JP2006098562A - Lens substrate manufacturing method, lens substrate, transmissive screen, and rear projector - Google Patents

Abstract

To provide a lens substrate capable of obtaining an image with excellent contrast, to provide a manufacturing method capable of efficiently manufacturing the lens substrate, and to a transmissive screen including the lens substrate. To provide a rear projector.
A method of manufacturing a lens substrate according to the present invention includes a step of forming a colored portion on a surface side of the lens substrate on which light is incident by applying a coloring liquid containing a colorant by printing. And The coloring liquid preferably contains a coloring agent, water, and a water-soluble polymer. The textile printing is preferably performed under a pressure condition at a temperature of 100 ° C. or lower.
[Selection figure] None

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, in such a method, it is very difficult to form a colored layer having a uniform concentration particularly in a large area because the dispersibility of the colorant in the resin serving as the base material tends to be uneven. As described above, if there is a variation in the density of the colored layer, it directly affects the variation in the transmittance, which may cause problems such as color unevenness in the projected image.
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 capable of obtaining an image with excellent contrast, to provide a manufacturing method capable of efficiently manufacturing the lens substrate, and to include the lens substrate. The object is to provide a transmissive screen and a rear projector.

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,
A step of applying a coloring liquid containing a colorant by printing to form a colored portion on the side of the lens substrate on which light is incident is provided.
Accordingly, it is possible to provide a manufacturing method capable of efficiently manufacturing a lens substrate capable of obtaining an image with excellent contrast.

In the method for manufacturing a lens substrate according to the present invention, it is preferable that the colored liquid contains a colorant and a binder.
Accordingly, it is possible to easily and surely provide a suitable colored portion while more reliably preventing the occurrence of adverse effects on the substrate body on which the colored portion is to be formed (for example, unintentional formation of the colored portion other than a desired portion). Can be formed.

In the method for manufacturing a lens substrate according to the present invention, the coloring liquid preferably contains a colorant, water, and a water-soluble polymer.
Accordingly, it is possible to easily and surely provide a suitable colored portion while more reliably preventing the occurrence of adverse effects on the substrate body on which the colored portion is to be formed (for example, unintentional formation of the colored portion other than a desired portion). Can be formed. In addition, it is possible to effectively prevent unnecessary components from remaining in the finally obtained lens substrate and adversely affecting the characteristics (particularly optical characteristics) of the lens substrate.

In the method for manufacturing a lens substrate according to the present invention, the colorant is preferably a dye.
Accordingly, it is possible to easily and surely provide a suitable colored portion while more reliably preventing the occurrence of adverse effects on the substrate body on which the colored portion is to be formed (for example, unintentional formation of the colored portion other than a desired portion). Can be formed.
In the method for producing a lens substrate according to the present invention, it is preferable to perform printing under pressure.
Accordingly, it is possible to easily and surely form a suitable colored portion while more surely preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of a constituent material of the substrate).

In the method for producing a lens substrate of the present invention, it is preferable to perform printing at a temperature of 70 ° C. or higher.
Thereby, even in a large area, the coloring speed can be increased uniformly and a suitable colored portion can be formed easily and reliably.
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 lens substrate manufacturing method of the present invention, it is preferable to have a step of performing a treatment with a treatment liquid containing benzyl alcohol on the substrate body to which the coloring liquid is applied, prior to the step of applying the coloring liquid.
Accordingly, it is possible to easily and surely form a suitable colored portion while more surely preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of a constituent material of the substrate).

In the method for manufacturing a lens substrate according to the present invention, the content of the benzyl alcohol in the treatment liquid is preferably 0.1 to 5.0 wt%.
Accordingly, it is possible to easily and surely form a suitable colored portion while more surely preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of a constituent material of the substrate).

In the method of manufacturing a lens substrate according to the present invention, the treatment liquid preferably contains a benzophenone compound and / or a benzotriazole compound.
Accordingly, it is possible to easily and surely form a suitable colored portion while more surely preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of a constituent material of the substrate).

In the method for producing a lens substrate of the present invention, the total content of the benzophenone compound and the benzotriazole compound in the treatment liquid is preferably 0.01 to 3.0 wt%.
Accordingly, it is possible to easily and surely form a suitable colored portion while more surely preventing an adverse effect on the substrate body on which the colored portion is to be formed (for example, deterioration of a constituent material of the substrate).

In the lens substrate manufacturing method of the present invention, it is preferable that the substrate body to which the colored 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 conventional coloring methods, coloring is difficult. On the other hand, in this invention, a colored part can be formed easily and reliably also with respect to the board | substrate body comprised with the acrylic resin of such a hard-to-color property (especially hard-to-dye property). 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 of manufacturing a lens substrate according to the present invention, the density of the colored portion is preferably 35 to 70% in terms of a Y value (D65 / 2 ° field of view) based on spectral transmittance.
Thereby, the contrast of the image can be made particularly excellent.
The lens substrate of the present invention is manufactured by the method of the present invention.
Thereby, it is possible to provide a lens substrate capable of obtaining an image with excellent contrast.

The transmission screen of the present invention is characterized by including the lens substrate of the present invention.
Thereby, it is possible to provide a transmission screen capable of obtaining 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 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 plan view of the lens substrate shown in FIG. 1, and FIG. 3 is shown in FIG. It is a typical longitudinal section showing a 1st embodiment of a transmission type screen of the present invention provided with a lens substrate. 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, and as shown in FIG. 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 a 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 3 as a light shielding layer as needed. FIG. 1 shows a state of being provided on the emission side.

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.
Specific examples of the constituent material of the substrate body 2 include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), cyclic polyolefin, modified polyolefin, polyvinyl chloride, poly Vinylidene chloride, polystyrene, polyamide (eg, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12, nylon 6-66), polyimide, polyamideimide, polycarbonate (PC) , Poly- (4-methylpentene-1), ionomer, acrylic resin, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer Polyoxymethylene, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester such as polycyclohexane terephthalate (PCT), polyether, polyether ketone (PEK), polyether ether ketone (PEEK), polyether imide, polyacetal (POM), polyphenylene oxide, modified polyphenylene oxide, polysulfone, polyether sulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer), poly Tetrafluoroethylene, polyvinylidene fluoride, other fluororesins, styrene, polyolefin, polyvinyl chloride, polyurea , Polyester, polyamide, polybutadiene, transpolyisoprene, fluororubber, chlorinated polyethylene, and other thermoplastic elastomers, epoxy resins, phenolic resins, urea resins, melamine resins, unsaturated polyesters, silicones Resins, urethane-based resins, etc., or copolymers, blends, polymer alloys, etc. mainly composed of these, and combinations of one or more of these (for example, blend resins, polymer alloys, laminates) 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, heat resistance, light resistance, workability, dimensional accuracy when molded, mechanical strength, etc. Although suitable, it was difficult to color with the conventional coloring method. On the other hand, in this invention, a colored part can be formed easily and reliably also with respect to the board | substrate body comprised with the acrylic resin of such a hard-to-color property (especially hard-to-dye property). 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 particularly 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.

  The diameter of the microlens 21 is preferably 10 to 500 μm, more preferably 30 to 300 μm, and still more preferably 50 to 100 μm. When the diameter of the microlens 21 is within the above range, the productivity of the microlens substrate 1 (transmission type screen 10) can be further increased while maintaining a sufficient resolution in the image projected on the screen. In the microlens substrate 1, the pitch between adjacent microlenses 21 to microlenses 21 is preferably 10 to 500 μm, more preferably 30 to 300 μm, and even more preferably 50 to 100 μm. preferable.

  Further, the radius of curvature of the microlens 21 is preferably 5 to 250 μm, more preferably 15 to 150 μm, and further preferably 25 to 50 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.

  Further, the arrangement method of the microlenses 21 is not particularly limited. Even if the arrangement is a periodic arrangement, the microlenses 21 are arranged in an optically random arrangement (when viewed from the main surface side of the microlens substrate 1 in plan view). May be arranged in a random positional relationship with each other), but a random arrangement as shown in FIG. 2 is preferable. By arranging the microlenses 21 at random, it is possible to more effectively prevent interference with light valves such as liquid crystal and Fresnel lenses, and it is possible to almost completely eliminate the occurrence of moire. Thereby, the excellent transmissive screen 10 with good display quality can be obtained. In this specification, “optically random” means that the arrangement of the microlenses is irregular and disturbed to such an extent that the occurrence of optical interference such as moire is sufficiently prevented and suppressed. To do.

  Each microlens 21 is formed as a convex lens protruding to the incident side, and is designed so that the focal point f is located in the vicinity of the substrate surface on the emission side. That is, parallel light La (parallel light La from a Fresnel lens portion 5 described later) incident on the microlens substrate 1 from a substantially perpendicular direction is condensed by each microlens 21 of the microlens substrate 1 and emitted. A focal point f is formed in the vicinity of the side substrate surface.

