JP2005128351A - Manufacturing method of lens substrate with light-shielding part, lens substrate with light-shielding part, transmissive screen, and rear projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens substrate with a light shielding part provided with a light shielding part accurately, and to provide a transmissive screen and a rear projector provided with the lens substrate with a light shielding part.
A lens substrate with a light-shielding portion includes a step of forming a plurality of microlenses (concave lenses) on the surface of the substrate to obtain a microlens substrate (lens substrate), and a microlens of the microlens substrate. And a step of forming a black matrix (light-shielding portion) 4 on a plane portion 34 between adjacent microlenses 32 on the surface where 32 (concave surface 321) is formed. The black matrix 4 is suitably formed by using a composition for forming a black matrix (composition for forming a light shielding part) having a viscosity in the vicinity of room temperature of 10 to 1000 cp.
[Selection] Figure 1

Description

  The present invention relates to a method of manufacturing a lens substrate with a light shielding part, a lens substrate with a light shielding part, a transmissive screen, and a rear projector.

In recent years, the demand for rear-type projectors is increasing as a display suitable for home theater monitors, large-screen televisions, and the like.
A transmissive screen used for a rear projector generally uses a lens array (lens substrate) in which a large number of minute lenses are arranged. Such a lens array is often provided with a light shielding portion (black mask) for the purpose of improving the contrast ratio of the projected image. Such a light shielding portion is usually formed by forming a film made of a photosensitive material such as a photopolymer on a lens array, and then performing exposure and development through the lens array (for example, , See Patent Document 1).

  However, such a method has the disadvantages of being multi-step and inferior in productivity. Further, such a method usually requires alignment, and is difficult to apply to a lens array having a relatively large area as used in a rear projector. A rear projector or the like may use a combination of a plurality of lens arrays having a relatively small area. In this case, however, there is a problem that a joint of each lens array appears in a projected image. It was.

JP 2001-74818 A (page 3, left column, lines 10 to 17)

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lens substrate with a light-shielding portion having a light-shielding portion accurately provided with good productivity, and to provide a transmissive screen and a rear projector provided with the lens substrate with a light-shielding portion. .

Such an object is achieved by the present invention described below.
The method of manufacturing a lens substrate with a light-shielding part of the present invention includes a step of forming a plurality of concave lenses on the surface of the substrate to obtain a lens substrate,
Forming a light shielding portion in an ineffective lens region between adjacent concave lenses on a surface of the lens substrate on which the concave lens is formed.
Thereby, it is possible to provide a lens substrate with a light-shielding part provided with a light-shielding part with high productivity.

In the method for manufacturing a lens substrate with a light-shielding part of the present invention, it is preferable that the light-shielding part is formed in a flat part between the adjacent concave lenses.
Thereby, the viewing angle characteristic can be made particularly excellent.
In the method for producing a lens substrate with a light shielding part of the present invention, it is preferable to form the light shielding part by applying a composition for forming a light shielding part to the ineffective lens region.
Thereby, a light shielding part can be formed more easily. Thereby, the adhesion of the formed light shielding part can be made particularly excellent.

In the method for manufacturing a lens substrate with a light-shielding part of the present invention, it is preferable to form the light-shielding part by immersing the ineffective lens region in a composition for forming a light-shielding part.
Thereby, a light shielding part can be formed more easily. This also makes it possible to easily and reliably form a light-shielding portion with small variations in film thickness at each part.
In the method for manufacturing a lens substrate with a light-shielding part of the present invention, the viscosity of the light-shielding part-forming composition near room temperature is preferably 10 to 1000 cp.
Thereby, the light-shielding part having an appropriate thickness can be easily and reliably formed.

In the manufacturing method of the lens substrate with a light shielding part of the present invention, the thickness of the light shielding part is preferably 0.01 to 5 μm.
Thereby, the function as a light-shielding part can be exhibited more effectively, preventing unintentional peeling, a crack, etc. of a light-shielding part more reliably.
In the manufacturing method of the lens substrate with a light-shielding part of the present invention, it is preferable to have a step of forming a diffusion part having a function of diffusing light on the surface side of the lens substrate on which the concave lens is formed.
Thereby, the viewing angle characteristic can be made particularly excellent.

In the manufacturing method of the lens substrate with a light-shielding part of the present invention, it is preferable to have a step of forming a diffusion part having a function of diffusing light at least along the concave surface of the concave lens.
Thereby, the viewing angle characteristics can be further improved. In addition, the light utilization efficiency can be further increased, and the function of the light shielding portion can be more effectively exhibited.
In the manufacturing method of the lens substrate with a light shielding part of the present invention, it is preferable that the diffusion part is formed after the light shielding part is formed.
Thereby, the viewing angle characteristic can be made particularly excellent.

In the method for manufacturing a lens substrate with a light-shielding portion according to the present invention, the concave lens is preferably a microlens.
Thereby, the viewing angle characteristic can be made particularly excellent.
In the method for manufacturing a lens substrate with a light-shielding part of the present invention, the microlens preferably has a diameter of 10 to 500 μm.
Thereby, sufficient resolution can be obtained, for example, when the lens substrate with a light-shielding part is applied to a transmission screen while the productivity of the lens substrate with the light-shielding part is sufficiently high.

In the method for manufacturing a lens substrate with a light-shielding part according to the present invention, the concave lens preferably has a radius of curvature of 5 to 250 μm.
Thereby, the viewing angle characteristic can be made particularly excellent. In particular, the viewing angle characteristics in the horizontal direction and the vertical direction (vertical direction) can both be made excellent.
The lens substrate with a light-shielding part of the present invention is manufactured using the manufacturing method of the present invention.
As a result, it is possible to provide a lens substrate with a light shielding part in which the light shielding part is accurately provided.

The lens substrate with a light shielding part of the present invention includes a lens substrate having a plurality of concave lenses and a light shielding part provided in an ineffective lens region between adjacent concave lenses.
As a result, it is possible to provide a lens substrate with a light shielding part in which the light shielding part is accurately provided.
In the lens substrate with a light shielding portion of the present invention, it is preferable that a diffusion portion having a function of diffusing light is provided on the surface side of the lens substrate on which the concave lens is formed.
Thereby, the viewing angle characteristic can be made particularly excellent.

The lens substrate with a light-shielding part of the present invention preferably includes a diffusion part having a function of diffusing light at least along the concave surface of the concave lens.
Thereby, the viewing angle characteristics can be further improved. In addition, the light utilization efficiency can be further increased, and the function of the light shielding portion can be more effectively exhibited.
In the lens substrate with a light-shielding part of the present invention, it is preferable that a ratio of the area occupied by the light-shielding part is 1 to 70% in an effective region where the concave lens is formed when the lens substrate is viewed in plan.
Thereby, the contrast of the obtained image can be made particularly excellent while the light utilization efficiency is sufficiently high.

The transmissive screen of the present invention includes the lens substrate with a light-shielding portion of the present invention.
As a result, it is possible to provide a transmissive screen including a lens substrate with a light shielding portion in which the light shielding portion is accurately provided. In particular, it is possible to provide a transmission screen capable of obtaining an image with excellent contrast and having excellent viewing angle characteristics.

The transmissive screen of the present invention, a Fresnel lens portion in which a Fresnel lens is formed on the light emission side,
It is provided with the lens board | substrate with the light-shielding part of this invention arrange | positioned at the light emission side of the said Fresnel lens part.
As a result, it is possible to provide a transmissive screen including a lens substrate with a light shielding portion in which the light shielding portion is accurately provided. In particular, it is possible to provide a transmission screen capable of obtaining an image with excellent contrast and having excellent viewing angle characteristics.

A rear projector according to the present invention includes the transmission screen according to the present invention.
Accordingly, it is possible to provide a rear projector including a lens substrate with a light shielding part in which the light shielding part is accurately provided. In particular, it is possible to provide a rear projector that can obtain an image with excellent contrast and that has excellent viewing angle characteristics.

The rear projector according to the present invention preferably includes a projection optical unit and a light guide mirror.
Accordingly, it is possible to provide a rear projector including a lens substrate with a light shielding part in which the light shielding part is accurately provided. In particular, it is possible to provide a rear projector that can obtain an image with excellent contrast and that has excellent viewing angle characteristics.

Hereinafter, a manufacturing method of a lens substrate with a light-shielding part, a lens substrate with a light-shielding part, a transmissive screen, and a rear projector according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
First, the structure of the lens substrate with a light-shielding part and the transmission screen of the present invention will be described.

