JP2000314926A - Plane type lens and manufacture thereof and rear projection type projection screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plane type lens which is manufactured without deteriorating transmissivity and also without causing warpage in the plane type lens constituted by using a tiny transparent sphere. SOLUTION: In the plane type lens 23, the tiny transparent sphere 2 is embedded in a transparent adhesive layer 6 and a transparent adhesive layer 5 on a transparent base material 4 so that about one half of a diameter thereof is exposed on a light incident side, and the tiny transparent spherical body 2 is caught in the transparent adhesive layer 6 on an opposite light emission side, and then the transparent adhesive layer 5 is colored in black, so that a light absorbing layer 3 is constituted. Thus, incident light is easily transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat lens suitable for use in, for example, a rear-projection projector screen, a method of manufacturing the same, and a rear-projection projector screen.

[0002]

2. Description of the Related Art In recent years, rear-projection projectors using liquid crystal light valves or CRTs have been actively developed as large-screen displays for HDTV (Hi-Vision) and theaters.

FIG. 32 shows a schematic configuration of a conventional rear projection type projector.

The illustrated example is a box-type projector, and the projected image light L from the image projection unit 101 is, for example,
The transmission screen 105 reflected by the reflection mirror 102
It is led to. The transmissive screen 105 includes a Fresnel lens 103 and a lenticular lens 104 which usually extends in a vertical direction. Then, the projected image light L incident from the rear surface of the transmissive screen 105 becomes almost parallel light by the Fresnel lens 103 and is then diffused mainly in the horizontal direction by the lenticular lens 104.

As shown in FIGS. 33 (a) and 33 (b), the lenticular lens 104 is provided with a ridge 104a extending in the vertical direction on the back side (light emission side). And a black stripe 104b for absorbing external light and improving the screen contrast. For example, by extrusion molding, the lenticular lens 10 including the ridges 104a is made of acrylic resin.
After forming into the shape of No. 4, black printing is performed only on the ridge portion 104a to form a black stripe 104b.

As shown in FIG. 33B, the width w of the black stripe 104b is usually 0.3 to 0.4 times the pitch p of the lenticular lens 104.

However, in the transmission type screen using the lenticular lens as described above, for example, a wide viewing angle can be obtained because light is widely diffused in the horizontal direction.
Since light is diffused only in a narrow range in the vertical direction, there is a disadvantage that the viewing angle in the vertical direction is narrow. In order to overcome this drawback, there is also a structure in which a lenticular lens extending in the vertical direction and a lenticular lens extending in the horizontal direction are combined, but there is a problem that component costs and manufacturing costs increase due to an increase in the number of components, In addition, there is a problem in that the thickness of the screen becomes large and heavy due to the increase in the number of layers of the screen, and the influence of multiple reflection between the respective layers also increases.

As described above, when a black stripe is provided for improving the contrast, it is necessary to form a ridge for black printing on the light exit side of the lenticular lens, and the ridge is projected. The area ratio of the external light absorbing portion formed by the black stripe usually stays at about 30 to 40% because it is necessary to form the width so as not to disturb the emitted light. For this reason, the effect of improving the contrast was relatively poor.

Therefore, instead of the lenticular lens, attention has been paid to a transmission screen using a planar lens formed by arranging transparent microspheres two-dimensionally (for example, US Pat. Nos. 2,378,252 and 3,552). , 822
And Japanese Utility Model Registration No. 2513508), and research and development for practical use on a large-screen high-definition display are being conducted.

[0010] For example, the present applicant has previously filed Japanese Patent Application No. 9-100 / 1997.
No. 590 (filed on Apr. 17, 1997). The configuration will be described with reference to FIGS.

FIG. 34 shows a main configuration of an open-type rear projection type projector. Projected image light L from an image projection unit 21 is transmitted through a transmission type screen 10 including a Fresnel lens 22 and a flat lens 23. Is diffused forward. As shown in the figure, the planar lens 23 is configured by two-dimensional close-packed arrangement of transparent microspheres 2 such as glass beads. Therefore, the projection microscopic light L can be diffused over a wide range in each of the horizontal direction and the vertical direction by the single-layer transparent microsphere 2.

FIG. 35 shows a box-type rear projection type projector. Projected image light L from an image projecting unit 21 disposed in a housing 25 is reflected by a reflection mirror 24, and is also connected to the Fresnel lens 22. The light is diffused forward through a transmission screen 10 including a flat lens 23 formed by the transparent microspheres 2.

FIG. 36 shows a planar lens 23 having the most basic configuration described in the above-mentioned application (hereinafter referred to as the prior application).

The most basic configuration of the flat lens 23
For example, a large number of transparent microspheres 2 such as glass beads are fixed on a transparent substrate 4 such as a glass plate by a colored layer (light absorbing layer) 3 having an adhesive or adhesive function. Each transparent microsphere 2 is embedded in the colored layer 3 so that about 50% of the diameter is exposed from the colored layer 3 on the light incident side, and is in contact with the transparent substrate 4 on the light emitting side.

The incident light Lin, which has entered through a Fresnel lens not shown, is converged by the transparent microspheres 2 and passes through the vicinity of the contact portion between each transparent microsphere 2 and the transparent substrate 4, as shown _in the figure. Diffused and emitted. L _out is emission light. On the other hand, most of the external light _Lex incident from the side of the transparent substrate 4 is absorbed by the colored layer 3, and the reduction in contrast due to the reflection of the external light _Lex is reduced.

At this time, in the flat lens 23, the area ratio of the light absorbing layer by the colored layer 3 on the light emission side is, for example,
It can be about 80% or more. Therefore, the external light L _ex
It is possible to greatly reduce a decrease in contrast due to reflection of light, and to realize a screen having a high contrast which is hardly affected by external light.

In the manufacture of the above-mentioned flat lens 23 according to the prior application, first, a colored layer 3 which is an adhesive or adhesive layer is formed on a transparent substrate 4 and a number of transparent microspheres 2 are sprayed thereon. A method has been adopted in which the transparent microspheres 2 are pressed from above and pressed into the colored layer 3.

[0018]

However, it has been found that the invention of the prior application has excellent performance capable of realizing a high-contrast screen, but still has room for improvement.

That is, in the manufacturing method as described in the prior application, for example, when the transparent microspheres 2 are pressed from above, the transparent microspheres 2 rotate, and the colored layer 3 adheres to the exposed surface of the transparent microspheres 2. Since the rate is reduced, there is a possibility that the brightness of the screen may be reduced.

When the transparent microspheres 2 are pushed in, it is usually necessary to raise the temperature in order to lower the viscosity of the colored layer 3, but relatively large-scale equipment is required for raising and cooling the temperature. Also, the occurrence of warpage of the transparent substrate 4 due to heat is a problem that cannot be ignored particularly in the case of a large screen display.

Therefore, an object of the present invention is to provide a flat lens made of transparent microspheres without lowering its transmittance and without warping. An object of the present invention is to provide a lens, a manufacturing method thereof, and a screen for a rear projection type projector.

