JP2007199212A - Microlens substrate, transmissive screen, and rear projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microlens substrate which is excellent in viewing angle characteristics and can display an image excellent in contrast, and to provide a transmissive screen and a rear projector provided with the microlens substrate. <P>SOLUTION: The microlens substrate includes: a substrate main body having a large number of microlenses; and a light intercepting film disposed opposite the microlens side of the substrate main body and having a large number of openings. Layers in vertical stripes arranged at a pitch of 400 nm or less are formed on the microlens side of the substrate main body. It is preferable that the light shielding film be formed from a material containing a metal element as its main constituent. It is also preferable that the layers be formed from a inorganic material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to 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 lens substrate such as a lenticular lens substrate or a microlens substrate is generally used for a transmissive screen used in a rear projector. Such a lens substrate (lens sheet) includes a substrate body on which a plurality of lenses are formed, and a light shielding film provided for the purpose of improving the contrast of an image (see, for example, Patent Document 1). .
The light shielding film is provided with an opening, and light transmitted through the lens (light refracted by the lens) passes through the opening and is emitted to the outside.

  However, in a lens substrate having such a light shielding film, light incident on a portion other than the opening described above is reflected between the light shielding film and the substrate body, and this reflected light becomes stray light in the substrate body, There was a problem that the contrast was lowered. Further, in such a lens substrate (lens sheet), when a light-shielding layer (light-shielding film) is not provided, for example, in the case of black display, a deep black color cannot be displayed. The contrast is extremely low. In addition, the lens substrate (lens sheet) provided with the lenticular lens has a problem that the left and right viewing angles are large but the top and bottom viewing angles are small (the viewing angles are biased).

JP 2002-350981 A

  An object of the present invention is to provide a microlens substrate capable of displaying an image having excellent viewing angle characteristics and excellent contrast, and a transmissive screen and a rear projector provided with such a microlens substrate. Is to provide.

Such an object is achieved by the present invention described below.
The microlens substrate of the present invention has a substrate body provided with a large number of microlenses, and a large number of openings provided on the surface of the substrate body opposite to the side where the microlenses are provided. A microlens substrate having a light shielding film,
A layer having a stripe shape in the vertical direction and an arrangement pitch of 400 nm or less is provided on the surface of the substrate body on which the microlenses are provided.
Thereby, it is possible to provide a microlens substrate capable of displaying an image having excellent viewing angle characteristics and excellent contrast.

In the microlens substrate of the present invention, it is preferable that the light shielding film is mainly composed of a material containing a metal element.
Thereby, the utilization efficiency of light can be improved more effectively.
In the microlens substrate of the present invention, the layer is preferably composed of an inorganic material.
Thereby, a stripe-shaped layer can be easily formed and the durability of the stripe-shaped layer can be improved.

In the microlens substrate of the present invention, the width of one stripe of the layer is preferably 40 to 50% of the arrangement pitch.
Thereby, P polarized light can be transmitted more selectively and S polarized light can be more reliably reflected.
In the microlens substrate of the present invention, the height of the layer is preferably 100 to 150 nm.
Thereby, P polarized light can be transmitted more selectively and S polarized light can be more reliably reflected.

The transmission screen of the present invention is characterized by including the microlens substrate of the present invention.
Thereby, it is possible to provide a transmissive screen capable of displaying an image having excellent viewing angle characteristics and excellent contrast.
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 that can display an image having excellent viewing angle characteristics and excellent contrast.

Hereinafter, 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. .
Although the use of the microlens substrate of the present invention is not particularly limited, in the present embodiment, 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. FIG. 4 is a schematic longitudinal sectional view showing a preferred embodiment of the transmission screen of the present invention provided with the microlens substrate shown in FIG. In the following description, the left side in FIGS. 1 and 4 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 transmission screen 10 to be described later, and as shown in FIG. 1, a substrate body 2 including a plurality of microlenses (convex lenses) 21 arranged in a predetermined pattern, A stripe layer 7 provided on the surface of the microlens 21 and a black matrix (light-shielding film) 3 having a function of absorbing external light (external light unfavorable for forming a projection image) are provided.

The substrate body 2 is usually made of a transparent material.
The constituent material of the substrate body 2 is not particularly limited, but is mainly composed of a resin material and is composed of a transparent material having a predetermined refractive index.
Specific examples of the constituent material of the substrate body 2 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, 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 , Polyester, polyamide, polybutadiene, transpolyisoprene, fluororubber, chlorinated polyethylene, and other thermoplastic elastomers, epoxy resins, phenolic 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.

The microlens substrate 1 includes a plurality of microlenses 21 as convex lenses having a convex surface on the light incident surface side.
The microlens 21 may have any shape, but in this embodiment, the microlens 21 has a horizontal width (horizontal direction) when the microlens substrate 1 is viewed in plan view. ) Having a flat shape (substantially oval or substantially bowl-shaped). 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.

  As described above, the microlenses 21 are arranged in a staggered pattern when the microlens substrate 1 is viewed in plan view. However, the microlenses 21 are adjacent to the first row 25 composed of the plurality of microlenses 21 and adjacent to them. It is preferable that the second row 26 is shifted by a half pitch in the lateral 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.

