular, in the present embodiment, the contact process is performed in the vacuum chamber 111 using a reduced-pressure vacuum apparatus 11 as shown in FIGS. 6B and 6C. The reduced-pressure vacuum device 11 includes a vacuum chamber 111 and a vacuum pump 112 connected to the vacuum chamber 111. By evacuating with the vacuum pump 112, the inside of the vacuum chamber 111 which accommodates the member 6 with a recessed part, the composition 23, and the sheet | seat material 24 is made into a pressure reduction state.

  As described above, the adhesion between the composition 23 and the sheet material 24 is performed under a reduced pressure condition, whereby air bubbles existing between the composition 23 and the sheet material 24 can be reliably removed, and the composition The air bubbles present in 23 can also be reliably removed. In addition, foreign matters such as dust can be prevented from being mixed between the composition 23 and the sheet material 24. As a result, the substrate body 2 can be obtained without uneven thickness. Thereby, the transmittance can be uniform over the entire surface without variation. Further, as will be described later (when using a method as described later), when the black matrix 3 is formed by self-alignment, the size of the opening 33 can be uniformly formed without variation. As a result, it is possible to more effectively prevent the occurrence of color unevenness, brightness unevenness and the like in the displayed image.

  As in this embodiment, the composition 23 and the sheet material 24 are brought into close contact with each other in the vacuum chamber, so that a reduced pressure state can be more suitably created, and the composition 23 applied onto the member 6 with a recess. In the manufactured microlens substrate 1 can be more effectively prevented from causing undesired thickness variations, and between the composition 23 and the sheet material 24. It is possible to more effectively prevent bubbles and the like from remaining on the surface. For example, when pressing using a flat plate (pressing member), a pressure roller, etc., those operations can be performed easily. Moreover, in order to release bubbles existing between the composition 23 and the sheet material 24 during the pressing, it is not necessary to apply a large pressure or to consider the moving direction of the pressure roller. Can be performed more easily.

The pressure in the reduced pressure is not particularly limited, for example, 1 × and even preferably at ¹⁰ -2 ^~1 × ¹⁰ 5 Pa, more preferably ^{1 × 10 1 ~1 × 10 3} Pa. If the pressure (atmospheric pressure) in the reduced pressure is a value within the above range, the microlens substrate 1 to be manufactured may have an undesired thickness variation, or in the composition 23 or in the composition 23 and the sheet material 24. It is possible to more effectively prevent the occurrence of inconvenience due to bubbles remaining in between. Thereby, the transmittance can be made more uniform over the entire surface without variation. Further, the sizes of the openings 33 of the black matrix 3 can be formed more uniformly without variation, and an image with excellent color contrast and the like can be obtained. Further, the viewing angle characteristics can be made particularly excellent.

The sheet material 24 is preferably made of a material having a refractive index comparable to that of the composition 23 (the composition 23 after solidification), and more specifically, the absolute refractive index of the constituent material of the sheet material 24. The absolute value of the difference between the solid refractive index and the absolute refractive index of the composition 23 after solidification is preferably 0.20 or less, more preferably 0.10 or less, and even more preferably 0.02 or less. .
The sheet material 24 may be made of any material, but is preferably made of polyethylene terephthalate. Polyethylene terephthalate has suitable optical properties and moderate flexibility, so that the adhesion process can be performed efficiently. Moreover, it is excellent also in the affinity with the various materials used as the composition 23, and the reliability of the manufactured microlens substrate 1 can be made particularly excellent.

Further, the sheet material 24 may be a relatively thick material, or may be a material that does not substantially have flexibility.
Although the thickness of the sheet | seat material 24 is not specifically limited, It is preferable that it is 20-200 micrometers, and it is more preferable that it is 35-75 micrometers. If the thickness of the sheet material 24 is within the above range, it is possible to more effectively prevent bubbles and the like from remaining in the microlens substrate 1, and wrinkles occur in the sheet material 24 in this step. Therefore, it is possible to more effectively prevent unintentional thickness variations in the manufactured microlens substrate 1.

  Further, for example, a groove (not shown) may be provided on the surface of the sheet material 24 on the side facing the composition 23. Since the sheet material 24 has a groove, the composition 23 can be evenly extended during pressurization (when the pressure from the sheet material 24 is applied to the composition 23), and the groove functions as a gas flow path. In addition, bubbles existing in the composition 23 or between the composition 23 and the sheet material 24 can be released more reliably. As a result, the thickness unevenness of the substrate body 2 can be more effectively prevented. As a result, it is possible to more reliably prevent variation in transmittance at each part of the microlens substrate 1, and to display an image with excellent contrast without color unevenness. Further, as described later, when the black matrix 3 is formed by self-alignment (by a method described later), the size of the openings 33 can be formed more uniformly without variation. As a result, it is possible to more effectively prevent the occurrence of color unevenness, brightness unevenness and the like in the displayed image.

  There may be one groove or a plurality of grooves provided in the sheet material 24, but a plurality of grooves are preferable. Thereby, the composition 23 provided on the member 6 with a recessed part can be extended more uniformly, and the variation in unintentional thickness generate | occur | produces more in the microlens board | substrate 1 (board | substrate main body 2) manufactured. While being able to prevent effectively, it can prevent more effectively that a bubble etc. remain between the composition 23 and the sheet | seat material 24. FIG. As a result, the microlens substrate 1 having particularly excellent optical characteristics can be obtained.

  When the sheet material 24 has a plurality of grooves, the sheet material 24 preferably has grooves provided substantially in parallel with each other. Thereby, the composition 23 provided on the member 6 with a recessed part can be extended more uniformly, and the variation in unintentional thickness generate | occur | produces more in the microlens board | substrate 1 (board | substrate main body 2) manufactured. While being able to prevent effectively, it can prevent more effectively that a bubble etc. remain between the composition 23 and the sheet | seat material 24. FIG. As a result, the microlens substrate 1 having particularly excellent optical characteristics can be obtained.

  The pitch P between adjacent grooves is preferably 10 to 200 μm, and more preferably 50 to 150 μm. When the pitch of the grooves is a value within the above range, the composition 23 applied on the recessed member 6 can be more evenly extended, and the microlens substrate 1 (substrate body 2) to be manufactured is unintentional. It is possible to more effectively prevent the thickness variation from occurring and to more effectively prevent bubbles and the like from remaining between the composition 23 and the sheet material 24. As a result, the microlens substrate 1 having particularly excellent optical characteristics can be obtained.

  The direction in which the grooves are formed is not particularly limited, but is preferably formed in the direction in which the composition 23 easily flows on the member 6 with recesses. Thereby, while being able to extend the composition 23 more uniformly at the time of pressurization, a bubble can be escaped more reliably. For example, when the member 6 with a recess has a recess having the shape as described above, the longitudinal direction of the groove preferably coincides with the minor axis direction of the recess 61. Thereby, the composition 23 provided on the member 6 with a recessed part can be extended more uniformly, and the variation in unintentional thickness generate | occur | produces more in the microlens board | substrate 1 (board | substrate main body 2) manufactured. While being able to prevent effectively, it can prevent more effectively that a bubble etc. remain between the composition 23 and the sheet | seat material 24. FIG. As a result, the microlens substrate 1 having particularly excellent optical characteristics can be obtained.

  The cross-sectional shape of the groove is not particularly limited, and examples thereof include various shapes such as a semicircular shape, a rectangular shape, a trapezoidal shape, and a triangular shape, and a semicircular shape is preferable. Thereby, the composition 23 provided on the member 6 with a recessed part can be extended more uniformly, and the variation in unintentional thickness generate | occur | produces more in the microlens board | substrate 1 (board | substrate main body 2) manufactured. While being able to prevent effectively, it can prevent more effectively that a bubble etc. remain between the composition 23 and the sheet | seat material 24. FIG. As a result, the microlens substrate 1 having particularly excellent optical characteristics can be obtained.

  Although the depth D of a groove | channel is not specifically limited, It is preferable that it is 20-200 micrometers, and it is more preferable that it is 50-100 micrometers. When the depth of the groove is a value within the above range, the composition 23 applied on the concave member 6 can be more uniformly extended, and the microlens substrate 1 (substrate body 2) to be manufactured is unwilling. As a result, it is possible to more effectively prevent the occurrence of variations in thickness, and more effectively prevent bubbles and the like from remaining between the composition 23 and the sheet material 24. As a result, the microlens substrate 1 having particularly excellent optical characteristics can be obtained.

