JP2007102044A - Method for manufacturing lens substrate, lens substrate, transmissive screen, and rear projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens substrate in which occurrence of color unevenness is sufficiently prevented and with which an image having excellent contrast is obtained, to provide a method for efficiently manufacturing the lens substrate, and to provide a transmissive screen equipped with the lens substrate, and a rear projector equipped the transmissive screen. <P>SOLUTION: The method for manufacturing the lens substrate has a step to form a coloring section for a substrate body constructed with a resin material on a side of a surface of the lens substrate on which light is made incident by imparting a coloring liquid containing a colorant and benzyl alcohol thereto, and is characterized by having a processing temperature of (Tg+30)°C or lower and 40-100°C in the step to impart the coloring liquid to the substrate body when the glass transition temperature of the resin material is represented by Tg[°C]. The content of benzyl alcohol in the coloring liquid is 0.01-10.0 wt.%. The substrate body to which the coloring liquid is imparted is mainly composed of an acrylic resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

In recent years, the demand for rear projectors (rear projection projection televisions) is increasing as a display suitable for home theater monitors, large screen televisions, and the like.
In such a rear projector, in order to increase the contrast of an image, it is required to suppress external light reflection while suppressing a decrease in intensity of image light.
In order to achieve such an object, a lenticular lens substrate including a colored layer formed using an ionizing radiation curable molding resin in which a colorant is mixed and dispersed on a light incident surface of a lenticular lens is manufactured. A method has been proposed (see, for example, Patent Document 1).

However, the lens substrate created by such a method has a structure in which the entire lens is colored, so when an image is viewed in a general room with illumination light, reflection by external light (illumination light) becomes large. There was a problem that the contrast was lowered.
In the method as described above, since the colored layer is formed by laminating the colored resin before curing on the surface of the transparent resin, in the obtained lenticular lens substrate, the colored layer and the transparent resin (non-colored layer) Interfacial delamination is likely to occur. In particular, when the application is such that a large amount of light is irradiated, such as a rear projector, such a tendency becomes remarkable. And when the above peeling occurs, the image quality of the projected image is significantly reduced.

JP-A-11-125704 (page 5, left column, lines 23-25, page 7, left column, lines 1-7, FIG. 12, FIGS. 1-3, FIG. 11)

  An object of the present invention is to provide a lens substrate that can sufficiently prevent occurrence of color unevenness and obtain an image with excellent contrast, and a manufacturing method that can efficiently manufacture the lens substrate. Another object of the present invention is to provide a transmissive screen and a rear projector provided with the lens substrate.

Such an object is achieved by the present invention described below.
The method for manufacturing a lens substrate according to the present invention is a method for manufacturing a lens substrate used by making light incident thereon,
Using a member with recesses having a large number of recesses, a step of transferring the surface shape of the surface provided with the recesses of the member with recesses to obtain a substrate body made of a resin material;
A step of providing a coloring liquid containing a colorant and benzyl alcohol to the substrate body, and forming a colored portion on a surface side on which light of the substrate body is incident;
When the glass transition point of the resin material is Tg [° C.], the processing temperature in the step of applying the coloring liquid to the substrate body is (Tg + 30) ° C. or lower and 40 to 100 ° C. And
Accordingly, it is possible to provide a manufacturing method capable of efficiently manufacturing a lens substrate capable of sufficiently preventing occurrence of color unevenness and obtaining an image having excellent contrast.

In the lens substrate manufacturing method of the present invention, the lens substrate is preferably a microlens substrate.
Thereby, the viewing angle characteristic when the lens substrate is applied to a transmissive screen or a rear projector can be made particularly excellent.
In the manufacturing method of the lens substrate of the present invention, the content of the benzyl alcohol in the coloring liquid is preferably 0.01 to 10.0 wt%.
Thereby, it is possible to easily and surely form a suitable colored portion while sufficiently preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of the constituent material of the substrate body).

In the method for manufacturing a lens substrate of the present invention, it is preferable that the coloring liquid is applied by dipping.
Thereby, a colored part (especially the colored part of uniform thickness) can be formed easily and reliably.
In the lens substrate manufacturing method of the present invention, it is preferable that the colored liquid contains a disperse dye as the colorant.
Thereby, it is possible to efficiently form the colored portion while sufficiently preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of the constituent material of the substrate body). In particular, even if the substrate body to which the coloring liquid is applied is made of a material that is difficult to be colored by a conventional method such as an acrylic resin, it is easily and reliably colored. Can do.

In the lens substrate manufacturing method of the present invention, it is preferable that the substrate body to which the coloring liquid is applied is mainly composed of an acrylic resin.
Acrylic resin has excellent transparency and is suitable for the constituent material of lens substrates because it has excellent heat resistance, light resistance, workability, dimensional accuracy when molded, mechanical strength, etc. In the conventional coloring method, coloring is difficult (particularly, it is difficult to form a colored portion having a uniform thickness and a uniform coloring density). On the other hand, in the present invention, a uniform thickness and a uniform color density can be easily and surely applied to a substrate body composed of such a difficult-to-color (especially difficult-to-dye) acrylic resin. The colored portion can be formed. Therefore, in the present invention, by using a substrate body mainly composed of an acrylic resin, it is possible to provide a lens substrate that is particularly excellent in various characteristics and excellent in reliability.

In the method for manufacturing a lens substrate according to the present invention, it is preferable that the density of the colored portion is 20 to 95% in terms of a Y value (D65 / 2 ° field of view).
Thereby, the contrast of the image can be made particularly excellent.
In the method for manufacturing a lens substrate according to the present invention, it is preferable that the coloring liquid contains a surfactant.
As a result, the coloring agent can be stably and uniformly dispersed even in the presence of benzyl alcohol, and the substrate body to which the coloring liquid is applied is colored by a conventional method such as an acrylic resin. Even those made of materials that are difficult to color can be easily and reliably colored.

In the method for producing a lens substrate of the present invention, it is preferable that the colored liquid contains at least one compound selected from a benzophenone-based compound and a benzotriazole-based compound in addition to the colorant and the benzyl alcohol.
Thereby, it is possible to easily form a suitable colored portion while sufficiently preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of the constituent material of the substrate body).

In the lens substrate manufacturing method of the present invention, the total content of the benzophenone compound and the benzotriazole compound in the coloring liquid is preferably 0.001 to 10.0 wt%.
Thereby, it is possible to easily form a suitable colored portion while sufficiently preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of the constituent material of the substrate body).

In the lens substrate manufacturing method of the present invention, the content of the benzyl alcohol in the coloring liquid is X [wt%], and the total content of the benzophenone compound and the benzotriazole compound is Y [wt%]. It is preferable that the relationship of 0.001 ≦ X / Y ≦ 10000 is satisfied.
Thereby, it is possible to easily form a suitable colored portion while sufficiently preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of the constituent material of the substrate body).

The lens substrate of the present invention is manufactured by the method of the present invention.
Accordingly, it is possible to provide a lens substrate that can sufficiently prevent occurrence of color unevenness and can obtain an image with excellent contrast.
The transmission screen of the present invention is characterized by including the lens substrate of the present invention.
Accordingly, it is possible to provide a transmission screen that can sufficiently prevent occurrence of color unevenness and can obtain an image with excellent contrast.

The transmissive screen of the present invention, a Fresnel lens portion in which a Fresnel lens is formed on the light emission side,
And a lens substrate of the present invention disposed on the light emission side of the Fresnel lens portion.
Accordingly, it is possible to provide a transmission screen that can sufficiently prevent occurrence of color unevenness and can obtain an image with 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 sufficiently prevent occurrence of color unevenness and can obtain an image with excellent contrast.