As described above, by strictly defining the shape, arrangement method, occupation ratio, etc. of the microlens, the viewing angle characteristics should be particularly excellent while effectively preventing the occurrence of moire due to light interference. Can do.
Each microlens 21 is formed as a convex lens protruding to the incident side, and is designed so that the focal point f is positioned in the vicinity of an opening (non-light-shielding portion) 33 provided in the black matrix 3 described later. ing. That is, parallel light La (parallel light La from a Fresnel lens portion 5 described later) incident on the microlens substrate 1 from a substantially perpendicular direction is condensed by each microlens 21 of the microlens substrate 1 and is black. A focal point f is formed near the opening 33 of the matrix 3. As described above, the microlens 21 is focused in the vicinity of the opening 33 of the black matrix 3, so that the light utilization efficiency can be made particularly excellent. In addition, since the micro lens 21 is focused in the vicinity of the opening 33, the area of the opening 33 can be reduced. That is, the ratio of the area covered with the black matrix 3 (region other than the opening 33) when the microlens substrate 1 is viewed in plan can be increased. As a result, the contrast of an image formed by light transmitted through the microlens substrate can be made particularly excellent.

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% or more in the effective region where the microlens 21 is formed. It is preferable that it is 96% or more, and it is more preferable that it is 97-99.5%. When the occupation ratio of the microlens 21 is 90% or more, the straight light passing through other than the microlens 21 can be further reduced, and the light utilization efficiency can be further improved. Note that the occupation ratio of the microlens 21 is the center (the center of the top) 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. In the line segment to be connected, the ratio of the length L ₃ [μm] of the portion where the microlens 21 is formed to the length L ₄ [μm] of the line segment (L ₃ / L ₄ × 100 [%]) (See FIG. 2).

A stripe layer 7 is provided on the light incident side of the substrate body 2 (the surface of the microlens 21).
The stripe layer 7 is a vertical stripe layer.
The stripe layer 7 has an arrangement pitch of 400 nm or less.
As described above, the present invention is characterized in that a layer (stripe layer) having a stripe shape in the vertical direction and an arrangement pitch of 400 nm or less is provided on the surface of the substrate body on which the microlens is provided. Have.
The layer having such a configuration has a function of selectively transmitting P-polarized light and reflecting S-polarized light among light components. That is, the layer having such a configuration has a function of selectively making P-polarized light incident on the substrate body out of the light irradiated on the substrate body.

By the way, in a conventional microlens substrate having a black matrix, light incident on a portion other than the opening of the light shielding film (black matrix) is reflected between the light shielding film and the substrate body, and the reflected light is reflected on the substrate. There has been a problem that it becomes stray light in the body and lowers the contrast.
As a result of intensive studies, the present inventors have found that the stray light as described above can be reduced by providing the microlens substrate with the layer having the above-described configuration. This is considered to be due to the following reasons.

  That is, most of the light incident on the substrate body passes through the opening of the light shielding film and is emitted to the outside, but a part of the light is irradiated to the light shielding film and reflected as shown in FIG. . The light incident on the light shielding film is almost P-polarized light, but the ratio of S-polarized light is increased by reflection. The light reflected by the light shielding film is applied to the stripe layer as shown in FIG. At this time, among the light reflected by the light shielding film, the P-polarized light passes through the stripe layer as it is, but the S-polarized light is reflected again by the stripe layer and emitted from the opening to the outside. From the above, it is considered that stray light inside the substrate body can be reduced and the contrast can be prevented from being lowered.

The stripe layer (layer) of the present invention has an arrangement pitch of 400 nm or less, preferably 300 nm or less, and more preferably 150 to 200 nm. Thereby, the effect of this invention becomes more remarkable. If the arrangement pitch exceeds the upper limit, it becomes difficult to selectively transmit P-polarized light and sufficiently reflect S-polarized light.
The material constituting the stripe layer 7 is not particularly limited, but it is preferable to use an inorganic material. Thereby, the stripe layer 7 can be easily formed, and the durability of the stripe layer 7 can be improved.
Examples of such an inorganic material include silver, aluminum, chromium, nickel and the like.

Further, the width of one stripe of the stripe layer 7 is preferably 40 to 50%, more preferably 45 to 50% of the arrangement pitch described above. Thereby, P polarized light can be transmitted more selectively and S polarized light can be more reliably reflected.
The height (thickness) of the stripe layer 7 is preferably 100 to 200 nm, and more preferably 100 to 150 nm. Thereby, P polarized light can be transmitted more selectively and S polarized light can be more reliably reflected.
A black matrix 3 having an opening 33 is provided on the surface of the substrate body 2 on the light emission side.

In the present embodiment, the black matrix (light shielding film) 3 includes a metal material layer 31 and an antireflection layer 32.
The metal-based material layer 31 can be formed, for example, by a vapor deposition method as will be described later, and is mainly composed of a metal-based material containing metal atoms. Thereby, the reflectance of the light of the surface which contacts the board | substrate body 2 of the black matrix 3 becomes high. Thus, when the reflectance is high, the ratio of S-polarized light in the reflected light reflected by the black matrix 3 can be effectively increased. The S-polarized light is reflected by the stripe layer 7 described above and can be emitted to the outside from the opening 33. As a result, the light utilization efficiency can be increased more effectively.

Examples of the metal material constituting the metal material layer 31 include metals such as Cr, Ti, and Ni, and metal oxides such as CrO, TiO, and NiO.
The metal-based material layer 31 is formed in a relatively thin layer shape.
The average thickness of the metal-based material layer 31 is preferably 1.0 μm or less, and more preferably 0.01 to 0.1 μm. When the average thickness of the metal-based material layer 31 is in such a range, a part of the light refracted by the microlens 21 is caused to pass through the wall surface (thickness direction) of the black matrix 3 in the opening 33 of the black matrix 3. It is possible to more effectively prevent the so-called vignetting phenomenon that the light is absorbed by being incident on the inner surface).

