JP2010181791A - Microlens substrate, method for producing the same and liquid crystal panel - Google Patents

Abstract

To provide a microlens substrate having high light transmittance and capable of being manufactured by a simple process, a manufacturing method thereof, and a liquid crystal panel.
A microlens substrate includes a lens forming substrate 11 for forming a microlens, a resin layer 12 laminated on a surface of the lens forming substrate 11 on which a microlens is formed, and the resin layer 12. And a barrier layer formed on the surface. A plurality of convex portions 121 are formed on the surface of the resin layer 12 to form a fine irregular shape. The convex part 121 is formed in a shape in which the cross-sectional area when it is cut along a plane parallel to the surface direction of the microlens substrate gradually changes. The distance D between the tip portions 122 of the adjacent convex portions 121 is not less than 100 nm and not more than 300 nm.
[Selection] Figure 2

Description

  The present invention relates to a microlens substrate, a manufacturing method thereof, and a liquid crystal panel.

Conventionally, a microlens substrate having a plurality of minute microlenses is known. This microlens substrate is used in a liquid crystal panel constituting a projection display device that projects an image on a screen.
A liquid crystal panel includes, for example, a thin film transistor (TFT) for controlling each pixel and a liquid crystal driving substrate (TFT substrate) having pixel electrodes, and a counter substrate for a liquid crystal panel provided with a black matrix, a common electrode, and the like. It is the structure joined via.

In the liquid crystal panel having such a configuration, in order to increase the light transmittance, a plurality of minute microlenses are provided on the counter substrate for the liquid crystal panel at positions corresponding to the respective pixels (for example, Patent Document 1). .
The microlens substrate described in Patent Document 1 includes a microlens forming layer provided on a transparent substrate, a resin layer, and a barrier layer. Further, a black matrix and a transparent conductive film are formed on the barrier layer of the microlens substrate to form a counter substrate for a liquid crystal panel.

JP 2001-51104 A

  However, as described in Patent Document 1, when the counter substrate for a liquid crystal panel has a configuration of a microlens forming layer, a resin layer, a barrier layer, a black matrix, and a transparent conductive film, the refractive index of the resin layer and the refractive index of the barrier layer If there is a large difference in the rate, reflection occurs at the interface between the resin layer and the barrier layer, which may reduce the light transmittance. Even if the refractive index of the barrier layer is set to the same refractive index as that of the resin layer, there is a large difference between the refractive index of the barrier layer and the refractive index of the transparent conductive film, so that incident light is reflected at these interfaces. There is a fear. Furthermore, even if there is no barrier layer, if there is a difference between the refractive index of the resin layer and the refractive index of the transparent conductive film, reflection may occur at the interface between the resin layer and the transparent conductive film.

  An object of the present invention is to provide a microlens substrate that has a high light transmittance and can be manufactured by a simple process, a manufacturing method thereof, and a liquid crystal panel.

  The microlens substrate of the present invention includes a lens-forming substrate having a plurality of microlenses, an antireflection-forming layer laminated on the lens-forming substrate, a layer adjacent to the antireflection-forming layer, and the reflection And an adjacent layer having a large refractive index difference from the anti-reflection layer, wherein the anti-reflection layer has an anti-reflection function.

The microlens substrate includes a lens forming substrate, an antireflection forming layer, and an adjacent layer, and the antireflection forming layer and the adjacent layer are laminated adjacently. Since there is a large difference between the refractive index of the antireflection forming layer and the refractive index of the adjacent layer, the light incident at the interface between the antireflection forming layer and the adjacent layer is easily reflected.
According to this invention, since the antireflection forming layer has an antireflection function, reflection of incident light can be suppressed. Therefore, a microlens substrate with high light transmittance can be provided.
Here, the antireflection forming layer and the adjacent layer correspond to two adjacent layers having a large refractive index difference among the layers laminated on the lens forming substrate. One of these two layers is an antireflection forming layer and has an antireflection function at the interface.

  In addition, the microlens substrate generally includes a substrate in which a resin layer and a barrier layer are laminated on a substrate having a plurality of microlenses. In this case, the resin layer and the barrier layer are formed in the antireflection formation of the present invention. Applicable to layers and adjacent layers. Further, when this microlens substrate is used as a counter substrate used in a liquid crystal panel, it may be referred to as a microlens substrate including a substrate in which a transparent conductive film as a common electrode is laminated. Therefore, when the refractive index difference between the transparent conductive film laminated on the barrier layer of the microlens substrate and the barrier layer is large, one of them becomes an antireflection forming layer and the other becomes an adjacent layer.

  In the microlens substrate of the present invention, the antireflection forming layer is formed so that a cross-sectional area when the antireflection forming layer is cut on a surface parallel to the surface direction of the microlens substrate is gradually changed on the surface in contact with the adjacent layer. It is preferable to have a plurality of fine protrusions formed.

  In the present invention, a plurality of fine protrusions are formed on the surface of the antireflection forming layer on the side in contact with the adjacent layer. The shape of the convex portion is a shape in which the cross-sectional area when it is cut along a plane parallel to the surface direction of the microlens substrate gradually changes. Further, the size of the convex portion is fine, for example, such that the distance between the tip portions of adjacent convex portions is 100 nm to 300 nm and the height is 50 nm to 500 nm. Due to such a shape of the convex portion, the refractive index gradually changes at the interface of the antireflection forming layer. Therefore, the interface between the antireflection forming layer and the adjacent layer becomes unclear, and reflection of incident light at the interface between the antireflection forming layer and the adjacent layer can be suppressed.