Hereinafter, a method for manufacturing a lens substrate, a lens substrate, a transmissive screen, and a rear projector of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
First, the configuration of the lens substrate and the transmission screen of the present invention will be described.
1 is a schematic longitudinal sectional view showing a first embodiment of a lens substrate (microlens substrate) of the present invention, FIG. 2 is a schematic plan view of the lens substrate shown in FIG. 1, and FIG. 1 is a schematic longitudinal sectional view showing a first embodiment of a transmission screen according to the present invention including the lens substrate shown in FIG. 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 (lens substrate) 1 is a member constituting a transmission screen 10 to be described later. As shown in FIG. 1, the microlens substrate 1 has a microlens substrate 1 with respect to a substrate body 2 having a plurality of microlenses 21. A colored portion (external light absorbing portion) 22 is provided on the light incident side (that is, the light incident side of the microlens 21).
Moreover, in order to diffuse the incident light from the light source, the substrate main body 2 may contain, for example, polystyrene beads, glass beads, organic cross-linked polymers, etc. as a diffusing material, as necessary. Note that the diffusing material may be included in the entire resin (the entire substrate body 2), or may be included in only a part thereof.
Moreover, you may provide the black matrix which is not shown in figure as a light shielding layer as needed. In such a case, the black matrix can be provided, for example, on the light emission side of the substrate body.

Although the constituent material of the substrate body 2 is not particularly limited, it is mainly composed of a resin material and is composed of a transparent material having a uniform refractive index.
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 resins, etc., or copolymers, blends, polymer alloys, etc. mainly composed of these, are mentioned, and one or more of these are combined (for example, blend resins, polymer alloys, laminates) Among them, polystyrene, polycarbonate, polyethylene terephthalate, and acrylic resin are preferable from the viewpoint of transparency, and acrylic resin is particularly preferable among them. Acrylic resin has excellent transparency and is excellent in heat resistance, light resistance, workability, dimensional accuracy when molded, mechanical strength, etc. Although suitable, coloring was difficult with the conventional coloring method. On the other hand, in the present invention, a colored portion can be easily and reliably formed even on a substrate body composed of such a difficult-to-color (particularly difficult-to-dye) acrylic resin. Therefore, in the present invention, by using a substrate body mainly composed of an acrylic resin, it is possible to provide a lens substrate (microlens substrate) that is excellent in various characteristics and excellent in reliability. In addition, acrylic resins are generally relatively inexpensive and advantageous from the standpoint of manufacturing costs.

  As an acrylic resin, for example, an acrylic resin having acrylic acid or a derivative thereof (for example, acrylic ester) as a constituent monomer, a methacrylic resin having a constituent monomer of methacrylic acid or a derivative thereof (for example, methacrylic ester), for example. Styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylic acid ester-methacrylic acid ester copolymer, styrene-α-chloroacrylic acid methyl copolymer, styrene-acrylonitrile-acrylic acid A copolymer containing (meth) acrylic acid such as an ester copolymer or a derivative thereof as a constituent monomer can be used, and one or more selected from these can be used in combination.

  Although the glass transition point (Tg) of the resin material which comprises the board | substrate body 2 is not specifically limited, It is preferable that it is 30-130 degreeC, It is more preferable that it is 45-120 degreeC, It is 70-110 degreeC. Is more preferable. When the glass transition point of the resin material constituting the substrate body 2 is a value within the above range, the durability of the microlens substrate 1 is sufficiently excellent, and details will be described later when the microlens substrate 1 is manufactured. The colored portion 22 as described below can be easily and reliably formed. When the substrate body 2 is composed of a plurality of types of resin components, the glass transition point of the resin material is the glass transition point for the mixture of these resin components, but the glass transition point as a mixture When measurement is difficult, the weighted average value of the glass transition points of each resin component can be adopted as the glass transition point of the resin material.

  In the present embodiment, the microlens 21 has a vertical width (width in the vertical direction (length indicated by X in the figure)) in the plan view of the microlens substrate 1 and a horizontal width (indicated by Y in the figure). It has a flat shape (substantially elliptical, substantially bowl-shaped) smaller than the length)). 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. Moreover, the brightness of the projected image can be made higher.

  When the length in the minor axis direction (vertical direction) of the microlens 21 in plan view is X [μm] and the length in the major axis direction (lateral direction) is Y [μm], 0.10 ≦ X / It is preferable to satisfy the relationship of Y ≦ 0.99, more preferable to satisfy the relationship of 0.50 ≦ X / Y ≦ 0.95, and to satisfy the relationship of 0.75 ≦ X / Y ≦ 0.90 More preferably. 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 100 μm. When the length of the microlens 21 in the short axis direction (vertical width of the microlens 21) is a value within the above range, the viewing angle characteristics of the microlens substrate 1, the contrast of the projected image, and the brightness are particularly excellent. However, sufficient resolution can be obtained in the projected image. Further, when the length of the microlens 21 in the short axis direction (vertical width of the microlens 21) is a value within the above range, it is possible to effectively prevent the occurrence of inconvenience such as moire and the microlens substrate. The productivity of 1 can be further increased.

  Moreover, it is preferable that the length of the major axis direction of the microlens 21 when viewed in plan is 15 to 120 μm. When the length of the microlens 21 in the major axis direction is a value within the above range, the viewing angle characteristics of the microlens substrate 1, the contrast of the projected image, and the luminance are particularly excellent, and the projected image Sufficient resolution can be obtained. Further, when the length of the microlens 21 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 and further increase the productivity of the microlens substrate 1. Can do.

The curvature radius of the microlens 21 is preferably 5 to 60 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.
Moreover, it is preferable that the height of the microlens 21 (the height of the microlens 21 as a convex part) is 5-60 micrometers. When the height of the microlens 21 is within the above range, the 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. . Further, 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 microlenses in the effective region where the microlenses are formed. 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 formed. % 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 effect of having the microlens of the shape and arrangement method as described above, and the coloring portion described in detail later The effects act synergistically, and particularly excellent effects (for example, particularly excellent viewing angle characteristics, light utilization efficiency, etc.) can be obtained.

Each microlens 21 is formed as a convex lens protruding to the incident side, and is designed so that the focal point f is located in the vicinity of the surface on the emission side of the substrate body 2. 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 The focal point f is set near the surface on the exit side of the main body 2.
Further, at this time, by forming the black matrix so as to open in the vicinity of the focal point f, the light utilization efficiency can be further improved.

  Further, as described above, the colored portion 22 is provided on the light incident side of the microlens substrate 1 (that is, the light incident side of the microlens 21). The coloring unit 22 can sufficiently transmit light incident from the incident side, and external light (for example, external light incident unintentionally from the light emitting side or the like) is reflected on the emission side. It has a function to prevent. By having such a colored portion, an image having excellent contrast can be obtained.

In particular, the colored portion 22 is formed by applying a colored liquid (particularly, a colored liquid having a characteristic in composition) to the substrate body 2 as described in detail later. More specifically, the coloring portion 22 is formed by impregnating the inside of the substrate body 2 (microlens 21) with a coloring agent by applying a coloring liquid as will be described in detail later to the substrate body 2. is there.
For this reason, compared with the case where a colored layer is laminated (externally attached) on the substrate body, the adhesion of the colored layer is enhanced. As a result, for example, it is possible to more reliably prevent an adverse effect on the optical characteristics of the microlens substrate due to a change in refractive index near the interface.

  In addition, since the colored portion 22 is formed by applying a coloring liquid to the substrate body 2, variations in thickness at each portion (particularly, variations in thickness not corresponding to the surface shape of the substrate body). Is small. Thereby, it is possible to prevent inconvenience such as color unevenness in the projected image. In particular, in the present invention, it is possible to more reliably prevent the occurrence of inconveniences such as color unevenness by applying the coloring liquid under a predetermined temperature condition.