  FIG. 1 is a schematic longitudinal sectional view showing a first embodiment of a lens substrate with a light shielding portion of the present invention, FIG. 2 is a plan view of a microlens substrate provided in the lens substrate with a light shielding portion shown in FIG. These are typical longitudinal cross-sectional views which show 1st Embodiment of the transmissive screen of this invention provided with the lens substrate with a light-shielding part shown in FIG. In the following description, the left side in FIGS. 1 and 3 is referred to as “(light) incident side”, and the right side is referred to as “(light) emission side”.

The lens substrate 1A with a light-shielding part is a member constituting a transmission screen 10 described later, and as shown in FIG. 1, a microlens substrate (lens substrate) 3 having a function of condensing incident light and a light-shielding property. It has a black matrix (light-shielding portion) 4 made of a material having a diffusion portion 5 having a function of diffusing incident light by irregular reflection.
The microlens substrate 3 has a large number of microlenses 32.
The microlens substrate 3 is mainly composed of a resin material, and is composed of a transparent material having a predetermined refractive index.

Each microlens 32 is formed as a concave lens having a concave surface 321 on the emission side.
The diameter of the microlens 32 is preferably 10 to 500 μm, more preferably 30 to 300 μm, and still more preferably 50 to 100 μm. When the diameter of the microlens 32 is a value within the above range, the productivity of the lens substrate 1A with the light-shielding part (transmission type screen 10) can be further enhanced while maintaining a sufficient resolution in the image projected on the screen. it can. In the microlens substrate 3, the pitch between the adjacent microlenses 32 to the microlenses 32 is preferably 10 to 500 μm, more preferably 30 to 300 μm, and further preferably 50 to 100 μm. preferable.

  Further, the curvature radius of the microlens 32 is preferably 5 to 250 μm, more preferably 15 to 150 μm, and further preferably 25 to 50 μm. When the radius of curvature of the microlens 32 is a value within the above range, the viewing angle characteristic can be made particularly excellent. In particular, the viewing angle characteristics in the horizontal direction and the vertical direction (vertical direction) can both be made excellent.

  Further, the arrangement method of the microlenses 32 is not particularly limited, and even if the arrangement is periodic, an optically random arrangement (plan view from the main surface side of the lens substrate 1A with a light-shielding portion (microlens substrate 3)) is obtained. In this case, the microlenses 32 may be arranged in a random positional relationship with each other, but a random arrangement as shown in FIG. 2 is preferable. By arranging the microlenses 32 at random, it is possible to more effectively prevent interference with a light valve such as a liquid crystal or a Fresnel lens, and it is possible to almost completely eliminate the occurrence of moire. Thereby, the excellent transmissive screen 10 with good display quality can be obtained. In this specification, “optically random” means that the arrangement of the microlenses is irregular and disturbed to such an extent that the occurrence of optical interference such as moire is sufficiently prevented and suppressed. To do.

  In the microlens substrate 3, a plane portion 34 is provided between the adjacent microlenses 32. By having such a plane portion, for example, a microlens (concave lens) 32 having a substantially semicircular concave surface 321 can be suitably formed, and a lens substrate 1A with a light-shielding portion (transparent screen 10, rear screen). The viewing angle characteristics of the projector 300) can be made particularly excellent. In addition, when such a planar portion 34 is provided, the black matrix 4 can be easily and reliably formed on the microlens substrate 3 in a manufacturing method as described later.

Further, in the microlens substrate 3, a convex portion 35 is formed by the adjacent microlenses 32 and microlenses 32.
The black matrix 4 is formed in the ineffective lens region between the adjacent microlenses (concave lenses) 32 on the surface of the microlens substrate (lens substrate) 3 where the microlenses 32 (concave portions 321) are formed. Has been. As described above, the present invention is characterized in that the light shielding portion is provided in the ineffective lens region between the concave lenses of the lens substrate. Thereby, the light shielding part can be easily and accurately formed by a method as described later. In addition, with such a configuration, for example, a lens substrate with a light shielding part can be manufactured without going through a photolithography process or the like, and the productivity of the lens substrate with a light shielding part is particularly excellent. Can do. In the present specification, the “ineffective lens region” refers to a region that does not function effectively as a lens by forming a light shielding portion (black matrix).

In particular, in the present embodiment, the black matrix 4 is formed on the flat portion 34.
The black matrix 4 is made of a light-shielding material. By having such a black matrix 4, the black matrix 4 can absorb external light (external light that is not preferable for forming a projection image), and the image projected on the screen has excellent contrast. Can be.

  In addition, the thickness (average thickness) of the black matrix 4 is preferably 0.01 to 5 μm, more preferably 0.01 to 3 μm, and further preferably 0.03 to 1 μm. When the thickness of the black matrix 4 is within the above range, it is possible to more effectively prevent the black matrix 4 from functioning as the black matrix 4 while preventing unintentional peeling and cracking. For example, the contrast of the projected image can be made particularly excellent in the transmissive screen 10 including the lens substrate 1 </ b> A with the light shielding portion.

  Further, when the microlens substrate 3 is viewed in plan from the light incident surface side (direction shown in FIG. 2), the black matrix (light-shielding portion) 4 is formed in the effective region where the microlens (concave lens) 32 is formed. The ratio of the occupied area (projected area) is preferably 1 to 70%, and more preferably 1 to 50%. When the ratio of the area occupied by the black matrix 4 is a value within the above range, the image projected on the screen can be made excellent in contrast while the light utilization efficiency is sufficiently high.

Further, a diffusing portion 5 is formed on the exit side surface of the microlens substrate 3.
The diffusion unit 5 has a function of diffusing incident light (incident light). By having such a diffusing portion 5, the viewing angle characteristics can be made excellent. In the present embodiment, the diffusing portion 5 has a configuration in which the diffusing material 51 is dispersed in a substantially transparent material (for example, acrylic resin, polycarbonate resin, etc.) having excellent light transmittance. When the diffusing portion 5 includes the diffusing material 51, the incident light (incident light) can be effectively diffusely reflected, and as a result, the light diffusibility (the property of efficiently diffusing light) of the diffusing portion 5 is particularly improved. It can be excellent. As the diffusing material 51, for example, fine particle (bead-shaped) silica, glass, resin, or the like can be used. Although the average particle diameter of the diffusing material 51 is not particularly limited, it is preferably 1 to 50 μm, and more preferably 2 to 10 μm.

Moreover, in this embodiment, the spreading | diffusion part 5 as a flat member is provided. Thereby, 1 A of lens substrates with a light-shielding part can be manufactured more easily, and the productivity of 1 A of lens substrates with a light-shielding part can be made especially excellent.
Although the thickness (average thickness) of the diffusion part 5 is not particularly limited, it is preferably 1 to 10 μm, and more preferably 1 to 5 μm. When the thickness of the diffusing portion 5 is a value within the above range, the light utilization efficiency (the ratio of the intensity of the emitted light to the intensity of the incident light) is maintained sufficiently high, and the light is more effectively diffused. Can do. On the other hand, when the thickness of the diffusing portion 5 is less than the lower limit, the effect of the diffusing portion 5 may not be sufficiently exhibited. Further, if the thickness of the diffusion portion 5 exceeds the upper limit value, the probability (frequency) that the light (photon) and the diffusion material 51 collide with each other in the diffusion portion 5 is increased, and quenching is likely to occur. Since the possibility that the light (photon) that has entered the diffusing unit 5 returns to the incident side again increases, the light use efficiency tends to decrease.

Next, the transmissive screen 10 including the above-described lens substrate with a light shielding part 1A will be described.
As shown in FIG. 3, the transmission screen 10 includes the Fresnel lens portion 2 and the lens substrate 1 </ b> A with the light shielding portion described above. The Fresnel lens unit 2 is installed on the incident side of light (image light), and the light transmitted through the Fresnel lens unit 2 is incident on the lens substrate 1A with a light shielding unit.

The Fresnel lens unit 2 has a prism-shaped Fresnel lens 21 formed on the exit side surface in a substantially concentric shape. The Fresnel lens unit 2 refracts image light from a projection lens (not shown) to make parallel light La parallel to the vertical direction of the main surface of the lens substrate 1A with a light shielding unit.
In the transmissive screen 10 configured as described above, the image light from the projection lens is refracted by the Fresnel lens unit 2 to become parallel light La. The parallel light La enters the microlens substrate 3, is collected by each microlens 32, and then enters the diffusion unit 5. The light incident on the diffusing unit 5 diffuses and is observed as a planar image by the observer.

