JP2001133601A - Microlens array, manufacturing method therefor, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microlens array where formation of bubbles is prevented, its manufacturing method, and a display device. SOLUTION: This method includes a first stage where a master disk 10 provided with a first area 12, where a curved surface part 16 corresponding to a lens is formed and a corner part is provided, and a second area 14 which is formed with a flat surface adjacent to the corner part 18 is prepared and the first area 12 is provided with a light-transmissive layer precursor 38 and a second stage, where the light-transmissive layer precursor 38 is spread on the master disk. In the first stage, a first part 41 of the light-transmissive layer precursor 38 is provided in the center part of the first area 12, and a second part 42 of the light-transmissive layer precursor 38 is provided in the vicinity of the corner part 18 in the first area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a microlens array, a method for manufacturing the same, and a display device.

[0002]

BACKGROUND OF THE INVENTION As a method of manufacturing a microlens array used for a liquid crystal display panel or the like, a resin is dropped on a master on which a plurality of curved surfaces corresponding to lenses are formed, and the resin is solidified to form a light transmitting layer. By forming and peeling this,
Methods for manufacturing microlens arrays are known.

Here, a master having a plurality of curved surface portions formed in a rectangular area and a flat area formed around the rectangular area is used. When the substrate and the master are brought into close contact with each other via a resin, air bubbles are formed at the corners of the rectangular area where the curved surface is formed.

The effect is presumed as follows. The distance from the center of the master to the corner of the rectangular area is longer than the distance from the center of the master to each side of the rectangular area. Therefore,
The resin is faster than the corners and extends over each side of the rectangular area to the flat area. Then, it is presumed that air bubbles are generated by enclosing the space by the resin that has advanced to the corners around the rectangular area in the flat area and the resin that has advanced to the corners from the center of the master. Since a microlens array with bubbles cannot be used, further improvement is required to increase the yield.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a microlens array in which bubbles are prevented from being formed, a method of manufacturing the same, and a display device.

[0006]

(1) In a method of manufacturing a microlens array according to the present invention, a first region having a plurality of curved surfaces having a shape corresponding to a lens and having a corner portion; A second region formed of a flat surface adjacent to the corner portion of the region,
A first step of providing a light-transmitting layer precursor in the first region of the master, and a second step of spreading the light-transmitting layer precursor on the master, wherein the first step includes: A first portion of the light-transmitting layer precursor is provided at a central portion of the first region, and a second portion of the light-transmitting layer precursor is provided near the corner in the first region.

In the present invention, a microlens array is manufactured by transferring a plurality of curved surface portions to a light transmitting layer precursor using a master as a mold. Once the master is manufactured, it can be used as many times as the durability permits, so that the master can be omitted in the manufacturing process of the second and subsequent microlens arrays, and the number of processes and cost can be reduced.

According to the present invention, a second portion of the light transmitting layer precursor is provided near the corner. Therefore, before the first portion of the light transmitting layer precursor is spread and merged from the two directions near the tip of the corner portion on the second region, the first portion is spread and corner portion is spread. To the tip of. Therefore, since the light-transmitting layer precursor does not surround the space at the corner, the generation of bubbles can be prevented. Thereby, the quality of the manufactured microlens array can be made uniform.

(2) In this method of manufacturing a microlens array, the second portion of the light transmitting layer precursor may be provided in a smaller amount than the first portion.

Since the second portion is closer to the end of the master than the first portion, by providing a smaller amount than the first portion, it is possible to reduce the outflow from the master.

(3) In the method of manufacturing a microlens array, the third portion of the light transmitting layer precursor may be provided at the position of the first region except for the vicinity of the central portion and the corner portion.
May be provided.

This makes it possible to supplement the amount of the light transmitting layer precursor.

(4) In the method of manufacturing a microlens array, the third portion of the light transmitting layer precursor may be provided in a smaller amount than the first portion.

Since the third portion is closer to the end of the master than the first portion, by providing a smaller amount than the first portion, it is possible to reduce the outflow from the master.

(5) In the method of manufacturing a microlens array, the second portion of the light transmitting layer precursor may be provided in a smaller amount than the third portion.

(6) In this method of manufacturing a microlens array, a portion other than the first portion of the light transmitting layer precursor is provided in an amount of about 30% to 90% of the first portion. You may.

(7) In this method of manufacturing a microlens array, the first region may be divided into a plurality of individual regions by a division screen formed by a flat surface.

