JP2001004806A - Plane lens and manufacture thereof and screen for rear projection type projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive plane lens having satisfactory function and allowing the arrangement of many minute spherical bodies at uniform distribution density under clean environment and a manufacturing method therefor. SOLUTION: In this manufacturing method for a plane lens, a transparent minute spherical body 2 is formed by covering a surface of an electrically conductive body part 2a with an insulation film 2b, and the transparent minute spherical body 2 is electrified with a negative charge and a transparent adhesive layer 5 is charged with positive charges by applying a voltage when the transparent minute spherical bodies 2 are supplied for the transparent adhesive layer 5 in which an electrification prevention layer 5b is formed on a light outgoing side or a transparent adhesive layer in which an electrification prevention agent is kneaded, thereby distributing the transparent minute spherical bodies 2 at equal density by the electrostatic force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[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). One embodiment of the prior invention 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.

[0017]

However, conventionally,
Such a flat lens manufacturing method, when filling a transparent substrate with transparent microspheres as optical components and arranging a single layer,
The worker presses the transparent microspheres against the adhesive material by hand while wearing gloves and arranges them without gaps, and the worker checks the arrangement state visually.

Therefore, there is a problem that the arrangement state of the transparent microspheres is not always constant depending on the operator. In particular, it is very difficult to make the distribution of the transparent microspheres uniform on the substrate, which causes a problem of uneven brightness, and there is a demand to automate the arrangement of the transparent microspheres.

In addition, in such a manufacturing method, the manufacturing time is prolonged as a whole, resulting in an increase in cost. In addition, since fine particles having a diameter of several tens of μm are handled, there is a problem in a manufacturing environment involving dust generation. Had become.

Therefore, an object of the present invention is to provide a clean environment
It is an object of the present invention to provide an inexpensive and high-performance planar lens in which a large number of microspheres are arranged at a uniform distribution density, a method for manufacturing the same, and a screen for a rear projection type projector.

[0021]

That is, the present invention holds a plurality of transparent microscopic bodies which are distributed in a plane or a curved shape, and each of which has at least a surface portion having electrical insulation, and a plurality of the transparent microscopic bodies. At least the light exit side has an adhesive layer provided with conductivity, and a part of the transparent micro body on the light incident side is embedded in the adhesive layer, and the plurality of transparent micro bodies are exposed such that the light exit side is exposed. The present invention relates to a flat lens in which a light absorbing layer is disposed in a gap between the flat lenses (hereinafter, referred to as a flat lens of the present invention).

According to the flat lens of the present invention, the surface portion of the transparent fine body has electrical insulation, and the light emitting side of the adhesive layer has conductivity. By charging the adhesive layer with a positive charge and charging the transparent microparticles with a negative charge using such a principle, it is possible to distribute the transparent microparticles on the adhesive layer at a uniform density in a short time by electrostatic force. it can. Therefore, it is possible to distribute the transparent micro-particles in a favorable environment without dust generation. As a result, the manufacturing time is shortened and the cost is reduced due to the automation of the transparent micro-particle supply. A lens can be realized.

Further, according to the present invention, a plurality of transparent fine bodies which are distributed in a plane or a curved shape and each of which has at least a surface portion having an electrical insulating property, the plurality of transparent fine bodies are held, and at least a light emitting side is provided. An adhesive layer provided with conductivity, a part of the transparent micro body on the light incident side is embedded in the adhesive layer, and light is absorbed in a gap between the plurality of transparent micro bodies so that a light emission side is exposed. When manufacturing a planar lens in which a layer is disposed, a step of forming the adhesive layer, and a step of imparting conductivity to at least the light emitting side of the adhesive layer,
Supplying the plurality of transparent microscopic bodies on the adhesive layer, embedding the plurality of transparent microscopic bodies in the adhesive layer to a predetermined depth, and exposing a predetermined region on the light emission side of the transparent microscopic bodies; Filling a gap between the bodies with a light absorbing material to form a light absorbing layer (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 with good reproducibility of a flat lens which has the same effect as the flat lens of the present invention.

Further, according to the present invention, a plurality of transparent fine bodies which are distributed in a plane or a curved shape and each of which has at least a surface portion having electrical insulation, and the plurality of transparent fine bodies are held, and at least a light emitting side is provided. An adhesive layer provided with conductivity, a part of the transparent micro body on the light incident side is embedded in the adhesive layer, and light is absorbed in a gap between the plurality of transparent micro bodies so that a light emission side is exposed. The present invention relates to a rear projection type projector screen (hereinafter, referred to as a projector screen of the present invention) in which layers are disposed and in which a planar lens is used.

According to the projector screen of the present invention, since the above-described flat lens of the present invention is used,
A good projector screen free from a phenomenon such as uneven brightness can be provided.

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 or transparent fine body, etc. may not necessarily be a completely transparent body as long as it can transmit most of the intended light. It is used in the meaning including.
In addition, the above-mentioned “micro body” originally refers to a body having at least a substantial part on the light incident side having a spherical shape and exhibiting a lens effect, and does not have to be a perfect sphere.

[0028]

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

In the above-described flat lens, manufacturing method and projector screen of the present invention, FIG.
As shown in FIG.
a and an electrically insulating material layer 26 covering the surface with a thickness of, for example, 1 to 5 μm.