Next, an example of a manufacturing method of the above-described lens substrate with a light shielding part 1A will be described.
4 and 5 are schematic longitudinal sectional views showing an example of a method for manufacturing the lens substrate with a light shielding portion shown in FIG. In the following description, the lower side in FIGS. 4 and 5 is referred to as “(light) incident side”, and the upper side is referred to as “(light) emission side”.
The method for manufacturing a lens substrate with a light shielding part described below includes a step of forming a plurality of microlenses (concave lenses) 32 on the surface of the substrate 7 to obtain a microlens substrate (lens substrate) 3, On the surface where the microlenses 32 are formed, a step of forming a black matrix (light-shielding portion) 4 in an ineffective lens region between adjacent microlenses 32, and a diffusion portion on the surface where the microlenses 32 are formed 5 is formed.
In manufacturing a lens substrate with a light-shielding part, a large number of recesses (microlens recesses) are actually formed on the substrate. Here, in order to make the explanation easy to understand, a part of the recesses is highlighted. It was.

[Manufacture of microlens substrate]
First, when the microlens substrate 3 is manufactured, the substrate 7 is prepared.
The substrate 7 having a uniform thickness and having no deflection or scratches is preferably used. The substrate 7 is preferably one whose surface is cleaned by washing or the like.
Examples of the material of the substrate 7 include soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass. Among them, soda glass, crystalline glass (for example, neo-serum), Alkali-free glass is preferred. Soda glass, crystalline glass, and alkali-free glass are easy to process, are relatively inexpensive, and are advantageous from the viewpoint of manufacturing cost.

<A1> As shown in FIG. 4A, a mask 8 is formed on the surface of the prepared substrate 7 (mask forming step). At the same time, a back surface protective film 89 is formed on the back surface of the substrate 7 (the surface opposite to the surface on which the mask 8 is formed). Of course, the mask 8 and the back surface protective film 89 can be formed simultaneously.
The mask 8 is preferably one that can form an initial hole 81 to be described later by laser light irradiation or the like and has resistance to etching in an etching step to be described later. In other words, the mask 8 is preferably configured so that the etching rate is substantially equal to or smaller than that of the substrate 7.

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

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

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

<A2> Next, as shown in FIG. 4B, a plurality of initial holes 81, which will be mask openings in the later-described etching, are randomly formed in the mask 8 (initial hole forming step).
The initial holes 81 may be formed by any method, but are preferably formed by a physical method or laser light irradiation. Thereby, the microlens substrate can be manufactured with high productivity. In particular, the concave portion can be easily formed even on a large-area substrate.

  Examples of the physical method for forming the initial hole 81 include blasting such as shot blasting and sand blasting, etching, pressing, dot printer, tapping, rubbing, and the like. When the initial hole 81 is formed by blasting, the initial hole 81 can be efficiently formed in a shorter time even on the substrate 7 having a relatively large area (area of the region where the microlens 32 is to be formed).

When the initial hole 81 is formed by laser light irradiation, the type of laser light to be used is not particularly limited, but a ruby laser, a semiconductor laser, a YAG laser, a femtosecond laser, a glass laser, a YVO ₄ laser, a Ne- Examples include He laser, Ar laser, CO ₂ laser, and excimer laser. Moreover, you may use wavelengths, such as SHG of each laser, THG, and FHG. When the initial holes 81 are formed by laser light irradiation, the size of the formed initial holes 81, the interval between the adjacent initial holes 81, and the like can be controlled easily and accurately. Further, when the initial hole 81 is formed by laser light irradiation, by controlling the irradiation condition, only the initial hole 81 can be formed without forming the initial concave portion 71 as described later, The initial recess 71 having small variations in shape, size, and depth can be easily and reliably formed.

It is preferable that the formed initial holes 81 are formed evenly over the entire surface of the mask 8. In addition, the formed initial hole 81 is such that when the recess 72 is formed by etching in step <A3> to be described later, the plane portion 34 having an appropriate size remains between the adjacent recesses 72. It is preferable that the small holes are arranged at a certain interval.
Specifically, for example, the shape of the formed initial hole 81 in a plan view is substantially circular, and the average diameter (diameter) is preferably 2 to 10 μm. The initial holes 81 are preferably formed on the mask 8 at a rate of 1,000 to 1,000,000 holes / cm ² , and are formed at a rate of 10,000 to 500,000 holes / cm ^2. More preferably. Needless to say, the shape of the initial hole 81 is not limited to a substantially circular shape.

  Further, when the initial hole 81 is formed in the mask 8, as shown in FIG. 4B, not only the mask 8 but also a part of the surface of the substrate 7 may be removed simultaneously to form the initial recess 71. Thereby, when etching is performed in an etching process described later, the contact area with the etching solution is increased, and erosion can be suitably started. Moreover, the depth of the recessed part 72 mentioned later can also be adjusted by adjusting the depth of this initial recessed part 71. FIG. Although the depth of the initial recessed part 71 is not specifically limited, It is preferable to set it as 5 micrometers or less, and it is more preferable to set it as about 0.1-0.5 micrometer. When the initial hole 81 is formed by laser irradiation, the variation in depth of the plurality of initial recesses 71 formed together with the initial hole 81 can be more reliably reduced. As a result, the variation in the shape and size (particularly depth) of each recess 72 formed in the substrate 7 is also reduced. In other words, variations in size and shape of each microlens 32 of the microlens substrate 3 are also reduced.

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

<A3> Next, as shown in FIG. 4C, the substrate 7 is etched using the mask 8 in which the initial holes 81 are formed, and a large number of recesses 72 are randomly formed on the substrate 7 (etching). Process).
The etching method is not particularly limited, and examples thereof include wet etching and dry etching. In the following description, a case where wet etching is used will be described as an example.

  By performing etching (wet etching) on the substrate 7 covered with the mask 8 in which the initial holes 81 are formed, the substrate 7 is removed from the portion where the mask 8 does not exist, as shown in FIG. A number of recesses 72 are formed on the substrate 7 by etching. As described above, since the initial holes 81 formed in the mask 8 are random, the formed recesses 72 are randomly arranged on the surface of the substrate 7.

In the present embodiment, when the initial hole 81 is formed in the mask 8 in the step <A2>, the initial recess 71 is formed on the surface of the substrate 7. Thereby, at the time of etching, the contact area with the etching solution is increased, and erosion can be suitably started.
Further, when the wet etching method is used, the concave portion 72 can be suitably formed. If, for example, an etching solution (hydrofluoric acid-based etching solution) containing hydrofluoric acid (hydrogen fluoride) is used as the etching solution, the substrate 7 can be etched more selectively, and the recess 72 is preferably formed. can do.

  When the mask 8 is mainly composed of Cr, an ammonium fluoride solution (ammonium monofluoride solution) is particularly suitable as the hydrofluoric acid etching solution. Since the ammonium fluoride solution (4 wt% or less) is not a poisonous or deleterious substance, it can prevent the human body and the environment from being affected during work. Further, when an ammonium fluoride solution is used as the etching solution, the etching solution may contain, for example, hydrogen peroxide. Thereby, the etching speed can be further increased.

In addition, wet etching can be performed with a simpler apparatus than dry etching, and more substrates can be processed at one time. As a result, productivity is improved and the microlens substrate 3 and the lens substrate 1A with a light-shielding portion can be provided at low cost.
By forming the concave portion 72 as described above, as a result, the microlens (concave lens) 32 having the concave surface 321 is formed.

  Further, the etching as described above is preferably performed to the extent that the plane portion 34 having an appropriate size remains between the adjacent recesses 72 on the surface side where the recesses 72 are formed. Thereby, for example, a microlens (concave lens) 32 having a substantially semicircular concave surface 321 can be suitably formed, and the viewing angle of the lens substrate 1A with a light-shielding portion (the transmissive screen 10, the rear projector 300). The characteristics can be made particularly excellent. In addition, when such a flat portion 34 is provided, the black matrix 4 can be easily and reliably formed in a process described later.

<A4> Next, as shown in FIG. 4D, the mask 8 is removed (mask removal step). At this time, the back surface protective film 89 is also removed together with the removal of the mask 8.
When the mask 8 is mainly composed of Cr, the removal of the mask 8 can be performed by, for example, etching using a mixture containing ceric ammonium nitrate and perchloric acid.