The microlens array manufactured by using this master is divided into a plurality of areas corresponding to a plurality of individual areas of the master, so that each area is cut into a plurality of chips. A microlens array can be obtained.

(8) In this method of manufacturing a microlens array, the first portion of the light transmitting layer precursor may be provided in at least one of the individual regions located at the center of the first region. Good.

(9) In this method of manufacturing a microlens array, the second portion of the light transmitting layer precursor may be placed in any one of the individual regions including a portion forming a corner of the first region. It may be provided.

(10) In this method of manufacturing a microlens array, a third step of solidifying the light-transmitting layer precursor to form a light-transmitting layer, and separating the master from the light-transmitting layer is provided. It may further include.

(11) In this method of manufacturing a microlens array, the second step may be performed by bringing the substrate and the master into close contact with each other via the light-transmitting layer precursor.

(12) In this method of manufacturing a microlens array, the substrate may have a light transmitting property, and the substrate may be left as a reinforcing plate for the light transmitting layer.

(13) In this method of manufacturing a microlens array, the substrate may be separated from the light transmitting layer after the second step.

(14) The microlens array according to the present invention is manufactured by the above method.

(15) A display device according to the present invention has the microlens array.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the following embodiments.

(First Embodiment) FIGS. 1 to 5 are diagrams illustrating a method of manufacturing a microlens array according to a first embodiment of the present invention.

(Master) FIG. 1 is a plan view of a master used in the present embodiment. The planar shape of the master 10 is not particularly limited, and may be a circle or a polygon such as a rectangle. The master 10 has a first region 12 and a second region 14 on at least one (only one or both) surfaces.
In FIG. 1, a region surrounded by a dashed line is a first region 12.
It is.

The planar shape of the first region 12 is a polygon such as a rectangle, for example, and has at least one (one or more) corner portions 18. The corner portion 18 is formed by joining a pair of sides of the first region 12. Corner 1
The side forming 8 may be drawn with a straight line or a curve.

A plurality of curved portions 16 are formed in the first area 12. Each curved surface portion 16 has a shape corresponding to the individual lens shape of the microlens array. For example, when a microlens array is formed directly from the master 10, the curved surface portion 16 has an inverted shape of a lens. That is, the curved surface portion 16 has a concave surface when forming a convex lens, and the curved surface portion 16 has a convex surface when forming a concave lens.

The first area 12 is divided into a plurality of individual areas 22 by a section screen 20. The section screen 20 is formed with a flat surface. The plurality of curved surface portions 16 are divided into a plurality of groups by a section screen 20 formed of a flat surface. The section screen 20 may include at least one (one or more) first band-shaped surfaces 24 and at least one (one or more) second band-shaped surfaces 26. FIG.
In the example shown in FIG. 5, a plurality of parallel first band-shaped surfaces 24 and a plurality of parallel second band-shaped surfaces 26 intersect at right angles,
The ward screen 20 has a lattice shape. Each microlens array chip is formed by the curved surface portion 16 formed in each individual region 22 partitioned by the partition screen 20. That is, the master 10 is for manufacturing a microlens array in which a plurality of chips are integrally collected, and individual chips are obtained by cutting the microlens array.

The second region 14 is formed with a flat surface. The second region 14 is formed adjacent to the corner 18 of the first region 12. The second area 14 is the first area 1
2 may be enclosed. When the first region 12 has a polygonal shape such as a rectangle, the second region 14 may be adjacent to each side of the first region 12. The second area 14 and the section screen 20 may be flush or a step may be formed.

(First Step) In the present embodiment, the master 10
Is prepared, and the first step of providing the light transmitting layer precursor 38 on the master 10 is performed.

FIGS. 2A to 2E are views showing an example of a manufacturing process of a master used in the present embodiment.

First, as shown in FIG.
A resist layer 30 is formed thereon. The curved surface portion 16 is formed by etching the base material 28. Therefore, the base material 28
The material is not particularly limited as long as it is an etchable material. However, silicon or quartz is preferable because the curved surface portion 16 can be easily formed with high precision by etching.

As a material for forming the resist layer 30,
For example, a commercially available positive resist in which a diazonaphthoquinone derivative is blended as a photosensitive agent with a cresol novolak resin, which is generally used in the manufacture of semiconductor devices, can be used as it is. Here, the positive resist is a substance that can be selectively removed by a developer when exposed to radiation according to a predetermined pattern.

The method for forming the resist layer 30 is as follows.
Spin coating, dipping, spray coating,
It is possible to use a method such as a roll coating method and a bar coating method.