  The width W of the groove (width at the opening of the groove) W is not particularly limited, but is preferably 20 to 200 μm, and more preferably 50 to 100 μm. When the width of the groove is a value within the above range, the composition 23 applied on the member 6 with a recess can be more evenly extended, and the microlens substrate 1 (substrate body 2) to be manufactured is unintentional. It is possible to more effectively prevent the thickness variation from occurring and to more effectively prevent bubbles and the like from remaining between the composition 23 and the sheet material 24. As a result, the microlens substrate 1 having particularly excellent optical characteristics can be obtained.

  The ratio of the projected area occupied by the grooves on the surface of the sheet material 24 where the grooves are provided is preferably 10 to 200%, and more preferably 50 to 150%. When the ratio of the projected area occupied by the groove is a value within the above range, the composition 23 applied on the member 6 with a recess can be more evenly extended, and the manufactured microlens substrate 1 (substrate body 2). In this case, it is possible to more effectively prevent unintentional thickness variation in the film and to more effectively prevent bubbles and the like from remaining between the composition 23 and the sheet material 24. it can. As a result, the microlens substrate 1 having particularly excellent optical characteristics can be obtained.

  When the sheet material 24 has a groove, the sheet material 24 is placed so that the groove is present in a portion other than the light collecting portion of the microlens 21 to be formed. Is preferred. Thereby, in the microlens substrate 1 to be manufactured, it is possible to reliably prevent the occurrence of unintentional refraction of the light for image formation at the interface between the solidified product 23 and the sheet material 24. In addition, the optical characteristics of the microlens substrate 1 can be controlled more reliably. In addition, even if the member 6 with a recess has a defective recess that does not have a predetermined shape, the opening 33 of the black matrix 3 is formed at a site corresponding to the defective recess in a method described later. Can be prevented. As a result, unintentional bright spots can be effectively prevented from occurring in the displayed image, and the reliability of the image quality of the displayed image can be made particularly excellent.

  Moreover, you may perform an adhesion | attachment process in the state which has arranged the spacer between the member 6 with a recessed part, and the sheet | seat material 24, for example. Thereby, the thickness of the board | substrate body 2 formed can be controlled more reliably. Moreover, when using a spacer, when solidifying the composition 23, the spacer should just be distribute | arranged between the member 6 with a recessed part, and the sheet | seat material 24, and the timing which supplies a spacer is not specifically limited. For example, the surface of the member 6 with recesses on the side where the recesses 61 are provided may be one in which spacers are dispersed in advance as the composition 23 to be applied, or the spacers are arranged on the member 6 with recesses. The composition 23 may be applied, or a spacer may be applied after the composition 23 is supplied.

In the case of using a spacer, the spacer is preferably made of a material having a refractive index comparable to that of the solidified composition 23, and more specifically, the absolute refractive index of the constituent material of the spacer and the solidified material. The absolute value of the difference from the absolute refractive index of the composition 23 is preferably 0.20 or less, more preferably 0.10 or less, still more preferably 0.02 or less, and after solidification The composition 23 and the spacer are most preferably composed of the same material.
The shape of the spacer is not particularly limited, but is preferably substantially spherical or substantially cylindrical. When the spacer has such a shape, the diameter thereof is preferably 10 to 300 μm, more preferably 30 to 200 μm, and further preferably 30 to 170 μm.

<B3> Next, the composition 23 is solidified (including curing (polymerization)) to obtain the substrate body 2 including the microlenses 21 (solidification step, see FIG. 6D).
In the case where the composition 23 is solidified by curing (polymerization), examples of the method include methods such as irradiation with light such as ultraviolet rays, irradiation with electron beams, and heating.
In particular, when the sheet material 24 has a groove as described above, the contact area between the solidified product 23 and the sheet material 24 is large. For this reason, in the manufactured board | substrate main body 2, the adhesiveness of the solidified material of the composition 23 and the sheet | seat material 24 will become excellent, and durability and reliability of the board | substrate main body 2 will be especially excellent.
In addition, in the composition 23 and / or the sheet material 24, for example, polystyrene beads, glass beads, organic cross-linked polymers, etc. may be mixed in advance as a diffusing material in order to diffuse incident light from the light source. good. Here, the diffusing material may be mixed in the entire composition 23 and / or the sheet material 24, or may be mixed only in part.

<B4> Next, the recessed member 6 is removed from the formed substrate body 2 (recessed member removing step, see FIG. 7E).
The recessed member 6 removed in this step can be used repeatedly for the production of the microlens substrate 1. Thereby, the stability of the quality of the microlens substrate 1 to be manufactured can be improved, and the manufacturing cost is advantageous.

<B5> Next, a black matrix (light-shielding film) 3 is formed on the exit-side surface of the substrate body 2 manufactured as described above.
In the present embodiment, the black matrix is formed by applying a positive photosensitive adhesive to the substrate body and forming an adhesive layer (adhesive layer forming step) and the substrate body 2 through the adhesive. A second step (light irradiation step) for applying light to the adhesive layer to reduce the adhesiveness of the photosensitive portion; and a light-shielding material layer composed of a light-shielding layer forming material on the adhesive layer. A third step (sticking step) for laminating the light-shielding material transfer sheet having the light-shielding material transfer sheet and the pasted light-shielding material transfer sheet are peeled off from the pressure-sensitive adhesive layer, and the light-shielding layer is selectively applied to the non-photosensitive portion of the photosensitive pressure-sensitive adhesive By transferring the forming material, the fourth step of forming a light shielding film having an opening (light shielding film forming step) is performed.

<B5-1> First, as shown in FIGS. 7 (f) and 7 (g), the light-sensitive part of the substrate body 2 has a reduced adhesiveness and the non-photosensitive part maintains the adhesiveness on the surface on the emission side. A positive-type photosensitive pressure-sensitive adhesive having characteristics is applied to form the pressure-sensitive adhesive layer 31 (pressure-sensitive adhesive layer forming step).
Although the formation method of the adhesive layer 31 is not specifically limited, In this embodiment, it forms using the sheet-like adhesive sheet 31 'comprised with the positive photosensitive adhesive.

As the photosensitive adhesive, for example, an adhesive resin, a photopolymerizable compound, a photopolymerization initiator, or the like can be used.
Examples of the adhesive resin include acrylic resins, rubber resins, silicone resins, urethane resins, and polyester resins, and acrylic adhesives that are excellent in terms of durability and adhesiveness are suitable. .

The acrylic adhesive resin contains, for example, an acrylic copolymer resin obtained by copolymerizing an acrylic acid alkyl ester, another monomer, and a functional monomer as a main component.
As the alkyl acrylate ester, those having 4 to 15 carbon atoms in the alkyl group are preferably used. For example, acrylic acid-n-butyl, acrylate-2-ethylhexyl, isooctyl acrylate, isononyl acrylate, etc. 1 type selected from these, or 2 or more types can be used in combination.

Examples of the other monomer include methyl acrylate, methyl methacrylate, styrene, acrylonitrile, vinyl acetate, and the like, and one or more selected from these can be used in combination.
Examples of the functional monomer include acrylic acid, methacrylic acid, itaconic acid, hydroxylethyl acrylate, hydroxylethyl methacrylate, propylene glycol acrylate, acrylamide, methacrylamide, glycidyl acrylate, glycidyl methacrylate, methacrylic acid. Examples include dimethylaminoethyl acid, tert-butylaminoethyl methacrylate, and the like, and one or more selected from these can be used in combination.

Moreover, you may use the acrylic copolymer resin which has a photoreactive group, for example, an unsaturated double bond, in a side chain.
The composition ratio (% by weight) of the acrylic acid alkyl ester, the other monomer, and the functional monomer in the acrylic copolymer resin is not particularly limited, but is 70 to 99: 0 to 20: 0.01 to 20. It is preferable that it is 80-95: 0-10: 0.1-15. The weight average molecular weight of the acrylic copolymer resin is not particularly limited, but is preferably 200,000 to 1,200,000, and more preferably 400,000 to 1,000,000.

