JPH1048404A - Plane type lens, and screen for rear surface-projection type projector using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the contrast, improve the luminance, reduce the electric power consumption, save the electric power, reduce the load of countormeasure heat to prevent the cost from increase, make it possible to observe bright images by the diffusion in both horizontal and perpendicular directions, expand the observation range, simplify the handling, improve the resolution, and the improve moires. SOLUTION: A transparent base material 11 is arranged on a light exit side or light incident side. This transparent base material 11 has a transparent microsphere arranging layer 14 which is arranged with transparent microspheres 12 in the state of twodimensionally bringing the adjacent transparent microspheres 12 into contact or proximity to or with each other by unit particle layer arrangement and has colored layers 13 for partly exposing the transparent microspheres outside on a light incident side. This transparent microsphere arranging layer 14 is constituted to enhance the light transparency at the light exit side ends of the transparent microspheres 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat lens, that is, a screen for a rear projection type projector, a viewing angle enlarging plate for a liquid crystal display device, a plasma display device, an electroluminescent display device or the like, or a backlight for a liquid crystal display. The present invention relates to a flat lens used as a light diffusion plate or the like for diffusing light from various illumination light sources and the like, and further relates to a screen for a rear projection type projector using the flat lens.

[0002]

2. Description of the Related Art In recent years, a projection type display device using a light valve such as a liquid crystal panel, which emits a light beam having a polarization characteristic, has been developed. In a projection display device using this liquid crystal, image light spatially modulated by a liquid crystal panel is enlarged and projected on a screen by a projection lens. This projection type display device includes a front projection type and a rear projection type.

FIG. 34 is a schematic diagram showing the configuration of a rear projection type display device for observing an image projected from the back of the screen from the front of the screen. The rear projection display device includes an image projection unit 1 for emitting light, a transmission screen 2, and projection image light L obtained from the image projection unit 1.
Is reflected by the reflection mirror 3 and guided to the transmission screen 2. The transmissive screen 2, that is, the screen for the rear projection type projector, is usually constituted by a Fresnel lens 4 and a lenticular lens 5 extending in the vertical direction, as shown in a perspective view of the main part in FIG.

In the rear-projection display device having the above-described configuration, the projected image light L from the image projection section 1 is converted into substantially parallel light by the Fresnel lens 4 and further diffused right and left by the lenticular lens 5. in this way,
In this conventional ordinary rear projection display device, the image projection unit 1
Is projected onto the transmission screen 2 in an enlarged manner. That is, the observer observes the projected image as light transmitted through the transmission screen 2.

[0005]

However, the rear projection display device described above is generally used in a bright room. In this case, external light such as room lighting is reflected by the surface of the lenticular lens 5, and this is reflected on the screen. There is a problem that the contrast of the image is reduced because it is observed together with the image light emitted from the light source 2. Traditionally,
As a countermeasure for this, separately on the front of the lenticular lens 5,
A method of providing a smoke plate (not shown) to absorb a part of disturbance light is performed, thereby suppressing a decrease in contrast.

However, when such a smoke plate is provided, a part of the image light is similarly absorbed when passing through the smoke plate, and the luminance of the image is reduced. In order to increase the luminance, it is necessary to use a light source that consumes more power, which hinders power saving, and also requires more strict heat measures accompanying such an increase in power. This raises a new problem of high cost.

[0007] Further, there are many problems in the flat lens using the above-mentioned lenticular lens, and in the transmission type screen using the same, ie, the screen for the rear projection type projector. The problems are listed below. (1) In a lenticular lens formed by extending the lens element in the vertical (horizontal) direction, the light is diffused widely in the (horizontal) direction, so that an image can be observed even when viewed obliquely, but is orthogonal to this. However, when the viewpoint is moved up and down, the range in which a clear image can be observed is extremely narrow. That is, for example, as shown in FIG. 36A, in a flat lens or screen using this lenticular lens, a region showing 50% or more of the luminance due to light perpendicularly incident on the plate surface is indicated by a in FIG. 36A. , A vertically flat elliptical cone. That is, as shown in FIG. B, for example, as shown in FIG. B, when an area showing 50% or more of the center luminance is in a range of about 30 °, a similar area in the vertical direction is shown in FIG. As shown, the range is about 20 °. (2) Furthermore, the lenticular lens has a precise lens shape formed over the entire surface, and even if a slight defect occurs in a part, the entire lens can be used. Great care must be taken.
Furthermore, with the recent increase in the image projection area, handling of the screen becomes more problematic, and there is a situation where high costs cannot be avoided. (3) A screen combining a Fresnel lens and a lenticular lens provides a wide viewing angle in the horizontal direction because the projection light is mainly spread in the horizontal direction, but the viewing angle in the vertical direction is narrow. The user may feel that the luminance distribution of the image is not uniform or that the image has partial non-uniformity. In some cases, the person may feel as a band of light in the horizontal direction. (4) In a lenticular lens, when a black stripe is provided between lens elements, the black stripe cannot be formed at a certain interval or less in order to have a sufficient lens effect, so that the contrast of a projected image is reduced. And the resolution is low. (5) Further, in general, the projection light in the above-described image projection unit 1 or the front projection type image display device or the like has an illuminance distribution in which the central part of the angle of view is bright and becomes darker toward the periphery, so that the observation image is obtained. Has a problem that the intensity distribution of steepness shows a steep gradient. (6) Further, in the screen using the combination of the Fresnel lens and the lenticular lens described above, since multiple reflection occurs between the Fresnel lens and the lenticular lens, there is a problem that observation images are observed in a multi-layered manner. is there. (7) Further, light interference may occur between the above-mentioned black stripe of the lenticular lens and the projected image, and a so-called moire pattern may occur in the observed image.