  Moreover, although the coloring part 22 is comprised with the material containing a coloring agent, the main component is the same as the main component of the board | substrate body 2 (micro lens 21) normally. Therefore, it is difficult for a sudden change in refractive index or the like near the boundary between the colored portion 22 and the other non-colored portion. Accordingly, it is easy to design the optical characteristics of the microlens substrate 1 as a whole, and the optical characteristics of the microlens substrate 1 are stable and highly reliable.

  The concentration of the colored portion 22 is not particularly limited, but it is preferably 20 to 95% in terms of Y value (D65 / 2 ° field of view), more preferably 30 to 85%, and 35 to 75%. Is more preferable. When the density of the colored portion 22 is within the above range, the contrast of an image formed by light transmitted through the microlens substrate can be made particularly excellent. On the other hand, if the density of the colored portion 22 is less than the lower limit, the transmittance of incident light is reduced, and sufficient luminance cannot be obtained in the obtained image, resulting in insufficient image contrast. there is a possibility. Further, if the density of the colored portion 22 exceeds the upper limit, it becomes difficult to sufficiently prevent reflection of external light (external light incident from the side opposite to the light incident side), and the entire light source is turned on in the bright room. When the light is turned off, the amount of increase in the front luminance (black luminance) of the black display increases, so that there is a possibility that the effect of improving the contrast of the image cannot be obtained sufficiently.

  The color of the colored portion 22 is not particularly limited, but a colorant based on blue, mixed with red, brown, or yellow is used. The appearance is achromatic and black, and controls the balance of the three primary colors of light from the light source. It is preferable to selectively absorb or transmit light having a specific wavelength. As a result, reflection of external light is prevented, the color tone of the image formed by the light transmitted through the microlens substrate is accurately expressed, color coordinates are wide (the range of color tone expression is sufficiently wide), and deeper Since black can be expressed, the contrast can be made particularly excellent as a result.

  Further, a black matrix may be provided on the light emitting surface of the microlens substrate 1. In this case, the black matrix is made of a light-shielding material and is formed in a layer shape. By having such a black matrix, the black matrix can absorb external light (external light unfavorable for forming a projection image), and the image projected on the screen is further excellent in contrast. Can be. In particular, the contrast of the image by the microlens substrate 1 can be made particularly excellent by having the coloring portion 22 as described above and the black matrix.

Such a black matrix desirably has an opening 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 of the black matrix. As a result, the light utilization efficiency of the microlens substrate 1 can be increased.
The size of the opening of the black matrix is not particularly limited, but the diameter is preferably 5 to 100 μm. Thereby, the image projected on a screen can be made more excellent in contrast.

  Moreover, it is preferable that the thickness (average thickness) of a black matrix is 0.01-5 micrometers. When the thickness of the black matrix is a value within the above range, the function as a black matrix can be more effectively exhibited while more reliably preventing unintentional peeling, cracking, etc. of the black matrix. In the transmissive screen 10 including the microlens substrate 1, the contrast of the projected image 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), in an effective region where the microlens 21 is formed, a black matrix (a region other than the opening portion of the black matrix). ) Is preferably 1 to 70%, and more preferably 1 to 50%. When the proportion of the area occupied by the black matrix is a value within the above range, the image projected on the screen can be made excellent in contrast while the light use efficiency is sufficiently high.

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. And this parallel light La injects from the surface side in which the coloring part of the micro lens board | substrate 1 was formed, is condensed by each micro lens 21, and is radiate | emitted from the other surface side. When the microlens substrate 1 has a black matrix, the light collected by each microlens 21 passes through the opening of the black matrix (light shielding layer).
At this time, the light incident on the microlens substrate 1 is transmitted through the microlens substrate 1 with sufficient transmittance. The light emitted from the microlens substrate 1 is diffused and observed as a planar image by the observer.

Next, an example of a method for manufacturing the above-described microlens substrate 1 will be described.
FIG. 4 is a schematic longitudinal sectional view showing a member with a recess 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. 6 and 7 are schematic longitudinal sectional views showing an example of a manufacturing method of the microlens substrate shown in FIG. In the following description, the lower side in FIGS. 6 and 7 (the same applies to FIG. 9) 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. Examples of the constituent material of the member 6 with recesses include soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass. Especially, as a constituent material of the member 6 with a recessed part, soda glass, crystalline glass (for example, neo-serum etc.), and an alkali free glass are preferable. Soda glass, crystalline glass, and alkali-free 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 (longitudinal direction) of the recess 61 in plan view is X [μm] and the length in the major axis direction (lateral direction) is Y [μm], 0.10 ≦ X /Y≦0.99 is preferably satisfied, 0.50 ≦ X / Y ≦ 0.95 is more preferable, and 0.75 ≦ X / Y ≦ 0.90 is satisfied. It is more preferable to satisfy. By satisfying the relationship as described above, the effects as described above become more remarkable.

  Moreover, it is preferable that the length (width | variety of the recessed part 61) of the minor axis direction of the recessed part 61 when planarly viewed is 10-100 micrometers. 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.

  Moreover, it is preferable that the length of the major axis direction of the recessed part 61 when it planarly views is 15-120 micrometers. 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 5-60 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 5-60 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. 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 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) 81 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 the present embodiment, first, as shown in FIG. 5A, the back surface protective film 89 is formed on the back surface of the prepared substrate 7 and the mask forming film 4 is formed on the surface of the substrate 7 (mask). (Formation film forming step) Thereafter, as shown in FIG. 5B, the mask 8 is obtained by forming the initial hole 81 in the mask formation film 4 (initial hole formation step). The mask forming film 4 and the back surface protective film 89 can be formed simultaneously.

The mask forming film 4 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 formation film 4 (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, as a material constituting the mask forming film 4 (mask 8), 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.
In addition, the mask forming film 4 (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 4 (mask 8) is not particularly limited, but is a laminate having a layer mainly composed of chromium and a layer mainly composed of chromium oxide. Preferably there is. The mask forming film 4 having such a configuration can easily and reliably 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 4 has excellent stability with respect to etching solutions having various compositions (the substrate 7 can be more reliably protected in an etching process described later). . Further, when the substrate 7 is made of glass and the mask forming film 4 (mask 8) has the above-described structure, for example, in an etching process described later, two hydrogen atoms are used as an etching solution. 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 4 (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 4 (mask 8) having the above-described configuration, the concave portion 61 having a desired shape can be easily and reliably formed.

  The method for forming the mask forming film 4 is not particularly limited, but the mask forming film 4 (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 4 can be suitably formed by, for example, a vapor deposition method or a sputtering method. When the mask forming film 4 (mask 8) is made of silicon, the mask forming film 4 can be suitably formed by, for example, a sputtering method or a CVD method.

  The thickness of the mask forming film 4 (mask 8) varies depending on the material constituting the mask forming film 4 (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 4 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 value is exceeded, depending on the constituent material of the mask forming film 4 and the like, it becomes difficult to form the initial hole 81 that penetrates in the initial hole forming step described later, and the mask forming film 4 (mask Due to the internal stress of 8), the mask forming film 4 (mask 8) may be easily peeled off.

  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. The back surface protective film 89 has the same configuration as the mask forming film 4 (mask 8), for example. Therefore, the back surface protective film 89 can be provided in the same manner as the mask forming film 4 simultaneously with the formation of the mask forming film 4.