  The metal-based material layer 31 may be composed of a plurality of types of materials. For example, the metal-based material layer 31 is a laminate having a layer mainly composed of chromium and a layer mainly composed of chromium oxide. May be. When the metal-based material layer 31 has such a configuration, the durability of the black matrix 3 (metal-based material layer 31) can be made particularly excellent, and the substrate body 2 of the black matrix 3 and The reflectance of the light in contact with the surface can be made higher.

  The antireflection layer 32 is made of a colored material and has a function of preventing reflection of external light. In other words, the antireflection layer 32 has a function of absorbing external light (external light that is not preferable for forming a projection image). By having such an antireflection layer 32, the black matrix 3 can absorb external light (external light that is not preferable for forming a projected image), and the image projected on the screen is particularly effective for contrast. It can be excellent.

Examples of the colored material constituting the antireflection layer 32 include various pigments and various dyes. Moreover, the resin material may be included as needed.
As shown in FIG. 1, the antireflection layer 32 is configured so that its thickness gradually decreases toward the opening 33. As described above, when the thickness of the antireflection layer 32 is gradually reduced toward the opening 33, the thickness of the black matrix 3 at the peripheral edge of the opening 33 can be made relatively thin. The occurrence of vignetting can be prevented more reliably.

  Further, the black matrix 3 has an opening 33 on the optical path of the light transmitted through each microlens 21. Thereby, the light condensed by each micro lens 21 can be efficiently passed through the opening 33 of the black matrix 3. As a result, the light utilization efficiency of the microlens substrate 1 can be increased. In particular, since the microlens substrate of the present invention is obtained by the method of the present invention as will be described later, the thickness of the black matrix at the peripheral edge of the opening is relatively thin. Is prevented, and the viewing angle characteristics and the light utilization efficiency are particularly excellent.

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 31 is substantially circular, the size of the opening 31 is not particularly limited, but the diameter is preferably 5 to 80 μm, more preferably 15 to 60 μm, and 20 to 50 μm. More preferably. Thereby, the image projected on a screen can be made more excellent in contrast.
The light utilization efficiency of the microlens substrate 1 as described above (ratio of the amount of light emitted from the exit surface side to the amount of light incident from the entrance surface side of the microlens substrate 1) is 60% or more. Is preferable, 70% or more is more preferable, and 80 to 95% is more preferable.

Next, the transmission screen 10 including the microlens substrate 1 as described above will be described.
As shown in FIG. 4, 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 on the surface of the microlens substrate 1 opposite to the surface on which the black matrix 3 is provided, is condensed by each microlens 21, is focused, and is diffused. At this time, the light incident on the microlens substrate 1 is transmitted through the microlens substrate 1 with sufficient transmittance. The light that has passed through the opening 33 diffuses and is observed as a planar image by the observer.

Hereinafter, the manufacturing method of the above-described microlens substrate will be described. Prior to that, a member with a recess (member with a recess for forming a microlens) that can be suitably used for manufacturing the above-described microlens substrate, and a manufacturing method thereof Will be described.
5 is a schematic longitudinal sectional view showing a member with a recess used for manufacturing a microlens substrate, FIG. 6 is a schematic longitudinal sectional view showing a method for manufacturing the member with a recess shown in FIG. 5, and FIGS. 10 is a schematic longitudinal sectional view showing an example of a manufacturing method of the microlens substrate shown in FIG. In the following description, the lower side in FIGS. 7 to 10 is referred to as “(light) incident side” and the upper side 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 recesses (the member with recesses for forming microlenses) used for manufacturing the microlens substrate will be described.

  The member with concave portions (member with concave portions for forming microlenses) 6 may be made of any material, but is preferably made of a material that is less likely to bend and is less likely to be 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 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 recesses (member with recesses for forming microlenses) 6 includes a plurality of recesses (recesses for forming microlenses) 61 arranged in a manner corresponding to the arrangement method of the microlenses 21 (transferred positional relationship). ing. 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 recess (microlens formation recess) 61 has a vertical width (width in the vertical direction) smaller than the horizontal width (width in the horizontal direction) when the member 6 with recesses is viewed in plan. It has a flat shape (substantially oval or 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 region where the concave portions are formed. 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 60 is prepared.
As the substrate 60, a substrate having a uniform thickness and free from bending and scratches is preferably used. The substrate 60 preferably has a surface cleaned by cleaning or the like.

<A1> A mask 8 having a large number of initial holes (openings) 81 is formed on the surface of the prepared substrate 60, and a back surface on the back surface (the surface opposite to the surface on which the mask 8 is formed) of the substrate 60. A protective film 89 is formed (see a masking process, FIGS. 6A and 6B).
In particular, in this embodiment, first, as shown in FIG. 6A, a back surface protective film 89 is formed on the back surface of the prepared substrate 60 and a mask forming film 80 is formed on the surface of the substrate 60 (mask). Forming film forming step), and then, as shown in FIG. 6B, the mask 8 is obtained by forming the initial hole 81 in the mask forming film 80 (initial hole forming step). The mask forming film 80 and the back surface protective film 89 can be formed simultaneously.

  The mask forming film 80 is preferably capable of forming an initial hole 81 to be described later by laser light irradiation or the like and having resistance to etching in an etching process to be described later. In other words, the mask forming film 80 (mask 8) is preferably configured so that the etching rate is substantially equal to or lower than that of the substrate 60.