In a screen, a so-called highly diffusive screen in which light is widely diffused has a gain (=
Therefore, a flat gain curve with a low luminance but a small variation with respect to the viewing angle can be obtained. On the other hand, a screen having a high directivity has a high gain, but the gain rapidly decreases as the viewing angle increases. This change indicates that, when the screen is observed with the naked eye, the brightness of the image displayed on the screen is easily changed by moving the observation position. Emori's "Rear Projection Screen Characteristics and Measurement Method" Optical Technology Contact v
ol. 11, No. 5 (1973) p17-p23,
In particular, as described in p18, the human eye has a logarithmic sensitivity to luminance, and thus appears to have uniform brightness with respect to a fluctuation of about twice the gain. However, it is said that when the fluctuation of the gain becomes three times or more, a so-called hot spot or hot band phenomenon, which looks bright around the peak gain portion (usually, the center of the screen). According to the above-mentioned literature, a screen having a peak gain of 3.5 and a gain at a bending angle (viewing angle) of 30 ° of 25% or more of the peak gain is optimal.

The meaning of showing the performance of the screen by showing the gain at a certain bending angle will be described with reference to FIGS. 37 and 38.

Assume that a rear projector is mounted on a screen and the naked eye observation is performed at a position just in front of the center point of the display screen on the screen and at a distance of three times the vertical height of the display screen. By the way, this distance is NTSC or HDT
This is the standard viewing distance in V (high definition). In this case, in a 9:16 wide screen such as HDTV, as shown in FIG. 37, a maximum bending of 9.5 ° in the vertical direction, a maximum of 16.5 ° in the horizontal direction, and a maximum of 18.8 ° in the diagonal direction. It will be horny.

Further, when there are a plurality of observers, the observers are arranged in front of the screen as shown in FIG. 38, for example, at the same height as the center point of the display screen and at the side edge of the display screen. The screen is viewed from a position three times the vertical height at the front, resulting in a maximum of 30.7 ° in the horizontal direction and a maximum of 31.90 in the oblique direction, as shown in FIG.
A bending angle of 6 ° will be obtained.

Even in the case described above, it is necessary that the screen does not cause shading, that is, so-called uneven brightness. Generally, shading is 15-50
% Does not pose any problem even when observed with the naked eye, but when it exceeds 70%, it becomes unacceptable. The area where the shading is within 50% when the display image on the screen is viewed is called a favorable area. If the favorable area is enlarged, an area suitable for observation can be expanded.

In an actual projector, the shading is evaluated in a form including the incident angle and uniformity of the image light projected on the screen. In the evaluation of the screen alone, the peak gain and the gain at a certain bending angle are evaluated. The shading can be evaluated numerically from the relationship

By the way, in recent years, as the development of a light projection unit using a light spatial modulation element (light valve) such as a TFT liquid crystal has been advanced, the light output has been increasing year by year, and the peak gain has been high. In addition to the conventional screen, which has been the first effect, a screen having an effect of expanding a region suitable for observation by having a certain degree of diffusivity has been required.

An object of the present invention is to solve various problems in a so-called planar lens using the above-mentioned lenticular lens and a screen for a rear projection type projector formed using the same.

Further, the present invention is intended to solve the problems of simultaneously securing the luminance of the screen and a certain degree of diffusivity, and the various problems including these and costs.

[0017]

In the flat lens according to the present invention, a transparent substrate is disposed on the light emitting side or the light incident side, and transparent microspheres, so-called transparent beads, are two-dimensionally arranged on the transparent substrate. Transparent microspheres adjacent to each other with a single particle layer arrangement are arranged in contact with or close to each other, and at least a colored layer for exposing a part of the transparent microspheres to the outside on the light incident side is provided. Has,
The transparent microsphere arrangement layer has a configuration in which light transmittance is increased at the light emission side end of the transparent microsphere.