Next, as shown in FIG. 5B, a plurality of initial holes (openings) 81 are formed in the mask forming film 4 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. Further, by forming the initial hole 81 in the mask forming film 4 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 conventional photolithography method. 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.
In addition to forming the initial hole 81 by irradiating the mask forming film 4 with laser light, for example, when forming the mask forming film 4 on the substrate 7, the foreign material is previously formed in a predetermined pattern on the substrate 7. Then, a defect may be positively formed in the mask forming film 4 by forming the mask forming film 4 thereon, and the defect may be used as the initial hole 81.

<A2> Next, as shown in FIG. 5C, the substrate 7 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 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.

By performing etching (wet etching) on the substrate 7 covered with the mask 8 in which the initial holes 81 are formed, as shown in FIG. 5C, the substrate 7 is a portion where the mask 8 does not exist ( A large number of recesses 61 are formed on the substrate 7 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 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 4) 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. The etching can be performed 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. 5D and 4, the member 6 with recesses in which a large number of recesses 61 are formed in a staggered pattern on the substrate 7 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 (by forming the initial holes 81 in the mask forming film 4 by laser irradiation). When the mask 8 is obtained and then etched using the mask 8 to form the recess 61 on the substrate 7, the following effects are obtained.
That is, by forming the initial hole 81 in the mask forming film 4 by laser light irradiation, the opening (with a predetermined pattern) can be easily and inexpensively compared with the case where the opening is 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.
6 and 7 are schematic longitudinal sectional views showing an example of a manufacturing method of the microlens substrate shown in FIG. In the following description, the lower side in FIGS. 6 and 7 is referred to as “(light) incident side”, and the upper side is referred to as “(light) emission side”.

  <B1> First, as shown in FIG. 6A, on the surface of the member 6 having the 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 the composition 23 is pressed with a flat plate (pressing member) 11 (pressing step). The flat plate 11 may be made of any material, but in the step (solidification step) described later, when the flat plate 11 and the solidified composition 23 are joined, the composition 23 (composition after solidification) The material 23) is preferably made of a material having the same refractive index as that of the object 23), and more specifically, the difference between the absolute refractive index of the constituent material of the flat plate 11 and the absolute refractive index of the composition 23 after solidification. The absolute value of is preferably 0.20 or less, more preferably 0.10 or less, and even more preferably 0.02 or less.

  In addition, you may perform the press of the composition 23 by the flat plate 11 in the state which has arrange | positioned the spacer between the member 6 with a recessed part, and the flat plate 11. FIG. 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 arrange | positioned between the member 6 with a recessed part, and the flat plate 11, 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.

<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. 6B).
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 flat plate 11, in order to diffuse the incident light from the light source, for example, polystyrene beads, glass beads, organic cross-linked polymer, etc. are mixed in advance as a diffusing material. Also good. Here, the diffusing material may be mixed in the composition 23 and / or the entire plate 11 or may be mixed only in part. The amount of the diffusing material is not particularly limited, but from the viewpoint of viewing angle characteristics, Haze (cloudiness: Td / Tt, Td: diffused light transmittance, Tt: total light transmittance) is, for example, 30 to 99%. It is preferable that

<B3> Next, the flat plate 11 is removed from the substrate body 2 (pressing member removing step, see FIG. 6C). In the solidification step, when the substrate body 2 is obtained as a joined body of the flat plate 11 and the solidified product 23, this step is omitted.
In addition, as shown in FIG. 9, the substrate body 2 is manufactured on the surface of the member 6 with the recesses on the side where the recesses 61 are formed. An unpolymerized (uncured resin material) is applied, a transparent film 24 is placed thereon, and the composition 23 is pressed by the flat plate (pressing member) 11 through the transparent film 24 (pressing step). 9 (a)), and then the composition 23 is solidified (including curing (polymerization)) to obtain the substrate body 2 composed of the joined body of the solidified product 23 and the transparent film 24. (Solidification step; see FIG. 9B) Next, the flat plate 11 may be removed from the substrate body 2 (pressing member removal step; see FIG. 9C). In such a case, the transparent film 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 structure of the transparent film 24. The absolute value of the difference between the absolute refractive index of the material 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. More preferably. The transparent film may be composed of any material, but is preferably composed of polyethylene terephthalate. In addition, the transparent film 24 may be a relatively thick film or a film that does not substantially have flexibility.

  <B4> Next, the substrate body 2 is removed from the recessed member 6 (recessed member removing step, see FIG. 7D). In this way, by removing the member 6 with the recesses, the member 6 with the recesses can be repeatedly used for manufacturing the substrate body 2 (microlens substrate 1). The stability of the quality of the lens substrate 1) can be increased.

<B5> After that, the colored liquid 22 is applied to the substrate body 2 removed from the recessed member 6 to form the colored portion 22 to obtain the microlens substrate 1 (colored liquid applying process, FIG. 7 (e). )reference).
The coloring liquid contains a coloring agent and benzyl alcohol. The present invention is characterized in that it has been found that by using such a coloring liquid, the substrate main body can be easily and reliably colored. In particular, it is possible to easily and reliably color a substrate body made of a material that is difficult to be colored by a conventional coloring method, such as an acrylic resin. This is considered to be due to the following reasons.

  That is, by using a colored liquid containing benzyl alcohol, the benzyl alcohol in the colored liquid penetrates deeply into the substrate body and diffuses, loosening the bonds (intermolecular bonds) that make up the substrate body, and the colorant enters. To secure space for The colorant is easily held deeply in the space secured by benzyl alcohol, so that the colorant is held in the space (which can be compared to a seat for the colorant (colored seat)), and the substrate body is It is colored and does not easily desorb.

Moreover, in this invention, the colored part of a uniform density | concentration can be formed easily and reliably by using the above colored liquids. In particular, the substrate body (work) to be colored has a fine structure such as a microlens on its surface (one with a small period of unevenness in the two-dimensional direction), and should be colored Even if the area is large, even if there are defects due to non-uniform polymerization of the resin, benzyl alcohol can loosen the bonding of the resin molecules itself, so even at a uniform concentration (uneven transmittance) No) Colored portion can be formed.
Here, benzyl alcohol has a strong function of securing the aforementioned colored seat, particularly for acrylic resins. For this reason, it becomes possible to incorporate the colorant into the substrate body more efficiently.

  Examples of methods for applying the coloring liquid include various application methods such as doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, roll coater, and textile printing, and dipping the substrate body 2 in the coloring liquid. Among these methods, dipping (particularly, dip dyeing) is preferable. Thereby, the colored part 22 (especially the colored part 22 of a uniform density | concentration) can be formed easily and reliably. In particular, when the coloring liquid is applied by dip dyeing, the substrate body 2 to which the coloring liquid is applied is made of a material that is difficult to be colored by a conventional method such as an acrylic resin. Even if it is a thing, it can be colored easily and reliably. This is because benzyl alcohol and dyes that can be used for dip dyeing are sufficiently present in the solution, so that benzyl alcohol ensures a sufficiently colored seat, facilitating coloring, and even in a large area. Because it can be done.

  In particular, in the present invention, the step of applying a colored liquid (colored liquid applying step) is performed under a predetermined temperature condition (see FIG. 10). More specifically, in the present invention, when the glass transition point of the resin material constituting the substrate body provided for the coloring liquid application step is Tg [° C.], the processing temperature in the coloring liquid application step is (Tg + 30) ° C. or less. It is characterized in that By applying the coloring liquid under such conditions, it is possible to form a colored portion with a uniform thickness and with suppressed unevenness in the coloring density. On the other hand, when the treatment temperature in the coloring liquid application step exceeds (Tg + 30) ° C., the softening of the resin starts abruptly. Since the impregnation is performed quickly, a large difference is caused in the degree of impregnation of the coloring liquid in the substrate surface. For this reason, the variation in the density of the colored portions to be formed rapidly increases, resulting in uneven color density. From the point where Tg is exceeded, the softening phenomenon of the resin itself starts with the molecular bond of the substrate body in the whole substrate, the molecular bond of the substrate body is loosened and the colored liquid is easily impregnated, but there is a difference in the degree of softening. Since it is not yet large, it is not so noticeable that the variation in the color density is visible. However, if the temperature exceeds (Tg + 30) ° C., a difference in the level of softening starts to occur in the surface, so that variations in the color density can be visually recognized. In addition, if the processing temperature in the color liquid application process is too high, the substrate main body is deformed, and a desired optical characteristic may not be obtained in the lens substrate, or significant coloring unevenness occurs.