Next, as shown in FIG.
2 is disposed above the resist layer 30, and only predetermined regions of the resist layer 30 are exposed to radiation 34 via the mask 32. The mask 32 is patterned so that the radiation 34 is transmitted only in a region required for forming the curved surface portion 16.

The radiation has a wavelength of 200 nm to 500 n.
It is preferable to use light in the region of m. The use of light in this wavelength region makes it possible to use the photolithography technology established in the liquid crystal panel manufacturing process and the like and the equipment used therefor, and to reduce costs.

When development processing is performed under predetermined conditions after exposing the resist layer 30 with the radiation 34, FIG.
As shown in (C), only in the exposed area 36 of the radiation 34, a part of the resist layer 30 is selectively removed to expose the surface of the base material 28, and in the other area, the resist layer 3 is exposed.
It remains in the state covered by 0.

When the resist layer 30 is patterned in this manner, as shown in FIG. 2D, the substrate 28 is etched to a predetermined depth using the resist layer 30 as a mask. More specifically, isotropic etching is performed on a region of the base material 28 exposed from the resist layer 30 so that the etching proceeds in any direction. For example, isotropic etching can be performed by immersing the base material 28 in a chemical solution (etching solution) by applying wet etching. When quartz is used as the base material 28, etching is performed using, for example, an aqueous solution (buffered hydrofluoric acid) in which hydrofluoric acid and ammonium fluoride are mixed as an etchant. By performing isotropic etching, a concave curved surface portion 16 is formed on the base material 28.

After completion of the etching, as shown in FIG. 2E, when the resist layer 30 is removed, the curved surface portion 16 is formed on the base material 28, and this becomes the master 10.

In the present embodiment, the master 10 is economical because once manufactured, it can be used as many times as the durability permits. Further, the manufacturing process of the master 10 can be omitted in the manufacturing process of the second and subsequent microlens arrays, and the number of processes and the cost can be reduced.

In the above process, a positive resist was used to form the curved portion 16 on the substrate 28. However, the region exposed to the radiation became insoluble in the developing solution, and the region not exposed to the radiation was used. May be a negative resist which can be selectively removed by a developer. In this case,
As the mask 32, a mask whose pattern is inverted is used. Alternatively, the resist may be directly exposed in a pattern by using a laser beam or an electron beam without using a mask.

After the master 10 is prepared, a light-transmitting layer precursor 38 is provided on the master 10 as shown in FIG.

Here, the light transmitting layer precursor 38 is preferably a liquid or liquefiable substance. By making the liquid, the light transmitting layer precursor 38 is placed inside the curved portion 16 if the curved portion is concave, and between the curved portions if the curved portion is convex.
Can be easily filled. As the liquid substance, a substance that can be cured by applying energy can be used, and as the liquefiable substance, a plastic substance can be used.

The light-transmitting layer precursor 38 is not particularly limited as long as the light-transmitting layer 40 (see FIG. 4C) has characteristics required for light transmission and the like when it is formed. Although not required, it is preferably a resin. The resin is
Those having energy curability or plasticity can be easily obtained and are suitable.

Examples of the resin having energy curability include:
Desirably, it can be cured by applying at least one of light and heat. For the use of light and heat, a general-purpose exposure apparatus, a heating apparatus such as a baking furnace or a hot plate can be used, and the equipment cost can be reduced.

Examples of such an energy-curable resin include acrylic resins, epoxy resins,
Melamine-based resins, polyimide-based resins, and the like can be used. In particular, an acrylic resin is preferable because it can easily be cured by irradiation with light by using various commercially available precursors and photosensitive agents (photopolymerization initiators).

Specific examples of the basic composition of the photocurable acrylic resin include a prepolymer or oligomer, a monomer, and a photopolymerization initiator.

As the prepolymer or oligomer,
For example, acrylates such as epoxy acrylates, urethane acrylates, polyester acrylates, polyether acrylates, and spiroacetal acrylates; methacrylates such as epoxy methacrylates, urethane methacrylates, polyester methacrylates, and polyether methacrylates; Is available.

As the monomer, for example, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone, carbitol acrylate, tetrahydrofurfuryl acrylate, isovol Monofunctional monomers such as nyl acrylate, dicyclopentenyl acrylate, and 1,3-butanediol acrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate,
Bifunctional monomers such as neopentyl glycol dimethacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate,
Polyfunctional monomers such as pentaerythritol triacrylate and dipentaerythritol hexaacrylate can be used.