At this time, the use efficiency of light can be further improved by forming the black matrix 3 so as to open the vicinity of the focal point f.
Further, when the microlens substrate 1 is viewed in plan from the light incident surface side (direction shown in FIG. 2), the area occupied by the microlens (lens portion) 21 in the effective region where the microlens 21 is formed ( The ratio of (projected area) is preferably 90% or more, and more preferably 96% or more. When the proportion of the area occupied by the microlens 21 is 90% or more, it is possible to further reduce the straight-ahead light passing through other than the microlens 21 and further improve the light utilization efficiency.

  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 impregnating the inside of the substrate body 2 (microlens 21) with a colorant by printing, as will be described in detail later.
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 on the substrate body 2 by a method that will be described in detail later, thickness variation in each part (particularly, a thickness that does not correspond to the surface shape of the substrate body). (Variation) is small. As a result, it is possible to more reliably prevent inconvenience such as color unevenness in the projected image.
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 is preferably 20 to 85%, more preferably 30 to 80% in terms of the Y value (D65 / 2 ° field of view) based on the spectral transmittance. More preferably, it is ˜70%. 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 surface brightness of black display (black brightness) becomes large, so that the effect of improving the contrast of the image may not be sufficiently obtained. The transmittance of incident light is reduced, and sufficient brightness cannot be obtained in the obtained image. As a result, the contrast of the image may be insufficient.

  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 the balance of the three primary colors of the light from the light source is controlled. 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, the black matrix 3 may be provided on the light emission side surface of the microlens substrate 1. In this case, the black matrix 3 is made of a light-shielding material and is formed in a layer shape. By having such a black matrix 3, the black matrix 3 can absorb external light (external light that is not desirable for forming a projection image), and the image projected on the screen can be further contrasted. It can be excellent. 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 3.
Such a black matrix 3 desirably has an opening 31 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 31 of the black matrix 3. As a result, the light utilization efficiency of the microlens substrate 1 can be increased.

Although the magnitude | size of the opening part 31 is not specifically limited, It is preferable that the diameter is 9-500 micrometers, It is more preferable that it is 9-450 micrometers, It is further more preferable that it is 20-90 micrometers. Thereby, the image projected on a screen can be made more excellent in contrast.
Further, the thickness (average thickness) of the black matrix 3 is preferably 0.01 to 5 μm, more preferably 0.01 to 3 μm, and further preferably 0.03 to 1 μm. When the thickness of the black matrix 3 is a value within the above range, the function as the black matrix 3 can be more effectively exhibited while preventing unintentional peeling, cracking, and the like of the black matrix 3 more reliably. For example, 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 (the direction shown in FIG. 2), in the effective region where the microlens 21 is formed, the region of the black matrix 3 (the region other than the opening 31). ) Is preferably 1 to 70%, and more preferably 1 to 50%. When the ratio of the area occupied by the black matrix 3 is a value within the above range, the image projected on the screen can be made excellent in contrast while the light utilization 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. The parallel light La enters the surface of the microlens substrate 1 where the colored portion is formed, is condensed by each microlens 21, and passes through the opening 31 of the black matrix (light shielding layer) 3.
At this time, the light incident on the microlens substrate 1 is transmitted through the microlens substrate 1 with sufficient transmittance. The light that has passed through the opening 31 diffuses and is 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 substrate with concave portions for microlenses used for manufacturing a microlens substrate, and FIG. 5 is a schematic longitudinal sectional view showing a method for manufacturing the substrate with concave portions for microlenses shown in FIG. FIG. 6 to 8 are schematic longitudinal sectional views showing an example of a method for manufacturing the microlens substrate shown in FIG. In the following description, the lower side in FIGS. 6 to 8 is referred to as “(light) incident side” and the upper side is referred to as “(light) emission side”.

In manufacturing a substrate with concave portions for microlenses, a large number of concave portions (microlens concave portions) are actually formed on the substrate. In manufacturing a microlens substrate, a large number of convex portions are actually formed on the substrate. A (convex lens) is formed, but here, in order to make the explanation easy to understand, a part thereof is highlighted.
First, prior to the description of the manufacturing method of the microlens substrate, the configuration of the substrate with concave portions for microlens used for manufacturing the microlens substrate and the manufacturing method thereof will be described.

As shown in FIG. 4, the substrate 6 with concave portions for microlenses has a plurality of concave portions (recesses for microlenses) 61 arranged at random.
By using such a substrate 6 with concave portions for microlenses, the microlens substrate 1 in which the microlenses 21 are randomly arranged as described above can be obtained.

In the present specification, “optically random” means that the arrangement of the microlenses is irregular and disturbed to the extent that the occurrence of optical interference such as moire is sufficiently prevented and suppressed.
Next, a manufacturing method of the substrate with concave portions for microlenses will be described with reference to FIG. In practice, a large number of microlens recesses are formed on the substrate. Here, in order to make the explanation easy to understand, a part thereof is shown in an emphasized manner.

First, when manufacturing the substrate 6 with concave portions for microlenses, a 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.
Examples of the material of the substrate 7 include soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass. Among them, soda glass, crystalline glass (for example, neo-serum), Alkali-free glass is preferred. Soda glass, crystalline glass, and alkali-free glass are easy to process, are relatively inexpensive, and are advantageous from the viewpoint of manufacturing cost.

<A1> As shown in FIG. 5A, a mask 8 is formed on the surface of the prepared substrate 7 (mask forming step). At the same time, a back surface protective film 89 is formed on the back surface of the substrate 7 (the surface opposite to the surface on which the mask 8 is formed). Of course, the mask 8 and the back surface protective film 89 can be formed simultaneously.
The mask 8 is preferably one that can form an initial hole 81 to be described later by laser light irradiation or the like and has resistance to etching in an etching step to be described later. In other words, the mask 8 is preferably configured so that the etching rate is substantially equal to or smaller than that of the substrate 7.

From this point of view, the material constituting the mask 8 is, for example, a metal such as Cr, Au, Ni, Ti, Pt, an alloy containing two or more selected from these, an oxide of the metal (metal oxide) ), Silicon, resin and the like. The mask 8 may have a laminated structure of a plurality of layers made of different materials such as Cr / Au or Cr / Cr oxide.
The method for forming the mask 8 is not particularly limited, but when the mask 8 is made of a metal material (including an alloy) such as Cr or Au, or a metal oxide (for example, Cr oxide), the mask 8 may be formed by, for example, vapor deposition or sputtering It can be suitably formed by a method or the like. When the mask 8 is made of silicon, the mask 8 can be suitably formed by, for example, a sputtering method or a CVD method.

  When the mask 8 is mainly composed of Cr oxide or Cr, the initial hole 81 can be easily formed in the initial hole forming process described later, and the substrate 7 is more reliably protected in the etching process described later. can do. Further, when the mask 8 is mainly composed of Cr oxide or Cr, for example, in the etching process described later, ammonium monohydrogen difluoride can be used as an etchant. Since ammonium monohydrogen difluoride is not a poisonous and deleterious substance, it can prevent the influence on the human body and the environment during work more reliably.

The thickness of the mask 8 varies depending on the material constituting the mask 8, but is preferably about 0.01 to 2.0 μm, and more preferably about 0.03 to 0.2 μm. If the thickness is less than the lower limit, the shape of the initial hole 81 formed in the initial hole forming step described later may be distorted. In addition, when wet etching is performed in an etching process described later, the masked portion of the substrate 7 may not be sufficiently protected. On the other hand, if the upper limit is exceeded, it will be difficult to form the initial hole 81 that penetrates in the initial hole forming step described later, and the mask 8 may be peeled off due to the internal stress of the mask 8 depending on the constituent material of the mask 8. It may be easier.
The back surface protective film 89 is for protecting the back surface of the substrate 7 in the subsequent steps. By this back surface protective film 89, erosion, deterioration, etc. of the back surface of the substrate 7 are preferably prevented. This back surface protective film 89 is made of, for example, the same material as that of the mask 8. For this reason, the back surface protective film 89 can be provided in the same manner as the mask 8 simultaneously with the formation of the mask 8.

<A2> Next, as shown in FIG. 5 (b), a plurality of initial holes 81, which serve as mask openings in the later-described etching, are randomly formed in the mask 8 (initial hole forming step).
The initial holes 81 may be formed by any method, but are preferably formed by a physical method or laser light irradiation. Thereby, the board | substrate with a recessed part for microlenses can be manufactured with sufficient productivity. In particular, the concave portion can be easily formed even on a large-area substrate.