As described above, as shown in FIG. 4D, the microlens substrate 3 on which a large number of microlenses 32 are randomly arranged is obtained.
The method of forming the microlenses 32 (recesses 72) at random is not particularly limited, but the method as described above (the initial hole 81 is formed in the mask 8 by physical method or laser light irradiation, and then the mask is formed. When etching is performed using 8, a method of forming the recess 72 on the substrate 7) provides the following effects.

  That is, by forming the initial hole 81 in the mask 8 by a physical method or laser light irradiation, the mask 8 can be formed in the mask 8 more easily and cheaply than in the case where the opening is formed in the mask by a conventional photolithography method. The opening (initial hole 81) can be formed in a predetermined pattern. Thereby, productivity is improved and the microlens substrate 3 can be provided at low cost.

Further, according to the method as described above, it is possible to easily perform processing on a large substrate. In the case of manufacturing a large substrate, it is not necessary to bond a plurality of substrates as in the prior art, and the seam of bonding can be eliminated. Thereby, a high-quality large-sized microlens substrate can be manufactured at a low cost by a simple method.
Further, after removing the mask 8 in the step <A4>, a new mask may be formed on the substrate 7, and a series of steps of mask formation-initial hole formation-wet etching-mask removal may be repeated. Thereby, the microlens substrate 3 in which the microlenses 32 (concave portions 72) are densely formed can be obtained.

[Formation of black matrix]
Next, on the surface of the microlens substrate 3 obtained as described above where the microlenses 32 (concave surface 321) are formed, the black matrix 4 is formed in the ineffective lens region between the adjacent microlenses 32. . Thus, by forming the black matrix 4 in the ineffective lens region between the adjacent microlenses 32, the positional accuracy of the formed black matrix 4 can be made particularly excellent. Thereby, the black matrix 4 can be formed easily and with high productivity.

  As described above, in the present embodiment, the microlens substrate 3 has the flat portion 34 on the surface on which the concave surface 321 is formed. In the present embodiment, the black matrix 4 is formed on the flat portion 34. In this way, by forming the black matrix 4 on the flat portion 34, it is possible to more reliably prevent light incident on the microlens substrate 3 from being emitted from the flat portion 34 as straight light. Thereby, inconveniences such as occurrence of luminance unevenness in the projected image can be prevented more effectively.

<B1> The formation method of the black matrix 4 is not particularly limited. In the present embodiment, first, a black matrix-forming composition having fluidity (a composition for forming a light-shielding portion) is placed near the plane portion 34 (ineffective). Lens area).
Examples of the method for applying the black matrix forming composition include various coating methods such as doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, roll coater, etc. For example, a method such as dipping may be used in which the portion (ineffective lens region) 34 is immersed in the composition for forming a black matrix.

Among the above methods, the black matrix 4 can be more easily formed particularly when the composition for forming a black matrix is applied by a coating method. Moreover, according to such a method, the adhesiveness of the black matrix 4 formed can be made more excellent.
In addition, among the above methods, when the black matrix forming composition is applied by a method (dipping) in which the planar portion (ineffective lens region) 34 of the microlens substrate 3 is immersed in the black matrix forming composition. The black matrix 4 can be formed more easily. Moreover, according to such a method, the black matrix 4 with small variations in film thickness at each part can be easily and reliably formed.

The application of the black matrix forming composition may be repeated a plurality of times as necessary (for example, when the thickness of the black matrix 4 to be formed is relatively large).
The viscosity of the black matrix forming composition around room temperature (for example, 25 ° C.) is preferably 10 to 1000 cp, more preferably 30 to 100 cp. When the viscosity of the black matrix forming composition is within the above range, the black matrix 4 having an appropriate thickness can be easily and reliably formed.

  The black matrix forming composition may be any composition as long as it has fluidity under the conditions for application to the ineffective lens region. Low) resin material in which a light-shielding component (material) is dispersed or dissolved can be used. As the resin material, any one of various thermoplastic resins, various thermosetting resins, various photosensitive resins (photopolymers) and the like may be used. Further, the black matrix forming composition may contain a solvent, a dispersion medium, and the like. Thereby, the fluidity | liquidity of the composition for black matrix formation can be optimized comparatively easily.

  <B2> After the application of the black matrix forming composition, the black matrix forming composition is solidified to form the black matrix 4 (see FIG. 5A). In addition, after application | coating of the composition for black matrix formation, you may perform processes, such as heat processing, such as heating and cooling, light irradiation, pressure reduction of an atmosphere, as needed. Thereby, solidification of the composition for black matrix formation can be accelerated | stimulated.

  Further, the steps <B1> and <B2> may be sequentially repeated as necessary (for example, when the thickness of the black matrix 4 to be formed is relatively large). Further, since the black matrix 4 only needs to have a light-shielding property, in the case where the steps <B1> and <B2> are sequentially repeated, for example, the lower layer side (side closer to the microlens substrate 3) Is formed using a material that does not contain a light-shielding component (a composition for forming a black matrix), and the light-shielding component is added when forming the upper layer side (the side far from the microlens substrate 3). A material (a composition for forming a black matrix) may be used.

[Diffusion part formation]
<C1> Next, the diffusion part 5 is formed on the surface of the microlens substrate 3 on which the black matrix 4 is formed on which the microlenses 32 (concave surface 321) are formed (see FIG. 5B).
In the present embodiment, the diffusion part 5 has a substantially flat plate shape. When the diffusion part 5 has such a shape, the diffusion part 5 can be formed more easily. More specifically, the flat plate member (diffusion part 5) made of the material of the diffusion part 5 is placed on the surface side of the microlens substrate 3 on which the black matrix 4 is formed on which the microlenses 32 (concave surface 321) are formed. By joining, a lens substrate 1A with a light-shielding part provided with a diffusion part 5 can be obtained.

The bonding method of the flat plate member made of the material of the diffusion portion 5 and the microlens substrate 3 on which the black matrix 4 is formed is not particularly limited, and examples thereof include methods such as adhesion and fusion.
Next, a description will be given of a lens substrate with a light shielding portion according to a second embodiment of the present invention.
FIG. 6 is a schematic longitudinal sectional view showing a second embodiment of the lens substrate with a light-shielding part of the present invention. In the following description, the left side in FIG. 6 is referred to as “(light) incident side” and the right side is referred to as “(light) emission side”.

  As shown in FIG. 6, in the lens substrate with a light shielding part 1 </ b> B of the present embodiment, the diffusing part 5 follows the shape of the surface of the microlens substrate 3 on which the black matrix 4 is formed on which the microlenses 32 are formed. , Provided. That is, in the lens substrate with a light shielding part 1 </ b> B of the present embodiment, the diffusion part 5 has a region provided along the concave surface 321 of the microlens 32. As described above, when the diffusing portion 5 is provided along the concave surface 321 of the microlens 32, the light emitted from the microlens substrate 3 can be efficiently diffused, and the viewing angle characteristic is particularly excellent. be able to. Further, since the diffusing portion 5 is provided along the concave surface 321 of the microlens 32, light can be sufficiently diffused even when the diffusing portion 5 is relatively thin. Therefore, by making the thickness of the diffusing portion 5 relatively thin, it is possible to further increase the light utilization efficiency while maintaining the light diffusibility sufficiently high. Moreover, the function of the black matrix (light-shielding part) 4 can be more effectively exhibited by making the diffusion part 5 relatively thin. That is, with the configuration shown in the figure, both the black matrix 4 and the diffusing unit 5 can more effectively exhibit their functions.

  In the case of the above configuration, the thickness (average thickness) of the diffusion portion 5 is not particularly limited, but is preferably 1 to 10 μm, and more preferably 1 to 5 μm. When the thickness of the diffusing portion 5 is a value within the above range, the light utilization efficiency (the ratio of the intensity of the emitted light to the intensity of the incident light) is maintained sufficiently high, and the light is more effectively diffused. Can do. On the other hand, when the thickness of the diffusing portion 5 is less than the lower limit, the effect of the diffusing portion 5 may not be sufficiently exhibited. Further, if the thickness of the diffusion portion 5 exceeds the upper limit value, the probability (frequency) that the light (photon) and the diffusion material 51 collide with each other in the diffusion portion 5 is increased, and quenching is likely to occur. Since the possibility that the light (photon) that has entered the diffusing unit 5 returns to the incident side again increases, the light use efficiency tends to decrease.