In the microlens substrate of the present invention, it is preferable that a refractive index of the antireflection forming layer is 1.3 or more and 1.7 or less, and a refractive index of the adjacent layer is 1.7 or more and 2.5 or less. .
The refractive index of the antireflection forming layer and the adjacent layer is within the range of 1.3 to 1.7 and the refractive index of the adjacent layer is within the range of 1.7 to 2.5. Designed to increase the difference.
According to the present invention, it is possible to suppress reflection occurring at the interface between the antireflection forming layer having the refractive index in the above range and the adjacent layer.

  The manufacturing method of the microlens substrate of the present invention includes a coating process for applying a resin to a lens forming substrate having a plurality of microlenses, and a pressing member having a concavo-convex shape on the surface to press the surface of the resin. A pressing step of forming an antireflection forming layer having a convex portion and an adjacent layer laminating step of laminating an adjacent layer on the antireflection forming layer after forming the antireflection forming layer. .

  The present invention is a method of manufacturing a microlens substrate by laminating an antireflection forming layer and an adjacent layer on a lens forming substrate. A resin is applied to the lens forming substrate, and the antireflection forming layer is formed by pressing the resin with a pressing member. A fine uneven shape is formed on the surface of the pressing member used here, and the uneven shape is transferred to the resin by pressing the resin with the pressing member. And an adjacent layer is laminated | stacked on the reflection preventing formation layer in which the fine uneven | corrugated shape was formed. Thus, since the uneven | corrugated shape is formed in the press member, a fine convex part can be easily formed in the surface of an antireflection formation layer with the manufacturing method which is not different from the conventional manufacturing method.

  The liquid crystal panel of the present invention is a liquid crystal panel provided with a microlens substrate for a counter substrate, and is laminated on the lens forming substrate having a plurality of microlenses, and has an antireflection function. An antireflection forming layer, and an adjacent layer laminated adjacent to the antireflection forming layer and having a large refractive index difference from the antireflection forming layer are provided.

  The present invention relates to a liquid crystal panel including a lens forming substrate, an antireflection forming layer, and an adjacent layer. Since there is a large difference between the refractive index of the antireflection forming layer and the refractive index of the adjacent layer, light incident on the interface between the antireflection forming layer and the adjacent layer is easily reflected, but the antireflection forming layer has an antireflection function. Therefore, reflection of incident light can be suppressed. Therefore, a liquid crystal panel with high light transmittance can be provided.

The typical sectional view showing the counter substrate for liquid crystal panels provided with the micro lens substrate concerning the embodiment of the present invention. The expanded sectional view which shows the interface of the resin layer in FIG. 1, and a barrier layer. It is a perspective view which shows the shape of the convex part of the resin layer in the said embodiment, (A) is a cone type, (B) is a pyramid type, (C) is a shell type, (D) shows a pillar type. Explanatory drawing which shows the manufacturing method of the micro lens board | substrate in the said embodiment. Explanatory drawing which shows the manufacturing method of the micro lens board | substrate in the said embodiment. Sectional drawing which shows the liquid crystal panel provided with the micro lens board | substrate in the said embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a microlens substrate and a counter substrate for a liquid crystal panel including the microlens substrate will be described.
[Configuration of microlens substrate and counter substrate for liquid crystal panel]
FIG. 1 shows a counter substrate 100 for a liquid crystal panel. The counter substrate for liquid crystal panel 100 includes a microlens substrate 10, a black matrix 20, and a transparent conductive film 30.

The microlens substrate 10 includes a lens forming substrate 11 for forming a microlens, a resin layer 12 laminated on a surface of the lens forming substrate 11 on which the microlens is formed, and a surface of the resin layer 12. And a formed barrier layer 13. In this embodiment, the resin layer 12 is the antireflection forming layer of the present invention, and the barrier layer 13 is the adjacent layer of the present invention.
The lens forming substrate 11 has a plurality of curved concave microlenses 111 formed on the surface thereof.
The microlens 111 preferably has a diameter of 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less when viewed in plan. If the diameter of the microlens 111 is within the above range, the resolution of the image projected by the liquid crystal panel including the microlens substrate 10 can be made sufficiently excellent. Further, as will be described later, when the resin layer 12 is laminated on the lens forming substrate 11, the inside of the microlens 111 formed in a curved concave shape can be filled with a resin without any gap. The adhesiveness with the resin layer 12 can be made excellent.

The average radius of curvature of the microlens 111 is preferably 2.5 μm or more and 50 μm or less, and more preferably 5 μm or more and 25 μm or less. By setting the average radius of curvature within the above range, excellent optical characteristics can be exhibited.
Further, the depth of the microlens 111 is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. When the depth of the microlens 111 is within the above range, the optical characteristics of the microlens substrate 10 can be made particularly excellent. Further, the adhesion between the lens forming substrate 11 and the resin layer 12 can be made excellent.

  The lens forming substrate 11 is made of quartz glass, and the refractive index of light with a wavelength of 550 nm in this quartz glass is 1.46. The refractive index of the lens forming substrate 11 is preferably 1.40 to 1.55, more preferably 1.46 to 1.50. When the refractive index is 1.40 or more and 1.55 or less, excellent optical characteristics can be exhibited.