[0022]

That is, the present invention comprises a plurality of transparent microspheres distributed in a plane or a curved surface, and a transparent pressure-sensitive adhesive layer holding the plurality of microspheres. A part of the transparent pressure-sensitive adhesive layer is embedded in the transparent pressure-sensitive adhesive layer, and at least a light incident side of the transparent pressure-sensitive adhesive layer is dyed between the plurality of microspheres to form a light-absorbing layer. (Referred to as a planar lens).

According to the flat lens of the present invention, at least the light incident side of the transparent adhesive layer between the microspheres partly embedded in the transparent adhesive layer is dyed to form a light absorbing layer. Is performed after the embedding of the microspheres, the non-embedded portions of the microspheres are not stained by staining, so that the transmission area of incident light passing through the microspheres is sufficiently maintained and the transmittance can be increased. The reflection of external light can be prevented by the light absorbing layer. In addition, since a high-temperature heat process is not particularly required, for example, a transparent substrate serving as a substrate of a flat lens hardly warps. As a result, it is possible to provide a flat lens capable of projecting image light with high transmittance and good contrast.

The present invention also provides a step of distributing a plurality of microspheres on a transparent pressure-sensitive adhesive layer in a planar or curved shape, and a step of embedding a part of the plurality of microspheres in the transparent pressure-sensitive adhesive layer. And a step of dyeing at least the light incident side of the transparent pressure-sensitive adhesive layer between the plurality of microspheres (hereinafter, referred to as a manufacturing method of the present invention).

According to the manufacturing method of the present invention, it is possible to provide a manufacturing method of a flat lens which can realize a flat lens having the same effects as described above with good reproducibility.

Further, the present invention has a plurality of transparent microspheres distributed in a plane or a curved surface, and a transparent adhesive layer holding the plurality of microspheres, and a part of the microspheres is a transparent adhesive. Screen for a rear projection type projector (hereinafter referred to as a book) using a flat lens embedded in an agent layer and at least a light incident side of the transparent adhesive layer is dyed between the plurality of microspheres to form a light absorbing layer. This is referred to as a projector screen of the present invention).

According to the projector screen of the present invention, since the above-described flat lens of the present invention is used,
It is possible to provide a projector screen that can project image light transmitted with high transmittance with good contrast.

In the present invention, the above-mentioned flat lens is mainly flat and flat, but may have a somewhat curved shape, and these are generally defined as "flat". . Also, the transparent adhesive layer and transparent microspheres etc.
The term "transparent" is not necessarily required to be a perfect transparent body as long as it can transmit most of the target light, and the term "transparent" is used to include a degree of transparency up to a so-called translucent degree. In addition, the above-mentioned “microsphere” refers to one having at least a substantial part on the light incident side having a spherical shape and exhibiting a lens action, and need not be a perfect sphere.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

In the following embodiment, FIG.
36 are denoted by the same reference numerals.

In the above-described flat lens, manufacturing method and projector screen of the present invention, as shown in FIG. It is desirable to bury the light absorbing layer 3.

Preferably, the predetermined portion is embedded in the non-stained transparent pressure-sensitive adhesive layer.

In this case, as shown in FIG. 1, the transparent pressure-sensitive adhesive layer is formed of a laminate of a first transparent pressure-sensitive adhesive layer 6 and a second transparent pressure-sensitive adhesive layer 5, and the second transparent pressure-sensitive adhesive layer 5 is formed. It is preferable that the pressure-sensitive adhesive layer is dyed to be the light absorbing layer, and a predetermined portion on the light emission side of the microsphere 2 is embedded in the first transparent pressure-sensitive adhesive layer 6.

As shown in FIG. 14, a transparent pressure-sensitive adhesive layer 5 is provided in a single layer and dyed to form the light absorbing layer, and a predetermined portion on the light emission side of the microsphere is embedded in the light absorbing layer 3. Alternatively, the light absorbing layer may be present on the light emitting side of the predetermined location with a sufficiently small thickness.

Further, as shown in FIG.
It is preferable to control the thickness of the transparent pressure-sensitive adhesive layers 5 and 6 so that about half of the diameter of the transparent pressure-sensitive adhesive layer is embedded.

Then, as shown in FIG. 5 (b), at the time of the dyeing, the microspheres 2 were added to the dye 9 dispersed in a solvent.
It is desirable to immerse the transparent pressure-sensitive adhesive layers 5 and 6 in which is embedded.

In this case, it is desirable that the dyeing speed of the portion of the transparent pressure-sensitive adhesive layer to be dyed is higher than that of the lower layer. Therefore, as shown in FIG. 14, when the transparent pressure-sensitive adhesive layer 5 is a single layer, the dyeing speed of the transparent pressure-sensitive adhesive layer 5 on the light incident side to be dyed is higher than on the light emitting side lower portion. More preferably, it is increased.

However, when the transparent pressure-sensitive adhesive layer has a two-layer structure as shown in FIG. 1, the dyeing speed of the second transparent pressure-sensitive adhesive layer 6 is made higher than that of the first transparent pressure-sensitive adhesive layer 6. It is desirable.

In this case, as shown in FIG. 5 (a), it is desirable to apply a masking 8 for preventing dyeing to unnecessary portions at the time of dyeing.

It is desirable that at least the light incident side of the transparent pressure-sensitive adhesive layer 5 is dyed black, so that the light absorbing layer 3 can be obtained.

After the dyeing, the transparent pressure-sensitive adhesive layer 5
It is desirable to wash the dyed portion with water and then dry it to remove excess dye.

Thus, as shown in FIG. 1 and FIG. 14, the transparent pressure-sensitive adhesive layer 5 dyed at least on the light incident side and the plurality of microspheres 2 partially embedded therein are provided.
Can be provided on the transparent substrate 4.

Further, as shown in FIGS. 2 and 15, a third transparent adhesive layer 11 is provided on the light incident side of the plurality of microspheres 2.
Or, it is desirable to further join the transparent substrate through 16.

This makes it possible to form a flat lens suitable for use in a screen for a rear projection type projector.

Hereinafter, the preferred embodiment of the present invention will be described in more detail.

FIGS. 1 to 13 show a first embodiment.

As shown in FIG. 1, a flat lens 23 according to the present embodiment has a rigid or flexible transparent substrate made of, for example, a glass plate, a plastic plate, a plastic film, or the like on the light emitting side. 4 is provided.

The substrate 4, the transparent pressure-sensitive adhesive layers 5 and 6, and the transparent microspheres 2 described later are not necessarily completely transparent as long as they can transmit most of the target light. It does not have to be.

That is, on the surface of the transparent substrate 4 on the light incident side,
For example, transparent pressure-sensitive adhesive layers 6 and 5 having adhesive and adhesive functions such as a UV (ultraviolet) curable resin are provided in this order, and a large number of transparent microspheres made of, for example, glass beads are provided on the transparent pressure-sensitive adhesive layers 5 and 6. 2 is embedded and held. The transparent pressure-sensitive adhesive layer 5 located in the gap between these transparent microspheres 2 on the light incident side of the transparent base material 4 is blackened by dyeing, and is light-absorbing layer (hereinafter sometimes referred to as a colored layer). 3 is formed.