Further, in the screen for a rear projection type projector according to the present invention, a transparent base material is disposed on a light emitting side or a light incident side, and a transparent microsphere is formed on the transparent base material.
Transparent microspheres that are adjacent to each other in a three-dimensional single particle layer arrangement are arranged in contact with or close to each other, and have at least a colored layer that exposes part of the transparent microspheres to the outside on the light incident side. The transparent microsphere arrangement layer has a spherical lens arrangement layer, and the transparent microsphere arrangement layer includes a flat lens having a configuration in which light transmittance is enhanced at an end of the transparent microsphere on the light emission side.

In the present specification, the term "transparent" means that a target light, that is, light to be transmitted through a lens or a screen can be transmitted therethrough. It is what we refer to.

According to the flat lens and the rear projection type projector screen having the above-described configurations, the incident light is converged by the lens action of the transparent microspheres and diverges therefrom. By being able to diffuse in both vertical and vertical directions, the viewing angle can be increased in both horizontal and vertical directions. In addition, most of the light that has not entered the transparent microspheres is absorbed by the colored layer of the transparent microsphere arrangement layer, and is prevented from being emitted. Further, external light incident on the lens or the screen for the rear projection type projector from the light emitting side is also absorbed by the colored layer of the transparent microsphere arrangement layer, so that the contrast can be improved.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a flat lens according to the present invention and a screen for a rear projection type projector using the same will be described. The planar lens according to the present invention has a schematic sectional view of the embodiment shown in FIGS.
A transparent substrate 11 is disposed on at least one of the light emitting side and the light incident side, and transparent microspheres 12 are two-dimensionally arranged in contact with or close to each other with a single particle layer arrangement on the transparent substrate 11. The light-incident side has a transparent microsphere arrangement layer 14 having at least a coloring layer 13 for exposing a part of the transparent microsphere to the outside. Further, the transparent microsphere arrangement layer 14 The light emitting side end is configured to have high light transmittance. As described later, since the incident light is converged by the transparent microspheres 12, the emission area (area) from the transparent microspheres 12 is very small.
The region 4 exhibiting high light transmittance may have a small area.

In the configuration of the flat lens 10 shown in FIG. 1, for example, a transparent base material 11 made of a rigid glass substrate, a plastic substrate, or a flexible so-called flexible substrate is arranged on the light emitting side of the lens. is there. That is, in this case, on the light incident side of the base material 11,
This is the case where the transparent microsphere arrangement layer 14 is formed. Also,
In this example, the transparent microsphere arrangement layer 14 is formed by attaching the transparent microspheres 12 to the colored layer 13 having adhesiveness or tackiness.
Adjacent transparent microspheres 12 are close enough to each other, or with close packing so as to be in contact with each other,
Each transparent microsphere 12 is fixed by embedding a part thereof. That is, each transparent microsphere 12
The light incident end side is a required portion from the colored layer 13, specifically, 30% of the diameter of the transparent microsphere 12 as described later.
The portion corresponding to the above is made to protrude, and on the opposite side is buried in the colored layer 13, but at the light emitting end, each transparent microsphere 12 is
The colored layer 13 is directly in contact with the transparent substrate 11, or the colored layer 13 is interposed with a sufficiently small thickness. In this configuration, the amount of light emitted from the transparent microspheres 12 is reduced from being absorbed by the colored layer 13. The region where the absorption by the colored layer 13 is reduced can be a minute region (area) on the light emitting end side of the transparent microsphere 12 as described above.

In the flat lens 10, the incident light Li such as a parallel light, such as a projected image, is projected from the side opposite to the transparent substrate 11 with respect to the transparent microsphere arrangement layer 14.
Is incident on the exposed transparent microspheres 12, the incident light Li is converged by the lens effect of the transparent microspheres 12, and then diverges. An angle magnifying flat lens is formed.

At the exit end of each transparent microsphere 12, a region for reducing the absorption by the colored layer 13 is formed, as described above, so that the exit light can be efficiently emitted to the lens 10.
However, since this region is converged and emitted from the transparent microspheres 12 in each of the transparent microspheres 12, a small area Since the colored layer 13, that is, the light absorbing layer is present around the colored layer 13, the external light Ld is effectively absorbed by the colored layer 13 and the stray light is effectively avoided. Therefore, this external light L
The reduction in contrast due to d is effectively avoided.

FIG. 2 shows another example of the planar lens 10 according to the present invention. In this example, the basic configuration is the same as that shown in FIG. 1, but in this case, the transparent microspheres are arranged. This is a case where the layer 14 has a two-layer structure of a colored layer 13 and a transparent layer 15 each having adhesiveness or tackiness. In this case, the transparent layer 15
Is arranged to increase the light transmittance on the end side so that a high output light amount can be obtained from the transparent microspheres 12. In the case of this configuration, the transparent microspheres 12 And the transparent layer 15, the transparent microspheres 12 are embedded.
Holding strength is increased.