  The lens substrate 1B with the light-shielding part having such a configuration is, for example, in the same manner as in the first embodiment, adjacent microlenses on the surface of the microlens substrate 3 on the side where the microlenses 32 (concave surface 321) are formed. After forming the black matrix 4 in the non-effective lens region between 32 (see FIG. 5 (a)), the flow side diffusing portion forming composition is applied to the surface of the microlens substrate 3 on which the black matrix 4 is formed. And then solidifying to form the diffusion part 5.

Examples of the method for applying the composition for forming a diffusion region include various application methods such as doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, roll coater, and the like, Examples of the method include dipping or the like in which the surface side on which the lens 32 (concave surface 321) is formed is immersed in the composition for forming a diffusion portion.
The application of the diffusion portion forming composition may be repeated a plurality of times as necessary (for example, when the thickness of the diffusion portion 5 to be formed is relatively large).

  The diffusion part forming composition may be any composition as long as it has fluidity under application conditions to the microlens substrate 3 on which the black matrix 4 is formed. For example, it has excellent light transmittance. A material in which the diffusion material 51 as described above is dispersed in a substantially transparent material (for example, acrylic resin, polycarbonate resin, or the like) can be used. Moreover, the composition for diffusion part formation may contain a solvent, a dispersion medium, etc. Thereby, the fluidity | liquidity of the composition for spreading | diffusion part formation can be optimized comparatively easily.

A part of the diffusion portion 5 may be removed as necessary after the diffusion portion 5 is formed.
Next, a description will be given of a lens substrate with a light shielding portion according to a third embodiment of the present invention.
FIG. 7 is a schematic longitudinal sectional view showing a third embodiment of the lens substrate with a light-shielding part of the present invention. In the following description, the left side in FIG. 7 is referred to as “(light) incident side” and the right side is referred to as “(light) emission side”.

  As shown in FIG. 7, in the lens substrate with a light shielding part 1 </ b> C of this embodiment, a diffusion part 5 is provided between the microlens substrate 3 and the black matrix 4. That is, in the lens substrate with a light shielding part 1 </ b> C of the present embodiment, the black matrix 4 is provided on the light emission side from the diffusion part 5. Thus, the arrangement of the black matrix 4 and the light shielding part 5 is not particularly limited. Further, with the configuration as shown in FIG. 7, the function of the black matrix 4 can be more effectively exhibited.

  For example, the lens substrate 1C with a light-shielding portion having the above-described configuration is manufactured in the same manner as in the first embodiment, after the microlens substrate 3 is manufactured (see FIG. 4D), The diffusion part 5 is formed by the same method as described in the second embodiment, and then the black matrix 4 is formed on the diffusion part 5 by the same method as described in the first embodiment. Can be manufactured.

Next, a description will be given of a lens substrate with a light shielding portion according to a fourth embodiment of the present invention.
FIG. 8 is a schematic longitudinal sectional view showing a fourth embodiment of the lens substrate with a light-shielding part of the present invention. In the following description, the left side in FIG. 8 is referred to as “(light) incident side” and the right side is referred to as “(light) emission side”.
As shown in FIG. 8, in the lens substrate 1 </ b> D with a light-shielding part of the present embodiment, the black matrix 4 is provided so as to contact the flat part 34 (ineffective lens region) of the microlens substrate 3. With such a configuration, straight light can be more effectively suppressed, and viewing angle characteristics can be made particularly excellent.

  For example, the lens substrate 1D with the light-shielding portion having the above-described configuration is formed at least after the diffusion portion 5 is formed on the surface of the microlens substrate 3 on which the concave surface 321 is formed, as in the third embodiment. The diffusion part 4 formed on the planar part 34 of the lens substrate 3 is removed, and then the black matrix 4 is formed on at least the exposed planar part 34 by the same method as described in the first embodiment. It can be manufactured by forming. A method for removing the diffusion portion 4 formed on the flat portion 34 of the microlens substrate 3 is not particularly limited, and examples thereof include various etching methods, machining such as grinding and polishing, and the like. When removing the diffusion portion 4 formed on the planar portion 34 of the microlens substrate 3, a part of the microlens substrate 3, for example, a region near the planar portion 34 is removed together with the diffusion portion 5. Good. Further, the black matrix 4 can be selectively formed on the flat surface portion 34 as shown in the drawing by selecting the removal conditions of the diffusion portion 5 according to the constituent materials of the microlens substrate 3 and the diffusion portion 5. Can do.

Moreover, by using the lens substrate with a light-shielding part of the second to fourth embodiments, the transmission screen of the present invention can be obtained as in the first embodiment.
Next, a rear projector using the transmission screen will be described.
FIG. 9 is a diagram schematically showing the configuration of the rear projector of the present invention.
As shown in the figure, the rear projector 300 has a configuration in which a projection optical unit 310, a light guide mirror 320, and a transmissive screen 10 are arranged in a housing 340.

Since the rear projector 300 uses the transmissive screen 10 having excellent viewing angle characteristics and light utilization efficiency as the transmissive screen 10, the rear projector 300 is an excellent rear projector with good display quality.
In particular, in the above-described lens substrates 1A, 1B, 1C, and 1D with the light-shielding portion, the microlenses 32 are randomly arranged (optically random). Hard to occur.

As mentioned above, although the manufacturing method of the lens board with a light-shielding part of the present invention, the lens board with a light-shielding part, a transmission type screen, and a rear type projector were explained based on the illustrated embodiment, the present invention is limited to these. is not.
For example, each part constituting the lens substrate with a light-shielding part, the transmissive screen, and the rear projector can be replaced with any structure that can exhibit the same function.

  In the above-described embodiment, the microlens substrate (lens substrate) 3 is described as being manufactured by etching, but any lens substrate (manufactured by any method) is used. May be. For example, the lens substrate may be manufactured as follows. That is, first, a lens substrate with convex portions is manufactured using the substrate with concave portions manufactured as a lens substrate in the above-described embodiment as a mold. Next, a lens substrate (microlens substrate) is manufactured using the substrate with projections as a mold. Thus, the productivity of the lens substrate can be improved by using the mold. Such an effect becomes particularly remarkable when the lens substrate is mass-produced. Further, by manufacturing a lens substrate using a mold, it is possible to reduce variation in characteristics among a plurality of manufactured lens substrates, thereby improving reliability.

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

In the above-described embodiment, the microlenses having a substantially circular shape when viewed in plan are described as randomly arranged. However, the shape and arrangement of the microlens are not limited to this. For example, the microlenses may be arranged in a lattice shape or may be formed in a honeycomb shape.
In the above-described embodiment, the transmission screen is described as including a lens substrate with a light shielding unit and a Fresnel lens. However, the transmission screen of the present invention does not necessarily include a Fresnel lens. Good. For example, the transmission type screen of the present invention may be substantially composed only of the lens substrate with a light shielding part of the present invention.

  In the above-described embodiment, the configuration including the microlens as the concave lens has been described. However, the concave lens is not limited thereto, and may be a lenticular lens, for example. By using the lenticular lens, the concave lens forming process can be simplified, and the productivity of the transmission screen can be improved. When a lenticular lens is used as the concave lens, a striped light shielding portion (black stripe) is formed instead of the black matrix. Even in such a configuration, the same operation and effect as in the above-described embodiment can be obtained.

In the above-described embodiments, the black matrix is described as being directly formed on the surface of the microlens substrate or the diffusion portion. However, the black matrix is, for example, a microlens substrate via an underlayer (adhesive layer) or the like. Alternatively, it may be bonded to the diffusion part.
In the above-described embodiment, the black matrix (light-shielding part) includes a black matrix-forming composition (light-shielding part-forming composition) containing a light-shielding material, a microlens substrate (lens substrate), and the surface of the diffusion part. However, the method of forming the black matrix (light-shielding portion) is not limited to this, and may be, for example, dyeing, (chemical) coloring, discoloration, or the like. .

In the above-described embodiment, the diffusing unit is described as being provided on the light emitting surface side of the lens substrate. However, the diffusing unit may be provided on the light incident surface side of the lens substrate. Further, it may be provided on both the light incident surface side and the light emitting surface side of the lens substrate.
In the above-described embodiment, the lens substrate with a light shielding part has been described as having a light shielding part. However, the lens substrate with a light shielding part may not have a diffusion part.