As the photopolymerization initiator, for example, 2,2-
Acetophenones such as dimethoxy-2-phenylacetophenone, butylphenones such as α-hydroxyisobutylphenone and p-isopropyl-α-hydroxyisobutylphenone, p-tert-butyldichloroacetophenone, p-tert-butyltrichloroacetophenone, α, halogenated acetophenones such as α-dichloro-4-phenoxyacetophenone, benzophenone,
Benzophenones such as N, N-tetraethyl-4,4-diaminobenzophenone; benzyls such as benzyl and benzyldimethylketal; benzoins such as benzoin and benzoin alkyl ether; 1-phenyl-1,2
Oximes such as -propanedione-2- (o-ethoxycarbonyl) oxime, 2-methylthioxanthone,
-Xanthones such as chlorothioxanthone, benzoin ethers such as benzoin ether and isobutyl benzoin ether, and radical generating compounds such as Michler's ketone and benzyl methyl ketal can be used.

If necessary, a compound such as an amine may be added to prevent curing inhibition by oxygen, or a solvent component may be added to facilitate coating. The solvent component is not particularly limited, and various organic solvents, for example, propylene glycol monomethyl ether acetate, methoxymethyl propionate, ethoxyethyl propionate, ethyl lactate, ethyl pyruvate, methyl amyl ketone, etc. Available.

These materials are preferable because they have good releasability from silicon or quartz, which is excellent as a material of the master 10 in that high-precision etching is possible.

As the resin having plasticity, for example, a resin having thermoplasticity such as a polycarbonate-based resin, a polymethyl methacrylate-based resin, and an amorphous polyolefin-based resin can be used. Such a resin is plasticized by heating it to a temperature equal to or higher than the softening point to form a liquid, and is provided on the master 10 as shown in FIG. The light-transmissive layer precursor 38 is preferably provided simply by dropping it.

In the present embodiment, the first portion 41 of the light-transmitting layer precursor 38 is provided at the center (the portion excluding the end) of the first region 12. A second portion 42 of the light transmitting layer precursor 38 is provided near the corner portion 18 of the first region 12.
The third portion 43 of the light-transmitting layer precursor 38 is provided at a position other than the central portion and the corner portion 18 of the first region 12.
The first, second and third portions 41, 42, 43 may be provided discontinuously and independently, but may be continuous.

The first portion 41 of the light transmitting layer precursor 38
Is preferably provided at the center of the first region 12. First
When one individual region 22 is located at the center of the region 12, the first portion 41 may be provided in the individual region 22. In that case, the second portion 42 may be provided in the individual region 22 or may be provided so as to protrude from the individual region 22. Alternatively, if the center of the first area 12 is located outside all the individual areas 22, the first area 1
The first portion 41 may be provided in at least one (one or more) individual regions 22 closest to the center of the two.

The second portion 42 of the light transmitting layer precursor 38
May be provided in the individual region 22 including a portion forming the corner portion 18 of the first region 12. In that case, the second portion 42 may be provided in the individual region 22 or may be provided so as to protrude from the individual region 22.

The third portion 43 of the light transmitting layer precursor 38
May be provided in the vicinity of each side of the first region 12 having a rectangular shape, or may be provided in at least one (one or more) individual regions 22 including a portion forming the side. In that case, the third portion 43 may be provided in one individual region 22 or may be provided so as to protrude from one individual region 22.

The second portion 42 of the light transmitting layer precursor 38
Is provided at a position closer to the end of the master 10 than the first portion 41, and therefore, by providing a smaller amount than the first portion 41, the amount flowing out of the master 10 can be reduced or eliminated. For example, the second part 42 may be provided in an amount of about 30% or more and 90% or less of the first part 41.

Similarly, the third portion 43 of the light-transmitting layer precursor 38 is provided at a position closer to the end of the master 10 than the first portion 41, so that the third portion 43 is smaller in amount than the first portion 41. By providing the above, the amount flowing out of the master 10 can be reduced or eliminated. For example, the third part 43 is
May be provided in an amount of about 30% or more and 90% or less of the portion 41 of FIG.

The second portion 42 of the light transmitting layer precursor 38
May be provided in a smaller amount than the third portion 43.

By providing the light transmitting layer precursor 38 as described above, the following steps can be performed satisfactorily.
The operation will be described later.

(Second Step) Next, the light transmitting layer precursor 38
Is performed in the second step. For example, as shown in FIG. 4A, the substrate 48 and the master 10 are brought into close contact with each other via the light-transmitting layer precursor 38, so that the light-transmitting layer precursor 38 is spread to a predetermined region.