As described above, in the present invention, the treatment temperature in the coloring liquid application step is (Tg + 30) ° C. or lower, preferably (Tg−70) to (Tg + 30) ° C., and (Tg−60) to (Tg + 20) ° C. is more preferable, and (Tg−60) to (Tg) ° C. is more preferable. In other words, when the glass transition point of the resin material constituting the substrate body is Tg [° C.] and the processing temperature in the colored liquid application step is T [° C.], T-Tg is −70 ° C. or less, but −70 It is preferably ˜ + 30 ° C., more preferably −60 to + 30 ° C., and further preferably −60 to 0 ° C. By satisfying such a condition, it is possible to more reliably form a colored portion having a uniform thickness and a suppressed unevenness in color density in a relatively short time.
Moreover, in this invention, the process temperature in a coloring liquid provision process is 40-100 degreeC. When the processing temperature is less than 40 ° C., the coloring speed is remarkably reduced, and it is impossible to color up to a necessary density. On the other hand, when the processing temperature exceeds 100 ° C., the resin of the substrate is deformed, the shape of the molded lens is deformed, the optical characteristics are affected, and the image quality is deteriorated.

As described above, the present invention is characterized in that the processing temperature in the coloring liquid application step satisfies a predetermined condition, that is, a temperature within a range indicated by a hatched portion in FIG.
Moreover, you may perform the process of providing a coloring liquid in the state (pressurized state) which raised atmospheric pressure, for example. Thereby, the penetration | invasion into the inside of a substrate main body of a coloring liquid can be accelerated | stimulated, As a result, the coloring part 22 can be formed efficiently in a short time. This method is particularly effective for a material having a high Tg. Further, by performing the coloring liquid application step in a state where the atmospheric pressure is increased, even when the processing temperature is relatively low, the processing time of this step can be made sufficiently short. A suitable colored portion 22 having particularly small variations in thickness and concentration can be efficiently formed in a short time.

The application of the coloring liquid may be repeated a plurality of times as necessary (for example, when the concentration of the colored portion 22 to be formed is to be increased).
Further, after the coloring liquid is applied, a heat treatment such as heating or cooling, light irradiation, pressurization of the atmosphere, or decompression may be performed as necessary. Thereby, fixing (stabilization) of the colored portion 22 can be promoted.

Hereinafter, the coloring liquid used in this step will be described in more detail.
Although the content rate of the benzyl alcohol in a coloring liquid is not specifically limited, It is preferable that it is 0.01-10.0 wt%, it is more preferable that it is 0.05-8.0 wt%, 0.1-5 More preferably, it is 0.0 wt%. When the content of benzyl alcohol is a value within the above range, while effectively preventing the occurrence of adverse effects on the substrate body on which the colored portion 22 is to be formed (for example, deterioration of the constituent materials of the substrate body 2), The suitable coloring part 22 can be formed easily and reliably.

  The colorant contained in the coloring liquid may be any dye or pigment, but is preferably a dye, more preferably a disperse dye and / or a cationic dye, and a disperse dye. More preferably. Thereby, the colored portion 22 can be efficiently formed while sufficiently preventing the occurrence of an adverse effect on the substrate body 2 on which the colored portion 22 is to be formed (for example, deterioration of the constituent material of the substrate body 2). In particular, even if the substrate body 2 to which the coloring liquid is applied is made of a material that is difficult to be colored by a conventional method such as an acrylic resin, it is easily and reliably colored. be able to. This is thought to be because the colorant as described above is more easily colored because the ester group (ester bond) of the acrylic resin or the like is used as a dyeing seat.

  Moreover, the coloring liquid should just contain a coloring agent and benzyl alcohol at least, However, It is preferable that a surfactant is further included. Thus, the coloring agent can be stably and uniformly dispersed even in the presence of benzyl alcohol, and the substrate body 2 to which the coloring liquid is applied is colored by a conventional method such as an acrylic resin. Even those composed of materials that are difficult to do can be easily and reliably colored. Examples of the surfactant include nonionic (nonionic), anionic surfactant, cationic surfactant, and amphoteric surfactant. Nonionic (nonionic) surfactants include, for example, ether surfactants, ester surfactants, ether ester surfactants, nitrogen-containing surfactants, and more specifically, , Polyvinyl alcohol, carboxymethyl cellulose, polyethylene glycol, acrylic acid ester, methacrylic acid ester and the like. Examples of the anionic surfactant include various rosins, various carboxylates, various sulfates, various sulfonates, various phosphates, etc. More specifically, gum rosin, polymerized rosin , Heterogenized rosin, maleated rosin, fumarized rosin, maleated rosin pentaester, maleated rosin glycerin ester, tristearate (for example, metal salt such as aluminum salt), distearate (for example, aluminum salt) , Metal salts such as barium salts), stearates (eg, metal salts such as calcium salts, lead salts, zinc salts), linolenate salts (eg, cobalt salts, manganese salts, lead salts, zinc salts, etc.) Metal salts, etc.), octanoates (eg, metal salts such as aluminum salts, calcium salts, cobalt salts, etc.), oleates (examples) For example, calcium salts, metal salts such as cobalt salts, etc.), palmitates (eg, metal salts such as zinc salts), naphthenates (eg, calcium salts, cobalt salts, manganese salts, lead salts, zinc salts, etc.) Metal salts, etc.), resinates (eg, metal salts such as calcium salt, cobalt salt, manganese lead salt, zinc salt etc.), polyacrylates (eg metal salts such as sodium salt, etc.), polymethacrylic acid Salt (for example, metal salt such as sodium salt), polymaleate (for example, metal salt such as sodium salt), acrylic acid-maleic acid copolymer salt (for example, metal salt such as sodium salt), cellulose , Dodecylbenzene sulfonate (eg, sodium salt), alkyl sulfonate, polystyrene sulfonate (eg, metal salt such as sodium salt), alkyl diphenyl ester, etc. Terujisuruhon salts (e.g., metal salts such as sodium salt), and the like. Examples of the cationic surfactant include various ammonium salts such as a primary ammonium salt, a secondary ammonium salt, a tertiary ammonium salt, and a quaternary ammonium salt. More specifically, (mono) Examples thereof include alkylamine salts, dialkylamine salts, trialkylamine salts, tetraalkylamine salts, benzalkonium salts, alkylpyridium salts, imidazolinium salts, and the like. Examples of amphoteric surfactants include various betaines such as carboxybetaine and sulfobetaine, various aminocarboxylic acids, and various phosphate esters.

  Further, for example, the coloring liquid may contain at least one compound selected from benzophenone compounds and benzotriazole compounds. Thereby, the effects as described above are exhibited more significantly. More specifically, for example, the substrate main body 2 can be colored more easily and reliably, and in particular, a substrate made of a material that is difficult to color by a conventional coloring method, such as an acrylic resin. The main body 2 can be colored easily and reliably. Moreover, even if it is a case where the process temperature in this process is made lower, the suitable coloring part 22 can be formed efficiently in a short time. This includes at least one compound selected from a benzophenone compound and a benzotriazole compound by using at least one compound selected from a benzophenone compound and a benzotriazole compound in combination with benzyl alcohol; It is considered that benzyl alcohol acts in a complementary manner, and as a result, a remarkable effect (synergistic effect) is exhibited by using these in combination. More specifically, it is considered that this is due to the following reason (mechanism).