  In the above-described embodiments, the lens substrate with a light-shielding portion is described as a member constituting a transmissive screen and a rear projector. However, the lens substrate with a light-shielding portion according to the present invention is a transmissive screen and a rear type. It is not limited to what is applied to a projector, What kind of use may be sufficient. For example, the substrate with a lens with a light shielding part of the present invention may be applied to a constituent member of a liquid crystal light valve of a projection display device.

(Example 1)
A microlens substrate provided with a microlens as a concave lens was manufactured as follows.
First, a 1.2 m × 0.7 m square, 4 mm thick soda glass substrate was prepared as a substrate.

This soda glass substrate was immersed in a cleaning solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide and etched by 6 μm to clean the surface.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.
Next, a Cr film having a thickness of 0.03 μm was formed on the soda glass substrate by sputtering. That is, a Cr film mask and a back surface protective film were formed on the surface of the soda glass substrate.

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

At this time, a concave portion and an altered layer (a chemically altered region, or a region in which minute cracks or defects were generated) having a depth of 0.1 μm were also formed on the surface of the soda glass substrate.
Next, the soda glass substrate was wet-etched to form a large number of recesses on the soda glass substrate. The formed many recessed portions (concave surfaces) had substantially the same radius of curvature (35 μm).

In the wet etching, an aqueous solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide was used as an etchant, and the immersion time was 5 hours.
Next, the mask and the back surface protective film were removed by etching using a mixture of ceric ammonium nitrate and perchloric acid.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.

  As a result, a wafer-like microlens substrate in which microlenses as concave lenses were randomly formed on the soda glass substrate was obtained. The diameter of the microlens (concave portion) of the microlens substrate thus obtained was 70 μm. Further, when the obtained microlens substrate was viewed in plan, the ratio of the area occupied by the black matrix in the effective region where the microlens (concave lens) was formed was 20%. Also, a number of distances between any two adjacent points (between the recesses and the recesses) on the microlens substrate were taken, and the standard deviation was determined from them. The standard deviation thus determined was 90% of their average. Further, the microlens obtained as described above had a flat portion between adjacent microlenses (concave portions).

  Next, the composition for forming a black matrix having fluidity is applied to the planar portion existing between adjacent microlenses (concave portions) of the microlens substrate obtained as described above by a roll coater in the vicinity of the planar portion. Was granted. As the black matrix forming composition, a material containing a light shielding material (carbon black) and an ultraviolet curable resin (V-2403 (manufactured by Nippon Steel Chemical Co., Ltd.)) was used. The viscosity at 25 ° C. of the black matrix forming composition was 30 cp.

Then, the ultraviolet curable resin was cured by irradiating ultraviolet rays of 10,000 mJ / cm ² from the side of the microlens substrate to which the composition for forming a black matrix was applied, thereby forming a black matrix. The average thickness of the black matrix thus formed was 0.5 μm.
On the other hand, using a material containing a diffusing material (silica beads having a diameter of 5 μm) and CSP-S025 (manufactured by Fuji Film Arch Co., Ltd.), a flat plate member of 1.2 m × 0.7 m square and 4 mm thickness is produced. did. The content rate of the diffusing material in the flat plate member was 50 wt%.

A lens substrate with a light-shielding part is bonded by using an acrylic adhesive (manufactured by Nippon Steel Chemical Co., Ltd., V-2403P) so that the flat member and the black matrix on the microlens substrate are opposed to each other. Got.
A transmissive screen as shown in FIG. 3 was obtained by assembling the light-shielding part-equipped lens substrate manufactured as described above and the Fresnel lens part produced by extrusion molding.

(Example 2)
A transmissive screen was produced in the same manner as in Example 1 except that the mask and the back surface protective film were formed as Cr oxide films. Note that the mask and the back surface protective film were formed by sputtering. The thickness of the Cr oxide film was 0.03 μm.
(Example 3)
A transmissive screen was produced in the same manner as in Example 1 except that the mask and the back surface protective film were formed as a Cr / Cr oxide laminate (a laminate in which Cr oxide was laminated on the outer surface side of Cr). . Note that the mask and the back surface protective film were formed by sputtering. The thickness of the Cr layer was 0.02 μm, and the thickness of the Cr oxide layer was 0.02 μm.

Example 4
A transmissive screen was manufactured in the same manner as in Example 1 except that the mask and the back surface protective film were formed as a Cr oxide / Cr laminate (a laminate in which Cr was laminated on the outer surface side of Cr oxide). . Note that the mask and the back surface protective film were formed by sputtering. The thickness of the Cr oxide layer was 0.02 μm, and the thickness of the Cr layer was 0.02 μm.

(Example 5)
First, a 1.2 m × 0.7 m square, 4 mm thick soda glass substrate was prepared as a substrate.
This soda glass substrate was immersed in a cleaning solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide and etched by 6 μm to clean the surface.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.

Next, a Cr film having a thickness of 0.03 μm was formed on the soda glass substrate by sputtering. That is, a Cr film mask and a back surface protective film were formed on the surface of the soda glass substrate.
Next, laser processing was performed on the mask to form a large number of initial holes in a range of 113 cm × 65 cm at the center of the mask.

The laser processing was performed using a YAG laser under the conditions of an energy intensity of 1 mW, a beam diameter of 3 μm, and an irradiation time of 60 × 10 ⁻⁹ seconds.
Thereby, initial holes were formed in a random pattern over the entire range of the mask. The average diameter of the initial holes was 5 μm.
At this time, a concave portion and an altered layer (a chemically altered region, or a region in which minute cracks or defects were generated) having a depth of 0.1 μm were also formed on the surface of the soda glass substrate.

Next, the soda glass substrate was wet-etched to form a large number of recesses on the soda glass substrate. The formed many recessed portions (concave surfaces) had substantially the same radius of curvature (35 μm).
In the wet etching, an aqueous solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide was used as an etchant, and the immersion time was 5 hours.

Next, the mask and the back surface protective film were removed by etching using a mixture of ceric ammonium nitrate and perchloric acid.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.
As a result, a wafer-like substrate with concave portions in which concave portions were randomly formed on the soda glass substrate was obtained.

  Next, a release agent (GF-6110) is applied to the surface of the substrate with recesses obtained as described above on which the recesses are formed, and further, an unpolymerized (uncured) UV curable resin. (V-2403 (manufactured by Nippon Steel Chemical Co., Ltd.)). At this time, a substantially spherical spacer (diameter 150 μm) was arranged in a region where the concave portion of the substrate with concave portions on the surface was not formed (ineffective lens region).

Next, the ultraviolet curable resin was pressed with a flat plate made of alkali-free glass. At this time, air was prevented from entering between the flat plate and the ultraviolet curable resin. Moreover, as a flat plate, the thing by which the mold release agent (GF-6110) was apply | coated to the surface at the side which presses an ultraviolet curable resin was used.
Then, the ultraviolet curable resin was hardened by irradiating ultraviolet rays of 10,000 mJ / cm ² from above the flat plate, and the flat plate and the substrate with concave portions were removed to obtain a substrate with convex portions.

Next, a mold release agent (GF-6110) is applied to the surface on which the convex portions of the substrate with convex portions obtained as described above are formed, and further, unpolymerized (uncured) ultraviolet curing. Resin (V-2403 (manufactured by Nippon Steel Chemical Co., Ltd.)) was applied. At this time, a substantially spherical spacer (diameter 3 μm) was arranged in a region (ineffective lens region) where the convex portion of the substrate with convex portions on the surface was not formed.
Next, the ultraviolet curable resin was pressed with a flat plate made of alkali-free glass. At this time, air was prevented from entering between the flat plate and the ultraviolet curable resin. Moreover, as a flat plate, the thing by which the mold release agent (GF-6110) was apply | coated to the surface at the side which presses an ultraviolet curable resin was used.

Thereafter, the ultraviolet curable resin is cured by irradiating ultraviolet rays of 10,000 mJ / cm ² from the flat plate, and the flat lens and the substrate with convex portions are removed, thereby providing a microlens substrate having microlenses as a large number of concave lenses. Got. The concave surfaces of the microlenses of the microlens substrate thus obtained had substantially the same radius of curvature (35 μm). The diameter of the microlens (concave portion) was 70 μm. Further, when the obtained microlens substrate was viewed in plan, the ratio of the area occupied by the black matrix in the effective region where the microlens (concave lens) was formed was 20%. Also, a number of distances between any two adjacent points (between the recesses and the recesses) on the microlens substrate were taken, and the standard deviation was determined from them. The standard deviation thus determined was 90% of their average. Further, the microlens obtained as described above had a flat portion between adjacent microlenses (concave portions).