In addition to the acrylic copolymer resin, the acrylic pressure-sensitive adhesive may contain, for example, a crosslinking agent such as a room temperature crosslinking type or a heat crosslinking type crosslinking agent, a tackifier, and the like.
Examples of the room temperature crosslinking type crosslinking agent include polyisocyanate compounds of polyisocyanates and trimers of these polyisocyanate compounds, terminal isocyanate urethane prepolymers obtained by reacting the above polyisocyanate compounds and polyol compounds, and these polyisocyanate compounds. Examples include isocyanate compounds and trimers of these polyisocyanate compounds. Specific examples of the polyvalent isocyanate include 2,4-tolylene diisocyanate, 2,5-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, Examples include 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, dicyclohexylmethane-2,4′-diisocyanate, and lysine isocyanate. Moreover, as a crosslinking agent, you may use metal chelate compounds, such as aluminum and titanium, and a polyfunctional epoxy compound, for example.

The room temperature crosslinking type crosslinking agent is preferably added at a rate of 0.005 to 20 parts by weight, and preferably at a rate of 0.01 to 10 parts by weight with respect to 100 parts by weight of the acrylic copolymer resin. Is more preferable.
Examples of the heat-crosslinking type crosslinking agent include methylol group-containing compounds obtained by reacting formaldehyde with melamine, benzoguanamine, urea, etc., and those obtained by etherifying a part or all of those methylol groups with an aliphatic alcohol. Is mentioned.
The heat-crosslinking type crosslinking agent is preferably added at a ratio of 0.01 to 25 parts by weight, particularly 0.1 to 20 parts by weight with respect to 100 parts by weight of the acrylic copolymer resin. Is more preferable.

Examples of the tackifier include rosin resins, terpene resins, xylene resins and the like.
Photopolymerizable compounds include, for example, photoradical polymerizable compounds, photocationic polymerizable compounds, photoanionic polymerizable compounds, compounds that initiate polymerization via photodimerization, etc. A radical photopolymerizable compound is preferred in view of the range, polymerization reactivity and the like.

  Examples of the photo-radical polymerizable compound include compounds having at least one addition-polymerizable ethylenically unsaturated double bond. Examples thereof include unsaturated carboxylic acids and salts thereof, unsaturated carboxylic acids and aliphatic polyvalent compounds. Examples thereof include esters with a polyhydric alcohol compound, and amide bonds between an unsaturated carboxylic acid and an aliphatic polyvalent amine compound. As more specific examples, the following are monomers of esters of aliphatic polyhydric alcohol compounds and unsaturated carboxylic acids. Examples of acrylic acid esters include ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, and trimethylolpropane triacrylate. , Trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol Tetraacrylate, dipentaerythritol diacryl Dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer, 2-phenoxyethyl acrylate, 2-phenoxyethyl acrylate, phenol ethoxylate monoacrylate, 2- (p-chlorophenoxy) ethyl acrylate, p-chlorophenyl acrylate, phenyl acrylate, 2-phenylethyl acrylate, bisphenol A (2-acrylic Oxyethyl) ether, ethoxylated bisph Nord A diacrylate, 2- (1-naphthyloxy) ethyl acrylate, o-biphenyl acrylate, o-biphenyl acrylate, 9,9-bis (4-acryloxydiethoxyphenyl) fluorene, 9,9-bis (4- Acryloxytriethoxyphenyl) fluorene, 9,9-bis (4-acryloxydipropoxyphenyl) fluorene, 9,9-bis (4-acryloxyethoxy-3-methylphenyl) fluorene, 9,9-bis (4 -Acryloxyethoxy-3-ethylphenyl) fluorene, 9,9-bis (4-acryloxyethoxy-3,5-dimethyl) fluorene and the like.

  Sulfur-containing acrylic compounds can also be used, such as 4,4′-bis (β-acryloyloxyethylthio) diphenyl sulfone, 4,4′-bis (β-acryloyloxyethylthio) diphenyl ketone, 4 , 4′-bis (β-acryloyloxyethylthio) -3,3 ′, 5,5′-tetrabromodiphenyl ketone, 2,4-bis (β-acryloyloxyethylthio) diphenyl ketone, and the like can be used. .

Examples of the methacrylic acid ester include, for example, compounds in which “acrylate” is “methacrylate”, “acryloxy” is “methacryloxy”, and “acryloyl” is “methacryloyl” among the acrylate compound names above. As mentioned.
These photopolymerizable compounds can also be used as one kind or a mixture of two or more kinds.

The photopolymerizable compound is preferably added at a rate of 0.1 to 200 parts by weight, more preferably 10 to 150 parts by weight, with respect to 100 parts by weight of the acrylic copolymer resin.
As a photoinitiator, it selects suitably by the polymerization system of the said photopolymerizable compound. Examples of the photopolymerization initiator that can be used for the photoradical polymerizable compound include imidazole derivatives, bisimidazole derivatives, N-arylglycine derivatives, organic azide compounds, titanocenes, aluminate complexes, organic peroxides, N- Examples thereof include alkoxypyridinium salts and thioxanthone derivatives. More specifically, 1,3-di (t-butyldioxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetrakis (t-butyldioxycarbonyl) ) Benzophenone, 3-phenyl-5-isoxazolone, 2-mercaptobenzimidazole, bis (2,4,5-triphenyl) imidazole, 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name) Irgacure 651, manufactured by Ciba Specialty Chemicals Co., Ltd., 1-Hide Roxy-cyclohexyl-phenyl-ketone (trade name Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (trade name Irgacure) 369, manufactured by Ciba Specialty Chemicals), bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl ) Titanium (trade name Irgacure 784, manufactured by Ciba Specialty Chemicals Co., Ltd.) and the like. In addition, aromatic iodonium salts, aromatic sulfonium salts, aromatic diazonium salts, aromatic phosphonium salts, triazine compounds, and the like can also be used, and more specifically, diphenyliodonium, ditolyliodonium, bis (p-tert). -Iodonium chloride such as -butylphenyl) iodonium and bis (p-chlorophenyl) iodonium, iodonium salts such as bromide, borofluoride, hexafluorophosphate salt, hexafluoroantimonate salt, triphenylsulfonium, 4-tert-butyltri Sulfonium salts such as phenylsulfonium, tris (4-methylphenyl) sulfonium, sulfonium chloride, bromide, borofluoride, hexafluorophosphate salt, hexafluoroantimonate salt, 2, 4, 6-tris (trichloromethyl) -1,3,5-triazine, 2-phenyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2-methyl-4,6-bis (trichloromethyl) And 2,4,6-substituted-1,3,5-triazine compounds such as 1,3,5-triazine.

These photopolymerization initiators are preferably blended in a proportion of 0.5 to 20 parts by weight, and in a proportion of 1 to 15 parts by weight, with respect to 100 parts by weight of the acrylic copolymer resin. More preferred.
A sensitizing dye can also be used for the purpose of improving the sensitivity to the wavelength of the exposure light source used to sensitize the photosensitive adhesive. Examples of sensitizing dyes include thiopyrylium salt dyes, merocyanine dyes, cyanine dyes, quinoline dyes, coumarin dyes, ketocoumarin dyes, xanthone dyes, thioxanthone dyes, rhodamine dyes, and cyclopentanone dyes. And cyclohexanone dyes.

These sensitizing dyes are preferably blended in a proportion of 0.01 to 15 parts by weight, and in a proportion of 0.1 to 5 parts by weight, with respect to 100 parts by weight of the acrylic copolymer resin. Is more preferable.
In addition, for example, various plasticizers, surfactants, and the like may be used for the purpose of controlling adhesiveness and improving coating suitability described later.

As the photosensitive adhesive, it is particularly preferable to use a photosensitive adhesive whose adhesiveness obtained by 180 ° peel strength measurement specified in JIS Z0237 is reduced by 50% or more with respect to the adhesiveness of the non-photosensitive part. . By using such a photosensitive adhesive, a light shielding layer having an opening at a desired site can be easily and reliably formed.
Examples of the photosensitive adhesive include acrylic copolymer resins, photopolymerizable compounds, photopolymerization initiators as described above, room temperature crosslinking type or heat crosslinking type crosslinking agent added as necessary, and tackifying An agent, a sensitizing dye, and other additives diluted with a solvent such as methyl ethyl ketone, toluene, ethyl acetate, ethanol, isopropanol (solvent adhesive) can be used. The solid content in the photosensitive adhesive is preferably 15 to 50% by weight, more preferably 20 to 35% by weight. For example, when the photosensitive adhesive is liquid, it can be used as it is without being dissolved in a solvent.