As shown in FIG. 2, the conductive property is imparted by applying an antistatic layer 5b made of an antistatic agent to the surface of the electrically insulating adhesive layer 5 to a thickness of, for example, 1 to 3 μm. Preferably, or as shown in FIG. 8, the antistatic agent is kneaded into an electrically insulating pressure-sensitive adhesive (internal kneading mode, kneading amount is, for example, 1 to 3% by weight). May be imparted.

It is desirable that the plurality of transparent microscopic bodies 2 are held by the transparent adhesive layer 5 in contact with each other.

Further, it is desirable that the plurality of transparent microscopic bodies 2 are arranged in a single layer, and that 30% or more of each of the transparent microscopic bodies 2 is embedded in the adhesive layer 5 on the light incident side.

In this case, as shown in FIG. 5 (d), the transparent fine body 2 having a part of the light incident side embedded in the adhesive layer 5 and a light absorbing layer (hereinafter referred to as a colored layer) disposed in the gap. Is preferably provided on a transparent substrate 4, and a transparent adhesive layer is desirably formed as the adhesive layer 5.

As shown in FIG. 6, it is desirable that the transparent substrate 1 is further joined to the light emitting side of the plurality of transparent microscopic bodies 2 via the second transparent adhesive layer 6.

With the above configuration, it is possible to configure a suitable flat lens used for a rear projection type projector screen.

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

In the following embodiment, parts corresponding to the above-described structures shown in FIGS.
The same reference numerals as in FIG. 36 are used.

First, a planar lens according to the first embodiment of the present invention will be described with reference to FIGS.

First, as shown in FIG. 3A, a transparent adhesive layer 5 is formed on the transparent substrate 4 on the light incident side. For example,
Acrylic ultraviolet (UV) with protective film 5a
The cured resin is, for example, polymethyl methacrylate (PM
MA) or the like is attached on a transparent substrate 4 made of an acrylic resin. 4a is a protective film for protecting the back side of the transparent substrate 4.

As the transparent substrate 4, other than the above-mentioned acrylic resin such as PMMA, for example, a rigid glass substrate or various plastic substrates having rigidity or flexibility can be used. Other than the acrylic resin and glass described above, for example, polycarbonate resin, polyolefin resin, vinyl chloride resin, polystyrene resin, polyethylene resin, epoxy resin, polyarylate resin, polyether sulfone resin, silicone resin, polyethylene terephthalate resin, and the like can be used. it can.

Since the transparent adhesive layer 5 has a large number of transparent microspheres 2 embedded therein and has to be fixed and held securely, it has an appropriate softness before light curing, so that the transparent microspheres can be easily embedded. In addition, it is particularly preferable that the light-cured resin be made of an acrylic ultraviolet curable resin that securely fixes and holds the transparent microspheres after photocuring. However, other acrylic resins and, for example, polycarbonate resin,
It may be composed of polyolefin resin, vinyl chloride resin, polystyrene resin, polyethylene resin, epoxy resin, polyarylate resin, polyether sulfone resin, silicone resin, polyethylene terephthalate resin, or the like.

Next, as shown in FIG. 3 (b), the protective film 5 a is peeled off from the transparent adhesive layer 5 while neutralizing static electricity by performing a static elimination blow 41 and removing dust by suction.

Next, for example, as shown in FIG.
An antistatic agent is applied onto the transparent adhesive layer 5 from the nozzle 42 to form an antistatic layer 5b. The antistatic agent is preferably, for example, an aqueous solution of the following alkylalanine-based amphoteric surfactant. Commercially available products include Lipomin LA manufactured by Lion Corporation.

Embedded image

As shown in FIG. 1B, each transparent microsphere 2 has at least a surface of a main body 2a made of, for example, conductive glass beads covered with an insulating film 2b made of an electrically insulating material. It is configured.

The main body 2a of each transparent microsphere 2 may be made of, for example, conductive plastic in addition to the above-mentioned conductive glass.

The insulating film 2b of each transparent microsphere 2 is
It can be formed by immersing the main body 2a in a solution in which an organic insulating polymer is dispersed, and then pulling up and drying. However, besides this, an inorganic insulating material such as S: O ₂ may be coated on the outside of the main body 2a by using a method such as vacuum deposition, or the like, and the main body 2a may be coated using a CVD method or a liquid phase growth method. The insulating film 2b may be formed outside.

Each of the transparent microspheres 2 may be entirely made of insulating glass or plastic.

In this case, examples of the plastic material include acrylic resin and polystyrene resin.

The refractive index of each transparent microsphere 2 is at least such that the refractive index of the main body 2a is larger than the refractive index of the transparent adhesive layer 5 in contact with the transparent microsphere 2 on the light incident side. 4 or more.

The size of the main body 2a of each transparent microsphere 2 is, for example, a diameter d = 50 to 100 [μm]. If this size is too large, the gap between the transparent microspheres 2 becomes too large, particularly when a screen for a rear projection type projector is formed, and the resolution may be reduced.

The variation in the size of the main body 2a of the transparent microsphere 2 is, for example, 10% or less of its average diameter. If this variation is too large, it may be difficult to distribute the transparent microspheres 2 uniformly.

Next, as shown in FIG. 3D, the transparent microspheres 2 are formed by applying a so-called electrostatic screen printing technique.
Is filled on the antistatic layer 5b on the transparent adhesive layer 5 to form a light diffusion layer.

That is, as shown in an enlarged manner in FIG.
A 100-300 mesh stainless screen 46 is attached to a screen frame 47, and the transparent microspheres 2 on which the insulating film 2b is formed are supplied thereon. The stainless steel screen 46 may have all openings thereof open.