  The material used as the lens forming substrate 11 is not limited to quartz glass, and may be made of a glass material that satisfies the refractive index. Examples of such a glass material include soda glass, crystalline glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass. Quartz glass has high mechanical strength and heat resistance, and has a very low coefficient of linear expansion, so there is little change in shape due to heat. Further, since it has a high transmittance in the short wavelength region and hardly deteriorates due to light energy, it is suitable as the lens forming substrate 11.

  The resin layer 12 is laminated on the surface of the lens forming substrate 11 on the side where the microlenses 111 are formed. As shown in FIG. 2, a plurality of convex portions 121 are formed on the surface of the resin layer 12 to form a fine uneven shape. The convex portion 121 is formed in a shape in which the cross-sectional area gradually changes when cut along a plane parallel to the surface direction of the microlens substrate 10, in this embodiment, a conical shape (see FIG. 3A). Other shapes include a pyramid shape (see FIG. 3B), a shell type (see FIG. 3C), a pillar type (see FIG. 3D), and the like.

  The plurality of convex portions 121 are preferably arranged regularly, and the distance D between the tip portions 122 of the adjacent convex portions 121 among the plurality of convex portions 121 is shorter than the wavelength of incident visible light. More preferably, it is 100 nm or more and 300 nm or less. When the distance D is not within the above range, incident light may interfere and a phenomenon such as reflection may occur. In addition, the convex part 121 should just be formed in the cone shape as a whole, and the front-end | tip part 122 of the convex part 121 may be a curved surface shape or planar shape.

Moreover, it is preferable that the height H of the convex part 121 is 50 nm or more and 500 nm or less. If the height H of the convex portion 121 is less than 50 nm or exceeds 500 nm, it is difficult to form the convex portion 121 and the antireflection property may not be sufficiently obtained.
As described above, in this embodiment, the distance D in the plurality of convex portions 121 is 200 nm, and the height H is 300 nm.
In order to form such a convex part 121 on the surface of the resin layer 12, when forming the resin layer 12, generally used nanoimprinting method, 2P method, and embossing method can be applied.

  As the resin layer 12 has a refractive index difference from the lens forming substrate 11, the movement of light at the interface of the microlens increases, and the degree of freedom in designing the lens increases. Therefore, a resin having a high refractive index is used. For example, a resin having a refractive index of 1.55 is used. The refractive index of light having a wavelength of 550 nm in the resin layer 12 is preferably 1.30 to 1.70, more preferably 1.50 to 1.70, and more preferably 1.55 to 1.70. More preferably, it is 70 or less. When the refractive index of the resin layer 12 is within the above range, excellent optical characteristics can be exhibited.

  Examples of the material constituting the resin layer 12 include an ultraviolet curable resin such as an epoxy resin, an acrylic resin, a phenol resin, a urethane resin, a polyimide resin, and a silicone resin, a thermosetting resin, and a photocuring agent. Resin, polyethylene, polypropylene, polyolefin such as ethylene-vinyl acetate copolymer, modified polyolefin, polyamide (example: nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12) , Nylon 6-66), thermoplastic polyimide, aromatic polyester, and other liquid crystal polymers, polyphenylene oxide, polyphenylene sulfide, polycarbonate, polymethyl methacrylate, polyether, polyether ether ketone, polyether imide, polyester Various thermoplastic elastomers such as thermoplastic resins such as acetal, styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluororubber, chlorinated polyethylene, etc. , Copolymers mainly containing these, blends, polymer alloys, and the like.

  Moreover, as a constituent material of the resin layer 12, for example, an organic-inorganic composite material in which an organic component and an inorganic component are bonded by a covalent bond can be used. The organic-inorganic composite material has a high hardness itself, and is excellent in optical characteristics (light transmittance, etc.) and heat resistance. In addition, since the organic-inorganic composite material has particularly high affinity with the constituent material of the barrier layer 13, the adhesion between the resin layer 12 and the barrier layer 13 can be made particularly excellent. Furthermore, since the organic-inorganic composite material has a chemical structure similar to that of the glass material in its molecule, the affinity between the organic-inorganic composite material and the glass material is high. Therefore, the adhesiveness between the resin layer 12 and the lens forming substrate 11 can be made excellent. From the above, the durability and reliability of the microlens substrate 10 can be made particularly excellent.

  Although the organic component which comprises an organic-inorganic composite material is not specifically limited, What has thermosetting property from the point which is excellent in light resistance is preferable. For example, epoxy resin (epoxy component), acrylic resin (acrylic component), phenolic resin (phenolic component), urethane resin (urethane component), polyimide resin (polyimide component), etc. Among these, epoxy resins (epoxy components) and acrylic resins (acrylic components) are preferable. According to this, the handling of the organic-inorganic composite material at the time of manufacturing the microlens substrate 10 is particularly excellent, and it is possible to more reliably prevent the generation of a gap between the microlens 111 and the resin layer 12. be able to. Thereby, the adhesion between the lens forming substrate 11 and the resin layer 12 can be made particularly excellent. In the curing process, it is very easy to form a fine uneven surface in any shape, particularly in this embodiment. Moreover, when the organic component which comprises an organic-inorganic composite material is acrylic resin (acrylic component), the light transmittance can be made especially high.

  Examples of the inorganic component constituting the organic-inorganic composite material include organopolysiloxane and silica. Among them, silica is preferable from the viewpoint of excellent durability (heat resistance, light resistance, etc.) of the resin layer 12. . Thereby, especially the adhesiveness with the lens formation board | substrate 11 comprised with the glass material can be made excellent.