  Examples of the physical method for forming the initial hole 81 include blasting such as shot blasting and sand blasting, etching, pressing, dot printer, tapping, rubbing, and the like. When the initial hole 81 is formed by blasting, the initial hole 81 can be efficiently formed in a shorter time even on the substrate 7 having a relatively large area (area of the region where the microlens 21 is to be formed).

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- Examples include He laser, Ar laser, CO ₂ laser, and excimer laser. Moreover, you may use wavelengths, such as SHG of each laser, THG, and FHG. When the initial holes 81 are formed by laser light irradiation, the size of the formed initial holes 81, the interval between the adjacent initial holes 81, and the like can be controlled easily and accurately. Further, when the initial hole 81 is formed by laser light irradiation, by controlling the irradiation condition, only the initial hole 81 can be formed without forming the initial concave portion 71 as described later, The initial recess 71 with small variations in shape, size, and depth can be easily and reliably formed.

It is preferable that the formed initial holes 81 are formed evenly over the entire surface of the mask 8. Further, the formed initial hole 81 has a small hole so that the flat surface of the surface of the substrate 7 disappears when the etching is performed in the step <A3> described later, and the recess 61 is formed with almost no gap. It is preferable that they are arranged at a certain interval.
Specifically, for example, the shape of the formed initial hole 81 in a plan view is substantially circular, and the average diameter (diameter) is preferably 2 to 10 μm. The initial holes 81 are preferably formed on the mask 8 at a rate of 1,000 to 1,000,000 holes / cm ² , and are formed at a rate of 10,000 to 500,000 holes / cm ^2. More preferably. Needless to say, the shape of the initial hole 81 is not limited to a substantially circular shape.

  Further, when the initial hole 81 is formed in the mask 8, as shown in FIG. 5B, not only the mask 8 but also a part of the surface of the substrate 7 may be removed simultaneously to form the initial recess 71. Thereby, when etching is performed in an etching process described later, the contact area with the etching solution is increased, and erosion can be suitably started. Further, by adjusting the depth of the initial recess 71, the depth of the recess 61 (maximum lens thickness) can be adjusted. Although the depth of the initial recessed part 71 is not specifically limited, It is preferable to set it as 5 micrometers or less, and it is more preferable to set it as about 0.1-0.5 micrometer. When the initial hole 81 is formed by laser irradiation, the variation in depth can be more reliably reduced with respect to the plurality of initial concave portions 71 formed together with the initial hole 81. Thereby, the variation of the depth of each recessed part 61 which comprises the board | substrate 6 with a concave part for microlenses becomes small, and the dispersion | variation in the magnitude | size and shape of each microlens 21 of the microlens board | substrate 1 finally obtained also becomes small. As a result, the variation in diameter, focal length, and lens thickness of each microlens 21 can be particularly reduced.

Further, not only the initial holes 81 are formed on the formed mask 8 by a physical method or laser light irradiation, but, for example, when the mask 8 is formed on the substrate 7, a predetermined pattern is previously formed on the substrate 7. It is also possible to form a defect on the mask 8 by forming a mask 8 on top of the foreign matter, and use the defect as the initial hole 81.
Thus, by forming the initial hole 81 in the mask 8 by a physical method or laser light irradiation, it is simpler and less expensive than the case where the opening is formed in the mask by a conventional photolithography method. Openings (initial holes 81) can be randomly formed in the mask 8. Further, according to a physical method or laser light irradiation, a large substrate can be easily processed.

<A3> 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 randomly formed on the substrate 7 (etching). Process).
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. A number of recesses 61 are formed on the substrate 7 by etching. As described above, since the initial holes 81 formed in the mask 8 are random, the formed recesses 61 are randomly arranged on the surface of the substrate 7.

In the present embodiment, when the initial hole 81 is formed in the mask 8 in the step <A2>, the initial recess 71 is formed on the surface of the substrate 7. Thereby, at the time of etching, the contact area with the etching solution is increased, and erosion can be suitably started.
Further, when the wet etching method is used, the concave portion 61 can be suitably formed. If, for example, an etchant (hydrofluoric acid-based etchant) containing hydrofluoric acid (hydrogen fluoride) is used as the etchant, the substrate 7 can be etched more selectively, and the recesses 61 are preferably formed. can do.

When the mask 8 is mainly composed of Cr, an ammonium fluoride solution (ammonium monofluoride solution) is particularly suitable as the hydrofluoric acid etching solution. Since the ammonium fluoride solution (4 wt% or less) is not a poisonous or deleterious substance, it can prevent the human body and the environment from being affected during work. Further, when an ammonium fluoride solution is used as the etching solution, the etching solution may contain, for example, hydrogen peroxide. Thereby, an etching speed can be made faster.
In addition, wet etching can be performed with a simpler apparatus than dry etching, and more substrates can be processed at one time. Thereby, productivity improves and the board | substrate 6 with a concave part for microlenses can be provided cheaply.

<A4> Next, as shown in FIG. 5D, the mask 8 is removed (mask removal step). At this time, the back surface protective film 89 is also removed together with the removal of the mask 8.
When the mask 8 is mainly composed of Cr, the removal of the mask 8 can be performed by, for example, etching using a mixture containing ceric ammonium nitrate and perchloric acid.

As described above, as shown in FIG. 5D and FIG. 4, the substrate 6 with concave portions for microlenses in which a large number of concave portions 61 are randomly formed on the substrate 7 is obtained.
The method for forming the random recesses 61 on the substrate 7 is not particularly limited, but the method as described above (the initial hole 81 is formed in the mask 8 by a physical method or laser light irradiation, and then the mask 8 is formed. The following effects are obtained when it is formed by etching using the method of forming the recess 61 on the substrate 7).

  That is, by forming the initial hole 81 in the mask 8 by a physical method or laser light irradiation, the mask 8 can be formed in the mask 8 more easily and cheaply than in the case where the opening is formed in the mask by a conventional photolithography method. The opening (initial hole 81) can be formed in a predetermined pattern. Thereby, productivity improves and the board | substrate 6 with a concave part for microlenses can be provided cheaply.

Further, according to the method as described above, it is possible to easily perform processing on a large substrate. In the case of manufacturing a large 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 substrate with a concave portion for a large microlens (microlens substrate) can be manufactured at a low cost by a simple method.
Further, after removing the mask 8 in the step <A4>, a new mask may be formed on the substrate 7, and a series of steps of mask formation-initial hole formation-wet etching-mask removal may be repeated. Thereby, the board | substrate 6 with a recessed part for microlenses in which the recessed part 61 was formed densely can be obtained.
Next, a method for manufacturing the microlens substrate 1 using the substrate 6 with concave portions for microlenses described above will be described.

  <B1> First, as shown in FIG. 6 (a), a resin 23 having fluidity (for example, a softened resin 23) is formed on the surface of the substrate 6 with concave portions for microlenses where the concave portion 61 is formed. And unpolymerized (uncured) resin 23). In the present embodiment, in this step, the spacer 9 is arranged in a region where the concave portion 61 of the substrate 6 with concave portions for microlenses is not formed, and the resin 23 is pressed by the flat plate 11. Thereby, the thickness of the formed microlens substrate 1 can be controlled more reliably, and the position of the focal point of the microlens 21 on the finally obtained microlens substrate 1 can be controlled more reliably. Can do.

When the spacer 9 is used as in the present embodiment, the shape of the spacer 9 is not particularly limited, but is preferably substantially spherical or substantially cylindrical. When the spacer 9 has such a shape, the diameter is preferably 10 to 300 μm, more preferably 30 to 200 μm, and further preferably 30 to 170 μm.
Prior to the application of the resin 23 and the pressing on the flat plate 11, the release agent is applied to the surface on the side where the concave portion 61 of the substrate 6 with concave portions for microlenses is formed or the surface on the side pressing the resin 23 of the flat plate 11. May be applied. Thereby, the board | substrate body 2 can be isolate | separated (peeled) easily and reliably from the board | substrate 6 with a recessed part for microlenses, and the flat plate 11 in the process mentioned later.

<B2> Next, the resin 23 is solidified (including curing (polymerization)), and then the flat plate 11 is removed (see FIG. 6B). Thereby, the board | substrate body 2 provided with the microlens 21 which consists of resin with which the recessed part 61 was filled and functions as a convex lens is obtained.
When the resin 23 is solidified by curing (polymerization), examples of the method include irradiation with light such as ultraviolet rays, irradiation with electron beams, and heating.

  Here, for example, polystyrene beads, glass beads, organic cross-linked polymers, etc. may be mixed in the substrate body 2 as a diffusing material in order to diffuse incident light from the light source, if necessary. Here, the diffusing material may be mixed in the entire resin 23 or may be mixed only in a part thereof. 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 desirable to become.