When there is an area where the transparent microspheres are not intentionally filled, such as when it is not desired to dispose the transparent microspheres 2 at the edge of the transparent substrate 4, the position of the area is determined. It is only necessary to close the eyes of the screen corresponding to.

The transparent substrate 4 on which the transparent adhesive layer 5 and the antistatic agent 5b have been applied in advance is coated with a metal plate 48 as a base of a printing machine.
Place on top of. Then, a DC high voltage V _H of, for example, 1000 to 3000 V is applied between the metal plate 48 and the screen frame 47 in the illustrated direction. Board 48
To form an electrostatic field with the positive electrode side.

The distance t ₁ between the stainless screen 46 and the upper end of the transparent substrate 4 is, for example, about 2 to 5 m.
m, the thickness t ₂ of the light absorbing layer 3 to be filled and formed is, for example, about 200 μm, and the thickness t ₃ of the transparent adhesive layer 5 is, for example, about 2 μm.
The thickness t ₄ of the transparent substrate 4 is, for example, about 2 mm. The diameter of each transparent microsphere 2 is, for example, about 5
0 μm. In FIG. 1A, the transparent substrate 4
The illustration of the protective film 5a on the back side is omitted.

In this state, for example, as shown in the figure, when the transparent microspheres 2 on the stainless steel screen 46 are rubbed by the brush 49, the transparent microspheres 2 negatively charged pass through the openings of the stainless steel screen 46. It is supplied during an electrostatic field. The negatively charged transparent microspheres 2 fall in the electrostatic field, are attracted to the surface of the positively charged transparent adhesive layer 5, and adhere thereto.

FIG. 2 is an enlarged view of a portion near the transparent adhesive layer 5 on which the transparent microspheres 2 have fallen and have been attracted. As shown in the figure, since the surface of the transparent adhesive layer 5 is provided with conductivity by forming the antistatic layer 5b, the surface is not charged, and the charged transparent microspheres 2 do not receive an electric repulsion. . In this case, for example, by grounding the transparent adhesive layer 5 through the antistatic layer 5b, the transparent substrate 4
It is preferable to reliably prevent the surface from being charged.

Next, as shown in FIG.
The transparent microspheres 2 are pressed from above with a pressure roll 31 of silicone rubber or the like, and the lowermost transparent microspheres 2 are embedded in the transparent adhesive layer 5 having an antistatic layer (not shown) 5b formed on the surface.

The amount of the transparent microspheres 2 embedded in the transparent adhesive layer 5 is, for example, 30% or more of the diameter thereof, more preferably about 50%. This ensures that the transparent adhesive layer 5 secures and holds each transparent microsphere 2, and increases the amount of light incident on each transparent microsphere 2. For example, when the transparent microsphere 2 is used for a rear projection type projector screen, The brightness increases.

Next, as shown in FIG. 4 (b), the surplus transparent microspheres 2 buried and not retained in the transparent adhesive layer 5 are removed by, for example, vacuum suction means 43.

Next, for example, as shown in FIG.
After checking the filling state of the transparent microspheres 2 with the camera 44, ultraviolet irradiation 45 is performed to cure the transparent adhesive layer 5 made of an ultraviolet curable resin and fix the transparent microspheres 2.

Next, as shown in FIG. 5A, a fine powder carbon toner is supplied to the entire surface by the hopper 33 to form the colored layer 3. The illustration of the antistatic layer 5b is omitted.

As the carbon toner, for example, ultrafine particles having a particle size of 0.05 to 0.2 μm using carbon black as a coloring agent and cellulose acetate as a fixing agent are used.

Cellulose acetate has many hydroxyl groups and is excellent in affinity with an uncrosslinked UV curable resin. this is,
It means that it is easily physically and chemically adsorbed on the surface of the transparent adhesive layer 5. The ultrafine particles having a particle size of 0.05 to 0.2 μm are in a state where each particle is aggregated via a fixing agent, but the aggregated state is easily deformed and each particle is easily dispersed. Therefore, these ultrafine particles are likely to enter a micro-gap in a beaded state, for example, and this property makes it easy to uniformly fill a gap in which micro-beads are densely packed.

As the carbon toner, there is a heat fixing type using an epoxy resin as a fixing agent. However, the epoxy resin has a strong affinity for the surface of glass beads.
Therefore, it is difficult to substantially completely remove the colored layer 3 at the light emitting portion of the transparent microspheres 2 later. Therefore, this type of carbon toner is not so preferable.

Next, as shown in FIG. 5B, for example,
Press the colored brush 3 against the colored layer 3 while rotating the rotating brush 34,
In this state, the rotating brush 34 is relatively moved to uniformly fill the gap between the transparent microspheres 2 with the carbon toner of the coloring layer 3.

FIG. 10 shows a configuration example of the rotating brush 34.

As shown in FIGS. 10 (a) and 10 (b), the rotating brush 34 is constituted by, for example, a brush portion 34c adhered and fixed to a rotating disk 34b attached to a rotating shaft 34a.

As shown in FIG. 10D, the brush bristles 3
As 4d, for example, an acrylic fiber having a diameter b of about 5 to 15 [μm] is suitable, and as shown in FIG. The hair is cut into pieces and implanted in the brush part 34c. The length of the bristles 34d is appropriately selected according to the type of toner, the state of the glass beads, and the like. The hair 34d can be planted in the brush portion 34c, for example, in a densely and uniformly planted state, or in a bundle of several to several tens of plants, and planted at an equal pitch. What is necessary is just to use properly according to the state of a glass bead side, etc.