  The method for applying the photosensitive adhesive onto the substrate body 2 is not particularly limited. For example, various application methods such as doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, roll coater, etc. The pressure-sensitive adhesive layer may be transferred onto the substrate body 2 using a sheet (pressure-sensitive adhesive sheet 31 ′) having a pressure-sensitive adhesive layer composed of a photosensitive pressure-sensitive adhesive on a supporting substrate. it can.

  In the present embodiment, the step of bonding the adhesive sheet 31 ′ onto the substrate body 2 is performed in a reduced pressure state using the above-described reduced pressure vacuum device 11. Thereby, it is possible to reliably prevent bubbles from being mixed between the substrate body 2 and the adhesive sheet 31 ′ when the substrate body 2 and the adhesive sheet 31 ′ are bonded together. In addition, it is possible to reliably prevent foreign matters such as dust from being mixed between the substrate body 2 and the adhesive sheet. As a result, the reliability of an image displayed using the microlens substrate 1 can be made particularly excellent.

The pressure in the reduced pressure is not particularly limited, for example, 1 × and even preferably at ¹⁰ -2 ^~1 × ¹⁰ 5 Pa, more preferably ^{1 × 10 1 ~1 × 10 3} Pa. If the pressure (atmospheric pressure) in the reduced pressure state is a value within the above range, the thickness of the microlens substrate 1 to be manufactured may be unintentionally varied, or bubbles may remain in the microlens substrate 1. The occurrence of inconvenience due to this can be prevented more effectively. Thereby, the transmittance can be made more uniform over the entire surface without variation. Further, the sizes of the openings 33 of the black matrix 3 can be formed more uniformly without variation, and an image with excellent color contrast and the like can be obtained. Further, the viewing angle characteristics can be made particularly excellent.

<B5-2> Next, the substrate body 2 is irradiated with light (exposure light) Lb from the surface side where the microlenses 21 are provided (light irradiation step).
The irradiated light (exposure light) Lb is refracted and collected by entering the microlens 21. Then, by collecting the light, the photosensitive adhesive constituting the adhesive layer 31 in the portion irradiated with light having a large luminous intensity (light flux) is exposed, and the other portions of the photosensitive adhesive are photosensitive. Otherwise, only the photosensitive adhesive of the portion irradiated with light having a reduced light amount and increased light intensity (light flux) is exposed to form a photosensitive portion 319 (see FIG. 7H). Since this photosensitive adhesive is a positive type, this reduces the adhesiveness of the photosensitive portion 319 and maintains the adhesiveness in other portions (non-photosensitive portion).
The light applied to the substrate body 2 is not particularly limited, but is preferably parallel light. As a result, the size of the opening 33 to be formed can be controlled more reliably, and as a result, the viewing angle characteristics of the microlens substrate 1 can be made particularly excellent, and the display The contrast of the displayed image can be made higher.

<B5-3> Next, as shown in FIGS. 7 (i) and 8 (j), the light-shielding material transfer sheet 13 having the light-shielding material layer 32 ′ made of the light-shielding layer forming material is bonded. (Attaching process).
The light-shielding material transfer sheet 13 is obtained by providing a light-shielding material layer 32 ′ made of a light-shielding layer forming material on a transfer sheet substrate 131. Examples of the constituent material of the transfer sheet base 131 include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene terephthalate-isophthalate copolymer, terephthalic acid-cyclohexanedimethanol-ethylene glycol. Polyester resins such as copolymers, cellulose films, polyamide resins, polyolefin resins, acrylic resins, vinyl resins, styrene resins, polycarbonate, and the like can be used. These materials are excellent in mechanical strength and excellent in heat resistance, chemical resistance, solvent resistance, flexibility and the like.

  The light shielding layer forming material usually contains a colorant, and may contain a resin material as necessary. When a thermoplastic resin is used as the resin material, transferability is particularly excellent. Examples of the thermoplastic resin constituting the light shielding layer forming material include vinyl chloride resin, acrylic resin, polyester resin, urethane resin, amide resin, and cellulose resin.

As the colorant, for example, various pigments and various dyes can be used, and carbon black is preferable.
In this step, the light-shielding material transfer sheet 13 is bonded to the pressure-sensitive adhesive layer 31 so that the light-shielding material layer 32 ′ and the pressure-sensitive adhesive layer 31 are in contact with each other.
In this embodiment, the process of bonding the light-shielding material transfer sheet 13 on the pressure-sensitive adhesive layer 31 is performed in a reduced pressure state using the above-described reduced-pressure vacuum apparatus 11. Thereby, it is possible to reliably prevent bubbles from being mixed between the pressure-sensitive adhesive layer 31 and the light-shielding material transfer sheet 13 when the pressure-sensitive adhesive layer 31 and the light-shielding material transfer sheet 13 are bonded together. In addition, foreign matters such as dust can be reliably prevented from being mixed between the pressure-sensitive adhesive layer 31 and the light-shielding material transfer sheet 13. As a result, the reliability of an image displayed using the microlens substrate 1 can be made particularly excellent.

The pressure in the reduced pressure is not particularly limited, for example, 1 × and even preferably at ¹⁰ -2 ^~1 × ¹⁰ 5 Pa, more preferably ^{1 × 10 1 ~1 × 10 3} Pa. When the pressure in the reduced pressure state (atmospheric pressure) is a value within the above range, each part of the pressure-sensitive adhesive layer 31 can be pressurized with a more uniform pressure while more reliably preventing bubbles from being mixed. It is possible to more effectively prevent the occurrence of inconvenience due to the unintentional thickness variation in the microlens substrate 1 and the remaining bubbles in the microlens substrate 1. Thereby, the transmittance can be made more uniform over the entire surface without variation.

  <B5-4> Thereafter, as shown in FIG. 8 (k), the light-shielding material transfer sheet 13 is peeled from the pressure-sensitive adhesive layer 31. As a result, the pressure-sensitive adhesive layer 31 on the photosensitive portion 319 together with the transfer sheet base material 131 is removed from the pressure-sensitive adhesive layer 31, and only the portion of the pressure-sensitive adhesive layer 31 that maintains the adhesiveness (non-photosensitive portion). The light shielding layer forming material is transferred to form the light shielding layer 32 having the openings 33 (light shielding film forming and transferring step).

<B6> Next, as shown in FIGS. 8 (l) and 8 (m), the diffusion portion 4 is formed on the surface of the substrate body 2 on which the black matrix 3 is provided (diffusion portion forming step). Thereby, the microlens substrate 1 is obtained.
The diffusing portion 4 can be formed by, for example, including a diffusing material and applying a diffusing portion forming material having fluidity, and then solidifying the material. However, the diffusing portion is formed into a plate shape in advance. It can be formed by joining the plates 4 '.

In particular, in the present embodiment, the step of bonding the diffusion plate 4 ′ on the substrate body 2 is performed in a reduced pressure state using the above-described reduced pressure vacuum apparatus 11.
The pressure in the reduced pressure is not particularly limited, for example, 1 × and even preferably at ¹⁰ -2 ^~1 × ¹⁰ 5 Pa, more preferably ^{1 × 10 1 ~1 × 10 3} Pa. When the pressure in the reduced pressure state (atmospheric pressure) is a value within the above range, each part of the light shielding layer 32 can be pressurized with a more uniform pressure while more reliably preventing bubbles from being mixed. It is possible to more effectively prevent the occurrence of inconvenience due to the unintentional thickness variation in the microlens substrate 1 or the remaining of bubbles in the microlens substrate 1. Thereby, the transmittance can be made more uniform over the entire surface without variation.

[Second Embodiment of Microlens Substrate Manufacturing Method]
Next, another example (second embodiment) of the method for manufacturing the microlens substrate 1 will be described. In this method, similarly to the method described above, the microlens substrate 1 (substrate body 2) is manufactured using the member 6 with a recess.
9 to 11 are schematic longitudinal sectional views showing an example (second embodiment) of the manufacturing method of the microlens substrate shown in FIG. In the following description, the lower side in FIGS. 9 to 11 is referred to as “(light) incident side”, and the upper side is referred to as “(light) emission side”.
Hereinafter, the manufacturing method of the microlens substrate of the second embodiment will be described focusing on the differences from the first embodiment described above, and the description of the same matters will be omitted.

<B1 ′> Same as <B1> in the first embodiment described above (composition applying step, see FIG. 9A). However, in this embodiment, it provides in the state which arranged the sealing member 12 explained in full detail in the vicinity of the peripheral part of the member 6 with a recessed part.
<B2 ′> Next, a sheet material (base film) 24 is placed on the composition 23 applied on the member 6 with recesses, and the sheet material 24 and the composition 23 are brought into close contact with each other (contact process). 9 (b) and FIG. 9 (c)).