FIG. 2 shows a more practical configuration of the flat lens 23. As shown in the drawing, in the basic configuration shown in FIG. 1, the transparent substrate 1 is laminated also on the light incident side via the transparent adhesive layer 11. The transparent adhesive layer 11 and the transparent substrate 1 can be made of the same material as the transparent adhesive layer 6 and the transparent substrate 4 on the light emission side, respectively.

With the structure in which the transparent microspheres 2 are sandwiched from both sides in this manner, the holding strength of the transparent microspheres 2 can be improved, and the transparent microspheres 2 and the colored layer 3 can be protected from the outside. it can.

[0052] FIG. 2 (b) but show the effect of the planar lens 23 schematically, the incident light L _in which substantially parallel light by the Fresnel lens is not shown, the light incident side transparent base Each transparent microsphere 2 through the material 1 and the transparent adhesive layer 11
And the light converged by each of these transparent microspheres 2 is
Through the transparent substrate 4 on the light emission side, the light is diffused and emitted forward as emission light _Lout .

[0053] At this time, the transparent microspheres 2 in the light incident side, since about half of its diameter is embedded in the transparent adhesive layer 11, a number of the incident light L _in incident to the transparent microspheres 2 I do. On the other hand, on the light emission side, only a limited area through which light passes is embedded in the transparent adhesive layer 6. Therefore, in the planar lens 23, the area ratio of the colored layer 3 on the light emission side can be increased in a state where the amount of transmitted light, that is, the luminance of the transmissive screen is increased. As a result, a decrease in contrast due to reflection of external light can be significantly reduced.

Next, a method of manufacturing the flat lens having the configuration shown in FIG. 2 will be described with reference to FIGS.

First, as shown in FIG. 3A, for example,
On a transparent substrate 4 made of a glass plate or a plastic plate such as PMMA, for example, a cross-linking reaction proceeds by UV curing and the resin is hardened, and the surface retains viscosity even after UV curing, and has an acrylic-based composition that is difficult to be dyed. Is applied to a thickness of, for example, about 5 μm. Furthermore, a transparent pressure-sensitive adhesive layer 5 made of an acrylic UV curable resin having a composition that easily cures while the cross-linking reaction proceeds due to UV curing and retains the surface viscosity even after UV curing, and is easily dyed, for example, It is applied to a thickness of about 15 μm.

Next, as shown in FIG. 3B, for example,
A large number of transparent microspheres 2 are supplied from the hopper 42 onto the transparent pressure-sensitive adhesive layer 5 so that the transparent microspheres 2 have a two-dimensional close-packed structure at least in the lowermost layer.

The size of each transparent microsphere 2 is, for example, micro glass beads having an average grain size (diameter) of about 50 μm. If the size is too large, the gap between the transparent microspheres 2 becomes too large, particularly when a rear projection type projector screen is configured, and the resolution may be reduced.

Each of the transparent microspheres 2 can be made of, for example, a plastic such as an acrylic resin or a polystyrene resin in addition to the above-mentioned glass.

Next, for example, as shown in FIG.
Ski zinc is performed by the doctor plate 39 to make the height of the transparent microspheres 2 uniform.

Next, for example, as shown in FIG.
The transparent microspheres 2 are pressed from above by a pressure roll 31 made of silicone rubber or the like, and the lowermost transparent microspheres 2 are embedded in the transparent adhesive layer 5.

Next, as shown in FIG. 3 (e), the surplus transparent microspheres 2 buried in the transparent pressure-sensitive adhesive layer 5 and not retained are suctioned and removed by, for example, vacuum suction means 43.

As a result, as shown in FIG. 4A, only the transparent microspheres 2 held on the transparent pressure-sensitive adhesive layer 5 remain.

Next, as shown in FIG. 4 (b), the transparent microspheres 2 are pressed from above by a pressure roll 31, and while the transparent pressure-sensitive adhesive layer 5 is slightly raised by this pressure, the lowermost transparent microspheres are pressed. 2 is embedded in the transparent pressure-sensitive adhesive layers 5 and 6 to about half of its diameter (= 25 μm). Details will be described later.

Next, as shown in FIG. 4C, the transparent pressure-sensitive adhesive layers 5 and 6 made of a UV-curable resin are cured by irradiating ultraviolet rays from an ultraviolet lamp 32, and the transparent microspheres 2 are fixed.

FIG. 13A is a sketch drawing based on an optical microscope photograph of a planar lens in which micro glass beads are actually arranged and fixed as described above.

Next, as shown in FIG. 5A, the light emitting surface of the transparent substrate 4 is subjected to a masking process for preventing staining. This may be a lamination process of the protective film 8 (for example, a PET film having a thickness of several tens of μm) or a spray-type protective film formation.

Although not shown in FIG. 5A, the section (side surface) of the transparent substrate 4 may be subjected to a masking process as necessary.

Next, as shown in FIG.
3 is filled with a staining solution 9, and a transparent substrate 4 having micro glass beads arrayed and fixed therein is immersed in the solution to perform a staining process.

As the dyeing solution, a general resin dye can be used. Further, a black material having excellent light-shielding properties is preferred, but other colors may be used according to the application.

As an example of the black dyeing solution, there is a solution in which a black disperse dye is dissolved in glycol ether containing an anionic surfactant. For example, a resin dye SDN color manufactured by Osaka Chemical Co., Ltd. is used.

The concentration of the dyeing solution, temperature, dyeing treatment time, etc.
It may be appropriately changed according to the use or the dyeing process. However, regarding the temperature, the treatment is usually carried out at room temperature to about 70 ° C.

Next, as shown in FIG. 5C, water is applied to the transparent substrate 4 from the cleaning nozzle 34 to rinse it with flowing water. Thereby, the surplus dyeing material is removed. After this,
Although not shown in FIG. 5C, the rinse water is removed through a drying step.

FIG. 5C shows the shower cleaning (rinsing) by the nozzle 34, but the rinsing method is not limited to this method, and may be a batch type rinsing method.

Next, as shown in FIG.
The protective film 8 which has been masked to prevent dyeing is peeled off from the light emitting surface of the substrate. Depending on the material of the protective material film, it can be removed by another method such as dissolution removal.

In the case where the transparent substrate 4 is not dyed or hardly dyed by the dyeing solution 9 and the dyeing does not cause a problem even if dyed (for example, when a glass substrate is used as the transparent substrate), 5 (a) to 5 (d)
It is possible to omit the masking process for preventing the light emission surface of the transparent base material 4 from being stained as shown in FIG.