For example, first, a long bristle 34d pushes the toner into the gap between the transparent microspheres 2 and then the bristle 3d.
The toner on each transparent microsphere 2 may be scraped to some extent by lightly rubbing a short 4d object to facilitate the subsequent toner removal step.

FIG. 10E shows that, for example, c = 5 [mm]
A brush part 34c in which several to several tens of bristles 34d of about the length are bundled and planted at an equal pitch is shown.

As described above, after the carbon brushes of the coloring layer 3 are uniformly filled in the gaps between the transparent microspheres 2 by the rotating brush 34, each transparent microsphere is removed by the toner removing step shown in FIG. The carbon toner in the region near the top of the sphere 2 is removed, and the light emitting portion of each transparent micro sphere 2 is exposed from the colored layer 3.

In this toner removing step, for example, as shown in an enlarged manner in FIG. 9, a microfiber cloth (a cloth woven with microfibers having a diameter of about several μm, for example, “Toraysee” manufactured by Toray Industries, Kanebosha Co., Ltd.) "Zavuna Minimax" etc. 35
It can be carried out by continuously contacting the upper surface of the colored layer 3 while relatively moving with respect to the transparent substrate 4, and trapping and accompanying the carbon toner between the fibers.

The ultrafine fiber cloth 35 is used, for example, while being processed into a tape shape and stretched over a mirrored cylindrical guide 36 so as to run continuously. Thereby, the ultrafine fiber cloth 3
By applying a certain tension to 5, the flatness of the contact portion with the colored layer 3 is maintained, and a new fiber surface is always in contact with the colored layer 3. It is also possible to configure the ultrafine fiber cloth 35 endlessly and use it continuously at a level that does not hinder the toner removal performance.

In the case of such an ultrafine fiber cloth 35, dusts due to falling off of the fibers are hardly generated, and the toner powder trapped between the fibers rarely separates from the fibers and falls. Very convenient for the removal step.

In place of the ultrafine fiber cloth 35, an adhesive tape having low adhesiveness may be used.

FIG. 9B is a plan view of the light absorption layer 3 formed in a state where the region near the top of each transparent microsphere 2 is exposed. s is the diameter of the opening 3 a of the light absorbing layer 3.

The opening area of each opening 3a of the light absorbing layer 3 formed by the above-described process is basically determined by the state of filling the transparent microspheres 2 on the transparent adhesive layer 5, and as shown in the figure, It is formed relatively uniformly as a whole.

In the case where a conductive substrate is used as the transparent substrate 4 or instead, the metal plate 48 (not shown) can be omitted. At this time,
When using an opaque substrate as the conductive substrate,
After manufacturing the flat lens or at an appropriate time during the manufacturing process, the substrate may be peeled off.

When a positively charged toner is used as the toner powder, the direction of the applied voltage is reversed. Note that a toner charged in advance may be used regardless of the polarity.

Next, as shown in FIG. 6A, the protective film 6a of the transparent adhesive layer 6 formed on the transparent substrate 1 on the light emitting side is peeled off, and the transparent substrate 4 on the light incident side is separated as described above.
Are laminated on the transparent microspheres 2 and the light absorbing layer 3 formed thereon. 1a is a protective film provided on the back side of the transparent substrate 1.

The transparent substrate 1 and the transparent adhesive layer 6 on the light emitting side may be the same as the transparent substrate 4 and the transparent adhesive layer 5 on the light incident side, respectively. For example, the transparent substrate 1 is made of an acrylic plate, and the transparent adhesive layer 6 is made of an acrylic ultraviolet curable resin.

Thereafter, as shown in FIG. 6B, for example, a pressure is applied by a pressure roll 37 so that a transparent adhesive layer is formed on the transparent microspheres 2 and the light absorbing layer 3 formed on the transparent substrate 4. Then, the transparent substrate 1 is pressure-bonded through the contact 6.

Thereafter, as shown in FIG. 6 (c), ultraviolet irradiation 51 is performed to cure the transparent adhesive layer 6 and strengthen its adhesion.

If the transparent pressure-sensitive adhesive layer 5 on the light incident side is capable of sufficiently fixing and holding the transparent microspheres 2 even before ultraviolet curing, the final ultraviolet curing of the transparent pressure-sensitive adhesive layer 5 is performed in this step. You may make it perform simultaneously.

Thereafter, the protective films 1a and 4a are peeled off to obtain a flat lens.

Next, a planar lens according to a second embodiment of the present invention will be described with reference to FIGS.

The first embodiment described above is different from the first embodiment in that the transparent adhesive layer 5 is provided with an antistatic layer 5 b
This embodiment is different from the first embodiment in that an antistatic agent is kneaded in advance into the transparent adhesive to form the transparent adhesive layer 15.

First, as shown in FIG. 7A, a transparent adhesive layer 15 into which an antistatic agent is kneaded is formed on the transparent substrate 4 on the light incident side. For example, an acrylic ultraviolet (UV) curable resin having a protective film 15a is attached on a transparent substrate 4 made of an acrylic resin such as polymethyl methacrylate (PMMA). 4a is a protective film for protecting the back side of the transparent substrate 4.

As the transparent substrate 4, the same material as in the first embodiment is used.