From this point of view, the material forming the mask forming film 80 (mask 8) is, for example, a metal such as Cr, Au, Ni, Ti, or Pt, an alloy containing two or more selected from these metals, Examples thereof include oxides (metal oxides), silicon, and resins.
Further, the mask forming film 80 (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 80 (mask 8) is not particularly limited. However, the mask forming film 80 (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 80 having such a configuration can easily and surely form an opening having a desired shape by irradiation of laser light as described later. The mask 8 obtained by using the mask forming film 80 has excellent stability with respect to etching solutions having various compositions (the substrate 60 can be more reliably protected in an etching process described later). . Further, when the substrate 60 is made of glass and the mask forming film 80 (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 80 (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 60 (particularly, adhesion in the etching process). ing. For this reason, by using the mask forming film 80 (mask 8) having the above-described configuration, it is possible to easily and reliably form the recess 61 having a desired shape.

  The method for forming the mask forming film 80 is not particularly limited, but the mask forming film 80 (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 80 can be suitably formed by, for example, a vapor deposition method or a sputtering method. When the mask forming film 80 (mask 8) is made of silicon, the mask forming film 80 can be suitably formed by, for example, a sputtering method or a CVD method.

  The thickness of the mask forming film 80 (mask 8) varies depending on the material constituting the mask forming film 80 (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 81 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 80 and the like. There is. In addition, when wet etching is performed in an etching process described later, the masked portion of the substrate 60 may not be sufficiently protected. On the other hand, if the upper limit value is exceeded, depending on the constituent material of the mask forming film 80, it becomes difficult to form the initial hole 81 that penetrates in the initial hole forming step described later, and the mask forming film 80 (mask Due to the internal stress of 8), the mask forming film 80 (mask 8) may be easily peeled off.

  The back surface protective film 89 is for protecting the back surface of the substrate 60 in the subsequent steps. By this back surface protective film 89, erosion, deterioration, etc. of the back surface of the substrate 60 are suitably prevented. This back surface protective film 89 has the same configuration as the mask forming film 80 (mask 8), for example. Therefore, the back surface protective film 89 can be provided in the same manner as the mask forming film 80 simultaneously with the formation of the mask forming film 80.

Next, as shown in FIG. 6B, a plurality of initial holes (openings) 81 are formed in the mask forming film 80 to obtain a mask 8 (initial hole forming step). The initial hole 81 formed in this step functions as a mask opening in the later-described etching.
A method for forming the initial hole 81 is not particularly limited, but a method using laser light irradiation is preferable. Thereby, the initial holes 81 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 81 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 81 in the mask forming film 80 by laser light irradiation, the opening (e.g., easier and less expensive than the case where the opening is formed in the resist film by a photolithography method as in the prior art. An initial hole 81) can be formed.

In addition, when the initial hole 81 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- He laser, Ar laser, CO ₂ laser, excimer laser or the like may be mentioned. Moreover, you may use wavelengths, such as SHG of each laser, THG, and FHG.

  The shape and size of the initial hole 81 formed in this step is not particularly limited, but is substantially circular and the 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 81 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 81 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 81 formed in this step has a flat shape, the width of the initial hole 81 (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 81 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.

  In addition, when the initial hole 81 formed in this step is a flat shape, the length of the initial hole 81 (length in the major axis direction) is preferably 0.5 to 30 μm, and 1.0 to 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 81 is a value within the above range, the concave portion 61 having the above-described shape can be more reliably formed in the etching process described later.

<A2> Next, as shown in FIG. 6C, the substrate 60 is etched using the mask 8 in which the initial holes 81 are formed, and a large number of recesses 61 are formed on the substrate 60 (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.

By performing etching (wet etching) on the substrate 60 covered with the mask 8 in which the initial holes 81 are formed, as shown in FIG. 6C, the substrate 60 has a portion where the mask 8 does not exist ( A large number of recesses 61 are formed on the substrate 60 by etching from a portion corresponding to the initial hole 81 of the mask 8. As described above, since the initial holes 81 formed 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 60. It will be arranged.
Further, when the wet etching method is used, the concave portion 61 can be suitably formed. For example, when an etchant containing ammonium monohydrogen difluoride is used as the etchant, the substrate 60 can be etched more selectively, and the recesses 61 can be suitably formed.

In the case where the mask 8 (mask forming film 80) is mainly composed of chromium or chromium oxide, a liquid containing ammonium monohydrogen difluoride is particularly suitable as the hydrofluoric acid-based etching solution. 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. 6D, 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.

As described above, as shown in FIGS. 6D and 5, the member 6 with recesses in which a large number of recesses 61 are formed in a staggered pattern on the substrate 60 is obtained.
The method of forming the plurality of recesses 61 arranged in a staggered pattern on the substrate 60 is not particularly limited, but the method as described above (the initial holes 81 in the mask forming film 80 by laser light irradiation). To obtain the mask 8, and then etching using the mask 8 to form the recess 61 on the substrate 60), the following effects are obtained.
That is, by forming the initial holes 81 in the mask forming film 80 by laser light irradiation, the openings (with a predetermined pattern) can be easily and inexpensively compared to the case where the openings are formed by a conventional photolithography method. A mask having initial holes 81) 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 lens substrate), it is not necessary to bond a plurality of substrates as in the prior art, and the seam of bonding can be eliminated. As a result, a high-quality large-sized substrate (a member with a recess, a lens substrate) can be manufactured at a low cost by a simple method.
Further, when the initial holes 81 are formed by laser irradiation, the shape, size, arrangement, and the like of the formed initial holes 81 can be managed easily and reliably.