In the configuration of the planar lens 10 shown in FIGS. 3 and 4, the transparent substrate 1 of the transparent microsphere arrangement layer 14 of the configuration shown in FIGS.
On the side opposite to 1, a protective transparent layer 25 having adhesiveness or tackiness with respect to the transparent microsphere arrangement layer 14 is arranged, and the transparent microsphere arrangement layer 14 and thus the side of the transparent microsphere 12 having the transparent substrate 11 are different from the transparent microsphere arrangement layer 14. This is the case when protection is applied on the other side.

The configuration of the planar lens 10 shown in FIGS. 5 and 6 is a case where the transparent base material 11 is arranged on the light incident side of the transparent microsphere arrangement layer 14 shown in FIGS. 1 and 2, respectively. In this case, the transparent microsphere arrangement layer 14
Is bonded to a transparent substrate 11 by a transparent layer 26 having adhesiveness or tackiness.

In the configuration of the planar lens 10 shown in FIGS. 7 and 8, the transparent base material 11 is sandwiched by the transparent microsphere arrangement layer 14 shown in FIGS. 1 and 5 or FIGS. 2 and 6, respectively. In the case where the protective transparent base material 41 and the transparent transparent base material 41 are disposed, this configuration can maintain the strength of the planar lens 10 and damage or damage the transparent microspheres 12 and the colored layer 13 of the transparent microsphere placement layer 14. This is a case in which contamination is prevented. The protective transparent substrate 41 may be made of the same material and the same material as the transparent substrate 11, but one of them may be composed of a rigid substrate and the other may be a flexible so-called flexible substrate.

2 to 8, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

The flat type lens 10 according to the present invention can constitute a screen for a rear projection type projector by itself, but as shown in FIGS. Can be combined with and integrated with a Fresnel lens 27 for allowing the light to enter as parallel light to form a rear projection type projector screen 10S.

FIGS. 9 to 12 show a case where the Fresnel lens 27 is formed on the transparent base material 31. In the example shown in FIG. This is a configuration in which the transparent layers 26 are joined. In the example shown in FIG. 10, the Fresnel lens 27 is bonded to the configuration shown in FIG. 2 by a transparent layer 26 having an adhesive or tacky property. In the example shown in FIG. 11, in the configuration shown in FIG.
This is a case where a Fresnel lens 27 is joined by a similar transparent layer 26 instead of the transparent substrate 11. In the example shown in FIG. 12, in the configuration shown in FIG.
The Fresnel lens 27 is formed by a similar transparent layer 26 instead of
This is the case in which

As described above, when the Fresnel lens 27 is joined instead of the transparent base material 11, the structure can be simplified.

9 to 12, the corresponding parts in FIGS. 1 to 8 are denoted by the same reference numerals, and redundant description will be omitted.

In each of the structures shown in FIGS. 1 to 12, as shown in FIGS. 13 to 24, an antireflection layer 28 is provided on the outermost surfaces on the light incident side and the light exit side, respectively. It can be formed by deposition. In this case, the incidence of the incident light and the emission of the emitted light can be obtained effectively. FIGS. 13 to 24 show the case where the antireflection layers 28 are respectively formed on both outermost surfaces on the light incident side and the light emission side, but they may be arranged on either one. . Further, an anti-glare layer (not shown) can be formed on these outer surfaces. Further, instead of or on the antireflection layer 28, or instead of one of the antireflection layers 28, a protective transparent layer such as a scratch-proof treatment layer for protecting the outermost transparent base material, the transparent microsphere arrangement layer, and the like. Layers can be formed. As described above, the formation of the anti-reflection layer 28 or the formation of the protective transparent layer such as the anti-scratch layer increases the light transmittance and reduces the reflectance.
Optical performance can be improved by avoiding the occurrence of damage.

13 to 24, FIGS.
The same reference numerals are given to the portions corresponding to 2 and duplicate description is omitted.

In the above-described flat lens and screen according to the present invention, the transparent substrates 11, 41 and 31
It can be made of a transparent or translucent rigid body, for example, having a relatively thick substrate or a relatively thin, flexible or flexible sheet that is transparent to light that causes a lens effect.

These transparent substrates 11, 41 and 31 are:
For example, glass, acrylic resin, polycarbonate resin,
It can be composed of polyolefin resin, vinyl chloride resin, polystyrene resin, polyethylene resin, epoxy resin, polyarylate resin, polyethersulfone resin, silicone resin, polyethylene terephthalate resin and the like.

The transparent microspheres 12 can be made of, for example, glass beads or plastic beads such as acrylic resin and polystyrene resin. The transparent microspheres 12 have a refractive index of 1.4 or more and are in contact with the light incident side. ,
For example, the protective transparent layer 25 is made of a material having a refractive index larger than that of the transparent layer 26 for bonding, and incident light is effectively introduced into the transparent microspheres 12 to form a lens. Be able to be affected.