  Next, the black matrix is obtained by immersing the planar portion of the microlens substrate obtained as described above between adjacent microlenses (concave portions) in a black matrix-forming composition having fluidity. The forming composition was applied near the plane portion. As the black matrix forming composition, a material containing a light shielding material (carbon black) and an ultraviolet curable resin (V-2403 (manufactured by Nippon Steel Chemical Co., Ltd.)) was used. The viscosity at 25 ° C. of the black matrix forming composition was 30 cp.

Then, the ultraviolet curable resin was cured by irradiating ultraviolet rays of 10,000 mJ / cm ² from the side of the microlens substrate to which the composition for forming a black matrix was applied, thereby forming a black matrix. The average thickness of the black matrix thus formed was 0.5 μm.
Thereafter, a diffusion material (silica beads having a diameter of 5 μm) and an ultraviolet curable resin (V-2403 (manufactured by Nippon Steel Chemical Co., Ltd.)) are used on the surface of the microlens substrate on which the black matrix is formed using a roll coater. The composition for diffused part formation containing was provided.

Then, the ultraviolet curable resin is cured by irradiating the ultraviolet ray of 10000 mJ / cm ² from the side of the microlens substrate to which the composition for forming the diffusion part is applied, thereby forming the diffusion part, and the lens substrate with the light shielding part Got. The average thickness of the diffusion portion thus formed was 5 μm. Moreover, the content rate of the diffusion material in a diffusion part was 50 wt%.
Thereafter, in the same manner as in Example 1, a transmissive screen was obtained by assembling a lens substrate with a light shielding part and a Fresnel lens part produced by extrusion molding.

(Comparative Example 1)
A substrate with concave portions for microlenses having concave portions for microlenses was manufactured as follows, and a microlens substrate was manufactured using the substrate with concave portions for microlenses.
First, a soda glass substrate having a size of 1.2 m × 0.7 m square and a thickness of 4.8 mm was prepared as a substrate.

This soda glass substrate was immersed in a cleaning solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide and etched by 6 μm to clean the surface.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.
Next, a Cr film having a thickness of 0.03 μm was formed on the soda glass substrate by sputtering. That is, a Cr film mask and a back surface protective film were formed on the surface of the soda glass substrate.

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

At this time, a concave portion and an altered layer (a chemically altered region, or a region in which minute cracks or defects were generated) having a depth of 0.1 μm were also formed on the surface of the soda glass substrate.
Next, the soda glass substrate was wet-etched to form a large number of recesses on the soda glass substrate. The formed many recesses had substantially the same radius of curvature (35 μm).

In the wet etching, an aqueous solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide was used as an etchant, and the immersion time was 5 hours.
Next, the mask and the back surface protective film were removed by etching using a mixture of ceric ammonium nitrate and perchloric acid.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.

  As a result, a wafer-like substrate with concave portions for microlenses in which a large number of concave portions for microlenses were randomly formed on a soda glass substrate was obtained. When the obtained substrate with recesses was viewed in plan, the proportion of the area occupied by the recesses in the effective region where the recesses were formed was 80%. In addition, a large number of distances between any two adjacent points (between the recesses and the recesses) of the substrate with recesses for the microlens were taken, and the standard deviation was obtained therefrom. The standard deviation thus determined was 90% of their average.

  Next, a release agent (GF-6110) is applied to the surface of the substrate with concave portions for microlenses obtained as described above on which the concave portions are formed, and further, unpolymerized (uncured) ultraviolet rays. A curable resin (V-2403 (manufactured by Nippon Steel Chemical Co., Ltd.)) was applied. At this time, a substantially spherical spacer (diameter 150 μm) was arranged in a region where the concave portion of the substrate with concave portions for microlenses on the surface was not formed (ineffective lens region).

Next, the ultraviolet curable resin was pressed with a flat plate made of alkali-free glass. At this time, air was prevented from entering between the flat plate and the ultraviolet curable resin. Moreover, as a flat plate, the thing by which the mold release agent (GF-6110) was apply | coated to the surface at the side which presses an ultraviolet curable resin was used.
Then, the ultraviolet curable resin was cured by irradiating ultraviolet rays of 10,000 mJ / cm ² from the flat plate, and the microlens substrate was obtained by removing the flat plate and the substrate with concave portions for microlenses. The thickness of the resin layer of the obtained microlens substrate was 40 μm, the radius of curvature of the microlens was 35 μm, and the diameter of the microlens was 70 μm. Further, when the obtained microlens substrate was viewed in plan, the ratio of the area (projected area) occupied by the black matrix in the effective region where the microlenses were formed was 20%.

Next, a composition in which carbon black as a light shielding material is dispersed in PC-403 (JSR Corporation) on the surface of the microlens substrate opposite to the surface on which the microlenses (convex portions) are formed. The composition was applied by a roll coater and then subjected to a heat treatment at 90 ° C. for 30 minutes to form a light-shielding film (light-shielding film).
Thereafter, a mask is formed and etched by photolithography (by irradiating a predetermined pattern of light from the surface of the microlens substrate on which the light-shielding film is formed), and then 200 ° C. × 60 minutes. By performing heat treatment and curing the composition, a black matrix having openings at portions corresponding to the microlenses of the coating was formed. The thickness of the formed black matrix was 1 μm, and the diameter of the opening was 100 μm.

Next, a composition in which a diffusing material (silica beads having a diameter of 5 μm) was dispersed in CSP-S025 was applied to the entire surface on which the black matrix was formed by a roll coater. Thereafter, the composition was cured by performing a heat treatment at 200 ° C. for 60 minutes to form a layered diffusion portion, thereby obtaining a lens substrate with a light shielding portion. The thickness of the formed diffusion part (light diffusion layer) was 3 μm.
A transmissive screen was obtained by assembling the lens substrate with the light shielding part manufactured as described above and the Fresnel lens part produced by extrusion molding.

(Comparative Example 2)
First, a soda glass substrate having a size of 1.2 m × 0.7 m square and a thickness of 4.8 mm was prepared as a substrate.
This soda glass substrate was immersed in a cleaning solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide and etched by 6 μm to clean the surface.

Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.
Next, a Cr film having a thickness of 0.03 μm was formed on the soda glass substrate by sputtering. That is, a Cr film mask and a back surface protective film were formed on the surface of the soda glass substrate.
Next, laser processing was performed on the mask to form a large number of linear grooves (holes) in a range of 113 cm × 65 cm in the central portion of the mask so as to be parallel to each other. The pitch between adjacent grooves was 70 μm.

The laser processing was performed using a YAG laser under the conditions of an energy intensity of 1 mW, a beam diameter of 3 μm, and an irradiation time of 60 × 10 ⁻⁹ seconds. Next, wet etching was performed on the soda glass substrate to form a groove-shaped recess on the soda glass substrate. The formed recesses had substantially the same radius of curvature (35 μm).
In the wet etching, an aqueous solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide was used as an etchant, and the immersion time was 5 hours.

Next, the mask and the back surface protective film were removed by etching using a mixture of ceric ammonium nitrate and perchloric acid.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.
Thus, a wafer-like substrate with concave portions for lenticular lenses in which a large number of concave portions (groove portions) for lenticular lenses were formed on a soda glass substrate was obtained.

  Next, a mold release agent (GF-6110) is applied to the surface on which the concave portion of the substrate with concave portions for lenticular lenses obtained as described above is formed, and further, unpolymerized (uncured) ultraviolet rays. A curable resin (V-2403 (manufactured by Nippon Steel Chemical Co., Ltd.)) was applied. Under the present circumstances, the substantially spherical spacer (diameter 30 micrometers) was distribute | arranged to the area | region where the recessed part of the board | substrate with a concave part for lenticular lenses of the said surface is not formed.

Next, the ultraviolet curable resin was pressed with a flat plate made of alkali-free glass. At this time, air was prevented from entering between the flat plate and the ultraviolet curable resin. Moreover, as a flat plate, the thing by which the mold release agent (GF-6110) was apply | coated to the surface at the side which presses an ultraviolet curable resin was used.
Then, the ultraviolet curable resin was hardened by irradiating ultraviolet rays of 10,000 mJ / cm ² from the flat plate to obtain a lenticular lens substrate. The refractive index of the obtained lenticular lens substrate (cured resin) was 1.5. Moreover, the thickness of the resin layer of the obtained lenticular lens substrate was 150 μm, and the radius of curvature of the lenticular lens was 35 μm.