  That is, first of all, the benzyl alcohol in the coloring liquid loosens the bonds of the resin molecules constituting the substrate body, and secures a space for other molecules to enter. Secondly, at least one compound selected from benzophenone compounds and benzotriazole compounds penetrates into this space and diffuses deeply in preference to the colorant. This is because benzophenone compounds and benzotriazole compounds, like benzyl alcohol, relax the bonding of the resin molecules that make up the substrate body and secure a space for other molecules to enter. This is because the space secured by alcohol is used to deepen and widen the space. Colorants do not have this function. Third, in parallel with the second action, the colorant enters and is retained in the space. Alternatively, it is partially substituted with a benzophenone compound and a benzotriazole compound. Thus, by using a benzophenone compound or a benzotriazole compound in combination with benzyl alcohol, the colorant can be diffused into the substrate body efficiently, deeply, in a relatively short time, and uniformly colored. It becomes possible.

  Examples of the benzophenone compounds include compounds having a benzophenone skeleton as represented by the following formula (I) or other limit structural formulas corresponding thereto, or tautomers thereof (hereinafter simply referred to as “formula (I)”. Or a derivative thereof (eg, an addition reaction product, a substitution reaction product, a reduction reaction product, an oxidation reaction product, etc.).

  Examples of such compounds include benzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4. Examples include '-tetrahydroxybenzophenone, 2-hydroxy-4-octylbenzophenone, 4-benzyloxy-2-hydroxybenzophenone, benzophenone anil, benzophenone oxime, and benzophenone chloride (α, α'-dichlorodiphenylmethane). Among them, a compound having a benzophenone skeleton represented by the above formula (I) is preferable, and 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone. Is more preferable. By using such a benzophenone-based compound, the effects as described above appear more remarkable. In addition, structural formulas (chemical formulas) of 2,2′-dihydroxy-4,4′-dimethoxybenzophenone and 2,2 ′, 4,4′-tetrahydroxybenzophenone are respectively represented by the following formula (II) and formula Shown as (III).

  The benzotriazole compounds include compounds having a benzotriazole skeleton as represented by the following formula (IV) or other limit structural formulas corresponding thereto, or tautomers thereof (hereinafter simply referred to as “formulas”). Or a derivative thereof (for example, an addition reaction product, a substitution reaction product, a reduction reaction product, an oxidation reaction product, or the like) can be used.

  Examples of such compounds include benzotriazole, 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole, 2- (2-hydroxy-4-octyloxyphenyl) -2H-benzotriazole, and the like. Can be mentioned. Among them, a compound having a benzotriazole skeleton represented by the above formula (IV) is preferable, and 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole, 2- (2-hydroxy-4-) Octyloxyphenyl) -2H-benzotriazole is more preferred. By using such a benzotriazole-based compound, the effects as described above appear more remarkable. The structural formulas (chemical formulas) of 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole and 2- (2-hydroxy-4-octyloxyphenyl) -2H-benzotriazole are respectively shown. The following formula (V) and formula (VI) are shown.

The colored liquid may contain at least one compound selected from the above-mentioned benzophenone compounds and benzotriazole compounds, but two or more compounds (particularly, one or more benzophenone compounds) may be used. A compound and one or more benzotriazole-based compounds) may be included. As a result, these compounds act in a complementary manner, and these compounds act in a complementary manner with benzyl alcohol, so that the above-described effects appear even more remarkable.
Further, the same effect can be obtained by immersing in a pretreatment liquid containing at least one compound selected from the above benzophenone compounds and benzotriazole compounds and benzyl alcohol and then immersing in the coloring liquid. .

  When the coloring liquid or pretreatment liquid contains at least one compound selected from benzophenone compounds and benzotriazole compounds, the total content of the benzophenone compounds and benzotriazole compounds in the coloring liquid or pretreatment liquid Is not particularly limited, but is preferably 0.001 to 10.0 wt%, more preferably 0.005 to 5.0 wt%, and still more preferably 0.01 to 3.0 wt%. . When the sum of the content ratios of the benzophenone compound and the benzotriazole compound is within the above range, an adverse effect on the substrate body 2 on which the colored portion 22 is to be formed (for example, deterioration of constituent materials of the substrate body 2) It is possible to easily and surely form a suitable colored portion 22 while preventing the above effectively.

  Further, when the content of benzyl alcohol in the coloring liquid or the pretreatment liquid is X [wt%] and the total content of the benzophenone compound and the benzotriazole compound is Y [wt%], 0.001 ≦ The relationship X / Y ≦ 10000 is preferably satisfied, the relationship 0.05 ≦ X / Y ≦ 1000 is more preferable, and the relationship 0.25 ≦ X / Y ≦ 500 is further satisfied. preferable. By satisfying the relationship as described above, the synergistic effect of combining the benzophenone compound and / or benzotriazole compound and benzyl alcohol is more significantly exhibited, and the substrate body 2 on which the colored portion 22 is to be formed. It is possible to easily and surely form a suitable colored portion 22 at a high speed while more effectively preventing the occurrence of adverse effects on the substrate (for example, deterioration of the constituent materials of the substrate body 2).

  As described above, in the production method of the present invention, a colored liquid containing benzyl alcohol is used, and the colored liquid is applied to the substrate body under predetermined conditions, so that it is difficult to color with the conventional method. Even this substrate (substrate body) can be easily colored uniformly. In the manufacturing method of the present invention, even a relatively large lens substrate (for example, a lens substrate having a diagonal length of 40 inches or more) can be preferably manufactured.

A rear projector using the transmission screen will be described below.
FIG. 8 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 transmissive screen 10 as described above, it is possible to obtain an image with high brightness and excellent contrast. Further, since the microlens substrate 1 (transmission type screen 10) as described above is provided, the viewing angle characteristics 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 lens substrate, the transmissive screen, and the rear projector can be replaced with any structure that can exhibit the same function.
In the above-described embodiment, the plate-shaped (or film-shaped) member (the substrate with the concave portion) is used as the member with the concave portion, but the member with the concave portion is not limited to such a form, For example, it may have a roll shape and have a recess on its peripheral surface.

In addition, prior to the coloring liquid applying step, for example, pretreatment may be performed on the substrate body for the purpose of improving the ease of coloring the substrate body. Examples of such pretreatment include a treatment of applying a liquid containing at least one selected from the group consisting of benzyl alcohol, benzophenone, and benzotriazole to the substrate body.
Moreover, each process of the manufacturing method of a lens substrate is not limited to what is performed in the order as mentioned above, You may change the order of each process.
Further, when forming the black matrix, the black matrix may be formed before the colored portion is formed, or the black matrix may be formed after the colored portion 22 is formed.

In the above-described embodiment, the coloring portion is described as being provided on the entire surface of the lens substrate on the light incident side. However, the coloring portion is provided only on a part of the light incident surface side. May be.
In the above-described embodiment, the microlens in the microlens substrate and the concave portion in the member with concave portions are described as having an elliptical shape when viewed in plan. For example, it may be a circle, a substantially square, a substantially hexagon, or the like.

In the above-described embodiment, the microlenses in the microlens substrate and the concave portions in the member with concave portions are described as being arranged in a staggered manner, but the arrangement of the microlenses and concave portions may be any, For example, it may be arranged in a square lattice shape or a honeycomb shape. Moreover, the microlens and the recess may be formed randomly.
In the above-described embodiments, the transmission screen is described as including a microlens substrate (lens substrate) and a Fresnel lens. However, the transmission screen of the present invention does not necessarily include a Fresnel lens. May be. For example, the transmission screen of the present invention may be substantially constituted only by the lens substrate of the present invention.