<B3> Here, a process for forming the black matrix 3 on the emission side surface of the substrate body 2 produced as described above will be described.
First, as shown in FIG. 6C, a positive type photopolymer 32 having a light shielding property is applied to the emission side surface of the substrate body 2. As a method for applying the photopolymer 32 to the surface of the substrate body 2, for example, various coating methods such as dip coating, doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, roll coater, etc. are used. be able to. The photopolymer 32 may be composed of a resin having a light shielding property, or may be a resin material (low light shielding property) dispersed or dissolved in a light shielding material. After application of the photopolymer 32, heat treatment such as pre-baking treatment may be performed as necessary.

  <B4> Next, as shown in FIG. 7D, the substrate body 2 is irradiated with the exposure light Lb in the direction perpendicular to the incident side surface. The irradiated exposure light Lb is condensed by passing through each microlens 21. As a result, the photopolymer 32 in the vicinity of the focal point f of the microlens 21 (at the portion where the condensed light is incident) is exposed, and the other portions of the photopolymer 32 are not exposed or the exposure amount is reduced. Only the photopolymer 32 in the vicinity of the focal point f is exposed.

Thereafter, development is performed. Here, since the photopolymer 32 is a positive photopolymer, the photopolymer 32 in the vicinity of the exposed focal point f is dissolved and removed by development. As a result, as shown in FIG. 7E, a black matrix 3 in which an opening 31 is formed in a portion corresponding to the optical axis L of the microlens 21 is formed. The development method varies depending on the composition of the photopolymer 32 and the like, but can be performed using, for example, an alkaline solution such as a KOH aqueous solution.
Further, after development, for example, a heat treatment such as a post-bake treatment may be performed as necessary.
Note that the black matrix 3 is not necessarily formed, and if not formed, the above steps <B3><B4> can be omitted.

  <B5> Next, the substrate body 2 is removed from the substrate 6 with concave portions for microlenses (see FIG. 8F). In this way, by removing the substrate 6 with the concave portion for microlens, the substrate 6 with the concave portion for microlens can be repeatedly used for the manufacture of the substrate body 2 (microlens substrate 1). The stability of the quality of the substrate body 2 (microlens substrate 1) can be improved.

  <B6> After that, the substrate body 2 removed from the substrate 6 with concave portions for microlenses is more easily colored than other portions of the substrate body 2 by performing a treatment using a treatment liquid containing benzyl alcohol. The easy coloring part 25 is formed (refer FIG.8 (g)). That is, prior to the step of applying the coloring liquid described later, the substrate body 2 is processed using a processing liquid containing benzyl alcohol. As described above, prior to the step of applying the coloring liquid described later, the substrate main body can be colored more easily and uniformly by performing a treatment using the treatment liquid containing benzyl alcohol on the substrate main body. Can do. In particular, even a substrate body made of a material that is difficult to be colored, such as an acrylic resin, can be easily and reliably colored at high speed and uniformly. This is considered to be due to the following reasons.

  That is, by using a treatment liquid containing benzyl alcohol, the benzyl alcohol in the treatment liquid penetrates deeply into the substrate body and diffuses, loosening the bonds (intermolecular bonds) that make up the substrate body, and the colorant penetrates. To secure space for Then, in the step of applying the color liquid described later, the colorant in the color liquid easily penetrates deeply, so that the colorant can be compared with the space (which can be compared to a seat for the colorant (colored seat)). It is held and the substrate body is colored and does not easily detach. In other words, this process is a process for preparing a space in the base material in advance so that the colorant in the coloring liquid can easily penetrate deeply in the coloring liquid application process described later.

  Further, by using the treatment liquid as described above prior to the coloring liquid application step, a colored portion having a uniform concentration can be formed more easily. 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 or there are defects due to non-uniform polymerization of the resin, the benzyl alcohol contained in the pre-treated liquid can loosen the resin molecular bonds themselves. Therefore, it is possible to more easily form an easily colored portion having a uniform concentration (colored portion having no uneven transmittance).

  Moreover, the following effects are also obtained by applying the treatment liquid as described above to the substrate main body before applying the coloring liquid. That is, when performing the two-stage treatment as described above, the concentration of benzyl alcohol in the first treatment liquid (the treatment liquid as described above) can be freely set, so that a higher concentration can be obtained in the subsequent coloring step. If you want to deeply color in the first treatment solution, increase the benzyl alcohol concentration setting in the first treatment solution. By reducing the concentration of benzyl alcohol, the depth and concentration of the colored layer in the second coloration step can be controlled more accurately, uniformly and easily. On the other hand, in the case of direct coloring in one step as in the prior art, it is difficult to control such a subtle colored layer because the space for coloring and the coloring step proceed almost simultaneously. . Further, in the second coloring step (coloring step by printing described later), the concentration control of the colored layer can be further simplified by using benzyl alcohol together with the colorant. In other words, the benzyl alcohol of the first treatment liquid as described above secures a space (colored seat) into which the colorant enters in the next coloring step. However, by performing this treatment sufficiently (concentration and treatment). Control of time) After sufficiently securing a space for the colorant to enter in advance, also in the second coloring step, the action of benzyl alcohol promotes the colorant to enter the space. It can be accelerated. Thereby, a coloring process can be performed more efficiently in a short time. Furthermore, by changing the benzyl alcohol concentration in the first treatment liquid and the benzyl alcohol concentration setting in the second coloring step, the diffusion rate of the colorant to the substrate can be controlled, resulting in Even in a large area, uniform coloring can be made possible.

Examples of the treatment liquid application method include various application methods such as doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, roll coater, and dipping in which the substrate body 2 is immersed in the processing liquid. And the like.
The step of applying the treatment liquid is preferably performed in a state where the treatment liquid and / or the substrate body 2 is set to 60 to 100 ° C. Thereby, even in a large area, the securing of the colored seat of benzyl alcohol can be promoted uniformly, the coloring speed can be increased, and the easily colored portion 25 can be efficiently formed.

Moreover, you may perform the process of providing a process liquid in the state (pressurized state) which raised atmospheric pressure, for example. Thereby, the penetration | invasion of the process liquid to the inside of a substrate main body can be accelerated | stimulated, As a result, the easily colored part 25 can be formed efficiently in a short time.
The application of the treatment liquid may be repeated a plurality of times as necessary (for example, when the thickness of the easily colored portion 25 to be formed is relatively large). Further, in such a case, by changing the conditions of the treatment liquid (for example, the content of benzyl alcohol in the treatment liquid) and the application conditions thereof, for example, the ease of coloring along the thickness direction can be easily changed. A colored portion 25 can be formed. For example, first, treatment is performed using a treatment liquid having a relatively low content of benzyl alcohol (particularly, treatment at a relatively long time and / or at a relatively high temperature), and then treatment having a relatively high content of benzyl alcohol. By processing with a liquid (especially, processing for a relatively short time and / or at a relatively low temperature), it has a region that is more easily colored on the outer surface side, and on the inner side (inner side), It is possible to form the easily colored portion 25 having a region that is more difficult to be colored. Thereby, a density difference can be given to the colored layer itself. That is, a colored layer having a low color density can be formed on the inner side, and a colored layer having a high color density can be formed on the outer side, so that a colored layer having a density difference can be formed even when external light is incident. Since light is refracted and reflected in a complicated manner, it is possible to attenuate external light without returning it to the outside. As a result, a screen with high contrast and good performance can be obtained.
Moreover, after application | coating of a process liquid, you may perform processes, such as heat processing, such as heating and cooling, light irradiation, pressurization of atmosphere, pressure reduction, as needed.

Hereinafter, the treatment liquid used in this step will be described in more detail.
Although the content rate of the benzyl alcohol in a process 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, it is easy to effectively prevent the occurrence of adverse effects on the substrate body on which the easy-to-color portions 25 are to be formed (for example, deterioration of the constituent materials of the substrate). And the suitable easy coloring part 25 can be formed reliably.

  Moreover, components other than benzyl alcohol may be contained in the treatment liquid. For example, the treatment liquid may contain at least one compound selected from benzophenone compounds and benzotriazole compounds. Thereby, the effects as described above are exhibited more significantly. For example, the substrate body can be colored more easily and reliably, especially for a substrate body made of a material that is difficult to color by conventional coloring methods, such as acrylic resins. And coloring can be given reliably. 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 complementarily, and as a result, a remarkable effect (synergistic effect) is exhibited by using these in combination.