By the above-described dyeing process, as shown in FIG. 5 (d), the light absorbing layer 3 for shielding the blackened light of the transparent pressure-sensitive adhesive layer 5 on the light incident side of the transparent microsphere 2 is reproducible. Well formed. At the same time, the transparent pressure-sensitive adhesive layer 6
Maintains transparency without being dyed. Therefore, a limited area through which light passes on the light emission side, that is, the transparent adhesive layer 6
The light transmission amount does not decrease because the portion located inside is not shaded.

FIG. 13B is a sketch diagram based on an optical microscope photograph in this state. The planar lens 23 having the most basic configuration shown in FIG. 1 is manufactured through the steps up to FIG.

Next, as shown in FIG. 6A, the transparent substrate 1 coated with the transparent pressure-sensitive adhesive layer 11 is sequentially applied from one end by, for example, a pressure roll 37 so as to prevent air bubbles from entering. Press and laminate. At this time, the transparent substrate 1 can be made of the same material as the transparent substrate 4, and the transparent adhesive layer 11 can be made of the same material as the transparent adhesive layer 6.

For example, when the transparent pressure-sensitive adhesive layer 11 is made of the same UV-curable resin as the transparent pressure-sensitive adhesive layer 6, after this bonding step, UV curing can be performed to increase the adhesive strength.

FIG. 7 shows details of the embedding of the transparent microspheres 2 shown in FIG. 4B. As shown in the figure, the depth D at which the convex portion 2a on the light emission side of the transparent microsphere 2 is embedded in the transparent pressure-sensitive adhesive layer 6 is, for example, 50 μm in diameter.
m, 5 μ in the case of glass beads having a refractive index n = 1.9
m is sufficient.

This can be seen from the ray tracing simulation shown in FIG. That is, the transparent pressure-sensitive adhesive layer 5 in the depth direction
Staining rate _{of: V A (m / sec)} , in the dyeing velocity V _B of the transparent adhesive layer 6 in the depth direction (m / sec),
It is faster than the staining speed B of the transparent adhesive layer 5 toward the dyeing speed A of the transparent adhesive layer _{5 (V A >> V B)} .

That is, the transparent pressure-sensitive adhesive layer 6 and the transparent pressure-sensitive adhesive layer 5
Has a difference in easiness of dyeing, and it is an essential condition to make a difference in dyeing speed.

For this purpose, the material of the transparent pressure-sensitive adhesive layer is based on the same acrylic resin for both layers 5 and 6, and
The average molecular weight of the acrylic resin of the transparent pressure-sensitive adhesive layer 5 is smaller than the average molecular weight of the acrylic resin of the transparent pressure-sensitive adhesive layer 6. Alternatively, as another material that is easily dyed, all layers are based on the same type of UV curable acrylic resin, and the transparent adhesive layer 6 is irradiated with an appropriate amount of UV light in advance to advance the crosslinking, so that the transparent adhesive is The transparent pressure-sensitive adhesive layer 6 is larger than the crosslink density of the layer 5
Crosslink density can be increased. Alternatively, the materials of layers 5 and 6 are changed, for example, the former is urethane acrylate,
The latter can be formed with a base polymer of epoxy acrylate. Thereby, the effect as shown in FIG. 8 can be obtained.

FIGS. 9 to 12 show various types of planar lenses 23 manufactured by the manufacturing method of the present embodiment.

FIG. 9 is a plan view of the most basic configuration shown in FIG. 1 in which the transparent pressure-sensitive adhesive layer 11 is directly applied to the light incident side and the transparent substrate 1 having the configuration shown in FIG. 2 is omitted. Mold lens 23A. For example, if the transparent pressure-sensitive adhesive layer 11
In the case of using a cured resin, after applying the transparent pressure-sensitive adhesive layer 11 and performing UV curing, even in this structure,
A sufficient colored layer 3 and transparent microspheres 2 can be protected.

Although the surface of the transparent pressure-sensitive adhesive layer 11 on the light incident side is drawn flat in FIG. 9, the beads may be coated so as to be uneven. For example, if a relatively low-viscosity UV-curable resin is coated by spin coating or the like, such a shape is exhibited.

The example shown in FIG. 10 is different from the most basic configuration shown in FIG. 1 in that a flat type lens 23B having an antireflection film 7 made of a silicon oxide (SiO ₂ ) film or the like on each of a light incident side and a light emitting side is provided. It is. The anti-reflection film 7 may be provided on only one of the light incident side and the light emission side.

The example of FIG. 11 is a planar lens 23C in which the antireflection film 7 is provided on each of the light incident side and the light exit side of the planar lens 23A having the configuration shown in FIG.

FIG. 12 shows an example in which the antireflection film 7 is provided on the light incident side and the light exit side of the planar lens 23 having the structure shown in FIG.
This is a flat lens 23D provided with.

According to the above-described first embodiment, since the transparent microspheres 2 are dyed after being arranged, even if the microspheres 2 are rotated when pressed into the adhesive layer by a pressure roller, for example, the surface of the microspheres 2 is rotated. Only adheres to the transparent adhesive, and if this is removed by cleaning, it will not be stained by the dyeing process. Further, since the transparent microspheres 2 are about half exposed compared to the colored layer 3, light is easily incident, and the transparent microspheres 2 bite into the unstained transparent adhesive layer 6 on the light emission side. Light is easily emitted. Moreover, the dyed colored layer 3 functions as a light shielding layer,
Good contrast can be obtained because external light is absorbed and not reflected.

Further, when the microspheres 2 are pressed, the pressure-sensitive adhesive layers 5 and 6 are both transparent and not colored, so that a high-temperature heat-generating material (ie, for lowering the viscosity) is required. No special process is required. So, for example,
The transparent substrate, which is the substrate of the planar lens, is less likely to warp, and is therefore particularly advantageous when applied to a large projector screen.

Further, since a relatively low-cost black dye is used as a coloring material, it is possible to achieve a reduction in cost as compared with, for example, a case where a black pigment is mixed with a transparent hot melt adhesive. it can.

FIGS. 14 to 22 show a second embodiment.

As shown in FIG. 14, this planar lens 2
In 4, a rigid or flexible transparent base material 4 made of, for example, a glass plate, a plastic plate, or a plastic film is provided on the light incident side.

The substrate 4, the transparent pressure-sensitive adhesive layer 5 and the microspheres 2 described later need not necessarily be completely transparent as long as they can transmit most of the intended light.

That is, on the surface of the transparent substrate 4 on the light incident side,
For example, a transparent pressure-sensitive adhesive layer 5 having an adhesive and adhesive function such as a UV (ultraviolet) curable resin is provided.
For example, a large number of transparent microspheres 2 made of glass beads or the like are embedded and held. The transparent pressure-sensitive adhesive layer 5 located in the gap between these transparent microspheres 2 on the light incident side of the transparent substrate 4 is blackened by dyeing, and the light absorbing layer 3
Form as

FIG. 15 shows a more practical configuration of the flat lens 24. As shown in the drawing, in the basic configuration shown in FIG. 14, the transparent substrate 1 is laminated also on the light incident side via the transparent adhesive layer 16. The transparent adhesive layer 16 and the transparent substrate 1 can be made of the same material as the transparent adhesive layer 5 and the transparent substrate 4 on the light emission side, respectively.