  Furthermore, the material which comprises the resin layer 12 may contain structural components other than the above. For example, by including a metal oxide such as titanium oxide, zirconium oxide, and aluminum oxide, the refractive index of the resin layer 12 can be made higher, and the optical characteristics of the microlens substrate 10 are made more excellent. be able to.

The barrier layer 13 is a silicon nitride (SiN) film laminated on the surface of the resin layer 12 and has a refractive index of 2.0. The barrier layer 13 prevents the components in the resin layer 12 from eluting. Further, when the microlens substrate 10 is used for a liquid crystal panel, the components in the liquid crystal layer of the liquid crystal panel are prevented from moving into the resin layer 12.
The refractive index of the barrier layer 13 is preferably 1.7 or more and 2.5 or less. When the refractive index of the barrier layer 13 is within the above range, excellent optical characteristics can be exhibited.
The material used for the barrier layer 13 is not limited to SiN, and other inorganic compound materials can be used as long as the refractive index is within the above range. For example, nitride-based inorganic compounds such as AlN, TiN, and BN are suitable as the barrier layer 13 because they have excellent barrier properties, high adhesion to the resin, and high adhesion to the metal film constituting the black matrix 20. It is.

  The black matrix 20 is a layer having a light shielding function, and is provided so as to correspond to the position of the microlens 111 described above. Specifically, the black matrix 20 is arranged so that the optical axis of the micro lens 111 passes through the opening 21. That is, in the counter substrate 100 for the liquid crystal panel, incident light incident from the surface facing the black matrix 20 is collected by the microlens 111 and passes through the opening 21.

Such a black matrix 20 is composed of, for example, a metal film such as Cr, Al, Al alloy, Ni, Zn, or Ti, a resin layer in which carbon, titanium, or the like is dispersed. The black matrix 20 composed of these materials is excellent in adhesion with the microlens substrate 10. The black matrix 20 is preferably composed of a Cr film or an Al alloy film among these materials. When a Cr film is used as the black matrix 20, the light shielding property can be improved.
The thickness of the black matrix 20 is preferably 0.1 μm or more and 1.0 μm or less, and more preferably 0.1 μm or more and 0.5 μm or less. When the thickness of the black matrix 20 is within the above range, the flatness of the counter substrate 100 for a liquid crystal panel can be made sufficiently high, and the light shielding property is excellent.

The transparent conductive film 30 is a transparent electrode and is laminated so as to cover the black matrix 20. As the transparent conductive film 30, indium tin oxide (ITO) is used, and its refractive index is 2.0. The material used for the transparent conductive film 30 is not limited to ITO, and for example, indium oxide (IO), tin oxide (SnO ₂ ), or the like may be used.
Moreover, the thickness of the transparent conductive film 30 is not particularly limited, but is preferably 0.1 μm or more and 1 μm or less, and more preferably 0.1 μm or more and 0.5 μm or less. By setting the thickness of the transparent conductive film 30 within the above range, it functions suitably as an electrode.

[Microlens substrate manufacturing method]
Next, a method for manufacturing the microlens substrate 10 will be described.
[1. Production of lens forming substrate 11]
First, an example of a manufacturing method of the lens forming substrate 11 constituting the microlens substrate 10 of the present invention will be described.
A glass substrate made of flat quartz glass having a uniform thickness is prepared, and a mask forming film is formed on the surface of the glass substrate. The mask forming film can form an initial hole described later and preferably has resistance to etching. For example, a metal such as Cr, Au, Ni, Ti, Pt, or two or more selected from these metals Alloys containing the above, oxides of the metals (metal oxides), silicon, resins, and the like. Further, the mask forming film 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 forming film is not particularly limited, but can be suitably formed by, for example, a vapor deposition method, a sputtering method, a CVD method, or the like.

  Next, an initial hole for etching is formed in the mask formation film by laser light irradiation. Thereby, a mask having a predetermined opening pattern is obtained. When the initial holes are formed by laser light irradiation, the size of the formed initial holes, the interval between adjacent initial holes, and the like can be controlled easily and accurately. Thereby, initial holes are formed without deviation over the entire surface of the mask.

Next, the glass substrate is etched using this mask to form a large number of recesses on the glass substrate. This concave portion becomes the microlens 111. The etching method is not particularly limited, and examples thereof include wet etching and dry etching.
Then, for example, etching is performed to remove the mask.
In this way, the lens forming substrate 11 having a plurality of microlenses 111 is obtained.

[2. Production of microlens substrate 10]
[2-1. Step of forming resin layer 12]
The resin layer 12 is laminated on the lens forming substrate 11 manufactured by the method described above.
As shown in FIG. 4A, a composition 122 for forming the resin layer 12 having fluidity is applied to the surface of the lens forming substrate 11 on which the microlenses 111 are formed. The viscosity of the composition 122 at room temperature (20 ° C.) is not particularly limited, but is preferably 10 mPa · s or more and 10,000 mPa · s or less. When the viscosity of the composition 122 is within the above range, the resin layer 12 having a relatively large thickness can be easily and reliably formed, and the microlens substrate 10 having excellent optical characteristics and reliability can be obtained. It can be manufactured easily and reliably. Further, it is possible to effectively prevent bubbles and the like from entering between the lens forming substrate 11 and the resin layer 12, and the adhesion between the lens forming substrate 11 and the resin layer 12 is particularly excellent. It can be. Furthermore, a fine uneven shape can be easily and reliably formed on the surface of the resin layer 12.