Since the transparent adhesive layer 15 has a large number of transparent microspheres 2 embedded therein as its base resin and must be fixed and held securely, the transparent microspheres 2 have an appropriate softness before photo-curing. Is easy to embed, and
After photocuring, it is particularly preferable to use an acrylic ultraviolet curable resin for securely fixing and holding those transparent microspheres. However, other acrylic resins, for example, polycarbonate resin, polyolefin resin, vinyl chloride resin, polystyrene resin, polyethylene resin, epoxy resin, polyarylate resin, polyether sulfone resin, silicone resin, polyethylene terephthalate resin etc. Of course, it is good.

Examples of the antistatic agent kneaded in the base resin include the following nonionic poly (oxyethylene) alkylamines, glycerin fatty acid esters, anionic alkylsulfonates, alkylbenzenesulfonates, and cationic antistatic agents. It is desirable to use quaternary ammonium chloride or the like.

Embedded image

Next, as shown in FIG. 7 (b), a static elimination blow 41 is performed to neutralize static electricity, and the protective film 15a is removed from the transparent adhesive layer 1 while removing dust by suction.
Peel from 5.

As shown in FIG. 1B, at least the surface of the main body 2a made of conductive glass beads is made of an electrically insulating material, as in the first embodiment. And is covered with an insulating film 2b.

Next, as shown in FIG. 7B, an antistatic agent is kneaded into the transparent microspheres 2 by applying an electrostatic screen printing method in the same manner as in the first embodiment described above. Is filled on the transparent adhesive layer 15 to form a light diffusion layer.

FIG. 8 is an enlarged view of a part near the transparent adhesive layer 15 on which the transparent microspheres 2 have fallen and are attracted.

In the present embodiment, since the antistatic agent is kneaded in the transparent adhesive layer 15, the mixed antistatic agent charges a positive charge by applying a voltage, and as shown in FIG. The transparent microspheres 2 negatively charged are attracted to the positively charged antistatic agent particles existing near the surface of the transparent adhesive layer 15 and adhere to the transparent adhesive layer 15.

The other manufacturing steps are performed in the same manner as in the first embodiment to obtain a flat lens.

FIG. 11 shows another embodiment for forming the light diffusion layer.

In this embodiment, for example, as shown in FIG. 11, an endless photoconductive screen 61 is used to continuously connect a plurality of transparent substrates 4 holding a large number of transparent microspheres (not shown) as described above. A light diffusion layer is formed.

The photoconductive screen is obtained by applying a photoconductive coating to the screen. For example, at a location 62, the entire surface is charged by corona discharge, and only a portion of the surface is irradiated with light so that only the portion is neutralized. Things. For example, the shape of the substrate 4 is photographed in advance by the CCD 63, and the light projection unit 65 is controlled via the computer 64 to irradiate the outer peripheral area (the portion where the substrate is not mounted) with light according to the substrate shape. . When the substrate 4 is transferred to the printing stage 68 by, for example, the belt conveyor 67, the portion of the photoconductive screen 61 where the corresponding electrostatic latent image is formed just moves to the printing stage 68. In this state, the transparent microspheres 2 are supplied from the transparent microsphere supply section 66, and the light diffusion layer is formed on the substrate 4.

In FIG. 11, reference numeral 69 denotes a pressure roll for embedding the lowest transparent microspheres 2 in the transparent adhesive layer 5 (15); 70, a bias roller for applying a bias potential to each substrate 4; A cleaner 72 for removing unnecessary (second or more layers) transparent microspheres 2 from the transparent substrate 4;
Is an ultraviolet lamp for curing the transparent adhesive layer.

FIGS. 12 to 31 show various aspects of the planar lens 23 taking the first embodiment as an example.

FIG. 12 shows an example in which the transparent substrate 4 on the light incident side is
This is a planar lens 23 having the most basic structure including the transparent adhesive layer 5 having the antistatic layer 5b formed on the upper surface, the transparent microspheres 2, and the light absorbing layer 3. When the protection of the transparent microspheres 2 and the light absorbing layer 3 on the light emission side is not particularly required, the form as it is can be used satisfactorily. In the following drawings, the antistatic layer 5b is not shown.

In the example shown in FIG. 13, in the most basic structure shown in FIG. 12, a transparent adhesive layer 6 is provided on the light emitting side to protect the transparent microspheres 2 and the light absorbing layer 3 on the light emitting side. Things.

In the example shown in FIG. 14, in the most basic structure shown in FIG. 12, a transparent substrate 1 is provided on the light emitting side, and stronger protection of the transparent microspheres 2 and the light absorbing layer 3 on the light emitting side is provided. It is intended. This structure is possible when the light absorbing layer 3 itself has an adhesive function.

FIG. 15 shows an example in which the transparent substrate 1 is provided on the light emitting side via the transparent adhesive layer 6 in the most basic structure shown in FIG. This is a structure manufactured by the described manufacturing process.

FIG. 16 shows an example in which the transparent substrate 4 on the light incident side is omitted from the structure shown in FIG. This structure can be manufactured, for example, by manufacturing the structure shown in FIG. 14 using a peelable substrate instead of the transparent substrate 4 on the light incident side, and peeling the substrate at an appropriate time during the process. .

In the example shown in FIG. 17, similarly, the transparent substrate 4 on the light incident side is omitted from the structure shown in FIG.

In the example shown in FIG. 18, after the structure shown in FIG. 16 is manufactured, a Fresnel lens 22 is bonded to the light incident side of the flat lens 23 to form the integral transmission screen 10. .