The substrate 48 may have at least the function required to spread the light transmitting layer precursor 38. One surface of the substrate 48 may be flat,
In that case, a flat surface may be brought into close contact with the light transmitting layer precursor 38. When the substrate 48 is left as a reinforcing plate for the light-transmitting layer 40, the substrate 48 may be one that satisfies optical properties such as light transmittance and characteristics such as mechanical strength required for a microlens array. It is not particularly limited, for example, it is possible to use quartz or glass, or a plastic substrate or film such as polycarbonate, polyarylate, polyether sulfone, polyethylene terephthalate, polymethyl methacrylate, and amorphous polyolefin. It is. If the substrate 48 is peeled in a later step, the substrate 4
8 need not be light transmissive.

When the master 10 and the substrate 48 are brought into close contact with each other via the light transmitting layer precursor 38 as necessary,
The light transmitting layer precursor 38 may be pressurized via at least one of the substrate 48 and the substrate 48. By pressurizing, the time required for the light-transmitting layer precursor 38 to spread can be reduced, so that workability is improved, and the curved surface portion 1 of the light-transmitting layer precursor 38 is improved.
6 or between the curved surface portions 16 is reliably filled.

By bringing the master 10 and the substrate 48 into close contact with each other via the light-transmitting layer precursor 38, the light-transmitting layer precursor 38
Has a shape corresponding to the curved portion 16 of the master 10. That is, the reverse pattern of the curved surface portion 16 can be transferred to the light transmitting layer precursor 38.

In the example shown in FIG. 4A, the light transmitting layer precursor 38 was placed on the master 10 in the first step, and the substrate 48 and the master 10 were brought into close contact with each other in the second step. The present invention is not limited to this. For example, in the first step, the light-transmitting layer precursor 38 is placed on the substrate 48 and the master 10 is placed thereon, thereby providing the light-transmitting layer precursor 38 on the master 10. And the light-transmitting layer precursor 3 depending on the master 10
8 may be spread. In the first step, the master 1
The light transmitting layer precursor 38 may be provided on both the substrate 0 and the substrate 48.

FIG. 5 is a diagram showing an operation when the light transmitting layer precursor 38 is spread. When the light-transmitting layer precursor 38 provided on the master 10 is spread, the master 1
It expands in the direction of the zero end. In the present embodiment, the master 10
Since the light transmitting layer precursor 38 is provided in the first region 12 of FIG.
The light-transmitting layer precursor 38 is spread over the second region 14.
Proceed to.

There are first and second streams 50, 52 in the light transmitting layer precursor 38 to be spread. The first flow 50 flows from the first region 12 to the second region 14, and flows on the second region 14 along two sides forming the corner portion 18 of the first region 12 toward the tip of the corner portion 18. It is. The second flow 52 is a flow on the first region 12 toward the tip of the corner portion 18.

In the present embodiment, the light transmitting layer precursor 38 is provided in the shape shown in FIG. As a result, before the first flow 50 of the light-transmitting layer precursor 38 merges in two directions near the tip of the corner 18, the second flow 52 of the light-transmitting layer precursor 38 becomes It reaches the tip of 18.

More specifically, as shown in FIG.
A second portion 42 of the light transmitting layer precursor 38 was provided near the corner 18 of the second. As a result, the second flow 52 reaches the corner 18 before the first flow 50, and the light-transmitting layer precursor 38 does not surround the space at the corner 18, so that bubbles are generated in the corner 18. Can be prevented.

Further, as shown in FIG. 4, since the third portion 43 of the light transmitting layer precursor 38 is provided, the light transmitting layer precursor 38 that advances in the direction of the four sides of the first region 12 is formed. The amount can be refilled. As a result, the light-transmitting layer precursor 38 can be uniformly spread, and the thickness of the light-transmitting layer 40 can be made uniform.

Through the above steps, a layer made of the light transmitting layer precursor 38 is formed between the master 10 and the substrate 48 as shown in FIG. Then, a solidification process corresponding to the light transmitting layer precursor 38 is performed. For example, when a photo-curable resin is used, light is irradiated under predetermined conditions. Thus, the light transmitting layer precursor 38 is solidified, and the light transmitting layer 40 can be formed as shown in FIG. 4B.

The light transmitting layer 40 is made of a photocurable substance.
Is formed, at least one of the substrate 48 and the master 10 needs to have light transmittance. Alternatively, when a plasticized resin heated to a temperature equal to or higher than the softening point is used as the light transmitting layer precursor 38, it can be solidified by cooling.