The size of the transparent microsphere 12 is 1 diameter.
It is selected to be not more than 00 μm, for example, about 50 μm in diameter. The reason why the diameter is selected to be 100 μm or less, preferably about 50 μm, is that when the size of the transparent microsphere 12 is larger than this, for example, when a screen for a rear projection type projector is formed, in a normal use mode, the transparent fine This is because it has been confirmed that the gap between the spheres 12 is easily observed by the observer with the naked eye, so that the resolution is reduced and the image quality of the projected image is impaired. By the way, this transparent microsphere 1
2 is 100 μm or less, for example, 100 μm
In the case of m, the resolution is 5 / mm, and in the case of 50 μm, the resolution is 10 / mm. However, when using a conventional lenticular lens, the resolution is about 1 / mm. Although the lower limit of the size of the transparent microspheres 12 is not particularly defined, if the size of the transparent microspheres 12 is too small, it becomes difficult to arrange the transparent microspheres 12 as a single particle layer, A state occurs in which it is difficult to form the adhesive layer and make the thickness uniform.

The size variation of the transparent microspheres 12 should be within a range of 10% or less of the average diameter. This is because it was recognized that if the variation in the diameter became large, the transparent microspheres 12 could not be satisfactorily and uniformly packed in the transparent microsphere placement layer 14 in a fine and uniform manner.

The refractive index of the transparent microsphere 12 is determined by its surroundings,
In particular, the refractive index is selected to be larger than the refractive index around the incident end, but in order to obtain a sufficient converging lens effect, the refractive index is actually selected to be 1.4 or more. As will be described later, the value of the refractive index around the incident end side of the transparent microsphere and the value of the refractive index of the transparent microsphere determine the convergence effect of light and the diffusion angle at the exit end side of the transparent microsphere. . Therefore, the diffusion angle of the flat lens and the screen in the present invention,
It is determined by the law of refraction in optics (Snell's law), and a desired diffusion angle can be obtained by selecting the refractive index of each member of the flat lens and the screen.

The surface of the transparent microsphere 12 may be configured to be subjected to one or both of an anti-reflection treatment and a water-repellent treatment.

The surface of the transparent microsphere 12 can be an optically smooth surface.
The scattering effect can be controlled and adjusted as a surface having fine irregularities to such an extent that the fine packing is not impaired. Alternatively, when it is desired to avoid unnecessary reflection and scattering on the surface of the transparent microsphere 12,
An anti-reflection treatment can be applied to the surface of the transparent microspheres 12, and a water-repellent treatment can be applied as necessary in the manufacturing process. For example, when a water-soluble colored layer is formed, the surface of the transparent microsphere 12 may be subjected to a water-repellent treatment in advance in order to prevent the colored layer from wrapping around the light incident end side of the transparent microsphere 12. it can.

Colored Layer 1 in Transparent Microsphere Arrangement Layer 14
3 is a black pigment such as carbon, a black pigment such as a so-called toner obtained by adding a binder to carbon, a black dye such as an aniline, or an acrylic resin;
Disperse a black pigment in a transparent resin such as polycarbonate resin, polyolefin resin, vinyl chloride resin, polystyrene resin, polyethylene resin, epoxy resin, polyarylate resin, polyether sulfone resin, silicone resin, polyethylene terephthalate resin, It can be constituted by a blackened material layer dyed with a black dye. The coloring layer 13 can be formed of a material layer having functions such as adhesiveness and adhesiveness as required in manufacturing. Further, the colored layer is not limited to black, and may have a spectral distribution such as red, green, and blue.
Further, the colored layer can be formed by mixing a plurality of pigments or dyes having different color distributions.

The colored layer 13 may have a structure in which its absorbance or spectral absorbance is changed stepwise or gradually in the thickness direction, for example, may be reduced toward the light emitting side. For example, the coloring layer 13 may have a configuration in which the concentration of the pigment or the dye is gradually changed in the thickness direction, a plurality of material layers may be stacked,
A configuration in which the concentration of the above-described pigment or dye is gradually changed can be adopted.

In the transparent microsphere arrangement layer 14,
The amount of projection of the transparent microspheres 12 from the light incident side, that is, the amount of exposure, from the colored layer 13 is at least 30%, preferably at least 40%, more preferably at least 50% of the diameter of the transparent microspheres 12. And If this is less than 30%, the amount of incident light taken into the transparent microspheres 12 will decrease, and the effect of diffusing the incident light by the effective transparent microspheres 12 may not be sufficiently performed. As the amount of exposure from the colored layer 13 increases, the amount of light incident on the transparent microspheres 12 increases, and the brightness can be increased. However, the upper limit is that the colored layer 1
3 is limited by the required thickness. That is, the thickness of the coloring layer 13 is a thickness corresponding to less than 70% of the diameter of the transparent microsphere 12, and the lower limit is determined according to the absorbance or the spectral absorbance of the coloring layer 13. That is, when the absorbance or the spectral absorbance is small, when the thickness of the colored layer 13 of the incident light is small,
3. The transmission of the incident light through 3 causes a large amount of light that is not affected by the diffusion effect of the transparent microspheres 12, thereby impairing the inherent characteristics of the flat lens and reducing the absorption of external light from the emission side. Causes a decrease in contrast.