With the structure in which the transparent microspheres 2 are sandwiched from both sides, the holding strength of the transparent microspheres 2 is improved, and the transparent microspheres 2 and the colored layer 3 are protected from the outside. Can be.

[0099] FIG. 15 (b), although the effect of this planar lens 24 illustrates schematically, the incident light L _in which substantially parallel light by the Fresnel lens is not shown, the light incident side transparent The light enters each transparent microsphere 2 via the base material 1 and the transparent pressure-sensitive adhesive layer 16, and the light converged by each transparent microsphere 2 is diffused forward as the emission light _Lout through the transparent base material 4 on the light emission side. Is emitted.

At this time, since about half of the diameter of each transparent microsphere 2 is embedded in the transparent pressure-sensitive adhesive layer 5 on the light incident side, a large amount of incident light Lin is _transmitted to each transparent microsphere 2.
Incident on. On the other hand, on the light emission side, a limited area through which light passes directly contacts the transparent substrate 4 on the light emission side, or the transparent substrate 4 is provided with a sufficiently thin dyed adhesive layer. Is in contact with Therefore, this planar lens 2
In No. 3, the area ratio of the colored layer 3 on the light emission side can be increased in a state where the light transmission amount, that is, the luminance of the transmission screen is increased. As a result, a decrease in contrast due to reflection of external light can be significantly reduced.

Next, referring to FIG. 16 to FIG.
A method of manufacturing the flat lens having the configuration shown in FIG.

First, as shown in FIG. 16A, a crosslinking reaction proceeds by, for example, UV curing on a transparent substrate 4 made of, for example, a glass plate or a plastic plate such as PMMA. A transparent pressure-sensitive adhesive layer 5 made of an acrylic UV curable resin that maintains the viscosity even after curing is applied to a thickness of, for example, about 10 to 20 μm.

Next, also in the case of the present embodiment, transparent microspheres are provided in the same manner as in the first embodiment described above (see FIGS. 3B to 3E). That is, as shown in FIG. 16B, for example, an average particle diameter (diameter) is formed on the transparent pressure-sensitive adhesive layer 5.
Supplies a large number of transparent microspheres 2 made of micro glass beads having a size of about 50 μm so that the transparent microspheres 2 have a two-dimensional close-packed structure at least in the lowermost layer.

Thereafter, squeezing, pressurization by a pressure roll, removal of excess transparent microspheres, etc.
Through the same steps as in the embodiment, only the transparent microspheres 2 held on the transparent pressure-sensitive adhesive layer 5 are left as shown in FIG.

Next, as shown in FIG. 16 (c), the transparent microspheres 2 are pressed from above by the pressure roll 31, and the transparent pressure-sensitive adhesive layer 5 is pressed until the transparent microspheres 2 come into contact with the transparent substrate 4. Embed in

Next, as shown in FIG. 16D, the transparent pressure-sensitive adhesive layer 5 made of a UV-curable resin is cured by irradiating ultraviolet rays with an ultraviolet lamp 32, and the transparent microspheres 2 are fixed.

Next, as shown in FIG. 17A, a masking process is performed on the light emitting surface of the transparent substrate 4 to prevent staining. This is because the protective film 8 (for example, several tens μm thick)
(A PET film) or a spray-type protective film may be formed.

Although not shown in FIG. 17A,
A masking process may be performed on the section (side surface) of the transparent substrate 4 as necessary.

Next, as shown in FIG. 17 (b), the dyeing tank 33 is filled with the dyeing solution 9, and the transparent substrate 4 on which the micro glass beads are arranged and fixed is immersed in the dyeing bath 9 for dyeing.

As a dyeing solution, a general resin dye can be used. Further, a black material having excellent light-shielding properties is preferred, but other colors may be used according to the application.

As an example of the black dyeing solution, there is a solution in which a black disperse dye is dissolved in glycol ether containing an anionic surfactant. For example, a resin dye SDN color manufactured by Osaka Chemical Co., Ltd. is used.

The concentration, temperature, dyeing time and the like of the dyeing solution may be appropriately changed according to the use and the dyeing process. However, regarding the temperature, the treatment is usually carried out at room temperature to about 70 ° C.

Next, as shown in FIG. 17 (c), water is applied to the transparent substrate 4 from the cleaning nozzle 34 to rinse it with flowing water. Thereby, the surplus dyeing material is removed. Thereafter, though not shown in FIG. 17C, a rinsing water is removed through a drying step.

In FIG. 17C, the shower cleaning (rinsing) by the nozzle 34 is shown, but the rinsing method is not limited to this method, and may be a batch type rinsing or the like.

Next, as shown in FIG. 17D, the light-exiting surface of the transparent substrate 4 is peeled off the protective film 8 which has been masked to prevent staining. Depending on the protective material, it can be removed by another method such as dissolution removal.

If the transparent substrate 4 is not dyed or hardly dyed by the dyeing solution 9 and it does not matter if it is dyed (for example, when a glass substrate is used as the transparent substrate), the following figure is used. 17 (a) to (d) can omit the masking processing for preventing the light emission surface of the transparent substrate 4 from being stained.

By the above-described dyeing step, as shown in FIG. 17D, the black light-shielding layer 3 is formed on the light emitting side of the transparent microsphere 2.

As a result, the state on the light emitting side as shown in the sketch drawing based on the optical microscope photographs shown in FIGS. 13A and 13B is formed in the same manner as in the first embodiment described above. be able to. The planar lens 24 having the most basic configuration shown in FIG. 14 is manufactured through the steps shown in FIG. 17D.

Next, as shown in FIG. 18A, the transparent base material 1 coated with the transparent pressure-sensitive adhesive layer 16 is sequentially moved from one end by, for example, a pressure roll 37 so as to prevent air bubbles from entering. Press and laminate. At this time, the transparent substrate 1 is made of the same material as the transparent substrate 4, and the transparent adhesive layer 11 is
The same material as that of the transparent pressure-sensitive adhesive layer 5 can be used.

For example, when the transparent pressure-sensitive adhesive layer 16 is made of the same UV curable resin as the transparent pressure-sensitive adhesive layer 5, after this bonding step, UV curing can be performed to increase the adhesive strength.

FIGS. 19 to 22 show various types of flat lenses 24 manufactured by the manufacturing method of the second embodiment.
Is shown.

In the example of FIG. 19, the transparent adhesive layer 16 is directly formed on the light incident side in the most basic configuration shown in FIG. 14, and the transparent substrate 1 having the configuration shown in FIG. 15 is omitted. Mold lens 24A. For example, the transparent adhesive layer 16
Is composed of a UV curable resin, the colored layer 3 and the transparent microspheres 2 can be sufficiently protected even with this structure by applying UV curing after applying the transparent pressure-sensitive adhesive layer 16.