  This mechanism will be described in more detail. First of all, the benzyl alcohol in the treatment solution loosens the molecular bonds of the substrate resin and secures a space for other molecules to enter. Second, at least one compound selected from benzophenone compounds and benzotriazole compounds penetrates into this space and diffuses deeply. This is because benzophenone compounds and benzotriazole compounds, like benzyl alcohol, relax the molecular bonds of the substrate resin and secure a space for other molecules to enter, which is ensured by benzyl alcohol. This is due to the fact that the space is deeper and wider and the space is expanded. The colorant used in the subsequent coloring process does not have this function. In the next coloring step, the colorant enters and is held in the space secured in this way, and the coloring is completed. In this way, by using benzyl alcohol in combination with at least one compound selected from benzophenone compounds and benzotriazole compounds, the colorant is efficiently, deeper, and faster in the substrate. It was possible to diffuse and uniformly color.

Here, benzyl alcohol, a benzophenone compound, and a benzotriazole compound, in particular, have a strong function of securing the above-described colored seat with respect to the acrylic resin. For this reason, it becomes possible to incorporate the colorant into the substrate body more efficiently.
Further, by using a benzophenone-based compound and / or a benzotriazole-based compound together with benzyl alcohol, the easily colored portion 25 can be more reliably formed even if the application condition of the treatment liquid is milder. . As a result, it is possible to more effectively prevent the occurrence of an adverse effect on the substrate body 2 on which the easily colored portions 25 are to be formed (for example, deterioration of the constituent materials of the substrate).

  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).

  In addition, the above benzophenone compounds have a relatively low melting point and boiling point, and also have a relatively high solubility (compatibility) in low molecular weight alcohols such as water and ethanol. As described above, the easily colored portion 25 (colored portion 22) having a desired thickness can be more reliably formed, and the effects of improving the manufacturing yield of the lens substrate can be made remarkable. It can be demonstrated.

  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.

  Further, when the treatment liquid contains two or more benzophenone compounds and benzotriazole compounds as described above (particularly, when the treatment liquid contains one or more benzophenone compounds and one or more benzotriazole compounds). ), These compounds interact with each other in a complementary manner, and when these compounds interact with each other in a complementary manner with benzyl alcohol, the above-described effects appear even more remarkable.

  When the treatment liquid contains a benzophenone compound and / or a benzotriazole compound, the total content of the benzophenone compound and the benzotriazole compound in the treatment liquid is not particularly limited, but is 0.001 to 10. It is preferably 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, the occurrence of an adverse effect on the substrate body on which the easily colored portion 25 is to be formed (for example, deterioration of the constituent materials of the substrate) is further increased. It is possible to easily and surely form a suitable easy coloring portion 25 while preventing effectively.

  Further, when the treatment liquid contains a benzophenone compound and / or a benzotriazole compound, the content of benzyl alcohol in the treatment liquid is X [wt%], the content of benzophenone compound and benzotriazole compound. When the total is Y [wt%], it is preferable to satisfy the relationship of 0.001 ≦ X / Y ≦ 10000, more preferable to satisfy the relationship of 0.05 ≦ X / Y ≦ 1000, and More preferably, the relationship of 25 ≦ X / Y ≦ 500 is satisfied. By satisfying the relationship as described above, the synergistic effect of combining the benzophenone compound and / or the benzotriazole compound with benzyl alcohol is more significantly exhibited, and the substrate body on which the easily colored portion 25 is to be formed. It is possible to form the easy-to-color portion 25 that is suitable for easy, sure, and high speed while more effectively preventing the occurrence of adverse effects on the substrate (for example, deterioration of the constituent materials of the substrate).

Further, in the treatment liquid, for example, a surfactant may be contained. As a result, the colorant and the benzophenone-based compound or benzotriazole-based compound 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 in a later step. However, even a material composed of a material that is difficult to be colored by a conventional method such as an acrylic resin 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 , Heterogeneous 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.
In addition, the treatment liquid contains, for example, a colorant (particularly, a colorant having a sufficiently low content so as not to substantially affect the optical characteristics (particularly, light transmittance) of the lens substrate). It may be. Thereby, in the manufacturing process of a lens substrate, the thickness of the easily colored part 25 can be recognized easily.

  <B7> Thereafter, a colored liquid 22 is applied to the substrate body 2 on which the easily colored portions 25 are formed, thereby forming the colored portions 22 and obtaining the microlens substrate 1 (see FIG. 8H). ). The textile printing process is described in detail. It can be divided into a process for placing a colorant on a colored part (printing) and a process for soaking and fixing a colorant in a base material (printing). (Liquid application process).

  Thus, the coloring part 22 can be easily and reliably formed by applying the coloring liquid to the substrate body 2 by printing. This is because, when printing is used as a method for applying the coloring liquid, the coloring liquid can be efficiently adhered to a desired portion of the substrate body 2, and the coloring agent in the coloring liquid is efficiently impregnated inside the substrate body 2. It seems that it is possible. In addition, by applying the coloring liquid by printing, the substrate body 2 to which the coloring liquid is applied is composed of a material that is difficult to be colored by a conventional method such as an acrylic resin. Even so, it can be easily and reliably colored.

Further, by applying the coloring liquid by printing, the coloring liquid can be efficiently colored with a small amount of the coloring liquid. Furthermore, the coloring liquid is efficiently (continuously) applied to the plurality of lens substrate bodies 2 being conveyed. be able to. As a result, the productivity of the microlens substrate 1 is improved, which can greatly contribute to the reduction of the manufacturing cost of the microlens substrate 1.
Further, by applying the coloring liquid by printing, for example, compared with the case where the coloring liquid is applied by dipping or the like, the manufacturing apparatus of the microlens substrate 1 can be downsized. In particular, when the substrate body (microlens substrate to be manufactured) is large (for example, when the length of the diagonal line is 1.2 m or more), it is necessary to enlarge the tank for immersing the substrate body. Yes, the trend is remarkable. In addition, when a method such as dipping is employed, if the tank in which the substrate body is immersed is enlarged, it is easy to cause uneven coloring (color unevenness) due to the flow of the colored liquid in the tank and the temperature variation of the colored liquid. In contrast, textile printing can effectively prevent such problems from occurring. By the way, the installation area of the tank can be reduced by immersing the substrate body so that the principal surface direction is the vertical direction. However, when the substrate body (microlens substrate to be manufactured) is large, the pressure (water pressure) due to the coloring liquid varies greatly in the depth direction, and a colored layer having a sufficiently uniform thickness is formed. It becomes particularly difficult.

  In addition, by applying the coloring liquid by printing, for example, it is possible to select only a desired portion without forming a protective film or the like on the back side of the substrate body 2 (the side on which the black matrix 3 is formed). Thus, the colored portion 22 can be formed. As a result, the productivity of the microlens substrate 1 is improved, which can greatly contribute to the reduction of the manufacturing cost of the microlens substrate 1.

In particular, in the present embodiment, the easy-to-color portion 25 is formed on the substrate body 2 prior to the application of the coloring liquid by printing (coloring liquid application process). For this reason, in this process (coloring liquid provision process), the colored part 22 can be formed particularly efficiently. That is, in this embodiment, the colored portion can be selectively formed more easily and reliably.
Specific methods of applying (printing) the colorant to the portion to be the colored portion include, for example, roller coating, screen printing, printing using a relief printing plate, rubber roll, or transfer printing from paper or film. Although not particularly limited as long as it can be placed on the surface of the substrate body such as spin coating, roller coating, screen printing, and transfer are preferable.
Note that the printing may be repeated a plurality of times as necessary.

Hereinafter, the coloring liquid used in this step will be described in more detail.
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, 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 materials of the substrate). 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 used in the printing 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 at least, However, It is preferable that a binder is further included. As a result, the coloring liquid can be efficiently adhered to a desired portion of the substrate body 2, and as a result, an adverse effect on the substrate body on which the colored portion is to be formed (for example, the absence of the colored portion other than the desired portion). It is possible to easily and reliably form a suitable colored portion while more reliably preventing the intentional formation and the like.

  As the binder (fixing agent), for example, an acrylic oil-in-water emulsion polymerization emulsion or the like is mainly used, which is a mixture of glue, acrylic resin such as acrylate resin, and urethane resin. , Acrylic / urethane copolymers, polyester resins, vinyl acetate resins, ethylene-vinyl acetate resins, water-soluble polymers, water-absorbing resins, and the like. In order to effectively prevent unnecessary components from remaining in the finally obtained microlens substrate 1 and adversely affecting the characteristics (particularly optical characteristics) of the lens substrate, it is desirable that the substrate is water-soluble.

  Examples of the types of paste include starch substances such as corn powder and wheat flour, cellulosic substances such as carboxymethylcellulose and hydroxyethylcellulose, polysaccharides such as sodium alginate, gum arabic, locust bean gum and guar gum, gelatin, and casein. Examples include natural polymers such as protein substances, synthetic polymers such as polyvinyl alcohol, polyethylene oxide compounds, acrylic acid water-soluble polymers, and maleic anhydride water-soluble polymers.