Next, a method of manufacturing the microlens substrate 1 using the above-described member 6 with a recess will be described.
<B1> First, as shown in FIG. 7A, on the surface of the member 6 with recesses on the side where the recesses 61 are formed, the composition 23 having fluidity (for example, a softened resin material, Polymerization (uncured resin material) is applied, and a base film 24 is placed thereon, and the composition 23 is pressed by the flat plate (pressing member) 11 through the base film 24 (pressing step). .

  The base film 24 is preferably made of a material having a refractive index comparable to that of the composition 23 (the composition 23 after solidification). More specifically, the base film 24 is an absolute constituent material of the base film 24. The absolute value of the difference between the 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 0.02 or less. Further preferred. The base film 24 may be made of any material, but is preferably made of polyethylene terephthalate. In addition, the base film 24 may be a relatively thick film or a film that is not substantially flexible.

  In addition, you may perform the press by the flat plate 11 in the state which has arrange | positioned the spacer between the member 6 with a recessed part, and the base film 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 base film 24, and the timing which supplies a spacer is not specifically limited. For example, the composition 23 in which spacers are dispersed in advance as a resin to be applied may be used on the surface of the member 6 with recesses where the recesses 61 are formed, or in a state where 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.

<B2> Next, the composition 23 is solidified (including curing (polymerization)) to obtain the substrate body 2 provided with the microlenses 21 (solidification step, see FIG. 7B).
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.
Here, if necessary, in the composition 23 and / or the base film 24, for example, polystyrene beads, glass beads, organic cross-linked polymers, etc. are used as a diffusing material in advance in order to diffuse the incident light from the light source. May be mixed. Here, the diffusing material may be mixed in the composition 23 and / or the entire base film 24, or may be mixed only in part.

  <B3> Next, the recessed member 6 and the flat plate 11 are removed from the formed substrate body 2 (pressing member / recessed member removing step, see FIG. 7C). The member 6 with concave portions and the flat plate 11 removed in this step can be repeatedly used for manufacturing 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.

<B4> Next, an uncured photosensitive resin material (photoresist) is applied on the obtained substrate body 2 to form a photoresist layer (photosensitive resin layer) 4 (photosensitive resin layer forming step). ).
In this embodiment, a negative photoresist is used as the photoresist.
The average thickness of the photoresist layer 4 is preferably about 0.5 to 10 μm, and more preferably about 0.5 to 1.0 μm.
Note that the formed photoresist layer may be subjected to a heat treatment such as a pre-bake treatment as necessary.

<B5> Next, as shown in FIG. 8E, the substrate body 2 is irradiated with light (exposure light) Lb (exposure process).
The irradiated light (exposure light) Lb is refracted and collected by entering the microlens 21. Then, the portion of the photoresist layer 4 irradiated with light having an increased luminous intensity (light flux) is exposed by being condensed, and the other portions of the photoresist layer 4 are not exposed or the exposure amount is increased. Only the photoresist layer 4 (photoresist) at the portion irradiated with light having a reduced luminous intensity (light flux) is exposed. Thereby, the exposed site | part hardens | cures and the hardening part 41 is formed.

  <B6> Next, after irradiation with light Lb, development is performed to remove the uncured portion of the photoresist layer 4. Here, since this photoresist layer 4 is composed of a negative type photoresist, a portion (uncured photoresist) other than the portion irradiated with the condensed light is dissolved and removed by development. As shown in FIG. 8F, only the hardened portion 41 remains. The development method varies depending on the composition of the photoresist, but can be performed using an alkaline solution such as a KOH aqueous solution, for example.

<B7> Next, a metal-based material containing a metal element is applied to the surface of the substrate main body 2 having the above-described cured portion 41 (the emission surface of the substrate main body 2) by a vapor deposition method. The layer 31 is formed (metal-based material layer forming step).
Examples of the vapor deposition method include a vapor deposition method, an ion plating method, and a sputtering method.

<B8> Next, as shown in FIG. 9H, the hardened portion 41 is removed, and the metal-based material layer 31 on the hardened portion 41 is removed (opening forming step). Thereby, the opening 33 is formed.
The removal of the cured portion 41 can be performed by, for example, development by a lift-off method.

  By forming the opening 33 by such a method, it is possible to selectively remove only a predetermined portion of the layer made of the metal-based material, and the thickness (opening) of the black matrix 3 to be formed. The thickness near 33) can be made relatively thin. As a result, it is possible to solve problems such as vignetting, and to efficiently obtain a microlens substrate that is excellent in light utilization efficiency and viewing angle characteristics and that can obtain an image that is particularly excellent in contrast.

<B9> Next, a hydrophilic material is applied on the metal-based material layer 31 in which the opening 33 is formed.
The hydrophilic material is hydrophilic. In this specification, the hydrophilic material is a material having a higher affinity for water than an affinity for a liquid having a low solubility in water (for example, a liquid having a solubility in 100 g of water at 25 ° C. of 10 g or less). Specifically, it is preferable that the contact angle of water with respect to a film having a smooth surface (for example, a film having a surface roughness Ra of 10 μm or less) made of the material is 30 ° or less. More preferably, the angle is 20 ° or less.

Since the metal-based material constituting the metal-based material layer 31 usually has a low affinity for water, when such a hydrophilic material is applied onto the metal-based material layer 31 in which the opening 33 is formed, the metal-based material layer 31 is hydrophilic. The material enters the surface of the substrate body 2 that is not covered with the metal-based material layer 31, that is, the opening 33 to form the hydrophilic portion 9 (see FIG. 9 (i)).
The hydrophilic material may be selectively applied in the vicinity of the opening 33 or may be applied to almost the entire surface of the metal-based material layer 31. Even in such a case, since the affinity between the metal-based material layer 31 and the hydrophilic material is low, the hydrophilic material should avoid contact with the first film 2 (substrate body 2). The hydrophilic portion 9 is selectively formed in the opening 33.