Although the surface of the transparent pressure-sensitive adhesive layer 16 on the light incident side is drawn flat in FIG. 19, the transparent pressure-sensitive adhesive layer 16 may be coated so as to conform to the irregularities of the beads. For example, a relatively low viscosity U
When the V-cured resin is coated by a spin coating method or the like, it takes on the shape as described above.

The example shown in FIG. 20 is different from the most basic configuration shown in FIG. 14 in that the antireflection film 7 made of a silicon oxide (SiO ₂ ) film or the like is provided on each of the light incident side and the light exit side. It is. The anti-reflection film 7 may be provided on only one of the light incident side and the light emission side.

The example shown in FIG. 21 is a flat lens 24C in which an antireflection film 7 is provided on each of the light incident side and the light emitting side of the flat lens 24A having the structure shown in FIG.

The example of FIG. 22 is a planar lens 24D in which the antireflection film 7 is provided on each of the light incident side and the light emitting side of the planar lens 24 having the configuration shown in FIG.

The example of FIG. 23 is a planar lens 24E in which the transparent substrate 4 on the light emission side is omitted in the most basic configuration shown in FIG. When the protection of the transparent microspheres 2 and the light absorbing layer 3 on the light emission side is not particularly required,
It can be used satisfactorily as it is.

The example of FIG. 24 is a planer lens in which a transparent adhesive layer 17 is provided on the light emitting side in the configuration shown in FIG. 23 to protect the transparent microspheres 2 and the light absorbing layer 3 on the light emitting side. 24F.

In the example of FIG. 25, a transparent substrate 4 is provided on the light emitting side in the configuration shown in FIG. 23, and the transparent microspheres 2 and the light absorbing layer 3 on the light emitting side are more firmly protected. The lens G.

The example of FIG. 26 is a planar lens 24H in which the transparent substrate 4 is provided on the light emission side via the transparent adhesive layer 17 in the configuration shown in FIG.

The example shown in FIG. 27 is different from the structure shown in FIG. 25 in that the transparent lens 1 on the light incident side is omitted.
I. This structure is, for example, a transparent substrate 4 on the light incident side.
Instead, the structure shown in FIG. 25 is manufactured using a peelable substrate, and the substrate can be manufactured by peeling the substrate at an appropriate time during the process.

The example of FIG. 28 is a planar lens 24J in which the transparent substrate 1 on the light incident side is omitted in the structure shown in FIG.

FIG. 29 shows the results of simulating ray tracing and screen gain in the planar lenses according to the first and second embodiments, respectively.

In the calculation, the transparent base materials 4 and 1 are set to have a refractive index n =
1.490 polymethyl methacrylate (PMMA),
The transparent adhesive layers 5 and 6 are made of an acrylic UV curable resin having a refractive index n = 1.490, and the transparent microspheres 2 are made of a refractive index n = 1.9.
Performed as 00 glass beads. The refractive index of air was set to n = 1.000.

The thickness of each layer is 100 μm for the transparent substrates 4 and 1, 30 μm for the transparent adhesive layer 5 and 2 μm for the colored layer 3.
5 μm, and the transparent adhesive layer 6 was 5 μm. Transparent microsphere 2
Has a configuration in which the diameter is 50 μm, and 25 μm of the half is embedded in the transparent adhesive layer 5. The transmittance of each layer was 100% except for the colored layer 3.

FIG. 29A and its enlarged view FIG.
As shown in (b), the light emitting portion of the transparent microsphere 2 has a certain area, and in this example, is a circle having a radius of about 10.8 μm. From this, as described above, by exposing a portion of each transparent microsphere 2 having a diameter s of about 21.6 μm or more from the coloring layer 3, it is possible to minimize the light loss at the light emitting portion. I understand.

Here, the plane filling rate of the transparent microspheres 2 is set to 9
Assuming 0%, the black area ratio of the screen viewed from the light emitting side is 1− {0.9 × (21.6 / 50.0) ² } 0.83, which is about 83%. That is, for example, the area ratio of the black portion of the conventional transmission screen in which the black stripes are provided on the lenticular lens as shown in FIG. In the transmissive screen used, the area ratio of the black portion can be greatly increased, and therefore a clear image with less reduction in contrast due to reflection of external light can be obtained.

FIG. 29B shows a change in screen gain depending on the light emitting direction.

In the figure, the horizontal axis represents the emission angle [degre] of the emitted light.
e], the vertical axis is the screen gain (= luminance in a certain exit angle direction / incident light amount).

The total light transmittance (= total outgoing light amount / total incident light amount) of this flat lens is about 77.4%, and the light transmittance at the transparent microsphere 2 portion (= total outgoing light amount / transparent minute). Light quantity incident on sphere 2 = Total light quantity / ｛Total light quantity x
(Area of transparent microsphere 2 per unit area / unit area)｝)
Was about 85.4%.

In the result of FIG. 29B, the peak gain at the center is about 2.21, and the angle range where a gain of 1/2 of this peak gain can be obtained is about 53.0 ° and 1/3. The angle range where the gain was obtained was about 71.9 °, and the angle range where the gain of 1/10 was obtained was about 162.6 °.

According to the above-described second embodiment, since the transparent microspheres 2 are dyed after being placed, even when the microspheres 2 are rotated, for example, when the microspheres 2 are pressed into the pressure-sensitive adhesive layer by a pressure roller, the surface of the microspheres 2 is not dyed. Only adheres to the transparent adhesive, and does not stain for the same reason as described above. Further, since the transparent microspheres 2 are about half as exposed as the colored layer 3, light is easy to enter. On the opposite exit side, the transparent microspheres 2 are in contact with the transparent substrate 4, so that light is The emission area is maintained without affecting the dyed colored layer 3. Moreover, since the dyed colored layer 3 functions as a light-shielding layer as in the first embodiment, good contrast can be obtained. In addition, the entire transparent pressure-sensitive adhesive layer 5 is dyed. Therefore, there is no need to specifically control the staining conditions.

Since a high-temperature thermal process is not particularly required as in the first embodiment, for example, a transparent substrate serving as a substrate of a flat lens hardly warps. Therefore,
Particularly, it is advantageous when applied to a large projector screen, and furthermore, as a relatively low-cost black dye is used as a coloring material, for example, a black pigment is mixed with a transparent hot melt adhesive. The cost can be reduced as compared with the case of using.

FIGS. 30 and 31 show screens for a rear projection type projector using these planar lenses, taking the basic structure of the first and second embodiments as examples. Of course, the planar lenses of the various embodiments described above can also be used.

FIG. 30 shows that after the first embodiment shown in FIG. 2 is manufactured, a Fresnel lens 22 is bonded to the light incident side of the flat lens 23 to form an integral transmission screen 10.
A is constructed.

FIG. 31 shows that after the second embodiment shown in FIG. 15 is manufactured, a Fresnel lens 22 is joined to the light incident side of the flat lens 24 to form an integral transmission screen 10B. It is composed.

The embodiments described above can be modified based on the technical idea of the present invention.