In the example shown in FIG. 19, similarly, after manufacturing the structure shown in FIG. 17, a Fresnel lens 22 is bonded to the light incident side of the planar lens 23, and the integrated transmission screen 1 is formed.
0.

In the example shown in FIG. 20, in the structure shown in FIG. 12, a planar lens 23 is manufactured by using a release substrate instead of the transparent substrate 4, and after removing the release substrate, the Fresnel lens 22 is placed on the light incident side. To form an integrated transmission screen 10. As described above, even when the substrate is not provided on the planar lens 23 itself, it is possible to secure the shape stability by joining the lens to the Fresnel lens 22.

In the example shown in FIG. 21, similarly, in the structure shown in FIG. 13, a flat lens 23 is manufactured using a release substrate instead of the transparent substrate 4, and after the release substrate is released, The Fresnel lens 22 is joined to form the integral transmission screen 10.

In the example of FIG. 22, an antireflection film 7 such as a silicon oxide (SiO ₂ ) film is provided on each of the light incident side and the light emission side of the planar lens 23 having the structure shown in FIG.

In the example shown in FIG. 23, similarly, the anti-reflection film 7 is provided on each of the light incident side and the light emitting side of the planar lens 23 having the structure shown in FIG.

In the example shown in FIG. 24, similarly, the anti-reflection film 7 is provided on each of the light incident side and the light emitting side of the planar lens 23 having the structure shown in FIG.

In the example of FIG. 25, similarly, the antireflection film 7 is provided on the light incident side and the light emission side of the planar lens 23 having the structure shown in FIG.

In the example of FIG. 26, similarly, the anti-reflection film 7 is provided on the light incident side and the light emission side of the planar lens 23 having the structure shown in FIG.

In the example shown in FIG. 27, similarly, the anti-reflection film 7 is provided on each of the light incident side and the light emitting side of the planar lens 23 having the structure shown in FIG.

In the example shown in FIG. 28, the light incident side of the Fresnel lens 22 and the flat lens 2 in the structure shown in FIG.
3 is provided with an anti-reflection film 7 on the light emission side.

In the example shown in FIG. 29, similarly, in the structure shown in FIG. 19, antireflection films 7 are provided on the light incident side of the Fresnel lens 22 and the light emitting side of the flat lens 23, respectively.

In the example shown in FIG. 30, similarly, the anti-reflection film 7 is provided on the light incident side of the Fresnel lens 22 and the light emitting side of the flat lens 23 in the structure shown in FIG.

In the example shown in FIG. 31, similarly, the anti-reflection film 7 is provided on the light incident side of the Fresnel lens 22 and the light emitting side of the flat lens 23 in the structure shown in FIG.

The flat lens 23 described above is particularly suitable for use in, for example, the transmission screen 10 for a rear projection projector shown in FIG. 34 or FIG.

According to the first and second embodiments, the transparent adhesive layer 5 on which the antistatic layer 5b is formed and the antistatic agent are mixed by applying a voltage when the transparent microspheres 2 are supplied. Since the transparent adhesive layer 15 is charged with a positive charge and the transparent microspheres 2 covered with the insulating film 2b are charged with a negative charge, the action of the electrostatic force causes the transparent microspheres 2 to form the transparent adhesive layer 5 (15). It is distributed at a uniform density on the surface. Therefore, as compared with the conventional case where the worker wears gloves to supply the transparent microspheres 2, it can be supplied in a uniform distribution density in a short time in an automated and clean environment. A good planar lens without uneven brightness can be obtained, and its cost can be reduced.

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

For example, in each of the embodiments, the transparent microspheres 2 are arranged in a plane, but the transparent microspheres 2 may be arranged in a curved shape along a slightly curved transparent substrate, for example. Further, the toner itself (first layer) may be used instead of the transparent adhesive layer 5.

Further, the planar lenses 23 were manufactured in order from the light incident side while each transparent microsphere 2 was held on the transparent adhesive layer 5 on the light incident side. For example, a structure as shown in FIG. , May be manufactured in order from the light emitting side. in this case,
For example, each transparent microsphere 2 is held by a light absorbing layer 3 formed to a certain thickness on a transparent substrate 1, and a predetermined thickness is further formed thereon by the electrostatic screen printing method described above. Can be laminated.

The pressure-sensitive adhesive (pressure-sensitive adhesive layer) can be formed by directly applying a pressure-sensitive adhesive, or by applying a UV-curable resin and controlling the amount of UV light to be irradiated to thereby form a UV-curable adhesive. The resin may be formed in a semi-cured state.

Further, the excess beads can be removed by inverting (turning over) the entire substrate. The screen 10 shown in FIGS. 34 and 35 can be used as a screen of another type of flat display in addition to the screen of the rear projector described above.

[0132]

As described above, according to the present invention, a plurality of transparent microscopic bodies which are distributed in a plane or a curved shape and each of which has at least a surface portion having an electrical insulating property, and the plurality of transparent microscopic bodies are held. At least a light emitting side has an adhesive layer provided with conductivity, and a part of the transparent micro body on a light incident side is embedded in the adhesive layer, and the plurality of transparent micro bodies are interposed so that the light emitting side is exposed. Since the light absorbing layer is arranged in the gap of, for example, if a positive charge is applied to the adhesive layer using a principle such as electrostatic printing and a negative charge is applied to the transparent minute body, electrostatic force is applied. The transparent microparticles can be distributed on the adhesive layer at a uniform density in a short time. Therefore, it is possible to distribute the transparent microparticles in a good environment without dust generation,
As a result, the manufacturing time is shortened and the cost is reduced by automating the supply of the transparent minute body, and a planar lens without uneven brightness can be realized.