Examples of methods for applying the hydrophilic material (method for forming the hydrophilic portion 9) include various coating methods such as dip coating, doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, and roll coater. Vapor deposition methods such as vapor deposition, ion plating, and sputtering, and wet plating methods such as electrolytic plating and electroless plating can be applied.
Examples of the hydrophilic material include water-based ink, gel ink, pigment ink, and the like, and one or more selected from these can be used in combination. Among these, a water-based ink is preferable as a constituent material of the first film 2. Such a material has a particularly low affinity with the constituent material of the metal-based material layer 31 and the constituent material of the antireflection layer 32 described later. The portion 9 can be formed, and the antireflection layer 32 having a more suitable shape can be easily and reliably formed in the antireflection layer forming step described later.
The thickness (height) of the hydrophilic portion 4 is not particularly limited, but is preferably 1 to 100 μm, more preferably 2 to 50 μm, and further preferably 3 to 10 μm. When the thickness (height) of the hydrophilic portion 9 is a value within the above range, the antireflection layer 32 having a suitable shape can be more reliably formed in the subsequent antireflection layer forming step.

<B10> Next, a colored and lipophilic antireflection layer forming material is applied to the surface of the metal-based material layer 31.
Since the antireflection layer forming material has lipophilicity, it is not on the hydrophilic portion 9 made of a hydrophilic material but on the surface of the metal-based material layer 31 (the surface of the portion excluding the opening 33). ) Is selectively formed on the antireflection layer 32 (see FIG. 9J).

  Thus, by forming the antireflection layer 32 using the difference in affinity with the hydrophilic portion 9, the antireflection layer 32 is directed toward the opening 33 as shown in FIG. 9 (h). The thickness is gradually reduced. Thereby, the thickness of the black matrix 3 in the peripheral part of the opening part 33 can be made comparatively thin, As a result, generation | occurrence | production of vignetting can be prevented more reliably.

  The antireflection layer forming material may be a colored material, for example, a colored component (for example, various pigments, various dyes, etc.) and a substantially colorless (transparent) component (for example, a resin material). It may be included. The antireflection layer forming material may contain a liquid medium such as a solvent or a dispersion medium. Thereby, the fluidity | liquidity of an antireflection layer forming material can be adjusted suitably, and the antireflection layer 32 of uniform thickness can be formed easily and reliably.

  The antireflection layer 32 can be formed by applying an antireflection layer forming material. Note that after the application of the second material, a heat treatment, a cooling treatment, a decompression treatment, or the like may be performed as necessary. The antireflection layer 32 is formed by various methods such as dip coating, doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, and roll coater. A vapor deposition method such as a coating method, a vapor deposition method, an ion plating method, or a sputtering method, or a wet plating method such as electrolytic plating or electroless plating can be applied.

<B11> Next, as shown in FIG. 9 (k), the hydrophilic portion 9 is removed (hydrophilic portion removing step). Thereby, the black matrix 3 having the opening 33 and composed of the metal material layer 31 and the antireflection layer 32 is formed.
The removal of the hydrophilic portion 9 can be performed, for example, by washing with an aqueous liquid (for example, water, an alcohol solvent such as methanol or ethanol, a ketone solvent such as acetone, or the like), heat treatment, or the like.

<B12> Next, as shown in FIG. 10L, a stripe layer forming layer 70 made of an inorganic material is formed on the surface on which the microlenses 21 are provided.
The stripe layer forming layer 70 can be formed, for example, by a vapor deposition method such as an evaporation method, an ion plating method, or a sputtering method.
<B13> Next, as shown in FIG. 10 (m), a resist is applied on the stripe layer forming layer 70 to form a resist layer 71.
Then, it exposes by the 2 light beam interference exposure method of a laser beam, and etches. Thereby, the stripe layer 7 is formed as shown in FIG.
As described above, the microlens substrate 1 as shown in FIG. 10 (n) and FIG. 1 is obtained.

Hereinafter, a rear projector using the transmission screen as described above will be described.
FIG. 11 is a diagram schematically showing the configuration of the rear projector of the present invention.
As shown in the figure, the rear projector 300 has a configuration in which a projection optical unit 310, a light guide mirror 320, and a transmissive screen 10 are arranged in a housing 340.

Since the rear projector 300 includes the transmission screen 10 as described above, an image with excellent contrast can be obtained. Furthermore, since the present embodiment has the above-described configuration, the viewing angle characteristics, light utilization efficiency, and the like are particularly excellent.
In particular, in the microlens substrate 1 described above, since the elliptical microlenses 21 are arranged in a staggered pattern (in a staggered pattern), the rear projector 300 is not particularly susceptible to problems such as moire.

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.
In the method for manufacturing a microlens substrate, an arbitrary step may be added.

In the above-described embodiments, the stripe layer is described as being formed on the surface of the substrate body. However, the microlens substrate of the present invention is not limited to this, and is provided on a member different from the substrate body. And a combination of the main body and the substrate body.
In the above-described embodiment, the light shielding film (black matrix) has been described as being composed of a metal material layer and an antireflection layer. However, the antireflection layer may not be provided, and the light shielding film may be a metal-based film. It may be composed of only a material layer. In this case, for example, a colored material may be used as the metal material constituting the metal material layer, so that an antireflection function may be imparted to the metal material layer itself.