For example, in the dyeing of a single-layer transparent pressure-sensitive adhesive layer as in the second embodiment, the dyeing is performed from the surface to an intermediate depth, or the transparent pressure-sensitive adhesive layer is controlled by controlling the dyeing conditions (eg, dyeing time). Provide a material layer to prevent dyeing in the middle position of the thickness of the, dye the adhesive layer on this material layer,
The lower part can be divided into a stained layer and a non-stained layer on the light incident side and the light emission side, for example, by forming a non-stained layer.

Further, in each of the embodiments, the transparent base material is provided on both sides or one side, but in any of the embodiments, the transparent base material may not be provided on both sides.

Further, the lens to be joined to the incident side of the flat lens manufactured in each embodiment is not limited to a Fresnel lens, but can be applied to a lens that generates parallel light.

Further, the configuration and structure of the flat lens, the coloring dye, and the like are not limited to the above-described embodiments, and can be appropriately performed.

[0152]

As described above, the present invention has a plurality of transparent microspheres distributed in a plane or a curved surface, and a transparent adhesive layer holding the plurality of microspheres. Part of the transparent pressure-sensitive adhesive layer is embedded in the transparent pressure-sensitive adhesive layer, and at least the light incident side of the transparent pressure-sensitive adhesive layer is dyed between the plurality of microspheres to form a light-absorbing layer. In this case, since the non-buried portion of the microspheres is not stained by staining, the transmission area of the incident light passing through the microspheres can be sufficiently maintained and the transmittance can be increased. Can be prevented from being reflected. In addition, since a high-temperature heat process is not particularly required, for example, a transparent substrate serving as a substrate of a flat lens hardly warps. As a result, it is possible to obtain a flat lens capable of projecting image light with high transmittance and good contrast.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the most basic configuration of a planar lens according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a more practical configuration of the planar lens.

FIG. 3 is a schematic cross-sectional view showing a method of manufacturing a planar lens in the order of steps.

FIG. 4 is a schematic cross-sectional view showing another manufacturing process of the planar lens in the order of processes.

FIG. 5 is a schematic cross-sectional view showing another manufacturing process of the planar lens in the order of processes.

FIG. 6 is a schematic cross-sectional view showing still another manufacturing process of the planar lens in the order of processes.

FIG. 7 is a schematic cross-sectional view showing details of embedding a transparent microsphere in the planar lens.

FIG. 8 is a simulation diagram showing the dyeing speed of the dye in the planar lens.

FIG. 9 is a schematic cross-sectional view showing the configuration of the planar lens.

FIG. 10 is a schematic sectional view showing another configuration of the planar lens.

FIG. 11 is a schematic sectional view showing another configuration of the planar lens.

FIG. 12 is a schematic sectional view showing still another configuration of the planar lens.

FIG. 13 is a sketch drawing based on a microphotograph of the planar lens, in which (a) shows a state in which transparent microspheres are arranged, and (b) shows a state in which a light emitting portion is formed in a colored layer. .

FIG. 14 is a schematic sectional view showing the most basic configuration of a planar lens according to a second embodiment of the present invention.

FIG. 15 is a schematic sectional view showing a more practical configuration of the planar lens.

FIG. 16 is a schematic cross-sectional view showing a method of manufacturing a planar lens in the order of steps.

FIG. 17 is a schematic cross-sectional view showing another manufacturing step of the planar lens in the order of steps.

FIG. 18 is a schematic cross-sectional view showing still another manufacturing step of the planar lens in the order of steps.

FIG. 19 is a schematic sectional view showing the configuration of the planar lens.

FIG. 20 is a schematic sectional view showing another configuration of the planar lens.

FIG. 21 is a schematic sectional view showing another configuration of the planar lens.

FIG. 22 is a schematic sectional view showing another configuration of the planar lens.

FIG. 23 is a schematic sectional view showing another configuration of the planar lens.

FIG. 24 is a schematic sectional view showing another configuration of the planar lens.

FIG. 25 is a schematic sectional view showing another configuration of the planar lens.

FIG. 26 is a schematic sectional view showing another configuration of the planar lens.

FIG. 27 is a schematic sectional view showing another configuration of the planar lens.

FIG. 28 is a schematic sectional view showing still another configuration of the planar lens.

FIG. 29 is a graph showing simulation results of ray tracing and screen gain in a planar lens manufactured by the manufacturing method of the present invention.

FIG. 30 is a schematic cross-sectional view showing one mode of a rear projection type projector screen using the planar lens according to the first embodiment.

FIG. 31 is a schematic sectional view showing one mode of a screen for a rear projection type projector using the planar lens of the second embodiment.

FIG. 32 is a schematic view showing a conventional rear projection type projector.

FIG. 33 is a schematic diagram and a cross-sectional view showing a configuration of a lenticular lens in a conventional rear projection type projector.

FIG. 34 is a schematic view showing an open-type rear projection type projector using a flat lens made of transparent microspheres.

FIG. 35 is a schematic diagram showing a box-type rear projection type projector using a flat lens made of transparent microspheres.

FIG. 36 is a schematic cross-sectional view showing a basic configuration of a flat lens made of transparent microspheres.

[Explanation of symbols]

1, 4: transparent base material, 2: transparent microsphere, 2a: convex portion, 3
... light absorbing layer (colored layer), 5, 6, 11, 16, 17 ... transparent adhesive layer, 7 ... anti-reflection film, 8 anti-staining protective film, 9 ... dye solution, 23, 24 ... flat lens, L: external light, L _in : incident light, L _out : outgoing light, A, B: staining speed trend line

Claims (38)