  Next, the flat plate used for pressing the ultraviolet curable resin is removed, and carbon black as a light-shielding material is applied to the exposed surface of the lenticular lens substrate (the surface on the side where the lenticular lens is formed). The composition dispersed in JSR Corporation) was applied by a roll coater, and then subjected to heat treatment at 200 ° C. for 60 minutes to cure the composition and form a light-shielding film (light-shielding film). .

  Then, by using a photolithography method (by irradiating a predetermined pattern of light from the surface of the lenticular lens substrate on which the light-shielding film is formed) to form and etch a mask, each lenticular lens of the film The black stripe (light-shielding part) which has an opening part in the site | part corresponding to is formed. The thickness of the formed black stripe was 1 μm, and the width of the opening was 100 μm.

  Next, a composition in which a diffusing material (silica beads having a diameter of 5 μm) was dispersed in CSP-S025 (manufactured by Fuji Film Arch Co., Ltd.) was applied to the entire surface on the side where the black stripes were formed using a roll coater. Thereafter, the composition was cured by performing a heat treatment at 200 ° C. for 60 minutes to form a layered diffusion portion, thereby obtaining a lens substrate with a light shielding portion. The thickness of the formed diffusion part (light diffusion layer) was 3 μm.

A transmissive screen was obtained by assembling the lens substrate with the light shielding part manufactured as described above and the Fresnel lens part produced by extrusion molding.
In Examples 1-5, the lens substrate with a light-shielding part and the transmissive screen could be manufactured with high productivity, whereas in Comparative Examples 1 and 2, a manufacturing method having a photolithography process was used. Productivity of the lens substrate with a light shielding part and the transmission type screen was inferior. In addition, Examples 1 to 5 were superior to Comparative Examples 1 and 2 in terms of manufacturing cost.

[Evaluation of transmission screen]
The light utilization efficiency was measured for the transmissive screens produced in Examples 1 to 5 and Comparative Examples 1 and 2. The measurement of the light utilization efficiency was carried out with a spectrophotometer using an integrating sphere under the condition of measuring the ratio of the amount of light transmitted through the screen of each example and each comparative example to the amount of light without the screen. .

[Production and evaluation of rear projector]
Using the transmissive screens of Examples 1 to 5 and Comparative Examples 1 and 2, rear projectors as shown in FIG. 9 were produced.
With the sample image displayed on the transmission screen of the obtained rear projector, the viewing angles in the vertical direction and the horizontal direction were measured.
The viewing angle was measured using a variable angle photometer (goniophotometer) under the condition of measuring at intervals of 5 degrees.

As a result, the rear projector provided with the transmissive screen obtained in Example 1 has an excellent viewing angle in the vertical direction (the angle at which the amount of light is halved) is 15 ° and the viewing angle in the horizontal direction is 20 °. It was confirmed to have viewing angle characteristics. Further, with this rear projector, a bright image was displayed, and no moiré was observed. Further, the same results (vertical viewing angle: 10 to 25 °, horizontal viewing angle: 10 to 25 °) were obtained for the rear projectors having the transmissive screens obtained in Examples 2 to 8. It was.
In contrast, the rear projector provided with the transmissive screen obtained in Comparative Example 2 was inferior in viewing angle characteristics with a vertical viewing angle of 10 °.

It is a typical longitudinal cross-sectional view which shows 1st Embodiment of the lens substrate with a light-shielding part of this invention. It is a top view of the micro lens board | substrate with which the lens board | substrate with a light-shielding part shown in FIG. It is a typical longitudinal cross-sectional view which shows 1st Embodiment of the transmissive screen of this invention provided with the lens board | substrate with a light-shielding part shown in FIG. It is a typical longitudinal cross-sectional view which shows an example of the manufacturing method of the lens substrate with a light-shielding part shown in FIG. It is a typical longitudinal cross-sectional view which shows an example of the manufacturing method of the lens substrate with a light-shielding part shown in FIG. It is a typical longitudinal cross-sectional view which shows 2nd Embodiment of the lens substrate with a light-shielding part of this invention. It is a typical longitudinal cross-sectional view which shows 3rd Embodiment of the lens substrate with a light-shielding part of this invention. It is a typical longitudinal cross-sectional view which shows 4th Embodiment of the lens substrate with a light-shielding part of this invention. It is a figure which shows typically the rear type projector to which the transmission type screen of this invention is applied.

Explanation of symbols

  1A, 1B, 1C, 1D... Lens substrate with light-shielding part 2... Fresnel lens part 21... Fresnel lens 3 ... Microlens substrate (lens substrate) 32 ... Microlens 321 ... Concave surface 34 ... Plane part 35 ...... Convex part 4 ...... Black matrix (light-shielding part) 5 ...... Diffusion part 51 ...... Diffusion material 7 ...... Substrate 71 ...... Initial concave part 72 ... Concave part 8 ... Mask 81 ... Initial hole 89 ...... Back side Protective film 9 ... Spacer 10 ... Transmission type screen 11 ... Flat plate 300 ... Rear type projector 310 ... Projection optical unit 320 ... Light guide mirror 340 ... Case

Claims (21)

Forming a plurality of concave lenses on the surface of the substrate to obtain a lens substrate;
Forming a light shielding portion in an ineffective lens region between adjacent concave lenses on a surface of the lens substrate on which the concave lens is formed. A method of manufacturing a lens substrate with a light shielding portion, comprising:   The method for manufacturing a lens substrate with a light-shielding part according to claim 1, wherein the light-shielding part is formed in a flat part between adjacent concave lenses.   The manufacturing method of the lens substrate with a light-shielding part according to claim 1 or 2, wherein the light-shielding part is formed by applying a composition for forming a light-shielding part to the ineffective lens region.   The method for manufacturing a lens substrate with a light shielding part according to claim 1, wherein the light shielding part is formed by immersing the ineffective lens region in a composition for forming a light shielding part.   The method for producing a lens substrate with a light-shielding part according to any one of claims 1 to 4, wherein the composition for forming a light-shielding part has a viscosity in the vicinity of room temperature of 10 to 1000 cp.   The method for manufacturing a lens substrate with a light-shielding part according to claim 1, wherein the light-shielding part has a thickness of 0.01 to 5 μm.   The method for manufacturing a lens substrate with a light-shielding part according to claim 1, further comprising a step of forming a diffusion part having a function of diffusing light on a surface side of the lens substrate on which the concave lens is formed.   The method for manufacturing a lens substrate with a light-shielding part according to claim 1, further comprising a step of forming a diffusion part having a function of diffusing light along the concave surface of the concave lens.   The method for manufacturing a lens substrate with a light shielding part according to claim 7 or 8, wherein the diffusion part is formed after the light shielding part is formed.   The method for manufacturing a lens substrate with a light-shielding part according to claim 1, wherein the concave lens is a microlens.   The method for manufacturing a lens substrate with a light-shielding part according to claim 1, wherein the microlens has a diameter of 10 to 500 μm.   The method of manufacturing a lens substrate with a light-shielding part according to claim 1, wherein a radius of curvature of the concave lens is 5 to 250 μm.   A lens substrate with a light-shielding part manufactured using the manufacturing method according to claim 1.   A lens substrate with a light-shielding part, comprising: a lens substrate having a plurality of concave lenses; and a light-shielding part provided in an ineffective lens region between adjacent concave lenses.   The lens substrate with a light-shielding portion according to claim 13 or 14, further comprising a diffusion portion having a function of diffusing light on a surface side of the lens substrate on which the concave lens is formed.   The lens substrate with a light-shielding part according to claim 13, further comprising a diffusion part having a function of diffusing light at least along the concave surface of the concave lens.   The light shielding part with a light shielding part according to any one of claims 13 to 16, wherein a ratio of an area occupied by the light shielding part is 1 to 70% in an effective area where the concave lens is formed when the lens substrate is viewed in plan. Lens substrate.   A transmissive screen comprising the lens substrate with a light-shielding portion according to claim 13. A Fresnel lens part having a Fresnel lens formed on the light exit side;
A transmissive screen comprising: the lens substrate with a light shielding portion according to claim 13, which is disposed on a light emission side of the Fresnel lens portion.   A rear projector comprising the transmissive screen according to claim 18 or 19.   21. The rear projector according to claim 20, further comprising a projection optical unit and a light guide mirror.

Images