Moreover, in embodiment mentioned above, although demonstrated as what gives compositions, such as a resin material, to the surface of a member with a recessed part, for example, a composition is provided to the surface of a flat plate, and this is pressed with a member with a recessed part. Thus, a lens substrate may be manufactured.
Moreover, in embodiment mentioned above, in manufacturing a lens substrate, a member with a recessed part does not necessarily need to be removed as what removes a member with a recessed part. In other words, the member with concave portions may constitute a part of the lens substrate.

In the above-described embodiment, the opening is formed after removing the recessed member from the substrate body. However, the opening may be formed before removing the recessed member.
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 lens substrate of the present invention.

In addition, the lens substrate and the transmissive screen of the present invention may have a diffusion part and a diffusion plate having a function of diffusing light transmitted through the substrate body. With such a configuration, for example, the viewing angle characteristics of a transmissive screen and a rear projector can be made particularly excellent.
In the above-described embodiments, the lens substrate (microlens substrate) has been described as a member constituting a transmissive screen and a rear projector, but the use of the lens substrate of the present invention is as described above. It is not limited to, and any thing may be used. For example, the lens substrate of the present invention is applied to a diffusion plate, a black matrix screen, a projection display device (front projector) screen (front projection screen), a liquid crystal light valve component of a projection display device (front projector), and the like. It may be done.

[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, a soda glass substrate (absolute refractive index n ₂ : 1.50) having a width of 1.2 m × length of 0.7 m square and a thickness of 4.8 mm was prepared as a substrate.
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 and a back surface protective film made of a chromium / chromium oxide laminate were formed on the surface of the 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 to form a large number of initial holes in a range of 113 cm × 65 cm at the center of the mask.
The laser processing was performed using a YAG laser under the conditions of an energy intensity of 1 mW, a beam diameter of 3 μm, and a scanning speed of 0.1 m / second.
Thus, initial holes having a predetermined length were formed in a staggered pattern over the entire range of the mask. The average width of the initial holes was 2 μm, and the average length was 2 μm.
At this time, a concave portion and a modified layer having a depth of 50 mm were also formed on the surface of the soda glass substrate.

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 56 μm, the length in the major axis direction was 64 μm, the radius of curvature was 36 μm, and the depth was 36 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 as shown in FIG. 2 in zigzag form was obtained. When the obtained member with recesses was viewed in plan, the proportion of the area occupied by the recesses in the effective region where the recesses were formed was 97%.

Next, a composition composed of an unpolymerized (uncured) styrene-methyl methacrylate copolymer was applied to the surface of the member with recesses where the recesses were formed. Under the present circumstances, the substantially spherical spacer (diameter 50 micrometers) comprised with the hardened | cured material of the styrene-methylmethacrylate copolymer was distribute | arranged to the substantially whole surface of the member with a recessed part. The spacers were arranged at a rate of about 3 pieces / cm ² .

Next, the acrylic resin was pressed with a flat plate made of soda glass. At this time, air was prevented from entering between the flat plate and the composition. Moreover, as the flat plate, the surface on which the composition was pressed was subjected to a gas phase surface treatment (mold release treatment) with hexamethyldisilazane.
Thereafter, the composition was cured by heating to 120 ° C. to obtain a substrate body provided with a large number of microlenses. The refractive index n ₁ of the obtained substrate main body (composition after curing) was 1.557. Further, the thickness of the resin layer (excluding the microlens) of the obtained substrate body was 50 μm. The flat (substantially oval) microlens had a short axis length (diameter) of 56 μm, a long axis length of 64 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%.

Next, the flat plate and the concave member were removed from the substrate body.
Next, a photoresist (photosensitive resin material) was applied to the surface of the substrate body on the emission side (the surface opposite to the surface on which the microlenses are formed) with a roll coater to form a photosensitive resin layer. (Photosensitive resin layer forming step). As a photoresist, a trade name “CFPR series” manufactured by Tokyo Ohka Co., Ltd. was used. Moreover, the average thickness of the formed photosensitive resin layer was 2 micrometers.

Next, ultraviolet rays as parallel light of 80 mJ / cm ² were irradiated from the surface of the substrate body on the side where the microlenses are formed, from the surface on the incident side of the substrate body (exposure process). Thereby, the irradiated ultraviolet rays were collected by each microlens, and the photosensitive resin material in the vicinity of the focal point f of each microlens was selectively exposed to form a cured portion.
Next, development processing was performed to remove portions other than the cured portion (exposed portion of the photoresist layer) (uncured resin removal step).

  Next, it is composed of a chromium (Cr) / chromium oxide (CrO) laminate (a laminate in which chromium oxide is laminated on the outer surface side of chromium) on the surface of the substrate main body where the hardened portion is formed. The metal material layer to be formed was formed by a sputtering method (metal material layer forming step). The thickness of the chromium layer constituting this metallic material layer was 0.015 μm, and the thickness of the chromium oxide layer was 0.045 μm.

Next, the hardened part was removed by a lift-off method, and the metal-based material layer (metal-based material) on the hardened part was removed to form an opening (opening forming process).
Next, a hydrophilic material was applied by brushing on the metal-based material layer in which the opening was formed. A water-based ink was used as the hydrophilic material.
As a result, the hydrophilic material entered the surface of the substrate body that is not covered with the metal material layer, that is, the opening of the metal material layer.

  Next, a colored and lipophilic antireflection layer forming material was applied to the surface of the metal material layer by spin coating, and an antireflection layer was formed on the metal material layer (on the surface of the portion excluding the opening). . As the antireflection layer forming material, relief printing ink was used. As a result, a black matrix was formed. The formed antireflection layer gradually decreased in thickness toward the opening as shown in FIG.