  In the above-described embodiment (first embodiment), the entire space (within the vacuum chamber 111) for housing the recessed member 6, the composition 23, and the sheet material 24 using the reduced-pressure vacuum device 11 (vacuum chamber 111). In the present embodiment, as shown in FIGS. 9B and 9C, the composition 23 and the sheet material 24 were bonded using the seal member 12. The material 23 and the sheet material 24 are bonded together. That is, only the space between the composition 23 and the sheet material 24 is selectively reduced in pressure, and the composition 23 and the sheet material 24 are bonded together. Thereby, a pressure-reduced state can be created more suitably, the composition 23 applied onto the recessed member 6 can be more evenly spread, and the thickness variation unintentionally in the manufactured microlens substrate 1. Can be more effectively prevented, and air bubbles can be more effectively prevented from remaining between the composition 23 and the sheet material 24. In addition, the contact process can be performed using a relatively simple and small apparatus.

  As described above, in the present embodiment, prior to the contact process, the seal member 12 is disposed on the surface of the member 6 with recesses on the side where the recesses 61 are formed. The seal member 12 is formed in, for example, a rectangular frame shape having a predetermined size (for example, the size of a screen), and a hole (exhaust port) 121 is provided in part. A vacuum pump 14 is connected to this hole.

In this step, first, the composition 23 is applied to the surface of the member 6 with recesses on the side where the recesses 61 are formed and surrounded by the seal member 12, and the sheet material 24 is placed on the seal member 12. Place it so that it hangs over.
When exhausted by the vacuum pump 14, the space 29 surrounded by the seal member 12, the composition 23, and the sheet material 24 is in a reduced pressure state. Then, the sheet | seat material 24 is pressed by atmospheric pressure, and the center part vicinity adhere | attaches the composition 23 (refer FIG.9 (b)). When the evacuation is continued, the contact portion between the composition 23 and the sheet material 24 spreads from the vicinity of the central portion of the sheet material 24 to the peripheral portion, and the entire sheet material 24 is in close contact with the composition 23 (FIG. 9). (See (c)).

  Even when the reduced pressure state is created as described above, the same effect as described in the first embodiment can be obtained. Furthermore, in this embodiment, since the space between the composition 23 and the sheet material 24 is selectively reduced in pressure, the reduced pressure can be more efficiently achieved using a relatively simple and small device. . Thereby, at the time of bonding of the composition 23 and the sheet material 24, bubbles present in the composition 23 or between the composition 23 and the sheet material 24 can be further reliably removed. It is possible to more reliably prevent foreign matters such as dust from entering between the sheet material 24 and the sheet material 24.

Moreover, according to this method, when providing the composition 23 on the member 6 with a recessed part, the supply amount of the composition 23 can be easily managed because the sealing member 12 is arranged. Thereby, the thickness of the obtained substrate body 2 can be easily managed.
Moreover, according to this method, since the composition 23 and the sheet material 24 are pressed by atmospheric pressure, the whole can be more uniformly pressurized as compared with the case where the sheet material is mechanically pressed using a pressing member. it can. Thereby, it is possible to more effectively prevent the unintentional thickness variation from occurring in the substrate body 2.

The pressure in the reduced pressure is not particularly limited, for example, 1 × and even preferably at ¹⁰ -2 ^~1 × ¹⁰ 5 Pa, more preferably ^{1 × 10 1 ~1 × 10 3} Pa. When the pressure in the reduced pressure state is a value within the above range, the thickness of the microlens substrate 1 to be manufactured may be unintentionally varied, or in the composition 23, between the composition 23 and the sheet material 24, or the like. It is possible to more effectively prevent the occurrence of inconvenience due to the remaining bubbles. Thereby, the transmittance can be made more uniform over the entire surface without variation. Further, the sizes of the openings 33 of the black matrix 3 can be formed more uniformly without variation, and an image with excellent color contrast and the like can be obtained. Further, the viewing angle characteristics can be made particularly excellent.

<B3 ′> Same as <B3> in the first embodiment described above (solidification step, see FIG. 9D).
<B4 ′> Similar to <B4> in the first embodiment described above (recessed member removing step, see FIG. 10E).
However, in the present embodiment, for example, by cutting the end portion on which the seal member 12 is arranged in the substrate body 2 that is in close contact with the member 6 with the recess, the sheet-shaped substrate body 2 having a predetermined size is obtained. Obtainable.

<B5 ′> Similar to <B5>(<B5-1> to <B5-4>) of the first embodiment described above (FIG. 10 (f), FIG. 10 (g), FIG. 10 (h), FIG. (See (i)).
However, in the step of bonding the substrate body 2 and the adhesive sheet 31 ′, the reduced pressure state may be created using the sealing member 12 as described above. Thereby, at the time of bonding of the board | substrate body 2 and adhesive sheet | seat 31 ', it can prevent reliably that a bubble mixes between the board | substrate body 2 and adhesive sheet | seat 31'. Moreover, it is possible to reliably prevent foreign matters such as dust from being mixed between the substrate body 2 and the adhesive sheet 31 ′. As a result, the reliability of an image displayed using the microlens substrate 1 can be made particularly excellent.

  Further, in the step of bonding the light-shielding material transfer sheet 13 on the pressure-sensitive adhesive layer 31, the reduced pressure state may be created using the sealing member 12 as described above. Thereby, it is possible to reliably prevent bubbles from being mixed between the pressure-sensitive adhesive layer 31 and the light-shielding material transfer sheet 13 when the pressure-sensitive adhesive layer 31 and the light-shielding material transfer sheet 13 are bonded together. In addition, foreign matters such as dust can be reliably prevented from being mixed between the pressure-sensitive adhesive layer 31 and the light-shielding material transfer sheet 13. As a result, the reliability of an image displayed using the microlens substrate 1 can be made particularly excellent.

<B6 ′> Same as <B6> in the first embodiment described above (diffusion part forming step; see FIG. 11 (j)).
However, in the step of bonding the diffusion plate 4 ′ on the substrate body 2 (black matrix 3), the reduced pressure state may be created using the sealing member 12 as described above. Thereby, it is possible to reliably prevent bubbles from being mixed between the substrate body 2 and the diffusion plate 4 ′ when the substrate body 2 and the diffusion plate 4 ′ are bonded to each other. In addition, foreign matters such as dust can be reliably prevented from entering between the substrate body 2 and the diffusion plate 4 ′. As a result, the reliability of an image displayed using the microlens substrate 1 can be made particularly excellent.

A rear projector using the transmission screen will be described below.
FIG. 12 is a diagram schematically showing the configuration of the rear projector of the present invention.
As shown in the figure, the rear projector 400 has a configuration in which a projection optical unit 410, a light guide mirror 420, and a transmissive screen 10 are arranged in a housing 440.
Since the rear projector 400 includes the transmission screen 10 as described above, color unevenness and luminance unevenness are prevented, and an image with excellent contrast can be obtained.

In particular, in the microlens substrate 1 described above, since the elliptical microlenses 21 are arranged in a staggered pattern (in a staggered pattern), problems such as moire are not particularly likely to occur in the rear projector 400.
As mentioned above, although this invention was demonstrated based on embodiment of illustration, this invention is not limited to these.

For example, each part of the microlens substrate, the transmissive screen, and the rear projector can be replaced with any structure that can exhibit the same function. Moreover, you may add arbitrary structures.
In the method for manufacturing a microlens substrate, an arbitrary step may be added.
Moreover, the order of each process in the manufacturing method of a microlens board | substrate is not limited to what was mentioned above, You may change the order as needed.

In the above-described embodiment, the sticking step, the pressure-sensitive adhesive layer forming step, and the diffusion portion forming step are described as being performed in a reduced pressure state in addition to the sticking step. However, in the present invention, at least the sticking step is reduced in pressure. The sticking step, the pressure-sensitive adhesive layer forming step, and the diffusion portion forming step may not be performed under reduced pressure.
In the above-described embodiment, the composition has been described as being applied to the surface of the concave member. For example, the composition is applied to the surface of a flat plate (or a sheet material placed on the flat plate). You may manufacture a microlens board | substrate by pressing with a member with a recessed part.