The above-mentioned protective transparent layer, for example, the transparent layer 25
And a transparent layer (not shown) formed on the outermost surface described above,
The transparent layer 26 and the transparent layer 15 of the transparent microsphere arrangement layer 14
For example, acrylic resin, polycarbonate resin, polyolefin resin, vinyl chloride resin, polystyrene resin,
It can be made of a transparent resin such as a polyethylene resin, an epoxy resin, a polyarylate resin, a polyether sulfone resin, a silicone resin, and a polyethylene terephthalate resin. Even when these are used for the same planar lens, they need not necessarily be made of the same material, and can be selected from appropriate materials according to the manufacturing method. For example, the transparent microsphere arrangement layer 1
The transparent layer 15 in 4 is made of a material that has adhesiveness and embeds and holds the light emitting side end of the transparent microsphere 12, and the transparent layer 16 is made of a material that has adhesiveness or tackiness.

The protective transparent layer 25 and the transparent layer 26, and the transparent layer 15 of the transparent microsphere arrangement layer 14, etc.
Each of them can be constituted by a single layer, but can also be constituted by lamination of a plurality of material layers selected from the above-mentioned transparent materials and the like.

The protective transparent layer such as the antireflection layer 28 and the anti-scratch layer is made of, for example, acrylic resin, polycarbonate resin, or the like.
In addition to polyolefin resin, vinyl chloride resin, polystyrene resin, polyethylene resin, epoxy resin, polyarylate resin, polyether sulfone resin, silicone resin, polyethylene terephthalate resin, etc., TEOS (tetra-ethyl-ortho-silicate) is CVD (chemical It can be formed by a vapor phase growth method or by depositing a thin film of SiO ₂ or a metal by vacuum evaporation, sputtering, a sol-gel method, or the like.

The coating of each of the above-mentioned transparent layers and coloring layers can be performed by knife coating, for example, roll coating, gravure coating, kiss coating, spray coating, blade coating, rod coating, or the like.

Screens using the above-described flat lens 10 according to the present invention, for example, FIGS. 9 to 12, FIGS. 21 to 24
25, the projection device 60 is disposed on the back of the screen 10S, as shown in FIG. 25, for example.
The projected image is projected onto the screen 10S, and the transmitted images diffused in both the vertical and horizontal directions by the screen 10S are observed from the front of the screen 10S.

Alternatively, as shown in FIG.
A screen 10S is arranged on the front of the screen 10S, and the image from the image projection unit 1 arranged in the housing 61 is reflected by the reflection mirror 3, and the transmitted image diffused in both the vertical and horizontal directions by the screen 10S is transformed into the screen 10S. Observe from the front of the camera.

In the planar lens 10 or the screen using the same according to the present invention, the transparent microspheres 12 of the transparent microsphere arrangement layer 14 may be composed of two or more kinds of transparent microspheres having different refractive indexes. it can.

That is, in each of the above-described configurations, the lens effect, that is, the convergence effect of the transparent microspheres 12 of the transparent microsphere arrangement layer 14 increases as the refractive index increases, and the diffusion angle increases. Curve 27 in FIG.
A, 27B, and 27C denote viewing angles (incident axes) on the emission side when light is vertically incident on the transparent substrate 51 on which the transparent microspheres 12 are arranged with one particle layer, as shown in FIG. Θ), the refractive index n of the transparent microsphere 12 is n = 1.7, n = 1.8, n = 1.
9 shows the viewing angle dependency of each gain, where the gain decreases as θ increases, but the refractive index increases in the range where θ is small, that is, when viewed from almost the front. It can be seen that the gain becomes smaller as the refractive index decreases, and the gain increases as the refractive index decreases. That is, in observation from almost the front, the larger the refractive index is, the darker the image is, and the smaller the refractive index is, the brighter the image is observed.

In the present invention, focusing on this phenomenon, 1
By using a mixture of two or more transparent microspheres having different refractive indices in a lens or a screen, or by arranging them with a required distribution, for example, stepwise or gradual refraction at the center and periphery thereof By using a configuration in which the rate changes, required brightness can be obtained in each part of one lens or screen.

That is, the irradiation light from a normal light source or an image within a predetermined angle of view from, for example, an image projection unit
As shown in FIG. 8A, the illuminance distribution is largest at the center and becomes smaller as the distance from the center increases.
When the irradiation light or the image is incident on the flat lens or the screen, the brightness on the exit side of the flat lens or the screen is large at the center and becomes darker toward the periphery.