[Brief description of the drawings]

FIGS. 1A and 1B show a method for supplying transparent microspheres according to a first embodiment of the present invention, wherein FIG. 1A is a schematic cross-sectional view and FIG. 1B is an enlarged cross-sectional view of the transparent microspheres.

FIG. 2 is a schematic enlarged cross-sectional view of a part near a transparent adhesive layer to which transparent microspheres are attached.

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 method of the planar lens in the order of steps.

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

FIG. 6 is a schematic sectional view showing still another manufacturing method of the planar lens in the order of steps.

FIG. 7 is a schematic view showing one manufacturing method of the planar lens according to the second embodiment in the order of steps.

FIG. 8 is a schematic enlarged cross-sectional view of a part near a transparent adhesive layer to which transparent microspheres are attached according to the second embodiment.

9A and 9B show a method of forming a light absorbing layer according to the first embodiment, wherein FIG. 9A is a schematic diagram and FIG. 9B is a schematic diagram showing a binary image of an array of transparent microspheres.

FIG. 10 is a schematic view of the rotary brush.

FIG. 11 is a schematic view showing another method of forming the light absorbing layer according to the embodiment.

FIG. 12 is a schematic sectional view showing one mode of the planar lens according to the first embodiment.

FIG. 13 is a schematic sectional view showing another embodiment of the present invention.

FIG. 14 is a schematic sectional view showing another embodiment of the present invention.

FIG. 15 is a schematic sectional view showing another embodiment of the present invention.

FIG. 16 is a schematic cross-sectional view showing another embodiment of the same.

FIG. 17 is a schematic sectional view showing another embodiment of the same.

FIG. 18 is a schematic sectional view showing one embodiment of a screen for a rear projection type projector.

FIG. 19 is a schematic sectional view showing another embodiment of the same.

FIG. 20 is a schematic cross-sectional view showing another embodiment of the same.

FIG. 21 is a schematic sectional view showing another embodiment of the same.

FIG. 22 is a schematic sectional view showing one mode of the planar lens according to the first embodiment.

FIG. 23 is a schematic sectional view showing another embodiment of the same.

FIG. 24 is a schematic cross-sectional view showing another embodiment of the present invention.

FIG. 25 is a schematic sectional view showing another embodiment of the same.

FIG. 26 is a schematic cross-sectional view showing another embodiment of the same.

FIG. 27 is a schematic sectional view showing another embodiment of the same.

FIG. 28 is a schematic sectional view showing one mode of another screen for a rear projection type projector.

FIG. 29 is a schematic sectional view showing one mode of another screen for a rear projection type projector.

FIG. 30 is a schematic sectional view showing one mode of another screen for a rear projection type projector.

FIG. 31 is a schematic sectional view showing an embodiment of another screen for a rear projection type projector.

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 the configuration of a flat lens made of transparent microspheres.

[Explanation of symbols]

1, 4: transparent substrate, 2: transparent microsphere, 2a: main body,
2b insulating film, 3 light absorbing layer, 3a opening, 4a, 5
a, 6a: protective film, 5, 6, 15: transparent adhesive layer,
5b: antistatic layer, 7: antireflection film, 10: transmissive screen, 21: image projection unit, 22: Fresnel lens,
23: flat lens, 24: mirror, 25: housing, 33
... hopper, 34 ... rotating brush, 35 ... ultrafine fiber cloth,
36: mirror surface cylindrical guide, 37: application roll, 41: static elimination blow, 42: nozzle, 43: vacuum suction means, 44: camera, 45, 51: ultraviolet lamp, 46: stainless steel screen, 47: screen frame, 48: metal Board, 49 ...
Brush, L: projected image light, L _in : incident light, L _OUT : outgoing light, L _EX : external light

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2H021 BA22 BA26 BA28 BA32 4F213 AD04 AD05 AD08 AE03 AH74 WA15 WA53 WA58 WB01 WB11 WC02 WF24 WF29 5C058 AA01 AA05 AB05 BA06 BA31 BA35 EA01 EA31 EA33

Claims (32)