(Third Step) Next, as shown in FIG. 4C, the master 10 is separated from the light transmitting layer 40 and the substrate 48. The light transmitting layer 40 has a plurality of lenses 54 corresponding to the curved surface portion 16 of the master 10, and thus becomes a microlens array. The light-transmitting layer 40 includes the master 10
Are divided into a plurality of regions by the flat surface 56 corresponding to the section screen 20 of the
A plurality of chips can be obtained by cutting along. That is, the microlens array composed of the entire light transmitting layer 40 is obtained by integrating a plurality of chip-shaped microlens arrays. Alternatively, the entire light transmitting layer 40 may be used as a finished product as it is. In that case,
It is preferable that the master 10 on which the section screen 20 is not formed is used and the flat surface 56 for partitioning is not formed on the light transmitting layer 40.

If the light-transmitting layer 40 alone can satisfy the characteristics such as mechanical strength required for a microlens array, the substrate 48 is not required.
The substrate 48 may be separated from the light transmitting layer 40. This peeling step may be before or after peeling the light-transmitting layer 40 from the master 10.

(Display Device) FIG. 6 is a view showing a part of a liquid crystal projector as an example of a display device to which the microlens array according to the present invention is applied. This liquid crystal projector is a microlens array manufactured by the above-described method (even a microlens array formed of the entire light transmitting layer 40 or a chip-shaped microlens array cut from the light transmitting layer 40). (Which may be present) and a lamp 70 as a light source. The light transmitting layer 40 is a microlens array, and a substrate 48 is provided on the light transmitting layer 40 as a reinforcing plate. In this case, the light transmitting layer 40 and the substrate 48 may be integrally referred to as a microlens array.

The micro lens array is arranged so that the surface of the lens 54 is concave when viewed from the lamp 70. Then, a second light transmitting layer 62 is formed on the lens 54, and a black matrix 64 is formed on the light transmitting layer 62.
Is provided. Further, a transparent common electrode 66 and an alignment film 68 are stacked on the black matrix 64.

The light valve 60 is provided with a TFT substrate 61 with a gap from the alignment film 68. T
On the FT substrate 61, a transparent individual electrode 63 and a thin film transistor 65 are provided.
Are formed. Further, the TFT substrate 61 includes the alignment film 6.
7 is arranged to face the alignment film 68.

A liquid crystal 69 is sealed between the alignment films 67 and 68, and the liquid crystal 69 is driven by a voltage controlled by the thin film transistor 65.

According to this liquid crystal projector, the lamp 7
Since the light 72 irradiated from 0 is condensed by the lens 54 for each pixel, a bright screen can be displayed.

As a premise, it is necessary that the light refractive index na of the second light transmitting layer 62 and the light refractive index nb of the light transmitting layer 40 have a relationship of na <nb. By satisfying this condition, light enters from a medium having a large refractive index to a medium having a small refractive index, and the light 72 is refracted and collected away from the normal to the interface between the two media. Then, the screen can be brightened.

(Second Embodiment) FIG. 7 is a view for explaining a method of manufacturing a microlens array according to a second embodiment of the present invention. A first region 82 and a second region 84 are formed on a master 80 used in the present embodiment. The first area 82 and the second area 84 include the first
1st area | region 12 and 2nd area | region 14 demonstrated in 1st Embodiment
The above applies. Further, the first area 82 includes a ward screen 9
0 (first and second belt-like surfaces 94 and 96) are formed, and are divided into a plurality of individual areas 98 by the section screen 90. The ward screen 90 (the first and second belt-like surfaces 24 and 26) and the individual area 98 include the ward screen 20 (the first and second belt-like surfaces 24 and 26) and the individual area 98 described in the first embodiment. The contents of the area 22 correspond. The master 80 shown in FIG. 7 has a rectangular shape.

In the present embodiment, the individual area 98 is provided off the center of the master 80. In this case, Master 8
The first portion 91 of the light-transmitting layer precursor is provided in at least one (one or more) individual regions 98 closest to the center of zero. In the example shown in FIG. 7, a first portion 91 is provided in each of a plurality of individual regions 98 located at the center (region near the center) of the master 80. The first portions 91 provided in the plurality of individual regions 98 may be discontinuous and independent, or may be continuous.