Examples of the water-absorbing resin include starch-based crosslinked bodies, cellulose-based crosslinked bodies, acrylate-crosslinked bodies, polystyrene crosslinked bodies, crosslinked acrylic acid-acrylamide copolymers, and isobutylene-maleic anhydride copolymers. A crosslinked body etc. are mentioned.
Moreover, the coloring liquid should just contain a coloring agent at least, However, It is preferable that a surfactant is further included. As a result, the colorant can be dispersed in water, and the above-mentioned binder can be added thereto to make the colorant optimal for printing. 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 , Heterogeneous 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.

The colored liquid may contain, for example, benzyl alcohol, a benzophenone compound, a benzotriazole compound, etc. as described above. Thereby, the further improvement of the coloring property of a board | substrate body can be aimed at.
In the printing process, after the printing as described above, the coloring liquid may be dried (removal of a liquid medium such as a solvent or a dispersion medium in the coloring liquid), heat treatment, washing, or the like. Good.

The coloring liquid can be dried using, for example, an oven, a hot plate, or steam heat of a boiler. By drying such a colored liquid, the colored liquid can be efficiently adhered to a desired portion of the substrate body 2.
Examples of the heat treatment include heat treatment with high-temperature steam and dry heat treatment with a dry gas. By performing such treatment, the fixing of the colorant can be efficiently advanced, and the reliability of the formed colored portion 22 (adhesiveness to the substrate body 2) can be improved.

Such heat treatment is preferably performed at 70 ° C. or higher, and more preferably at 70 ° C. or higher and below the heat resistant temperature of the substrate. Thereby, the colored portion 22 is efficiently prevented while preventing the 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, change in the radius of curvature of the lens portion, etc.) more reliably. Can be formed.
Further, it is more preferable that the textile printing (especially the heat treatment as described above) is performed under a pressurized condition (in a state where the atmospheric pressure is increased). Thereby, the penetration | invasion into the inside of the substrate main body 2 of a coloring liquid can be accelerated | stimulated, As a result, the colored part 22 can be formed efficiently in a short time. At this time, the pressure (atmospheric pressure) is not particularly limited, but is preferably 1.1~15.0kgf / cm ^2, is preferably from 1.5~10.0kgf / cm ^2, 2~5kgf / cm ² is preferred.

Examples of washing after the heat treatment include washing with water, washing with high pressure, ultrasonic washing, washing with various detergents (surfactants), and the like. By performing such treatment, it is possible to effectively prevent the binder and the like in the coloring liquid from remaining on the microlens substrate 1.
Moreover, after washing as described above, for example, it may be placed under reduced pressure, or dried by heating (heating), blowing, or the like.

In the illustrated configuration, in this step, the whole easy-to-color part 25 is colored and becomes the colored part 22, but there may be an uncolored region in the easy-to-color part 25.
As described above, in the manufacturing method of the present embodiment, even when an acrylic resin that is difficult to be colored is used for a substrate by using printing, uniform coloring can be easily performed at a high speed even in a large area. In particular, the concentration of the colored layer can be controlled uniformly and easily.

A rear projector using the transmission screen will be described below.
FIG. 9 is a diagram schematically showing the configuration of the rear projector of the present invention.
As shown in the figure, the rear projector 300 has a configuration in which a projection optical unit 310, a light guide mirror 320, and a transmissive screen 10 are arranged in a housing 340.
Since the rear projector 300 includes the transmission screen 10 as described above, an image with excellent contrast can be obtained. Furthermore, since the present embodiment has the above-described configuration, the viewing angle characteristics, light utilization efficiency, and the like are particularly excellent.

In particular, in the microlens substrate 1 described above, since the microlenses 21 are randomly arranged (optically random), the rear projector 300 hardly causes problems such as moire.
As mentioned above, although the manufacturing method of the lens board | substrate of this invention, the lens board | substrate, the transmission type screen, and the rear type projector were 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.
Further, in the above-described embodiment, it has been described as having a step of performing a treatment with a treatment liquid containing benzyl alcohol on the substrate body prior to the step of applying the coloring liquid by printing. The step of performing the treatment using the liquid may be omitted.

  In the above-described embodiment, the initial hole forming step of the method for manufacturing the microlens recessed substrate is described as forming the initial recessed portion 71 in the substrate 7 together with the initial hole 81. May not be formed. By appropriately adjusting the conditions for forming the initial hole 81 (for example, the laser energy intensity, the beam diameter, the irradiation time, etc.), the initial recess 71 having a desired shape is formed or the initial hole 71 is not formed. Only 81 can be selectively formed.

In the above-described embodiment, the black matrix 3 is formed as necessary before forming the easily colored portion 25 and the colored portion 22, but the easily colored portion 25 and the colored portion 22 are formed as necessary. The black matrix 3 may be formed after the formation of.
In the above-described embodiment, the lens (lens portion) included in the lens substrate is described as a convex lens. However, the lens (lens portion) included in the lens substrate may be a concave lens, for example.

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 microlenses having a substantially circular shape when viewed in plan are described as randomly arranged. However, the shape and arrangement of the microlens are not limited to this. For example, the microlenses may be arranged in a lattice shape or may be formed in a honeycomb shape.

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 a 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 portion, a striped light shielding layer (black stripe) is formed 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.
In the above-described embodiment, the black matrix (light shielding layer) is described as being formed by attaching a photopolymer containing a light shielding material to the surface of the microlens substrate (lens substrate). The method for forming the (light-shielding layer) is not limited to this, and may be, for example, dyeing, (chemical) color development, discoloration, or the like.

Further, in the above-described embodiment, the case where the lens substrate has a black matrix has been described, but it goes without saying that the lens substrate may not have such a black matrix as described above. .
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
A substrate with concave portions for microlenses having concave portions for microlenses was manufactured as follows, and a microlens substrate was manufactured using the substrate with concave portions for microlenses.
First, a soda glass substrate having a size of 1.2 m × 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 Cr / Cr oxide laminate (a laminate in which Cr oxide was laminated on the outer surface side of Cr) was formed on this soda glass substrate by sputtering. That is, a mask and a back surface protective film made of a Cr / Cr oxide laminate were formed on the surface of a soda glass substrate. The thickness of the Cr layer was 0.02 μm, and the thickness of the Cr oxide layer was 0.02 μm.

Next, laser processing was performed on the mask to form a large number of initial holes in a range of 113 cm × 65 cm at the center of the mask.
The laser processing was performed using a YAG laser under the conditions of an energy intensity of 1 mW, a beam diameter of 3 μm, and an irradiation time of 60 × 10 ⁻⁹ seconds.
Thereby, initial holes were formed in a random pattern over the entire range of the mask. The average diameter of the initial holes was 5 μm, and the formation density of the initial holes was 40,000 holes / cm ² .

At this time, a 0.1 μm deep recess and an altered layer were also formed on the surface of the soda glass substrate.
Next, the soda glass substrate was wet-etched to form a large number of recesses on the soda glass substrate. The formed many recesses had substantially the same radius of curvature (35 μm).

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 5 hours.
Next, the mask and the back surface protective film were removed by etching using a mixture of ceric ammonium nitrate and perchloric acid.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.

  As a result, a wafer-like substrate with concave portions for microlenses in which a large number of concave portions for microlenses were randomly formed on a soda glass substrate was obtained. When the obtained substrate with recesses was viewed in plan, the ratio of the area occupied by the recesses in the effective region where the recesses were formed was 97%. In addition, a large number of distances between any two adjacent points (between the recesses and the recesses) of the substrate with recesses for the microlens were taken, and the standard deviation was obtained therefrom. The standard deviation thus determined was 32% of their average.

  Next, a release agent (GF-6110) is applied to the surface of the substrate with concave portions for microlenses obtained as described above, on which the concave portions are formed, and further kneaded with polystyrene beads as a diffusing material. An unpolymerized (uncured) acrylic resin (PMMA resin (methacrylic resin)) was applied. Under the present circumstances, the substantially spherical spacer (diameter 30 micrometers) was distribute | arranged to the area | region where the recessed part of the board | substrate with a concave part for microlenses of the said surface is not formed. The content of the diffusing material was adjusted so that Haze (cloudiness: Td / Tt, Td: diffused light transmittance, Tt: total light transmittance) was 70%.

Next, the acrylic resin was pressed with a flat plate made of soda glass. At this time, air was prevented from entering between the flat plate and the acrylic resin. Moreover, as a flat plate, the thing by which the mold release agent (GF-6110) was apply | coated to the surface at the side which presses acrylic resin was used.
Thereafter, the acrylic resin was cured by heating from above the flat plate to obtain a substrate body. Further, the thickness of the resin layer of the obtained substrate body was 2 mm, the radius of curvature of the microlens was 35 μm, and the diameter of the microlens was 70 μm. Further, when the obtained substrate body was viewed in plan, the ratio of the area occupied by the microlens (projected area) in the effective region where the microlens was formed was 97%.