  In the above-described embodiment, a positive photosensitive adhesive is applied to the substrate body, and then a light irradiation process is performed to reduce the adhesiveness of the photosensitive portion, and light shielding is performed on a portion other than the photosensitive portion. It has been described that a black matrix (light-shielding film) having an opening is formed by applying a light-sensitive material, but using a positive photopolymer as a light-shielding film forming material, a process of irradiating light is performed, A black matrix (light-shielding film) having an opening may be formed by developing the photosensitive part.

  A material other than the photopolymer may be used. For example, a reversal developing material such as a silver salt photosensitive material may be used as the light shielding film forming material. When a silver salt photosensitive material (reversal developing material) is used, after exposure as described above, once the exposed portion is processed to be desalted, and then further exposed and developed. The first exposed portion can be a light transmissive non-light-shielding portion, and the other portions can be light-shielding portions (light-shielding regions). In addition, a photosensitive material may not be used for forming the light shielding film. For example, after a film made of a material for forming a light-shielding film other than a photosensitive material is formed on the substrate body, it is condensed by a microlens by irradiating light (energy rays), and the energy density increases. A black matrix (light-shielding film) having an opening may be formed by blowing off a part of the film made of the light-shielding film-forming material or evaporating the light.

  In the above-described embodiment, the black matrix (light-shielding film) is formed by irradiating light (exposure light) with the recessed member removed, but the recessed member is applied to the substrate body. You may form a black matrix in the attached state. That is, when irradiating light to the light-shielding film forming material, the light may be irradiated through a member with a recess.

Further, in the above-described embodiment, the member with the concave portion is described as being removed, but the member with the concave portion may not necessarily be removed. That is, the member with a recess may constitute a part of the microlens substrate.
Moreover, in embodiment mentioned above, although demonstrated as what manufactures a board | substrate body using a plate-shaped member with a recessed part (board | substrate with a recessed part), a board | substrate body is manufactured using a roll-shaped member with a recessed part, for example. May be.

In the above-described embodiment, the diffusion part is formed by joining the diffusion plates formed in a plate shape in advance. However, the diffusion part forming material including the diffusion material and having fluidity is used. After the application, the material may be solidified.
In the above-described embodiment, the microlens substrate has been described as having a layered diffusion portion, but the shape of the diffusion portion is not limited to this. For example, the diffusion portion may be provided in a convex shape at a portion corresponding to the opening of the black matrix. Even in such a case, the effects described above can be obtained. In addition, by forming such a diffusion portion, it is possible to more effectively prevent reflection of external light at a portion other than the opening portion of the black matrix, so that the contrast of the obtained image is particularly excellent. can do.

In the above-described embodiment, the microlens substrate has been described as having a substrate body, a black matrix (light-shielding film), and a diffusion part. However, the microlens substrate of the present invention has a light-shielding film and a diffusion part. It does not have to be provided. For example, the microlens substrate of the present invention may be substantially composed only of the substrate body.
The substrate body constituting the microlens substrate may have a colored portion formed by staining near the surface on the side where the microlens is provided.

  In the above-described embodiment, the substrate body constituting the microlens substrate is provided with a microlens as a convex lens, and a member with a concave portion having a concave portion having a shape corresponding to the convex lens is used as a molding die. However, the substrate body may include a microlens as a concave lens. In such a case, as the mold, a member with a convex portion provided with a convex portion having a shape corresponding to the concave lens can be used.

In the above-described embodiment, the transmission screen is described as including a microlens substrate and a Fresnel lens. However, the transmission screen of the present invention does not necessarily include a Fresnel lens. For example, the transmission screen of the present invention may be substantially constituted only by the microlens substrate of the present invention.
In the above-described embodiment, the microlens substrate is described as a member constituting a transmissive screen and a rear projector. However, the use of the microlens substrate of the present invention is limited to the above. It may be anything. For example, the microlens substrate of the present invention is used as a diffusion plate, a black matrix screen, a projection display device (front projector) screen (front projection screen), a component of a liquid crystal light valve of a projection display device (front projector), or the like. It may be applied.

[Production of microlens substrate and transmissive screen]
Example 1
The member with a recessed part provided with the recessed part for microlens formation was manufactured as follows.
First, as a substrate, a soda glass substrate having a width of 1.2 m × length of 0.7 m and a thickness of 4.8 mm was prepared.

This soda glass substrate was immersed in a cleaning solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide and etched by 6 μm to clean the surface.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.
Next, a chromium / chromium oxide laminate (a laminate in which chromium oxide was laminated on the outer surface side of chromium) was formed on the soda glass substrate by sputtering. That is, a mask formation film and a back surface protection film composed of a chromium / chromium oxide laminate were formed on the surface of a soda glass substrate. The thickness of the chromium layer was 0.03 μm, and the thickness of the chromium oxide layer was 0.01 μm.

Next, laser processing was performed on the mask forming film to form a large number of initial holes in a range of 113 cm × 65 cm in the central portion of the mask forming film, thereby forming a mask.
The laser processing was performed using an excimer laser under the conditions of an energy density of 1.2 J / cm ² , a beam diameter of 2 μm at the processing point, and a scanning speed of 0.1 m / sec.
As a result, substantially circular initial holes were formed in a staggered pattern over the entire range of the mask forming film. The diameter of the initial hole was 2 μm.

Next, wet etching was performed on the soda glass substrate to form concave portions (recesses for forming microlenses) having a flat shape (substantially elliptical shape) when viewed in plan on the soda glass substrate. The formed many recesses had substantially the same shape as each other. The length (pitch) in the minor axis direction of the formed recess was 54 μm, the length in the major axis direction was 72 μm, the radius of curvature was 40 μm, and the depth was 40 μm. Moreover, the occupation rate of the recessed part in the effective area | region in which the recessed part was formed was 100%.
In the wet etching, an aqueous solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide was used as an etchant, and the immersion time was 2.0 hours.

Next, the mask and the back surface protective film were removed by etching using a mixture of ceric ammonium nitrate and perchloric acid.
Next, cleaning with pure water and drying (removing pure water) using N ₂ gas were performed.
Thereafter, a gas phase surface treatment (silylation treatment) with hexamethyldisilazane was performed on the surface side of the substrate where the concave portions were formed, thereby forming a release treatment portion.
Thereby, the member with a recessed part in which many recessed parts for microlens formation were arranged on the soda glass substrate in zigzag form was obtained.

Next, a composition composed of unpolymerized (uncured) acrylic resin (PMMA resin (methacrylic resin)) was applied to the surface of the member with recesses on the side where the recesses were formed.
Next, a sheet material (thickness: 0.075 mm) made of polyethylene terephthalate (PET) was placed on the composition applied on the member with recesses. The refractive index (absolute refractive index n ₁ ) of polyethylene terephthalate constituting the sheet material was 1.656. Further, as the sheet material, a sheet material in which a large number of grooves were formed on the surface facing the composition was used. The grooves of the sheet material were parallel to each other, had a semicircular cross-sectional shape, an opening width of 30 μm, a depth of 15 μm, and a pitch of 30 μm. Further, the ratio of the projected area occupied by the groove on the surface provided with the groove of the sheet material was 50%. Further, the sheet material was placed so that the longitudinal direction of the groove was parallel to the short axis direction of the concave portion of the concave member. Further, the sheet material was placed so that the groove was present in a portion other than the light condensing portion of the microlens to be formed.

The step of placing the sheet material on the composition was performed in a vacuum state in a vacuum chamber. At this time, the atmospheric pressure in the vacuum chamber was 10 Pa.
Thereafter, the composition was completely cured by irradiating the composition with ultraviolet rays while maintaining the reduced pressure state, thereby obtaining a substrate body. The obtained substrate main body had a microlens having a shape corresponding to the concave portion of the concave member. The formed microlens had a flat shape (substantially elliptical shape), and had a length in the major axis direction of 72 μm, a radius of curvature of 36 μm, and a height of 36 μm. Further, the occupation ratio of the microlens in the effective region where the microlens is formed was 100%. Further, the refractive index (absolute refractive index n ₁ ) of the material constituting the formed cured portion was 1.56.

Next, the member with a recess was removed from the substrate body.
Next, an acrylic photosensitive pressure-sensitive adhesive as a positive photosensitive pressure-sensitive adhesive is applied to the surface of the substrate body on the emission side (the surface opposite to the surface on which the microlenses are formed), and the pressure-sensitive adhesive layer is formed. Formed.
In the vacuum chamber, the pressure-sensitive adhesive layer is formed in a reduced pressure state (15 Pa) with a sheet-like pressure-sensitive adhesive sheet composed of a positive photosensitive pressure-sensitive adhesive (acrylic photosensitive pressure-sensitive adhesive) on the composition. It was done by placing.