In the present invention, as shown in FIG. 29, for example, in the plane lens 10 or the screen 10S, the refractive index n = 1.
9, transparent microspheres 12 having an index of refraction n = 1.8 in an outer peripheral region B, and a refractive index n = 1.7 in an outermost region C.
Are disposed.

Alternatively, as shown in FIG. 30, in the planar lens 10 or the screen 10S, the refractive index gradually increases from the center to the outermost periphery from n = 1.9 to n = 1.
It is configured to change gradually to 7, that is, gently.
In this case, the transparent microspheres 12 having different refractive indices are used.
Of transparent microspheres 12 having sequentially different refractive indexes
Can be arranged concentrically, but by changing the mixing ratio of the transparent microspheres 12 having different refractive indices, as a result, the refractive index gradually increases from the center to the outermost periphery from n = 1.9 to n =
It is possible to adopt a configuration in which the value is gradually changed to 1.7, that is, gradually.

When the flat lens 10 or the screen 10S is configured such that the refractive index changes from the center to the periphery as described above, as shown schematically in FIG. The diffusion angle region showing% is large at the center of the screen and small at the periphery, as shown by the conical shapes a and c. For example, the refractive index n = 1.9
31B, the horizontal and vertical divergence angles α ≧ 45 ° as shown in FIG. 31B, and in the region where the refractive index n = 1.7, as shown in FIG. 31C, the horizontal and vertical divergence angles α Is about 15 °.

That is, as shown in FIG. 28B, the gain distribution of the flat lens 10 or the screen 10S is small at the center and large at the periphery, so that the illuminance distribution shown in FIG. The brightness after transmission of the screen 10S can be flattened as shown in FIG. 28C.

In the above-described example, when the illuminance distribution is largest at the center and becomes smaller as the distance from the center increases, the brightness is made uniform. Conversely, FIG. 32A shows the illuminance distribution. In the case where the illuminance distribution of light applied to the flat lens 10 or the screen 10S is small at the center and becomes large as the distance from the center increases, the uniformity of the brightness is described above. By the same method, on the contrary, the refractive index n of the transparent microsphere 12 in the flat lens 10 or the screen 10S is small at the center,
As shown in FIG. 32B, the gain increases toward the periphery and decreases as the distance increases from the center, as shown in FIG. 32B. 10S
Can be made flat, ie, uniform in brightness after transmission.

In the above-described example, the flat lens 10
Alternatively, although the brightness of the transmitted light of the screen 10S is made uniform in each part, the transparent microspheres 12 are not limited to the uniformity, and may be positively corrected to a predetermined distribution.
May be configured to change the refractive index.

As described above, when two or more types of transparent microspheres having different refractive indices are used in one lens or screen, the refractive index of the transparent microsphere 12 and each mixing ratio are numerically limited. By doing
A flat lens having a peak gain of 2.4 or more and a gain at a bending angle of 30 ° of 1/3 or more of the peak gain and a screen for a rear projection projector can be realized.

FIG. 39 shows a method of measuring luminance (gain) when the bending angle is changed in the screen of the present invention. That is, as shown in FIG.
The light emitted from the screen is made incident on the back surface of the screen, and the light emitted from the vicinity of the center of the front surface is kept at a predetermined distance from the screen, for example, at every 5 ° angle, at an angle of 5 °.
To measure the luminance of the emitted light.

This screen, as shown in FIG.
For example, the incident side transparent substrate 103, the incident side transparent adhesive layer 10
4, a transparent microsphere 12, a light absorbing layer 105, an emission side transparent adhesive layer 106, and an emission side transparent substrate 107 having a six-layer structure were used. The incident side transparent substrate 103 is made of acrylic resin (polymethyl methacrylate), the incident side transparent adhesive layer 104 is made of an acrylic adhesive, the transparent microspheres 12 are made of glass, the light absorbing layer 105 is made of toner (carbon-based powder), and the emission side is made. The transparent adhesive layer 106 can be formed of an acrylic adhesive, and the emission side transparent substrate 107 can be formed of an acrylic resin (polymethyl methacrylate).

In measuring the brightness of the screen, the refractive index n of the transparent microspheres 12 in the layers constituting the screen is set to 1.5, 1.6, 1.7, 1.8,.
It is arbitrarily selected from 9 and 2.1, and the refractive indexes of the other layers are fixed to arbitrary values. In the luminance measurement, it is assumed that parallel rays of light are incident on the light from the incident side, refraction and absorption occur in each constituent layer, and the amount of light emitted at each angle on the exit side is measured. Alternatively, calculation by simulation using the ray tracing method is performed.