Next, the flat plate was removed.
Next, a positive type photopolymer (PC405G: manufactured by JSR Corporation) in which a light-shielding material (carbon black) is added to the surface of the substrate main body on the emission side (surface opposite to the surface on which the microlens is formed). ) Was applied by a roll coater. The content of the light shielding material in the photopolymer was 20 wt%.

Next, a pre-bake treatment at 90 ° C. for 30 minutes was performed.
Next, ultraviolet light as parallel light of 80 mJ / cm ² was irradiated from the surface opposite to the surface on which the concave portion of the substrate with concave portions for microlenses was formed. Thereby, the irradiated ultraviolet rays were collected by each microlens, and the photopolymer near the focal point f (near the center in the thickness direction of the black matrix) of each microlens was selectively exposed.

Thereafter, development was performed for 40 seconds using a 0.5 wt% aqueous KOH solution.
Thereafter, pure water cleaning and drying using N ₂ gas (removal of pure water) were performed, and a post-baking treatment at 200 ° C. for 30 minutes was further performed. Thereby, a black matrix having openings corresponding to the respective microlenses was formed. The thickness of the formed black matrix was 2 μm, and the diameter of the opening was 45 μm.

Thereafter, the substrate body was removed from the substrate with concave portions for microlenses.
Then, the easily coloring part was formed by immersing the board | substrate body in the process liquid containing benzyl alcohol. At this time, the entire surface side on which the microlenses were formed was in contact with the processing liquid, and the processing liquid was not in contact with the surface side on which the black matrix was formed. Further, the temperature of the substrate body and the treatment liquid when applying the treatment liquid was adjusted to 100 ° C. As the treatment liquid, benzyl alcohol: 15 parts by weight, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone (benzophenone compound): 3 parts by weight, 2- (2-hydroxy-5-methylphenyl) -2H -A mixture of 2 parts by weight of benzotriazole (benzotriazole-based compound), 2 parts by weight of surfactant, and 1000 parts by weight of pure water was used.

After the substrate main body and the processing liquid were brought into contact with each other for 15 minutes under the above conditions, the colored portion was formed by printing on the substrate main body on which the easily colored portion was formed as follows.
First, printing was performed by a roll coater provided with a roller having a diameter of 10 cm and a width of 80 cm. The temperature of the substrate body and the coloring liquid at the time of printing was 30 ° 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. A mixture of 05 parts by weight, starch paste as a binder (water-soluble polymer): 500 parts by weight, acrylic oil-in-water emulsion polymerization emulsion: 250 parts by weight, and pure water: 350 parts by weight was used.

Then, the substrate main body provided with the coloring liquid was placed under a condition of 60 ° C. for 10 minutes using an oven, and the coloring liquid was dried.
Next, this substrate body is put into a printing pot and treated for 30 minutes in steam at a temperature of 90 ° C. and a pressure of 3 kgf / cm ² to fix the colorant to obtain a microlens substrate (heat treatment). .

Thereafter, the microlens substrate was taken out from the printing pot, sufficiently washed with water, unnecessary materials such as a binder were removed, and water adhering to the vicinity of the surface was removed by natural drying to obtain a microlens substrate.
By the printing as described above, a colored portion was selectively formed on the easily colored portion of the lens substrate. Further, the density of the colored portion formed by printing as described above was 55% in terms of the Y value (D65 / 2 ° field of view) based on the spectral transmittance.

In the microlens substrate thus obtained, when the microlens substrate is viewed in plan, the ratio of the area occupied by the opening (projected area) in the effective region where the microlens is formed is 50%. It was.
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 7)
Benzyl alcohol, benzophenone compound, benzotriazole compound content in treatment liquid, type of benzophenone compound, benzotriazole compound, temperature of substrate body and treatment liquid when applying treatment liquid, at room temperature of coloring liquid A microlens substrate and a transmissive screen were produced in the same manner as in Example 1 except that the conditions of viscosity, heat treatment temperature and pressure in printing were changed as shown in Table 1. The content of benzyl alcohol, benzophenone compound, and benzotriazole compound in the treatment solution was changed by increasing or decreasing the pure water so as to correspond to these. The viscosity of the colored liquid was changed by increasing or decreasing the binder content in the colored liquid and increasing or decreasing the pure water content to correspond to this.
(Example 8)
A microlens substrate and a transmission screen were manufactured in the same manner as in Example 1 except that the black matrix was not formed on the substrate body.

(Comparative Example 1)
A microlens substrate and a transmissive screen were manufactured in the same manner as in Example 8 except that the easy coloring portion and the coloring portion were not formed on the substrate body.
(Comparative Example 2)
First, a soda glass substrate having a size of 1.2 m × 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 Cr film having a thickness of 0.03 μm was formed on the soda glass substrate by sputtering. That is, a Cr film mask and a back surface protective film were formed on the surface of the soda glass substrate.

Next, laser processing was performed on the mask to form a large number of linear grooves (holes) in a range of 113 cm × 65 cm in the central portion of the mask so as to be parallel to each other. The pitch between adjacent grooves was 140 μm.
The laser processing was performed using a YAG laser under the conditions of an energy intensity of 1 mW, a beam diameter of 3 μm, and an irradiation time of 60 × 10 ⁻⁹ seconds.

At this time, a 0.1 μm deep recess and an altered layer were also formed on the surface of the soda glass substrate.
Next, wet etching was performed on the soda glass substrate to form a groove-shaped recess on the soda glass substrate. The formed recesses had substantially the same radius of curvature (35 μm).

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 5 hours.
Next, the mask and the back surface protective film were removed by etching using a mixture of ceric ammonium nitrate and perchloric acid.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.

Thus, a wafer-like substrate with concave portions for lenticular lenses in which a large number of concave portions (groove portions) for lenticular lenses were formed on a soda glass substrate was obtained.
Next, a release agent (GF-6110) is applied to the surface on which the concave portion of the substrate with concave portions for lenticular lenses obtained as described above is formed, and unpolymerized (uncured) acrylic. System resin (PMMA resin (methacrylic resin)) was applied. Under the present circumstances, the substantially spherical spacer (diameter 30 micrometers) was distribute | arranged to the area | region where the recessed part of the board | substrate with a concave part for lenticular lenses of the said surface is not formed.

Next, the acrylic resin was pressed with a flat plate made of soda glass. At this time, air was prevented from entering between the flat plate and the acrylic resin. Moreover, as a flat plate, the thing by which the mold release agent (GF-6110) was apply | coated to the surface at the side which presses acrylic resin was used.
Thereafter, the acrylic resin was cured by heating to obtain a lenticular lens substrate. Moreover, the thickness of the resin layer of the obtained lenticular lens substrate was 1 mm, and the radius of curvature of the lenticular lens was 35 μm.
Next, the flat plate used for pressing the acrylic resin and the substrate with concave portions for the lenticular lens were removed to obtain a lenticular lens substrate.
A transmissive screen was obtained in the same manner as in Example 1 by assembling the lenticular lens substrate manufactured as described above and the Fresnel lens portion.

(Comparative Example 3)
As described below, a lenticular lens substrate was manufactured according to the method described in JP-A-11-125704.
First, as shown in FIG. 10, a roll T51 around which a base member T15 made of a continuous film-like acrylic resin is wound, and a transparent surface diluted with a solvent on one side (light incident side) of the base member T15. Formed by coater T52 for coating uncolored unpolymerized (uncured) acrylic resin (transparent resin) T12A, dryer T53 for drying transparent resin T12A coated on base member T15, and lenticular lens-shaped mold A molded roll T54, a dispenser T55 for applying a colored unpolymerized (uncured) acrylic resin (colored resin) T13 to the mold roll T54, and a colored resin T13 to the mold roll T54. A nip roll T56 that nips the base member T15 across the transparent resin T12A, and a colored resin T1 in the mold of the mold roll T54 A lenticular lens substrate manufacturing apparatus T50 including a UV lamp T57 for irradiating UV to the transparent resin T12A, a release roll T58 for releasing the molded lenticular lens substrate (lenticular lens sheet) T10 from the mold roll T54, and the like. Prepared.

In this lenticular lens substrate manufacturing apparatus T50, a film-like base member T15 is coated with a high-viscosity transparent resin T12A using a coater T52 after being diluted with a solvent (transparent resin coating step). Drying with warm air (solvent drying step) formed a transparent resin layer with reduced fluidity.
Next, the colored resin T13 is applied to the mold roll T54, and the base member T15 coated with the transparent resin T12A is colored by the nip roll T56 on the mold roll T54 coated with the colored resin T13. Nipping was performed such that the resin T13 and the transparent resin T12A were laminated.