Next, ultraviolet rays as parallel light of 60 mJ / cm ² were irradiated from the surface side of the substrate body on which the microlenses were formed, using a MA6 aligner (Zuose Microtech).
The irradiated ultraviolet rays were collected by each microlens, and the photosensitive adhesive at the site irradiated with the collected ultraviolet rays was selectively exposed.
As a result, in the pressure-sensitive adhesive layer, the tackiness of the photosensitive portion was selectively lowered, and the non-photosensitive portion was held in a state having tackiness. When the peel strength of the pressure-sensitive adhesive layer was measured based on JIS Z0237, it was 500 gf / inch at the photosensitive part and 30 gf / inch at the non-photosensitive part.

Next, a light-shielding material transfer sheet composed of a transfer sheet substrate and a light-shielding material layer was bonded to the surface of the partially exposed pressure-sensitive adhesive layer. The step of attaching the light-shielding material transfer sheet on the pressure-sensitive adhesive layer was performed in a reduced pressure state (100 Pa) in a vacuum chamber.
Thereafter, the transfer sheet substrate was peeled from the pressure-sensitive adhesive layer. Thereby, the light shielding layer forming material constituting the light shielding material layer is attached (transferred) only to the non-photosensitive portion of the pressure-sensitive adhesive layer, and the light shielding layer having an opening at a portion corresponding to the light condensing portion of each microlens. Formed. The opening was substantially circular and had a diameter of 25 μm. The formed light shielding layer had a thickness of 2 μm. As the light-shielding material transfer sheet, a sheet provided with a light-shielding material layer made of carbon black on a transfer sheet base material was used.

Next, a diffusion part was formed on the side of the substrate body on which the black matrix was formed to obtain a microlens substrate. The diffusion portion was formed by bonding a diffusion plate having a configuration in which a diffusion material (silica particles having an average particle size of 8 μm) was dispersed in an acrylic resin in a vacuum state (100 Pa) in a vacuum chamber. In addition, the thickness of the diffusion part was 2.0 mm.
A transmissive screen as shown in FIG. 3 was obtained by assembling the microlens substrate manufactured as described above and the Fresnel lens portion manufactured by extrusion molding.

(Examples 2 to 4)
A microlens substrate and a transmissive screen were produced in the same manner as in Example 1 except that the atmospheric pressure in the reduced pressure state was changed as shown in Table 1.
(Example 5)
A microlens substrate and a transmissive screen were manufactured in the same manner as in Example 1 except that a sheet material having no grooves formed on the surface thereof was used.

(Example 6)
First, a member with a recess was manufactured in the same manner as in Example 1.
Next, as shown in FIG. 8A, an unpolymerized (uncured) acrylic material is provided by placing a seal member formed in a rectangular frame shape on the surface of the member with recesses on the side where the recesses are formed. A composition composed of a resin (PMMA resin (methacrylic resin)) was applied.

Next, a sheet material (thickness: 50 mm) made of polyethylene terephthalate (PET) was placed on the seal member. The refractive index (absolute refractive index n ₁ ) of polyethylene terephthalate constituting the sheet material was 1.656. Further, as the sheet material, a sheet material in which a large number of grooves were formed on the surface facing the composition was used. The grooves of the sheet material were parallel to each other, had a semicircular cross-sectional shape, an opening width of 60 μm, a depth of 30 μm, and a pitch of 100 μm. The ratio of the projected area occupied by the grooves on the surface provided with the grooves of the sheet material was 60%. Further, the sheet material was placed so that the longitudinal direction of the groove was parallel to the short axis direction of the concave portion of the concave member. Further, the sheet material was placed so that the groove was present in a portion other than the light condensing portion of the microlens to be formed.

By evacuating with a vacuum pump connected to the seal member, the space surrounded by the seal member, the composition and the sheet material was brought into a reduced pressure state (10 Pa). As a result, the sheet material was adhered onto the composition by being pressed by atmospheric pressure.
Thereafter, the composition was completely cured by irradiating the composition with ultraviolet rays while maintaining the reduced pressure state, thereby obtaining a substrate body. The obtained substrate main body had a microlens having a shape corresponding to the concave portion of the concave member. The formed microlens had a flat shape (substantially elliptical shape), and had a length in the major axis direction of 72 μm, a radius of curvature of 36 μm, and a height of 36 μm. Further, the occupation ratio of the microlens in the effective region where the microlens is formed was 100%. Further, the refractive index (absolute refractive index n ₁ ) of the material constituting the formed cured portion was 1.56.

Next, the member with a recess was removed from the substrate body.
Next, an acrylic photosensitive pressure-sensitive adhesive as a positive photosensitive pressure-sensitive adhesive is applied to the surface of the substrate body on the emission side (the surface opposite to the surface on which the microlenses are formed), and the pressure-sensitive adhesive layer is formed. Formed.
Next, ultraviolet rays as parallel light of 60 mJ / cm ² were irradiated from the surface side of the substrate body on which the microlenses were formed, using a MA6 aligner (Zuose Microtech).

The irradiated ultraviolet rays were collected by each microlens, and the photosensitive adhesive at the site irradiated with the collected ultraviolet rays was selectively exposed.
As a result, in the pressure-sensitive adhesive layer, the tackiness of the photosensitive portion was selectively lowered, and the non-photosensitive portion was held in a state having tackiness. When the peel strength of the pressure-sensitive adhesive layer was measured based on JIS Z0237, it was 500 gf / inch at the photosensitive part and 50 gf / inch at the non-photosensitive part.

Next, a light-shielding material transfer sheet composed of a transfer sheet substrate and a light-shielding material layer is pressure-bonded to the surface of the partially exposed pressure-sensitive adhesive layer, and 5 kg at a temperature of 80 ° C. using a laminator. Lamination was performed at a pressure of / cm ² , and then the transfer sheet substrate was peeled from the adhesive layer. Thereby, the light shielding layer forming material constituting the light shielding material layer is attached (transferred) only to the non-photosensitive portion of the pressure-sensitive adhesive layer, and the light shielding layer having an opening at a portion corresponding to the light condensing portion of each microlens. Formed. The opening was substantially circular and had a diameter of 40 μm. The formed light shielding layer had a thickness of 3 μm. As the light-shielding material transfer sheet, a sheet provided with a light-shielding material layer made of carbon black on a transfer sheet base material was used.

Next, a diffusion part was formed on the side of the substrate body on which the black matrix was formed to obtain a microlens substrate. The diffusion portion was formed by joining a diffusion plate having a configuration in which a diffusion material (silica particles having an average particle size of 8 μm) was dispersed in an acrylic resin in a vacuum state (10 Pa) in a vacuum chamber. In addition, the thickness of the diffusion part was 2.0 mm.
Using the microlens substrate manufactured as described above, a Fresnel lens portion produced by extrusion molding was assembled in the same manner as in Example 1 to obtain a transmission screen as shown in FIG. .

(Examples 7 to 9)
A microlens substrate and a transmissive screen were manufactured in the same manner as in Example 6 except that the atmospheric pressure in the reduced pressure state was changed as shown in Table 1.
(Example 10)
A microlens substrate and a transmissive screen were manufactured in the same manner as in Example 6 except that a sheet material having no grooves formed on the surface thereof was used.

(Comparative example)
A microlens substrate and a transmissive screen were manufactured in the same manner as in Example 10 except that all steps were performed under atmospheric pressure and the adhesion step was performed by pressing using a flat pressing member.
Table 1 summarizes the conditions in the reduced pressure state (pressure reduction method, pressure during pressure reduction) for each of the above Examples and Comparative Examples.

[Evaluation of transmittance]
The transmittance was evaluated for the transmissive screens of the examples and comparative examples.
The transmittance is evaluated using a spectrophotometer (manufactured by Otsuka Electronics Co., Ltd., instantaneous multi-photometry system “MCPD-1000 (28C)”), and the transmittance of light having a wavelength of 400 nm with respect to the microlens formation region of the microlens substrate. Was measured.

The results were evaluated according to the following four-stage criteria.
A: The transmittance is 90% or more.
○: The transmittance is 80% or more and less than 90%.
Δ: The transmittance is 70% or more and less than 80%.
X: The transmittance is less than 70%.