  In the above-described embodiment, the configuration including the microlens as the lens portion having a more desirable shape has been described from the viewpoint of the viewing angle. However, the lens portion (lens) configuring the lens substrate is not limited thereto. For example, a lenticular lens may be used. By using the lenticular lens, the manufacturing process of the lens portion can be simplified, and the productivity of the transmission screen can be improved. When a lenticular lens is used as the lens unit, a striped light shielding layer (black stripe) can be provided instead of the black matrix. Even in such a configuration, the same operation and effect as in the above-described embodiment can be obtained.

In the above-described embodiment, the black matrix is described as being directly formed on the surface of the substrate body. However, the black matrix is bonded to the substrate body via, for example, a base layer (adhesive layer). It may be.
Moreover, in embodiment mentioned above, although demonstrated as what gives a composition to the surface of a member with a recessed part, for example, a lens board | substrate is provided by applying a composition to the surface of a flat plate, and pressing this with a member with a recessed part. 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 and a flat plate. In other words, the concave member and the flat plate may constitute a part of the lens substrate.

In addition, the lens substrate and the transmission type screen of the present invention may have a diffusion part and a diffusion plate having a function of diffusing light transmitted through the convex lens. With such a configuration, for example, the viewing angle characteristics of a transmissive screen and a rear projector can be further improved.
In the above-described embodiments, the lens substrate is described as a member constituting a transmissive screen and a rear projector. However, the lens substrate of the present invention is applied to a transmissive screen and a rear projector. The present invention is not limited to this, and may be used for any purpose. For example, the lens-equipped substrate of the present invention may be applied to a constituent member of a liquid crystal light valve of a projection display device (front projector).

[Production of lens 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 forming film and a back surface protective film made 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.
Thereby, initial holes having a predetermined length were formed in a staggered pattern over the entire range of the mask forming film. The average width of the initial holes was 2 μm, and the average length 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. In addition, the occupation ratio of the concave portions in the effective area where the concave portions are formed was almost 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 a recess was viewed in plan, the ratio of the area occupied by the recess in the effective region where the recess was formed was 100%.

Next, a composition composed of unpolymerized (uncured) acrylic resin (resin material mainly composed of PMMA resin (methacrylic resin)) is applied to the surface of the member with recesses on the side where the recesses are formed. did.
Next, the acrylic resin was pressed with a flat plate made of soda glass while maintaining a gap of 2 mm. 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., slowly cooled, the flat plate of the presser and the mold (member with recesses) were removed, and a substrate body provided with a large number of microlenses was obtained. The refractive index n ₁ of the obtained substrate main body (composition after curing) was 1.557. Moreover, the glass transition point Tg of the resin material which comprises a board | substrate body was 120 degreeC. Further, the thickness of the resin layer (excluding the microlens) of the obtained substrate body was 2 mm. The flat (substantially oval) microlens had a short axis length (diameter) of 54 μm, a long axis length of 72 μm, a radius of curvature of 40 μm, and a height of 40 μm. In addition, the occupation ratio of the microlens in the effective region where the microlens is formed is almost 100%.

Next, the flat plate was removed.
Thereafter, the substrate body was removed from the member with a recess.
Thereafter, a coloring liquid was applied to the substrate body by dip dyeing (coloring liquid application process). At this time, the entire surface side on which the microlens was formed was in contact with the coloring liquid, and the coloring liquid was not in contact with the back surface side. Further, the temperature of the substrate body and the coloring liquid when applying the coloring liquid was adjusted to 70 ° C. Disperse dye (Blue (manufactured by Futaba Sangyo)): 2 parts by weight, disperse dye (Red (manufactured by Futaba Sangyo)): 0.1 part by weight, disperse dye (Yellow (manufactured by Futaba Sangyo)): 0. 05 parts by weight, benzyl alcohol: 20 parts by weight, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone (benzophenone-based compound): 3 parts by weight, 2- (2-hydroxy-5-methylphenyl) -2H— A mixture prepared by dissolving 3 parts by weight of benzotriazole (benzotriazole-based compound) and 2 parts by weight of a surfactant in 1000 parts by weight of pure water was used.

Under the conditions described above, the substrate main body and the coloring liquid were brought into contact with each other for 120 minutes, and then the substrate main body was taken out of the tank in which the coloring liquid was stored, sufficiently washed with water, and then dried.
Thereafter, by drying (removal of pure water) using pure water cleaning and N ₂ gas, to obtain a microlens substrate on which the colored portion is formed. The density of the formed colored portion was 52% in terms of Y value (D65 / 2 ° field of view).
A transmissive screen as shown in FIG. 3 was obtained by assembling the microlens substrate manufactured as described above and the Fresnel lens portion.

(Examples 2 to 4)
The treatment temperature and treatment time in the coloring liquid application step, the content of benzyl alcohol, benzophenone compounds, benzotriazole compounds in the coloring liquid, and the types of benzophenone compounds and benzotriazole compounds are changed as shown in Table 1. Produced a microlens substrate and a transmission screen in the same manner as in Example 1. In addition, the content of benzyl alcohol, benzophenone compounds, and benzotriazole compounds in the coloring liquid is changed by increasing or decreasing the amount of pure water used together with the amount used, and other components (colorant, interface) The content of the activator) was made constant.

(Example 5)
As a resin material constituting the substrate body, an ultraviolet curable resin mainly composed of a methacrylate monomer was used as an ultraviolet curable acrylic resin having a glass transition point of 60 ° C., and molded by the 2P method. Between the member with concave portions in which a large number of concave portions for forming microlenses formed in Example 1 are arranged in a staggered manner, and a transparent acrylic plate with a thickness of 2 mm containing a minute bead diffusing agent to be a 2P base material, In a state where the ultraviolet curable acrylic resin was sandwiched so as not to contain air bubbles, ultraviolet rays were irradiated from the side of the member with concave portions to completely cure the acrylic resin. Thereafter, the member with concave portions was removed to obtain a lens substrate in which a microlens was molded on the surface of the 2P base material. Thereafter, a microlens substrate and a transmissive screen were produced in the same manner as in Example 1 except that the treatment temperature in the coloring liquid application step was 60 ° C. and the treatment time was 80 minutes.

(Examples 6 to 8)
The treatment temperature and treatment time in the coloring liquid application step, the content of benzyl alcohol, benzophenone compounds, benzotriazole compounds in the coloring liquid, and the types of benzophenone compounds and benzotriazole compounds are changed as shown in Table 1. Produced a microlens substrate and a transmission screen in the same manner as in Example 5. In addition, the content of benzyl alcohol, benzophenone compounds, and benzotriazole compounds in the coloring liquid is changed by increasing or decreasing the amount of pure water used together with the amount used, and other components (colorant, interface) The content of the activator) was made constant.

Example 9
Molded by the 2P method in the same manner as in Example 5, using an ultraviolet curable resin mainly composed of an acrylate monomer as an ultraviolet curable acrylic resin having a glass transition point of 30 ° C. as a resin material constituting the substrate body. did.
Thereafter, a microlens substrate and a transmissive screen were produced in the same manner as in Example 1 except that the treatment temperature in the coloring liquid application step was 50 ° C. and the treatment time was 70 minutes.

(Examples 10 to 11)
The treatment temperature and treatment time in the coloring liquid application step, the content of benzyl alcohol, benzophenone compounds, and benzotriazole compounds in the coloring liquid, and the types of benzophenone compounds and benzotriazole compounds were changed as shown in Table 2. Produced a microlens substrate and a transmission screen in the same manner as in Example 9. In addition, the content of benzyl alcohol, benzophenone compounds, and benzotriazole compounds in the coloring liquid is changed by increasing or decreasing the amount of pure water used together with the amount used, and other components (colorant, interface) The content of the activator) was made constant.