[Claims] 1. A method comprising: a plurality of transparent microspheres distributed in a plane or a curved surface; and a transparent adhesive layer holding the plurality of microspheres, wherein a part of the microspheres is located in the transparent adhesive layer. A planar lens that is embedded and at least a light incident side of the transparent pressure-sensitive adhesive layer is dyed between the plurality of microspheres to form a light absorbing layer. 2. The flat lens according to claim 1, wherein a portion other than a predetermined portion on the light incident side of the microsphere is embedded in the light absorbing layer. 3. The flat lens according to claim 2, wherein the predetermined portion is embedded in the unstained transparent pressure-sensitive adhesive layer. 4. The transparent pressure-sensitive adhesive layer is formed of a laminate of a first transparent pressure-sensitive adhesive layer and a second transparent pressure-sensitive adhesive layer, and the second transparent pressure-sensitive adhesive layer is dyed and A predetermined portion on the light emission side of the microsphere is the first layer.
The flat lens according to claim 1, which is embedded in the transparent pressure-sensitive adhesive layer. 5. The light-adhesive layer is provided in a single layer and is dyed to form the light-absorbing layer. Is a predetermined portion of the light-emitting side of the microsphere embedded in the light-absorbing layer? 2. The flat lens according to claim 1, wherein the light absorption layer has a sufficiently small thickness on the light emission side of the predetermined location. 3. 6. The flat lens according to claim 1, wherein the thickness of the transparent pressure-sensitive adhesive layer is controlled so that about half of the diameter of the microsphere is embedded. 7. The dyeing speed of a portion of the transparent pressure-sensitive adhesive layer to be dyed is higher than the dyeing speed of a lower layer thereof.
The planar lens according to claim 1. 8. The flat lens according to claim 4, wherein the dyeing speed of the second transparent pressure-sensitive adhesive layer is higher than that of the transparent pressure-sensitive adhesive layer. 9. The flat lens according to claim 1, wherein at least the light incident side of the transparent pressure-sensitive adhesive layer is dyed black. 10. The flat mold according to claim 1, wherein the transparent pressure-sensitive adhesive layer dyed at least on a light incident side and the plurality of microspheres partially embedded therein are provided on a transparent substrate. lens. 11. A third light-emitting side on the light incident side of the plurality of microspheres.
The planar lens according to claim 1, wherein a transparent substrate is further joined through the transparent pressure-sensitive adhesive layer. 12. The flat lens according to claim 1, which is used for a screen for a rear projection type projector. 13. A step of distributing a plurality of transparent microspheres on a transparent pressure-sensitive adhesive layer in a planar or curved shape; a step of embedding a part of the plurality of microspheres in the transparent pressure-sensitive adhesive layer; Dyeing at least the light incident side of the transparent pressure-sensitive adhesive layer between the microspheres. 14. The method of manufacturing a flat lens according to claim 13, wherein a portion other than a predetermined portion on the light incident side of the microsphere is embedded in the light absorbing layer. 15. The method of manufacturing a flat lens according to claim 14, wherein the predetermined portion is embedded in the non-stained transparent pressure-sensitive adhesive layer. 16. The transparent pressure-sensitive adhesive layer is formed of a laminate of a first transparent pressure-sensitive adhesive layer and a second transparent pressure-sensitive adhesive layer, and
14. The flat lens according to claim 13, wherein the transparent pressure-sensitive adhesive layer is dyed to form the light absorbing layer, and a predetermined portion on the light emission side of the microsphere is embedded in the first transparent pressure-sensitive adhesive layer. Production method. 17. The method according to claim 17, wherein the transparent pressure-sensitive adhesive layer is provided as a single layer, and the light-absorbing layer is dyed to form a light absorbing layer. 14. The method for manufacturing a flat lens according to claim 13, wherein the light absorbing layer is provided with a sufficiently small thickness on the light emitting side of the flat lens. 18. The method according to claim 13, wherein the thickness of the transparent pressure-sensitive adhesive layer is controlled so that about half of the diameter of the microsphere is embedded. 19. The method according to claim 13, wherein the transparent pressure-sensitive adhesive layer in which the microspheres are embedded is immersed in a dye dispersed in a solvent during the dyeing. 20. The method of manufacturing a flat lens according to claim 13, wherein a dyeing speed of a portion of the transparent pressure-sensitive adhesive layer to be dyed is set to be higher than a dyeing speed of a lower layer thereof. 21. The method according to claim 16, wherein the dyeing speed of the second transparent pressure-sensitive adhesive layer is set higher than that of the transparent pressure-sensitive adhesive layer. 22. The method of manufacturing a flat lens according to claim 19, wherein masking for preventing dyeing is performed on unnecessary portions at the time of dyeing. 23. The method according to claim 13, wherein at least the light incident side of the transparent pressure-sensitive adhesive layer is dyed black. 24. After the dyeing, the dyed portion of the transparent pressure-sensitive adhesive layer is washed with water and dried to remove excess dye.
A method for manufacturing a flat lens according to claim 13. 25. The method of manufacturing a flat lens according to claim 13, wherein the transparent pressure-sensitive adhesive layer at least on the light incident side is dyed and the plurality of microspheres partially embedded in the transparent pressure-sensitive adhesive layer are provided on a transparent substrate. Method. 26. A third light-incident side of the plurality of microspheres.
14. The method for manufacturing a flat lens according to claim 13, further comprising bonding a transparent substrate through the transparent pressure-sensitive adhesive layer. 27. The method for manufacturing a flat lens according to claim 13, which is used for a screen for a rear projection type projector. 28. A method comprising: a plurality of transparent microspheres distributed in a plane or a curved surface; and a transparent pressure-sensitive adhesive layer holding the plurality of microspheres, wherein a part of the microspheres is located in the transparent pressure-sensitive adhesive layer. A screen for a rear projection type projector using a flat lens that is embedded and at least a light incident side of the transparent pressure-sensitive adhesive layer is dyed between the plurality of microspheres to form a light absorbing layer. 29. The screen for a rear projection type projector according to claim 28, wherein a flat lens embedded in the light absorbing layer except for a predetermined portion on the light incident side of the microsphere is used. 30. The screen for a rear projection type projector according to claim 29, wherein a flat lens whose predetermined portion is embedded in the non-stained transparent pressure-sensitive adhesive layer is used. 31. The transparent pressure-sensitive adhesive layer is formed of a laminate of a first transparent pressure-sensitive adhesive layer and a second transparent pressure-sensitive adhesive layer,
The second transparent pressure-sensitive adhesive layer is dyed to form the light-absorbing layer, and a predetermined lens on the light-emitting side of the microsphere is embedded in the first transparent pressure-sensitive adhesive layer. 29. The rear projection type projector screen according to claim 28, which is used. 32. The transparent pressure-sensitive adhesive layer is provided as a single layer,
The light-absorbing layer is dyed, and a predetermined portion on the light-emitting side of the microsphere is not embedded in the light-absorbing layer, or the light-absorbing layer is sufficiently provided on the light-emitting side of the predetermined portion. Using a flat lens that exists at a small thickness,
A screen for a rear projection type projector according to claim 28. 33. The rear projection type projector according to claim 28, wherein a flat lens whose thickness of the transparent pressure-sensitive adhesive layer is controlled so that about half of the diameter of the microsphere is embedded. screen. 34. The screen for a rear projection type projector according to claim 28, wherein a dyeing speed of a portion of the transparent pressure-sensitive adhesive layer to be dyed is higher than a dyeing speed of a lower layer thereof. 35. A flat lens in which the dyeing speed of the second transparent pressure-sensitive adhesive layer is higher than that of the transparent pressure-sensitive adhesive layer,
A screen for a rear projection type projector according to claim 31. 36. The screen for a rear projection type projector according to claim 28, wherein a flat lens in which at least the light incident side of the transparent pressure-sensitive adhesive layer is dyed black. 37. A flat lens in which at least the transparent pressure-sensitive adhesive layer dyed on the light incident side and the plurality of microspheres partially embedded therein are provided on a transparent substrate. 29. The screen for a rear projection type projector according to 28. 38. A third light-incident side of the plurality of microspheres
29. The screen for a rear projection type projector according to claim 28, wherein a flat lens to which a transparent substrate is further bonded via a transparent pressure-sensitive adhesive layer is used.