Next, a degassing process is performed on the composition 122 on the lens forming substrate 11 (a degassing step). Thereby, it is possible to effectively prevent the atmosphere (air) from remaining between the surface of the lens forming substrate 11 and the composition 122 in the pressing step described later. Further, it is possible to more reliably prevent bubbles and the like from remaining in the resin layer 12.
The method of the deaeration treatment is not particularly limited, and examples thereof include a method of placing the lens forming substrate 11 provided with the composition 122 in a reduced pressure atmosphere. When such a method is employed, the pressure of the atmosphere in which the lens forming substrate 11 provided with the composition 122 is placed is preferably 50 Pa or less, and more preferably 5 Pa or less.

Next, as shown in FIG. 4B, the composition 122 on the lens forming substrate 11 is pressed with a pressing member 80 (pressing step).
The pressing member 80 is made of quartz, and has a minute uneven shape formed on the surface on the side pressing the composition 122. In this embodiment, in order to form the above-mentioned convex part 121, it is a member in which many conical concave parts similar to the convex part 121 are formed on the surface of the pressing member 80.

  There is no particular limitation on the method for forming the concave-convex shape in quartz as the pressing member 80. For example, a method of applying a resist that reacts to an electron beam on the surface of a quartz substrate, drawing a concavo-convex pattern on the resist with the electron beam, and performing dry etching, a metal film such as Cr on the surface of the quartz substrate A method of etching a metal film by applying a resist on the metal film, drawing a concavo-convex pattern with an electron beam and etching the metal film using this metal film, laser or focused ion beam (FIB) , Directly processed by Focused Ion Beam), directly processed by shot blasting, fine nuclei with catalytic function are formed on the surface of the quartz substrate, and needles are formed on the nuclei by chemical vapor deposition, epitaxy or electroforming. A method of etching using a needle-like shape as a mask, applying a resist to a quartz substrate, and applying this resist An uneven pattern is formed by the speed of light interference exposure method and a method of performing dry etching.

  Further, a resin may be used as the pressing member 80. As a method for forming a concavo-convex shape on a resin, for example, a concavo-convex pattern is formed by machining using nickel-phosphorus (Ni-P), brass, copper, or the like using a single crystal diamond. A resin capable of transmitting ultraviolet light is applied to the coated surface to transfer the uneven pattern. In addition, by applying the above-described method of forming a concavo-convex shape in quartz to a resin that can transmit ultraviolet rays, a resinous pressing member having a concavo-convex pattern can be obtained.

Further, the surface of the pressing member 80 on which the concavo-convex shape is formed may be subjected to a mold release process. Thereby, the pressing member 80 can be efficiently removed from the surface of the resin layer 12 in a process described later. The mold release treatment includes, for example, the formation of a film using a fluorine-based compound solution containing metaxylene hexaforolide as a main component, the release of a silicone-based resin such as alkylpolysiloxane, and a fluorine-based resin such as polytetrafluoroethylene. Examples thereof include formation of a film composed of a material having type properties, surface treatment with a silylating agent such as hexamethyldisilazane ([(CH ₃ ) ₃ Si] ₂ NH), and surface treatment with a fluorine-based gas.

  In the present embodiment, the composition 122 is pressed in a state where the spacer 123 is disposed between the lens forming substrate 11 and the pressing member 80. Thereby, the thickness of the resin layer 12 to be formed can be controlled more reliably, and the occurrence of inconveniences such as color unevenness when using the finally obtained microlens substrate 10 can be prevented more effectively. can do.

  The spacer 123 can be disposed, for example, in a region (ineffective region) other than the effective region where the microlens 111 is provided on the lens forming substrate 11. By disposing the spacer 123 in the ineffective area of the lens forming substrate 11, for example, when the lens forming substrate 11 has a plurality of regions corresponding to one microlens substrate 10 for a liquid crystal panel ( In the case where a plurality of aggregate patterns of microlenses 111 corresponding to one microlens substrate 10 for a liquid crystal panel are arranged on the lens forming substrate 11), a flat portion which is an ineffective region is formed. Many spacers 123 can be arranged. As a result, the influence of the deflection of the lens forming substrate 11 and the pressing member 80 is effectively eliminated, and the thickness of the obtained microlens substrate 10 is more reliably controlled. can do.

Further, the following spacer 123 may be used.
The spacer 123 is made of a material having a refractive index comparable to that of the solidified product (cured product) of the composition 122. Specifically, the absolute value of the difference between the absolute refractive index of the constituent material of the spacer 123 and the absolute refractive index of the composition 122 after solidification is preferably 0.20 or less, and is 0.10 or less. Is more preferably 0.02 or less, and the spacer 123 is most preferably composed of the same material as the solidified product (cured product) of the composition 122.
According to this, even when the spacer 123 is disposed in the part of the lens forming substrate 11 where the microlens 111 is formed, the optical characteristics of the microlens substrate 10 from which the spacer 123 is obtained are adversely affected. It can be effectively prevented. As a result, a relatively large number of spacers 123 can be disposed over almost the entire effective area of the main surface of the lens forming substrate 11 (the surface side on which the microlenses 111 are formed). The influence of the deflection of the substrate 11 and the pressing member 80 can be effectively eliminated, and the thickness of the obtained microlens substrate 10 can be controlled more reliably.