  Thereafter, ultraviolet rays were irradiated from the base member T15 side by the UV lamp T57 (irradiation process), and the colored resin T13 and the transparent resin T12A were cured. Finally, the lenticular lens substrate T10 on which the lens portion T12 made of the colored resin T13 and the transparent resin T12A was formed on the base member T15 was peeled from the mold roll T54 to obtain the lenticular lens substrate T10.

  The obtained lenticular lens substrate T10 was 1.2 m × 0.7 m square, and a large number of linear lenticular lenses were formed in a range of 113 cm × 65 cm at the center so as to be parallel to each other. The thickness of the resin layer of the obtained lenticular lens substrate was 150 μm. The density of the colored portion was 65% in terms of the Y value (D65 / 2 ° field of view) based on the spectral transmittance. The pitch between adjacent grooves (grooves) (lens) was 70 μm. The formed lenticular lenses had substantially the same radius of curvature (35 μm).

In addition, PMMA resin (methacrylic resin) was used as acrylic resin which comprises base member T15, transparent resin T12A, and colored resin T13. Further, as the colored resin T13, a resin generally kneaded in advance with a pigment called a Tint material was used. Further, although a diffusing material is mixed in the resin, for comparison, it is set to 70% Haze as in other levels.
A transmissive screen was obtained in the same manner as in Example 1 by assembling the lenticular lens substrate manufactured as described above and the Fresnel lens portion.

(Comparative Example 4)
A microlens substrate and a transmissive screen were produced in the same manner as in Example 8 except that the formation of the colored portion was attempted by dipping the substrate body into the coloring liquid without forming the easily colored portion. did.
Table 1 summarizes the treatment liquid application process, the printing conditions, the thickness of the colored portion, and the standard deviation of the thickness of the colored portion for each of the examples and comparative examples. 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 indicated by “C” and 2- (2-hydroxy-4-octyloxyphenyl) -2H-benzotriazole is indicated by “D”.

As is clear from Table 1, the lens substrate (microlens substrate) of the present invention has a small variation (standard deviation) in the thickness of the colored portion, whereas the lens substrates of Comparative Examples 3 and 4 have The thickness variation was large.
[Evaluation of contrast]
Contrast evaluation was performed on the transmissive screens produced in the respective Examples and Comparative Examples. Contrast is the amount of increase in front luminance (white luminance) LW (cd / m ² ) of white display when all the white of 410 lx is incident in the dark room and 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]
Using the transmissive screens of the respective Examples and Comparative Examples, rear type projectors as shown in FIG. 9 were produced.
[Evaluation of uneven color]
The spectral transmittance of the transmissive screens of the rear projectors of the respective examples and comparative examples is measured in 20 planes, and the maximum value and the minimum value of the Y value (D65 / 2 ° field of view) based on the spectral transmittance are measured. The difference ΔT (Y)% was defined as color unevenness, and the occurrence of color unevenness was evaluated according to the following four-stage criteria.
A: ΔT (Y): less than 3%. No color unevenness is observed.
○: ΔT (Y): 3 to 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.

[Measurement of viewing angle]
The viewing angles in the vertical direction and the horizontal direction were measured in a state where the sample images were displayed on the transmissive screens of the rear projectors of the respective Examples and Comparative Examples.
The viewing angle was measured with a variable angle photometer (goniophotometer) MPC3100 (manufactured by Shimadzu Corporation) under the condition of measuring at intervals of 1 degree.

[Evaluation of long-term stability]
The produced transmission type screen was installed immediately before the light emitting portion of the projection optical unit of the rear projector that radiates 450 lx light, and the long-term stability was evaluated at an accelerated rate.
The transmittance difference (change amount ΔT (Y)) around 10 hours from the start of light irradiation was defined as deterioration and unevenness of the transmission screen, and evaluated according to the following four criteria.

(Double-circle): Deterioration and nonuniformity are not recognized at all. Change amount ΔT (Y) is less than 3%.
○: Deterioration and unevenness are hardly observed. Change amount ΔT (Y) 3 to 5%.
Δ: Slight deterioration or unevenness is observed. Change ΔT (Y) 5-10%.
X: Deterioration and unevenness are noticeable. Change amount ΔT (Y) exceeds 10%.
These results are summarized in Table 2.

As is clear from Table 2, the present invention provided excellent contrast, and was excellent in viewing angle characteristics and long-term stability. In the present invention, an excellent image without color unevenness could be displayed. That is, in the present invention, an excellent image can be stably displayed over a long period of time.
On the other hand, in the comparative example, a satisfactory result was not obtained. Among them, in Comparative Examples 1, 2, and 4, sufficient contrast was not obtained, and in particular, in Comparative Examples 1 and 2 that did not have a colored portion, the contrast was very low. Further, in Comparative Example 3 in which the colored portion was formed by laminating a colored resin before curing on the surface of the transparent resin, the transmittance variation was remarkable and only low-quality images could be displayed. This is considered to be because the variation in the density of the colored portion is large in the plane.

It is a typical longitudinal section showing a 1st embodiment of a lens substrate (micro lens substrate) of the present invention. It is a top view of the lens substrate shown in FIG. It is a typical longitudinal cross-sectional view which shows 1st Embodiment of the transmission type screen of this invention provided with the lens board | substrate (micro lens board | substrate) shown in FIG. It is a typical longitudinal cross-sectional view which shows the board | substrate with a concave part for microlenses used for manufacture of a microlens board | substrate. It is a typical longitudinal cross-sectional view which shows the manufacturing method of the board | substrate with a recessed part for microlenses 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 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 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 figure which shows the structure of the manufacturing apparatus used for manufacture of the lenticular lens board | substrate in a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Micro lens board | substrate (lens board | substrate) 2 ... Board | substrate main body 21 ... Micro lens (lens part) 22 ... Colored part (external light absorption part) 23 ... Resin 25 ... Easy coloring part 3 ... Black matrix (light-shielding layer) 31 ... Opening Part 32 ... Photopolymer 5 ... Fresnel lens part 51 ... Fresnel lens 6 ... Substrate with concave part for microlens 61 ... Concave part 7 ... Substrate 71 ... Initial concave part 8 ... Mask 81 ... Initial hole 89 ... Back surface protective film 9 ... Spacer 10 ... Transmission Type screen 11 ... Flat plate 300 ... Rear type projector 310 ... Projection optical unit 320 ... Light guide mirror 340 ... Case T50 ... Lenticular lens substrate manufacturing device T10 ... Lenticular lens substrate (lenticular lens sheet) T12A ... Transparent and non-colored unpolymerized (Uncured) acrylic resin (transparent resin) T13 ... unpolymerized (not yet Cured) acrylic resin (colored resin) T15 ... base member T51 ... roll T52 ... coater T53 ... dryer T54 ... mold roll T55 ... dispenser T56 ... nip roll T57 ... UV lamp T58 ... release roll

Claims (16)

A method of manufacturing a lens substrate that is used with light incident thereon,
A method for producing a lens substrate, comprising a step of forming a colored portion on a side of the lens substrate on which light is incident by applying a coloring liquid containing a colorant by printing.   The method for manufacturing a lens substrate according to claim 1, wherein the coloring liquid contains a colorant and a binder.   The method for manufacturing a lens substrate according to claim 1, wherein the coloring liquid contains a colorant, water, and a water-soluble polymer.   The method of manufacturing a lens substrate according to claim 1, wherein the colorant is a dye.   The method for producing a lens substrate according to any one of claims 1 to 4, wherein the printing is performed under a pressurized condition.   6. The method for producing a lens substrate according to claim 1, wherein the printing is performed at a temperature of 70 [deg.] C. or higher.   The method for manufacturing a lens substrate according to claim 1, wherein the lens substrate is a microlens substrate.   The manufacturing of the lens substrate according to any one of claims 1 to 7, further comprising a step of performing a treatment with a treatment liquid containing benzyl alcohol on a substrate body to which the coloring liquid is applied prior to the step of applying the coloring liquid. Method.   The method for manufacturing a lens substrate according to claim 8, wherein a content ratio of the benzyl alcohol in the treatment liquid is 0.1 to 5.0 wt%.   The method for manufacturing a lens substrate according to claim 8, wherein the treatment liquid contains a benzophenone compound and / or a benzotriazole compound.   The method for manufacturing a lens substrate according to claim 10, wherein the total content of the benzophenone compound and the benzotriazole compound in the treatment liquid is 0.01 to 3.0 wt%.   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 35 to 70% in terms of a Y value (D65 / 2 ° field of view) based on spectral transmittance.   A lens substrate manufactured by the method according to claim 1.   A transmissive screen comprising the lens substrate according to claim 14. A rear projector comprising the transmissive screen according to claim 15.

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