[Production of rear projector]
Using the transmissive screens of the examples and comparative examples, rear projectors as shown in FIG. 12 were produced.
[Evaluation of uneven color and brightness]
Sample images were displayed on the transmissive screens of the rear projectors of the examples and comparative examples. The displayed image was evaluated for the occurrence of uneven color and uneven brightness according to the following four criteria.
A: Color unevenness and luminance unevenness are not recognized at all.
○: Color unevenness and luminance unevenness are hardly observed.
Δ: Color unevenness and luminance unevenness are slightly observed.
X: Color unevenness and luminance unevenness are remarkably recognized.

[Evaluation of contrast]
Contrast evaluation was performed on the rear projectors of each of the examples and comparative examples.
As contrast (CNT), the front luminance (white luminance) LW [cd / m ² ] of white display when all white light of 413 lx is incident in the dark room, and the front luminance of black display when the light source is completely turned off in the bright room The ratio LW / LB with the increase amount (black luminance increase amount) LB [cd / m ² ] was obtained. The black luminance increase amount is an increase amount with respect to the black display luminance in the dark room. The measurement in the bright room was performed under an environment where the ambient light illuminance was about 185 lx. The measurement in the dark room was performed in an environment where the external light illuminance was 0.1 lx or less.

[Measurement of viewing angle]
With the sample images displayed on the transmissive screens of the rear projectors of the examples and comparative examples, the viewing angles in the vertical direction (up and down direction) and the horizontal direction (left and right direction) were measured.
The viewing angle was measured under the condition of measuring with a variable angle photometer (goniophotometer) at intervals of 1 degree.

[Evaluation of diffracted light]
Sample images were displayed on the transmissive screens of the rear projectors of the examples and comparative examples. About the displayed image, the generation condition of diffracted light (including moire) was evaluated according to the following four-stage criteria.
A: No diffracted light is observed.
A: Almost no diffracted light is observed.
Δ: Slight diffraction light is observed.
X: Remarkably diffracted light is recognized.
These results are summarized in Table 2.

  As is apparent from Table 2, in the present invention, it was possible to display an image having high transmittance and suppressed occurrence of color unevenness and luminance unevenness. In the present invention, the contrast is high and the viewing angle characteristics are excellent. In the present invention, an excellent image without diffracted light could be displayed. That is, in the present invention, an excellent image can be stably displayed. On the other hand, in the comparative example, a satisfactory result was not obtained.

It is a typical longitudinal section showing a suitable embodiment of a micro lens substrate of the present invention. FIG. 2 is a plan view of the microlens substrate shown in FIG. 1. It is a typical longitudinal cross-sectional view which shows suitable embodiment of the transmission type screen of this invention provided with the microlens board | substrate shown in FIG. It is a typical longitudinal section showing a member with a crevice used for manufacture of a micro lens substrate. It is a typical longitudinal cross-sectional view which shows the manufacturing method of the member with a recessed part shown in FIG. It is a typical longitudinal cross-sectional view which shows an example (1st Embodiment) of the manufacturing method of the micro lens board | substrate shown in FIG. It is a typical longitudinal cross-sectional view which shows an example (1st Embodiment) of the manufacturing method of the micro lens board | substrate shown in FIG. It is a typical longitudinal cross-sectional view which shows an example (1st Embodiment) of the manufacturing method of the micro lens board | substrate shown in FIG. It is a typical longitudinal cross-sectional view which shows another example (2nd Embodiment) of the manufacturing method of the micro lens board | substrate shown in FIG. It is a typical longitudinal cross-sectional view which shows another example (2nd Embodiment) of the manufacturing method of the micro lens board | substrate shown in FIG. It is a typical longitudinal cross-sectional view which shows another example (2nd Embodiment) of the manufacturing method of the micro lens board | substrate shown in FIG. It is a figure which shows typically the rear type projector to which the transmission type screen of this invention is applied.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Micro lens board | substrate 2 ... Board | substrate main body 21 ... Micro lens (convex lens) 211 ... Center 23 ... Composition 24 ... Sheet material (base film) 25 ... 1st line 26 ... 2nd line 29 ... Space 3 ... Black Matrix (light-shielding film) 31 ... Adhesive layer 31 '... Adhesive sheet 319 ... Photosensitive part 32 ... Light-shielding layer 32' ... Light-shielding material layer 33 ... Opening part 4 ... Diffusion part 4 '... Diffusion plate 5 ... Fresnel lens part 51 ... Fresnel lens 6 ... Member with recess (member with recess for microlens formation) 61 ... Recess (recess for microlens formation) 7 ... Substrate 8 ... Mask 81 ... Mask formation film 82 ... Initial hole (opening) 89 ... Back Protective film 10 ... Transmission type screen 11 Depressurized vacuum device 111 ... Vacuum chamber 112 ... Vacuum pump 12 ... Seal member 121 ... Hole (exhaust port) 13 ... light-shielding material transfer sheet 131 ... transfer sheet substrate 14 ... vacuum pump 400 ... rear projection 410 ... projection optical unit 420 ... light guide mirror 440 ... housing La ... light Lb ... light (exposure light)

Claims (13)

A method of manufacturing a microlens substrate including a substrate body having a number of microlenses,
A composition applying step for applying a composition having fluidity on the surface of a mold having an inverted shape on the surface side where the microlenses of the substrate body to be manufactured are provided;
An adhesion step for closely adhering the sheet material to the composition;
A solidification step for solidifying the composition,
The method for producing a microlens substrate, wherein the adhesion step is performed in a reduced pressure state in which a space between the composition and the sheet material is reduced.   The method for producing a microlens substrate according to claim 1, wherein a space including the composition and the entire sheet material is brought into the reduced pressure state by using a vacuum chamber.   The method for producing a microlens substrate according to claim 1, wherein only the space between the composition and the sheet material is selectively brought into the reduced pressure state by using a sealing material. A positive photosensitive adhesive is applied to the surface of the substrate body manufactured through the composition application step, the adhesion step, and the solidification step, opposite to the surface side provided with the microlens. And forming a pressure-sensitive adhesive layer,
A light irradiation step of applying light to the pressure-sensitive adhesive layer through the substrate body to reduce the adhesiveness of the photosensitive portion;
A sticking step of bonding a light-shielding material transfer sheet having a light-shielding material layer composed of a light-shielding layer forming material on the pressure-sensitive adhesive layer;
The light-shielding material transfer sheet bonded is peeled off from the pressure-sensitive adhesive layer, and the light-shielding layer forming material is selectively transferred to the non-photosensitive portion of the photosensitive pressure-sensitive adhesive, thereby forming a light-shielding film having an opening. A light shielding film forming step to be formed;
The method for manufacturing a microlens substrate according to any one of claims 1 to 3, wherein the attaching step is performed in a reduced pressure state in which a space between the pressure-sensitive adhesive layer and the light-shielding material transfer sheet is reduced. The pressure-sensitive adhesive layer forming step is performed by bonding a pressure-sensitive adhesive sheet composed of a photosensitive pressure-sensitive adhesive on the substrate body,
The method for producing a microlens substrate according to claim 4, wherein the pressure-sensitive adhesive layer forming step is performed in a reduced pressure state in which a space between the substrate main body and the pressure-sensitive adhesive sheet is reduced. A diffusion plate is bonded to the surface of the substrate body manufactured through the composition application step, the adhesion step, and the solidification step, opposite to the surface side where the microlenses are provided. A diffusion part forming step to be formed;
The method of manufacturing a microlens substrate according to claim 1, wherein the diffusion portion forming step is performed in a reduced pressure state in which a space between the substrate body and the diffusion plate is reduced. The method for producing a microlens substrate according to claim 1, wherein the pressure in the reduced pressure state is 1 × 10 ⁻² to 1 × 10 ⁵ Pa.   The method of manufacturing a microlens substrate according to claim 1, wherein the sheet material has a thickness of 20 to 200 μm.   The method for manufacturing a microlens substrate according to any one of claims 1 to 8, wherein the sheet material is made of polyethylene terephthalate.   A microlens substrate manufactured by the method according to claim 1.   A transmissive screen comprising the microlens substrate according to claim 10. A Fresnel lens portion provided with a Fresnel lens on the light exit side;
The transmissive screen according to claim 11, further comprising: the microlens substrate disposed on the light emission side of the Fresnel lens unit. A rear projector comprising the transmissive screen according to claim 11.

Images