  Further, when the spacer 123 is composed of the same material as the solidified product (cured product) of the composition 122, the adhesion between the solidified product (cured product) of the composition 122 and the spacer 123 is particularly excellent. The reliability and durability of the microlens substrate 10 can be made particularly excellent. If the spacer 123 is made of the same material as the solidified product (cured product) of the composition 122, the spacer 123 has a particularly high hardness, so that the thickness of the formed resin layer 12 can be further increased. It can be reliably controlled.

The shape of the spacer 123 is not particularly limited, but is preferably substantially spherical or substantially cylindrical. When the spacer 123 has such a shape, the diameter is preferably 20 μm or more and 100 μm or less, and more preferably 20 μm or more and 50 μm or less.
In the case where the spacer 123 is used as described above, the spacer 123 may be disposed between the lens forming substrate 11 and the pressing member 80 when the composition 122 is solidified. Is not particularly limited. For example, the composition 122 may be applied in a state where the spacer 123 is disposed on the lens forming substrate 11, or the spacer 123 may be applied after the composition 122 is supplied.

  Moreover, you may perform this process, performing the deaeration process as mentioned above. In other words, the pressing step and the deaeration step may be performed as the same step. Thereby, it is possible to more effectively prevent the atmosphere (air) from remaining between the surface of the lens forming substrate 11 and the composition 122.

Next, the composition 122 is solidified (cured) to form the resin layer 12.
Solidification (curing) of the composition 122 can be performed by ultraviolet irradiation, light irradiation, heating, cooling, or the like, depending on the type of resin used for the resin layer 12.
Thereafter, as shown in FIG. 4C, the resin layer 12 is formed by removing the pressing member. A large number of convex portions 121 shown in FIG. 2 are formed on the surface of the resin layer 12.

[2-2. Barrier layer forming step]
Next, the barrier layer 13 is formed on the surface of the resin layer 12.
As shown in FIG. 5A, a barrier layer 13 made of a silicon nitride (SiN) film is formed on the surface of the resin layer 12 opposite to the surface in contact with the lens forming substrate 11. The SiN film can be formed by, for example, a vapor phase film forming method such as a sputtering method, a CVD method, or a vapor deposition method, or a method in which SiN dissolved in a solvent is applied to the resin layer 12 and baked. Among these, according to the vapor phase film forming method, the barrier layer 13 having high density and high adhesion can be formed. In particular, according to the sputtering method, the thickness unevenness and variation of the barrier layer 13 can be made extremely small, and the adhesion can be made very high. Furthermore, composition adjustment and stress adjustment can be easily performed.
In the vapor deposition method, Si is sufficiently combined with N by performing in a nitrogen gas atmosphere, and thus the formed barrier layer 13 is unlikely to deteriorate with time. In this case, the N ₂ partial pressure is preferably 1% or more and 50% or less, and more preferably 5% or more and 30% or less. In addition, it is preferable that the total pressure at this time is 1 × 10 ⁻³ Torr or more and 10 × 10 ⁻³ Torr or less.
As described above, the microlens substrate 10 including the lens forming substrate 11, the resin layer 12, and the barrier layer 13 is obtained. The plurality of convex portions 121 formed on the resin layer 12 have a very small shape at the nano level, and thus the surface of the barrier layer 13 laminated on the convex portion 121 is not substantially affected and is substantially It is formed in a flat shape.

[Method of manufacturing counter substrate for liquid crystal panel]
Next, a manufacturing method of the counter substrate 100 for the liquid crystal panel using the microlens substrate 10 will be described.
[Black matrix formation process]
As shown in FIG. 5B, a black matrix 20 having openings 21 is formed on the barrier layer 13 of the microlens substrate 10. At this time, the black matrix 20 is arranged so as to correspond to the position of the microlens 111. Specifically, an opening pattern is formed such that the optical axis passing through the center of the microlens 111 passes through the opening 21.

Specifically, first, a thin film to be the black matrix 20 is formed on the barrier layer 13 by a vapor deposition method such as sputtering. Next, a resist film is formed on the thin film to be the black matrix 20. Next, the resist film is exposed so that the openings 21 of the black matrix 20 are positioned corresponding to the microlenses 111, and a pattern of the openings 21 is formed on the resist film. Next, wet etching is performed to remove only the portion of the thin film that becomes the opening 21. Next, the resist film is removed. As the stripping solution when performing wet etching, for example, when the thin film to be the black matrix 20 is made of an Al alloy or the like, a phosphoric acid-based etching solution can be used.
Note that the black matrix 20 in which the openings 21 are formed can also be preferably formed by dry etching using a chlorine-based gas or the like.

[Transparent conductive film forming step]
Next, a transparent conductive film 30 that is a common electrode is formed over the barrier layer 13 so as to cover the black matrix 20 (see FIG. 5C). The transparent conductive film 30 can be formed by, for example, a vapor deposition method such as sputtering.
As described above, the counter substrate 100 for a liquid crystal panel shown in FIG. 1 can be obtained.

[LCD panel]
Next, a liquid crystal panel (liquid crystal light shutter) using the microlens substrate 10 and the liquid crystal panel counter substrate 100 will be described with reference to FIG.
As shown in FIG. 6, a liquid crystal panel (TFT liquid crystal panel) 200 according to the present invention includes a TFT substrate (liquid crystal drive substrate) 40, a counter substrate 100 for liquid crystal panel bonded to the TFT substrate 40, a TFT substrate 40, and a liquid crystal. A liquid crystal layer 50 made of liquid crystal sealed in a gap with the counter substrate 100 for a panel.