[Claims] 1. A plurality of transparent fine bodies distributed in a planar or curved shape, each of which has at least a surface portion having electrical insulation, holding the plurality of transparent fine bodies, and at least imparting conductivity to a light emitting side. And a part of the transparent micro body on the light incident side is embedded in the adhesive layer, and a light absorbing layer is disposed in a gap between the plurality of transparent micro bodies so that a light emission side is exposed. Have a flat lens. 2. The planar lens according to claim 1, wherein the transparent microscopic body is formed by a conductive main body and an electrically insulating material layer covering the surface of the main body. 3. The conductivity is imparted by applying an antistatic agent to the surface of the electrically insulating pressure-sensitive adhesive layer.
The planar lens according to claim 1. 4. The flat lens according to claim 1, wherein the conductivity is imparted by kneading an antistatic agent into an electrically insulating adhesive. 5. The method according to claim 1, wherein the plurality of transparent fine bodies are held by the transparent adhesive layer while being in contact with each other.
The planar lens described in 1. 6. The method according to claim 5, wherein the plurality of transparent microscopic bodies are arranged in a single layer, and at least 30% of the transparent microscopic bodies are embedded in the adhesive layer on the light incident side. Flat lens. 7. The transparent micro body in which a part on the light incident side is embedded in the adhesive layer and the light absorbing layer disposed in the gap,
The flat lens according to claim 1, which is provided on a transparent substrate. 8. The flat lens according to claim 1, wherein a transparent adhesive layer is formed as the adhesive layer. 9. A second light-emitting side of the plurality of transparent micro-objects
A transparent substrate is further joined via a transparent adhesive layer of
A flat lens according to claim 8. 10. The flat lens according to claim 1, which is used for a screen for a rear projection type projector. 11. A plurality of transparent fine bodies distributed in a plane or a curved surface, each of which has at least a surface portion having electrical insulation, holding the plurality of transparent fine bodies, and imparting conductivity at least on a light emitting side. And a part of the transparent micro body on the light incident side is embedded in the adhesive layer, and a light absorbing layer is disposed in a gap between the plurality of transparent micro bodies so that a light emission side is exposed. A step of forming the pressure-sensitive adhesive layer, a step of imparting conductivity to at least a light emission side of the pressure-sensitive adhesive layer, and supplying the plurality of transparent microscopic bodies on the pressure-sensitive adhesive layer. Embedding the adhesive layer to a predetermined depth, and filling a gap between the plurality of transparent microscopic bodies with a light absorbing material so that a predetermined area on the light emission side of the transparent microscopic body is exposed. Forming a layer Method of manufacturing a lens. 12. The method of manufacturing a flat lens according to claim 11, wherein the transparent minute body is formed by coating a surface of a conductive main body with an electrically insulating material. 13. The method for manufacturing a flat lens according to claim 11, wherein the conductivity is imparted by applying an antistatic agent to the surface of the electrically insulating adhesive layer. 14. The conductivity is imparted by kneading an antistatic agent into an electrically insulating pressure-sensitive adhesive.
3. The method for manufacturing a planar lens described in 1. above. 15. The method for manufacturing a flat lens according to claim 11, wherein the transparent microscopic object is electrostatically attracted to the adhesive layer and supplied onto the adhesive layer. 16. An electric field generated by applying a predetermined voltage between an electrostatic screen for charging and supplying the transparent minute body to a first polarity and an electrode for charging the adhesive layer to a second polarity. The method according to claim 15, wherein the supply is performed in a non-contact manner under the action of (1). 17. The method according to claim 1, wherein after the plurality of transparent microscopic bodies are embedded in the adhesive layer, unnecessary transparent microscopic bodies are removed.
2. The method for manufacturing a flat lens according to item 1. 18. The method according to claim 11, wherein the plurality of transparent microscopic bodies are held on the transparent adhesive layer while being in contact with each other.
3. The method for manufacturing a planar lens described in 1. above. 19. The method according to claim 19, wherein the plurality of transparent microscopic bodies are arranged in a single layer,
19. The method for manufacturing a flat lens according to claim 18, wherein 30% or more of each of the transparent microscopic bodies is embedded in the adhesive layer on the light incident side. 20. The planar lens according to claim 11, wherein the transparent micro body having a part on the light incident side embedded in the adhesive layer and a light absorbing layer disposed in the gap are provided on a transparent substrate. Manufacturing method. 21. The method according to claim 11, wherein a transparent adhesive layer is formed as the adhesive layer. 22. The method of manufacturing a flat lens according to claim 11, wherein a transparent substrate is further joined to the light emitting side of the plurality of transparent microscopic bodies via a second transparent adhesive layer. 23. The method of manufacturing a flat lens according to claim 11, wherein the flat lens is used for a rear projection type projector screen. 24. A plurality of transparent fine bodies distributed in a plane or a curved surface, each of which has at least a surface portion having electrical insulation, and the plurality of transparent fine bodies are held, and at least a light emitting side has conductivity. And a part of the transparent micro body on the light incident side is embedded in the adhesive layer, and a light absorbing layer is disposed in a gap between the plurality of transparent micro bodies so that a light emission side is exposed. Screen for a rear projection type projector using a flat lens. 25. A rear projection type projector according to claim 24, wherein a flat lens is used in which the transparent micro body is formed by a conductive main body and an electrically insulating material layer covering the surface. screen. 26. The rear projection type projector screen according to claim 24, wherein a flat lens is used, which is provided with the conductivity by applying an antistatic agent to the surface of an electrically insulating adhesive layer. 27. The rear projection type projector screen according to claim 24, wherein a flat lens is used, which is provided with the conductivity by kneading an antistatic agent into an electrically insulating adhesive. 28. The screen for a rear projection type projector according to claim 24, wherein a flat lens is used, wherein the plurality of transparent fine bodies are held in contact with each other by the transparent adhesive layer. 29. The transparent fine bodies are arranged in a single layer, and 30% of the transparent fine bodies on the light incident side.
29. The screen for a rear projection type projector according to claim 28, wherein a flat lens is used, which is embedded in the adhesive layer. 30. A planar lens, wherein the transparent microscopic body having a part on the light incident side embedded in the adhesive layer and the light absorbing layer disposed in the gap are provided on a transparent substrate. The screen for a rear projection type projector according to claim 24, which is used. 31. The screen for a rear projection type projector according to claim 24, wherein a flat lens on which a transparent adhesive layer is formed is used as the adhesive layer. 32. The rear projection type projector according to claim 31, wherein a flat lens is used, wherein a transparent substrate is further bonded to the light emitting side of the plurality of transparent microscopic bodies via a second transparent adhesive layer. For screen.