The master 80 is provided with a second portion 92 of the light transmitting layer precursor near the corner 88 of the first area 82. The master 80 is provided with a third portion 93 of the light-transmitting layer precursor at a position other than a position where the first and second portions 91 and 92 are provided. These points apply to the contents described in the first embodiment. Further, the contents described in the first embodiment may be applied to the ratio of the amounts of the first, second, and third portions 91, 92, and 93.

In the present embodiment, the third portions 93 of the light transmitting layer precursor are provided at different positions in different amounts. For example, a third portion 93 provided in the individual region 98 near the individual region 98 where the first portion 91 is provided, and a third portion provided in the individual region 98 near the individual region 98 where the second portion 92 is provided. The portion 93 differs in quantity. First
When the amount of the second portion 92 is smaller than the amount of the portion 91, the amount of the second portion 92 is smaller than the amount of the third portion 93 provided in the individual region 98 near the individual region 98 where the first portion 91 is provided. The amount of the third portion 93 provided in the individual region 98 close to the individual region 98 in which the portion 92 is provided may be reduced.

Except for the contents described above, the contents described in the first embodiment may be applied to the present embodiment. Also in the present embodiment, the corner portion 88 of the first region 82
The second portion 92 of the light-transmitting layer precursor is provided in the vicinity of, so that bubbles can be prevented from being formed in the vicinity of the corner portion 88.

(Third Embodiment) FIGS. 8A to 9
(C) is a figure explaining the manufacturing method of the master concerning a 3rd embodiment to which the present invention is applied.

In the first embodiment, the concave curved surface portion 16
The method for manufacturing the master 10 having the above has been described. In the present embodiment, a method for manufacturing a master 100 having a plurality of convex curved portions 102 shown in FIG. 9C will be described.

First, as shown in FIG.
4 is formed thereon. This step and the materials of the base material 104 and the resist layer 106 are described in the first section.
This is the same as the embodiment.

Next, as shown in FIG.
08 is placed on the resist layer 106, and only predetermined regions of the resist layer 106 are exposed to the radiation 34 via the mask 108. The mask 108 has a pattern formed so that the radiation 34 is not transmitted in a region required for forming the curved surface portion 102 shown in FIG. 9C.

When development processing is performed under predetermined conditions after exposing the resist layer 106 with the radiation 34, FIG.
As shown in (C), only in the exposed area 110 of the radiation 34, the resist layer 106 is selectively removed to expose the surface of the base material 104, and in the other areas, the resist layer 1 is exposed.
06 remains covered.

When the resist layer 106 is thus patterned, the resist layer 106 is heated in a reflow step. When the resist layer 106 is melted by heat, the surface of the resist layer 106 has a curved shape due to surface tension as shown in FIG. 8D.

Subsequently, as shown in FIG. 8D, using the resist layer 106 as a mask, the base material 104 is etched by a predetermined depth using an etchant 112. Specifically, dry etching such as anisotropic etching, for example, reactive ion etching (RIE) is performed.

FIGS. 9A to 9C are views showing the process of etching the substrate. The base material 104 is partially covered with a resist layer 106 having a curved shape. The base material 104 is first etched in a region not covered by the resist layer 106. Then, the resist layer 106 is etched by the etchant 112, and gradually decreases from a region indicated by a two-dot chain line to a region indicated by a solid line as shown in FIGS. 9A and 9B. Here, since the resist layer 106 has a curved shape, when the resist layer 106 having this shape gradually decreases, the base material 104 is gradually exposed, and the exposed region is continuously and gradually etched. To go. Thus,
Since the base material 104 is continuously and gradually etched, the surface shape of the base material 104 after the etching becomes a curved surface. Finally, as shown in FIG. 9C, a convex curved surface portion 102 is formed on the base material 104, and the master 100 is obtained.

By using the master 100, a light-transmitting layer having a concave curved surface can be formed, contrary to the light-transmitting layer 40 of the first embodiment.

FIG. 10 is a diagram showing a part of a liquid crystal projector as an example of a display device incorporating a microlens array manufactured by using the master 100 described above. In this liquid crystal projector, the lens 124 formed on the light transmitting layer 120 is a concave lens. Further, the second light transmitting layer 6
It is necessary that the light refractive index na of No. 2 and the light refractive index nc of the light transmitting layer 120 have a relationship of na> nc. By satisfying this condition, light enters from a medium having a small refractive index to a medium having a large refractive index, and the light 72 is refracted and condensed so as to approach the normal to the interface between the two media. And
The screen can be brightened.

[Brief description of the drawings]

FIG. 1 is a diagram showing a master used for manufacturing a microlens array according to a first embodiment of the present invention.