The TFT substrate 40 is a substrate for driving the liquid crystal of the liquid crystal layer 50, and is provided in the vicinity of the glass substrate 4, a large number of pixel electrodes 5 provided on the glass substrate 4, and the pixel electrodes 5. A number of thin film transistors (TFTs) 6 corresponding to the respective pixel electrodes 5 are provided.
In this liquid crystal panel 200, the TFT substrate 40 and the liquid crystal panel counter substrate 100 are arranged so that the transparent conductive film (common electrode) 30 of the liquid crystal panel counter substrate 100 and the pixel electrode 5 of the TFT substrate 40 face each other. They are joined at a certain distance.

The glass substrate 4 is preferably made of quartz glass. Thereby, it can be set as the thing which was hard to produce curvature, a deflection | deviation, etc., and was excellent in stability.
The pixel electrode 5 drives the liquid crystal of the liquid crystal layer 50 by charging and discharging with the transparent conductive film (common electrode) 30. The pixel electrode 5 is made of, for example, the same material as that of the transparent conductive film 30 described above.

  The thin film transistor 6 is connected to the corresponding pixel electrode 5 in the vicinity. The thin film transistor 6 is connected to a control circuit (not shown) and controls a current supplied to the pixel electrode 5. Thereby, charging / discharging of the pixel electrode 5 is controlled. For example, the TFT substrate 40 may be provided with an alignment film on the inner surface side (the surface side facing the liquid crystal layer 50).

The liquid crystal layer 50 contains liquid crystal molecules (not shown), and the alignment of the liquid crystal molecules, that is, the liquid crystal changes corresponding to the charge / discharge of the pixel electrode 5.
In the liquid crystal panel 200, one micro lens 111, one opening 21 of the black matrix 20 corresponding to the optical axis Q of the micro lens 111, one pixel electrode 5, and the pixel electrode are usually provided. One thin film transistor 6 connected to 5 corresponds to one pixel.

  Incident light L incident from the lens forming substrate 11 side is condensed while passing through the microlens 111 of the lens forming substrate 11, and the resin layer 12, the barrier layer 13, the opening 21 of the black matrix 20, and transparent. The conductive film 30, the liquid crystal layer 50, the pixel electrode 5, and the glass substrate 4 are transmitted. At this time, since a polarizing plate (not shown) is usually disposed on the incident side of the lens forming substrate 11, when the incident light L passes through the liquid crystal layer 50, the incident light L is linearly polarized light. It has become. At this time, the polarization direction of the incident light L is controlled in accordance with the alignment state of the liquid crystal molecules in the liquid crystal layer 50. Therefore, the luminance of the emitted light can be controlled by transmitting the incident light L transmitted through the liquid crystal panel 200 to a polarizing plate (not shown).

The polarizing plate is composed of, for example, a base substrate and a polarizing substrate laminated on the base substrate, and the polarizing substrate is added with a polarizing element (iodine complex, dichroic dye, etc.), for example. Made of resin.
For example, the liquid crystal panel 200 is subjected to an alignment process (for example, an alignment film coating process) on the TFT substrate 40 and the liquid crystal panel counter substrate 100 manufactured by a known method, and then a sealing material (not shown). Then, the two can be joined together, and then liquid crystal can be injected into the gap from the gap hole (not shown) formed thereby, and then the hole is closed. Thereafter, a polarizing plate may be attached to the incident side or the emission side of the liquid crystal panel 200 as necessary.
In the liquid crystal panel 200, a TFT substrate is used as the liquid crystal drive substrate. However, a liquid crystal drive substrate other than the TFT substrate, such as a TFD substrate or an STN substrate, may be used as the liquid crystal drive substrate.

[Effects of this embodiment]
If it is this embodiment as mentioned above, there can exist the following effects.
The surface of the resin layer 12 formed on the lens forming substrate 11 on the microlens 111 side has a fine concavo-convex shape in which a large number of convex portions 121 are formed. The convex portion 121 has a conical shape, and the cross-sectional area when cut along a plane parallel to the surface direction of the microlens substrate 10 becomes a shape that becomes smaller toward the tip end portion 122. Since the refractive index changes according to the volume occupancy of the resin, the refractive index gradually changes at the interface between the resin layer 12 and the barrier layer 13 by having the convex portion 121 having such a shape. Yes.
Therefore, the interface between the resin layer 12 and the barrier layer 13 becomes unclear, and reflection of incident light can be suppressed. Therefore, the microlens substrate 10, the liquid crystal panel counter substrate 100, and the liquid crystal panel 200 having such a structure on the surface of the resin layer 12 have high light transmittance.

  Moreover, since the reflection at the interface between the resin layer 12 and the barrier layer 13 can be prevented by forming a large number of convex portions 121, the type of resin used for the resin layer 12 and the barrier layer 13 is Not limited. Therefore, the degree of freedom in element design can be improved. For example, the cost can be reduced by using an inexpensive resin.

Further, the pressing member 80 is formed with a large number of concave portions similar to the conical shape of the convex portion 121 described above. By pressing the resin layer 12 with the pressing member 80, a large number of convex portions are formed on the surface of the resin layer 12. The part 121 can be formed. In other words, a large number of convex portions 121 can be formed by performing the same pressing step as in the prior art, except that the surface of the pressing member 80 has an uneven shape.
Therefore, the microlens substrate 10 having a high transmittance can be manufactured by a simple process that is not different from the conventional one.