(Example 12 (comparative example))
A microlens substrate and a transmissive screen were manufactured in the same manner as in Example 1 except that no colored portion was formed on the substrate body.
(Example 13 (comparative example))
A microlens substrate and a transmissive screen were formed in the same manner as in Example 1 except that a colored liquid containing no benzyl alcohol, benzophenone-based compound, and benzotriazole-based compound and having a high content of pure water was used. Manufactured.
About each said Example, Y value (D65 / 2 degree visual field) is represented as the conditions of the coloring liquid used for formation of a colored part, the processing conditions of a coloring liquid provision process, and the density | concentration (transmittance) of the formed colored part. 1 is shown collectively. In Table 1, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone is “A”, 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole is “B”, 2,2 ', 4,4'-tetrahydroxybenzophenone is represented by “C”, 2- (2-hydroxy-4-octyloxyphenyl) -2H-benzotriazole is represented by “D”, and the glass transition of the resin material constituting the substrate body The point was indicated by Tg [° C.], the treatment temperature in the color liquid application step was T [° C.], and the color liquid application treatment (contact) time in the color liquid application step was indicated by t [min].

[Evaluation of contrast]
Contrast evaluation was performed on the transmissive screens produced in each of the above examples. Contrast is the amount of increase in the front luminance of white display (white luminance) LW (cd / m ² ) when 410 lx all white light 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. (Black luminance increase amount) A ratio with LB (cd / m ² ), LW / LB, was obtained. The bright room was measured in a room with an outside light illuminance of 185 lx (bright room). A luminance meter BM-7 manufactured by Topcon was used for the luminance measurement.
[Production of rear projector]
Rear-type projectors as shown in FIG. 8 were produced using the transmission screens of the respective examples.

[Evaluation of uneven color]
The Y value (D65 / 2 ° field of view) of the transmissive screen of the rear projector of each of the above examples was measured in 20 planes, and the difference ΔT (Y) (%) between the maximum value and the minimum value of the transmittance was Color unevenness was defined, and the occurrence of color unevenness was evaluated according to the following four criteria.
A: ΔT (Y) (%) less than 3%. No color unevenness is observed.
○: ΔT (Y) (%) 3 to less than 5%. There is almost no color unevenness.
Δ: ΔT (Y) (%) 5 to 10%. Slight color unevenness is observed.
X: ΔT (Y) (%) more than 10%. Color unevenness is noticeable.

[Evaluation of screen distortion]
When the transmissive screen prepared in each of the above examples was set on a rear projector, the screen was distorted with the deformation of the substrate. The state of occurrence of screen distortion was evaluated according to the following four criteria.
A: No screen distortion is observed.
○: Almost no distortion of the screen is observed.
Δ: Slight screen distortion is observed.
X: The distortion of a screen is recognized notably.
These results are summarized in Table 2.

As can be seen from Table 2, in the present invention, an image excellent in contrast without color unevenness and screen distortion could be displayed.
On the other hand, in the comparative example, a satisfactory result was not obtained. Especially, in Example 12 (comparative example) which does not have a coloring part and Example 13 (comparative example) which was not able to be substantially fully colored, since contrast was especially low, it was excluded from the measuring object. Further, in Examples 4, 8, and 11 (all of which are comparative examples) in which the coloring liquid application step was not performed under a predetermined temperature condition, the coloring liquid could not be substantially colored, or color unevenness and screen distortion were remarkable. Only low-quality images could be displayed. This is considered to be because an appropriate processing temperature condition was not selected in the coloring step.

It is a typical longitudinal section showing a 1st embodiment of a lens substrate (micro lens substrate) of the present invention. FIG. 2 is a schematic plan view of the lens substrate shown in FIG. 1. It is a typical longitudinal cross-sectional view which shows 1st Embodiment of the transmissive screen of this invention provided with the lens board | substrate (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 (manufacturing method of a substrate main body) of the lens board | substrate (microlens board | substrate) shown in FIG. It is a typical longitudinal cross-sectional view which shows an example of the manufacturing method of the lens board | substrate (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. It is a typical longitudinal cross-sectional view which shows another example of the manufacturing method (manufacturing method of a substrate main body) of the lens board | substrate (microlens board | substrate) shown in FIG. It is a figure (graph) which shows the relationship between the processing temperature of the coloring liquid provision process in this invention, and the glass transition point of the resin material which comprises a substrate main body.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Micro lens board | substrate (lens board | substrate) 2 ... Board | substrate main body 21 ... Micro lens (lens part) 211 ... Center 22 ... Colored part (external light absorption part) 23 ... Composition 24 ... Transparent film 25 ... 1st line 26 ... Second row 4 ... Mask forming film 5 ... Fresnel lens portion 51 ... Fresnel lens 6 ... Member with recess (member with micro lens forming recess) 61 ... Concavity 7 ... Substrate 8 ... Mask 81 ... Initial hole 89 ... Back surface protection Film 10 ... Transmission type screen 11 ... Flat plate (pressing member) 300 ... Rear projector 310 ... Projection optical unit 320 ... Light guide mirror 340 ... Case

Claims (15)

A method of manufacturing a lens substrate that is used with light incident thereon,
Using a member with recesses having a large number of recesses, a step of transferring the surface shape of the surface provided with the recesses of the member with recesses to obtain a substrate body made of a resin material;
A step of providing a coloring liquid containing a colorant and benzyl alcohol to the substrate body, and forming a colored portion on a surface side on which light of the substrate body is incident;
When the glass transition point of the resin material is Tg [° C.], the processing temperature in the step of applying the coloring liquid to the substrate body is (Tg + 30) ° C. or lower and 40 to 100 ° C. A method for manufacturing a lens substrate.   The method for manufacturing a lens substrate according to claim 1, wherein the lens substrate is a microlens substrate.   3. The method for manufacturing a lens substrate according to claim 1, wherein a content ratio of the benzyl alcohol in the coloring liquid is 0.01 to 10.0 wt%.   4. The method for manufacturing a lens substrate according to claim 1, wherein the coloring liquid is applied by dipping.   The method for producing a lens substrate according to claim 1, wherein the color liquid contains a disperse dye as the colorant.   The method of manufacturing a lens substrate according to claim 1, wherein the substrate body to which the coloring liquid is applied is mainly composed of an acrylic resin.   The method of manufacturing a lens substrate according to claim 1, wherein the density of the colored portion is 20 to 95% in terms of a Y value (D65 / 2 ° field of view).   The method for manufacturing a lens substrate according to claim 1, wherein the coloring liquid contains a surfactant.   9. The lens substrate according to claim 1, wherein the coloring liquid contains at least one compound selected from a benzophenone compound and a benzotriazole compound in addition to the colorant and the benzyl alcohol. Production method.   The method for manufacturing a lens substrate according to claim 9, wherein a total content of the benzophenone compound and the benzotriazole compound in the coloring liquid is 0.001 to 10.0 wt%.   When the content of the benzyl alcohol in the colored liquid is X [wt%] and the total content of the benzophenone compound and the benzotriazole compound is Y [wt%], 0.001 ≦ X / The method for manufacturing a lens substrate according to claim 9 or 10, wherein a relationship of Y≤10000 is satisfied.   A lens substrate manufactured by the method according to claim 1.   A transmissive screen comprising the lens substrate according to claim 12. A Fresnel lens part having a Fresnel lens formed on the light exit side;
A transmissive screen comprising: the lens substrate according to claim 12 disposed on a light emission side of the Fresnel lens portion.   A rear projector comprising the transmission screen according to claim 13 or 14.

Images