Next, the hydrophilic part was removed by washing with water.
Next, a layer made of aluminum was formed by vapor deposition, and a layer for forming a stripe layer was formed.
Next, a resist was applied on the formed stripe layer forming layer to form a resist layer, and then exposed by laser beam two-beam interference exposure and etched. Thereby, a stripe layer was formed.

The arrangement pitch of the formed stripe layer was 150 nm, the width of one stripe was 75 nm, and the height (thickness) was 150 nm.
As described above, a microlens substrate as shown in FIGS. 1 and 2 was obtained.
A transmissive screen as shown in FIG. 4 was obtained by assembling the microlens substrate manufactured as described above and the Fresnel lens portion manufactured by extrusion molding.

(Examples 2 to 4)
The shape and arrangement of the recesses of the member with recesses can be changed by changing the irradiation conditions of the laser beam when forming the member with recesses (the shape of the initial holes to be formed, the depth of the initial recesses) and the immersion time in the etching solution. By changing the pattern, the shape and arrangement pattern of the microlenses formed on the microlens substrate are shown in Table 1, and the configuration of the metal-based material layer in the metal-based material layer forming step is shown in Table 1. In addition to the above, except that the stripe layer forming material, the thickness of the stripe layer forming layer, the exposure conditions by the two-beam interference exposure method were changed, and the configuration of the stripe layer was as shown in Table 1. In the same manner as in Example 1, a microlens substrate and a transmission screen were produced.
(Example 5)
A microlens substrate and a transmissive screen were produced in the same manner as in Example 1 except that the metal-based material layer having openings was formed as a black matrix without forming an antireflection layer.

(Comparative Example 1)
A microlens substrate and a transmission screen were manufactured in the same manner as in Example 1 except that the stripe layer was not formed.
(Comparative Example 2)
A microlens substrate and a transmissive screen were manufactured in the same manner as in Example 1 except that the arrangement conditions of the stripe layers were changed as shown in Table 1 by changing the exposure conditions by the two-beam interference exposure method.
Table 1 summarizes the microlens shape, arrangement pattern, black matrix configuration, stripe layer configuration, etc. of the manufactured microlens substrate for each of the above Examples and Comparative Examples.

[Evaluation of light utilization efficiency]
The light use efficiency was evaluated for the transmissive screens of the respective Examples and Comparative Examples.
The evaluation of the light utilization efficiency is based on the luminance B [cd / m ² ] of light measured on the light exit surface side of the transmissive screen when A (= 300) [cd / m ² ] white light is incident. ] (B / A). It can be said that the larger the value of B / A, the better the light utilization efficiency.

[Production of rear projector]
Using the transmissive screens of the respective Examples and Comparative Examples, rear type projectors as shown in FIG. 9 were produced.
[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 and the horizontal 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, moire and color unevenness]
Sample images were displayed on the transmissive screens of the rear projectors of the examples and comparative examples. The displayed images were evaluated for the occurrence of diffracted light, moire and color unevenness according to the following four criteria.
A: No diffracted light, moire, or color unevenness is observed.
○: Almost no diffracted light, moire or color unevenness is observed.
Δ: At least one of diffracted light, moire, and color unevenness is slightly observed.
X: At least one of diffracted light, moire and color unevenness is remarkably recognized.
These results are summarized in Table 2.

  As is apparent from Table 2, all of the present invention were excellent in light utilization efficiency, excellent contrast was obtained, and viewing angle characteristics were also excellent. In the present invention, an excellent image free from diffracted light, moire and color unevenness 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 fragmentary sectional view of the micro lens substrate shown in FIG. 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 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 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 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 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 23 ... Composition 24 ... Base film 25 ... 1st row | line 26 ... 2nd row 3 ... Black matrix (light shielding film) 31 ... Metal-type material layer 32 ... Antireflection layer 33 ... opening 4 ... photosensitive resin layer (photoresist layer) 41 ... cured part 5 ... Fresnel lens part 51 ... Fresnel lens 6 ... member with recess (member with recess for forming microlens) 60 ... substrate 61 ... Recessed portion (recessed portion for forming microlenses) 7 ... stripe layer 70 ... stripe layer forming layer 71 ... resist layer 8 ... mask 80 ... mask forming film 81 ... initial hole (opening) 89 ... back surface protective film 9 ... hydrophilic portion DESCRIPTION OF SYMBOLS 11 ... Flat plate 10 ... Transmission type screen 211 ... Center 300 ... Rear type projector 310 ... Projection optical unit 320 ... Light guide Error 340 ... housing

Claims (7)

A microlens comprising a substrate body having a large number of microlenses, and a light-shielding film having a large number of openings provided on the surface of the substrate body opposite to the side on which the microlenses are provided. A substrate,
A microlens substrate, wherein a layer having a vertical stripe shape and an arrangement pitch of 400 nm or less is provided on a surface side of the substrate body on which the microlens is provided.   The microlens substrate according to claim 1, wherein the light shielding film is mainly made of a material containing a metal element.   The microlens substrate according to claim 1, wherein the layer is made of an inorganic material.   The microlens substrate according to any one of claims 1 to 3, wherein the width of one stripe of the layer is 40 to 50% of the arrangement pitch.   The microlens substrate according to claim 1, wherein a height of the layer is 100 to 150 nm.   A transmissive screen comprising the microlens substrate according to claim 1. A rear projector, comprising the transmission screen according to claim 6.

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