[Modification]
The present invention is not limited to the above embodiment.
For example, when manufacturing the counter substrate 100 for a liquid crystal panel, for example, the transparent conductive film 30 may be formed directly on the barrier layer 13 without forming the black matrix 20.
Further, when the barrier layer 13 is not formed on the microlens substrate 10, the black matrix 20 and the transparent conductive film 30 may be formed on the resin layer 12. In this case, the transparent conductive film 30 functions as an adjacent layer of the present invention. That is, the resin layer 12 having a large refractive index difference and the transparent conductive film 30 are laminated adjacent to each other. Similar to the above-described embodiment, by forming the plurality of convex portions 121 on the surface of the resin layer 12, reflection at the interface between the resin layer 12 and the transparent conductive film 30 can be suppressed, and the light transmittance can be reduced. A high microlens substrate can be provided.

  And when the refractive index of the resin layer 12 and the refractive index of the barrier layer 13 are equivalent, the refractive index difference of the barrier layer 13 and the transparent conductive film 30 becomes large. In this case, convex portions similar to the multiple convex portions formed on the resin layer 12 in this embodiment may be formed at the interface with the transparent conductive film 30 of the barrier layer 13. Thereby, reflection at the interface between the barrier layer 13 and the transparent conductive film 30 can be suppressed.

  The microlens substrate 10 of the present invention is widely used in various optical devices such as an optical pickup such as a laser disk and a solid-state imaging device such as a CCD, in addition to being used as a counter substrate of a liquid crystal panel. Can do.

EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated in more detail, this invention is not restrict | limited to these description content at all.
Example 1
Synthetic quartz glass (refractive index 1.46) was prepared as the lens forming substrate 11, and the microlens substrate 10 was formed by the method described in the above embodiment. Then, an ultraviolet curable epoxy resin (“Adeka Optomer”, manufactured by Adeka Co., Ltd.) (refractive index of 1.55) was applied as the resin layer 12 to the surface on which the microlens substrate 10 of synthetic quartz glass was formed. .

Next, it pressed by pressing the surface by which the uneven | corrugated shape of the press member formed with transparent quartz was formed on the surface of an ultraviolet curable epoxy resin. Here, the concavo-convex shape formed on one surface of the pressing member is a shape in which a plurality of bullet-shaped concave portions are formed.
Next, the surface of the resin layer 12 was irradiated with ultraviolet rays through the pressing member 80 to cure the resin.
Then, the pressing member 80 was detached from the resin layer 12. Thus, the distance (pitch) between the front-end | tip parts of several convex parts of the surface of the resin layer 12 formed is 200 nm, and the height of a convex part is 300 nm.
Next, a silicon nitride (refractive index 2.0) film as a barrier layer 13 was formed on the surface of the resin layer 12 using a plasma CVD method. The thickness of the silicon nitride film is 2 μm.

(Comparative Example 1)
A microlens substrate was manufactured in the same manner as in Example 1 except that the uneven shape was not formed on the surface of the resin layer 12.

(Evaluation)
The microlens substrates of Example 1 and Comparative Example 1 were irradiated with light having wavelengths of 400 nm, 600 nm, and 800 nm, and their transmittance was measured using a spectrophotometer (“UV3600”, manufactured by Shimadzu Corporation). did. The measurement results are shown in Table 1 below.

  As can be seen from Table 1, in the visible light of all wavelengths, the transmittance of the microlens substrate of Example 1 is superior to the transmittance of the microlens substrate of Comparative Example 1 in which the resin layer surface has no uneven shape. Yes. That is, even if there is a large difference between the refractive index of the resin layer 12 and the refractive index of the barrier layer 13, the light transmittance can be improved by forming a fine uneven shape on the surface of the resin layer 12. .

  DESCRIPTION OF SYMBOLS 10 ... Microlens board | substrate, 11 ... Lens formation board | substrate, 111 ... Microlens, 12 ... Resin layer, 13 ... Barrier layer, 20 ... Black matrix, 30 ... Transparent electrically conductive film, 100 ... Opposite board | substrate for liquid crystal panels.

Claims (5)

A lens forming substrate having a plurality of microlenses;
An antireflection forming layer laminated on the lens forming substrate;
A layer adjacent to the antireflection forming layer and having a large refractive index difference from the antireflection forming layer, and
The antireflection forming layer has an antireflection function. A microlens substrate, wherein: The microlens substrate according to claim 1,
The antireflection forming layer has a plurality of fine protrusions formed on a surface in contact with the adjacent layer so that a cross-sectional area when the surface is cut in a plane parallel to the surface direction of the microlens substrate is gradually changed. A microlens substrate having a portion. The microlens substrate according to claim 1 or 2,
The refractive index of the antireflection forming layer is 1.3 or more and 1.7 or less,
The refractive index of the adjacent layer is 1.7 or more and 2.5 or less. An application step of applying a resin to a lens forming substrate having a plurality of microlenses;
A pressing step of forming an antireflection forming layer having a plurality of convex portions by pressing a pressing member having an uneven shape on the surface against the surface of the resin;
An adjacent layer stacking step of stacking an adjacent layer on the antireflection formation layer after forming the antireflection formation layer. A liquid crystal panel provided with a microlens substrate for a counter substrate,
A lens forming substrate having a plurality of microlenses;
An antireflection forming layer laminated on the lens forming substrate and having an antireflection function;
A liquid crystal panel comprising: an adjacent layer that is laminated adjacent to the antireflection forming layer and has a large refractive index difference from the antireflection forming layer.

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