FIGS. 2A to 2E are diagrams illustrating a method of manufacturing a master used in the first embodiment.

FIG. 3 is a diagram illustrating the method of manufacturing the microlens array according to the first embodiment.

FIGS. 4A to 4C are diagrams illustrating a method for manufacturing a microlens array according to the first embodiment.

FIG. 5 is a diagram illustrating the method of manufacturing the microlens array according to the first embodiment.

FIG. 6 is a diagram illustrating a display device incorporating the microlens array according to the first embodiment.

FIG. 7 is a diagram illustrating a method for manufacturing a microlens array according to a second embodiment of the present invention.

FIGS. 8A to 8E are diagrams illustrating a method of manufacturing a master used in a third embodiment to which the present invention is applied.

FIGS. 9A to 9C are diagrams illustrating a method of manufacturing a master used in the third embodiment.

FIG. 10 is a diagram illustrating a display device incorporating a microlens array according to a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Master disk 12 1st area 14 2nd area 16 Curved surface part 18 Corner part 20 Section screen 22 Individual area 24 1st band surface 26 2nd band surface 38 Light transmissive layer precursor 40 Light transmissive layer 41 Light transmissivity First part of layer precursor 42 Second part of light-transmitting layer precursor 43 Third part of light-transmitting layer precursor 48 Substrate 54 Lens 80 Master 82 First area 84 Second area 88 Corner 90 Section screen 91 First portion of light-transmitting layer precursor 92 Second portion of light-transmitting layer precursor 93 Third portion of light-transmitting layer precursor 98 Individual region 100 Master 102 Curved portion 120 Light-transmitting Layer 124 lens

Claims (15)

[Claims] 1. A first region having a plurality of curved surface portions corresponding to a lens and having a corner portion, and a second region formed of a flat surface adjacent to the corner portion of the first region. A first step of preparing a master having the following, and providing a light-transmitting layer precursor in the first region of the master; and a second step of spreading the light-transmitting layer precursor on the master.
And a step of: providing a first portion of the light-transmitting layer precursor at the center of the first region in the first step, and providing the light-transmitting layer near the corner in the first region. A method for manufacturing a microlens array comprising providing a second portion of a layer precursor. 2. The method of manufacturing a microlens array according to claim 1, wherein the second portion of the light transmitting layer precursor is provided in a smaller amount than the first portion. . 3. The method of manufacturing a microlens array according to claim 1, wherein the light-transmitting layer precursor is located at a position of the first region excluding the vicinity of the center and the corner. 3. A method for manufacturing a microlens array provided with a third part. 4. The method of manufacturing a microlens array according to claim 3, wherein the third portion of the light transmitting layer precursor is provided in a smaller amount than the first portion. . 5. The method of manufacturing a microlens array according to claim 4, wherein the second portion of the light transmitting layer precursor is provided in a smaller amount than the third portion. A method for manufacturing a microlens array. 6. The method for manufacturing a microlens array according to claim 1, wherein a portion other than the first portion of the light transmitting layer precursor is formed by:
A method for manufacturing a microlens array provided in an amount of about 30% or more and 90% or less of the first portion. 7. The method for manufacturing a microlens array according to claim 1, wherein the first region is divided into a plurality of individual regions by a division screen formed by a flat surface. A method for manufacturing a microlens array. 8. The method for manufacturing a microlens array according to claim 7, wherein the first portion of the light-transmitting layer precursor is provided on at least one of the individual regions located at the center of the first region. A method for manufacturing a micro lens array to be provided. 9. The method of manufacturing a microlens array according to claim 7, wherein the second portion of the light transmitting layer precursor includes a portion forming a corner of the first region. A method for manufacturing a microlens array provided in any one of the individual regions. 10. The method for manufacturing a microlens array according to claim 1, wherein the light transmitting layer precursor is solidified to form a light transmitting layer.
A method for manufacturing a microlens array, further comprising a third step of separating the master from the light transmitting layer. 11. The method of manufacturing a microlens array according to claim 1, wherein in the second step, a substrate and the master are brought into close contact with each other via the light transmitting layer precursor. The manufacturing method of the microlens array performed by doing. 12. The method of manufacturing a microlens array according to claim 11, wherein the substrate has a light transmitting property, and the substrate is left as a reinforcing plate of the light transmitting layer. 13. The method of manufacturing a microlens array according to claim 11, wherein the substrate is separated from the light transmitting layer after the second step. 14. A microlens array manufactured by the method according to claim 1. 15. A display device comprising the microlens array according to claim 14.