FIG. 41 is a diagram showing the results of a case where one type of transparent microsphere 12 is used and the luminance is measured while changing the refractive index n of the transparent microsphere. In FIG. 41,
Curve 41a has n = 1.5, 41b has n = 1.6, 41c
Is n = 1.7, 41d is n = 1.8, 41e is n = 1.
Reference numerals 9 and 41f denote luminance curves in each case where n = 2.1. FIG. 42 shows a simulation result. In FIG. 42, curve 42a has n = 1.5, 42
b is n = 1.6, 42c is n = 1.7, 42d is n =
1.8 and 42e show the luminance curves in the cases where n = 1.9 and 42f, respectively, where n = 2.1. FIG. 41 and FIG. 42
Since the gain curves match, it can be seen that this simulation result is equivalent to a measurement experiment.

Table 1 shows the peak gain of the screen and the bending angle of 30 ° when one type of transparent microsphere 12 was used.
3 shows the simulation results for the gain at, and the shading at a bending angle of 20 °. In this case, a peak gain of 2.4 or more and a bending angle of 30
When the gain in ° is 1/3 or more of the peak gain, that is, 33% or more, each is marked with a circle,
Each of them is indicated with a cross mark below.

[0069]

[Table 1]

As shown in Table 1, for a screen using one kind of transparent microspheres 12, the peak gain is 2.4 or more, and the gain at a bending angle of 30 ° is one of the peak gains. It can be seen that a material satisfying the condition of / 3 or more, that is, 33% or more cannot be obtained.

FIG. 43 is a diagram showing the results of measuring the luminance when two types of transparent microspheres having different refractive indices n are mixed and used at a ratio of 8: 2. In FIG. 43, a curve 43a shows that n = 1.9 and n = 1.5 are 8: 2 and 43b.
Is 8: 2 for n = 1.9 and n = 1.6, and 43c is n =
1.9 and n = 1.7 are 8: 2, and 43d is the case where n = 1.9 and n = 1.8 are 8: 2. 43d is 1.
9 shows respective brightness curves when used alone.

FIG. 44 shows that the refractive index n is 1.9, respectively.
It is a figure which shows the result at the time of measuring the brightness of the screen at the time of using two types of 1.6 transparent microspheres. However, in FIG. 44, the curve 44a is a case where only the transparent microsphere having the refractive index n of 1.6 is used. Curves 44b-4
4h is the mixing ratio of transparent microspheres with n = 1.9 and n = 1.6, respectively, curve 44b is 1: 9, curve 44c is 3: 7, curve 44d is 5: 5, and curve 44e is 7 : 3, curve 44f is 8: 2, curve 44g is 8.5: 1.5, and curve 44h is 9: 1. Also, the curve 44i
Shows a luminance curve when only a transparent microsphere having a refractive index n of 1.9 is used.

FIG. 45 shows that the refractive index n is 1.9 and 1.
FIG. 9 is a diagram showing a simulation result of screen luminance when two types of transparent microspheres No. 6 are used. FIG.
In the curve 45a, when the transparent microsphere with n = 1.6 is used alone, the curve 45a shows 20% with n = 1.9 and n = 1.6 with 45b.
Is 80%, 45c is 60% for n = 1.9 and 40% for n = 1.6, and 42d is 95% for n = 1.9 and 5 for n = 1.6.
%, 42e are 97% for n = 1.9, 3% for n = 1.6,
45f shows a luminance curve in each case where n = 1.9 is used alone. 44 and 45 show that the simulation results are appropriate because the gain curves match at the same mixture ratio.

Table 2 shows that the refractive indices n are 1.9 and 1.6.
Peak gain, gain at a bending angle of 30 °, and bending angle of 20 when using two types of transparent microspheres
The simulation result about shading in ° is shown. In this case, for those having a peak gain of 2.4 or more, and those having a gain at a bending angle of 30 ° which is 以上 or more of the peak gain, that is, 33% or more, each of them is marked with a circle. X
Marked and shown.

[0075]

[Table 2]

As shown in Table 2, the refractive index n is 1.9.
And the screen in which two types of transparent microspheres of 1.6 are used, the peak gain is 2.4 or more,
And the gain at a bending angle of 30 ° is 1 / the peak gain.
Those satisfying the condition of 3 or more, that is, 33% or more, are such that n = 1.9 is 97%, n = 1.6 is 3%, and n = 1.
9 is 96% and n = 1.6 is 4%,
It can be seen that it can be obtained.

FIG. 46 is a diagram showing a simulation result of screen brightness when two kinds of transparent microspheres having a refractive index n of 2.1 and 1.9 are used. In FIG. 46, when the curve 46a uses n = 1.9 alone, the curve 46b has n = 2.1 at 20%, n = 1.9 at 80%, and 46c has n at 1.9.
= 2.1 is 40%, n = 1.9 is 60%, 46d is n =
2.1 is 60%, n = 1.9 is 40%, 46e is n =
2.1 is 80%, n = 1.9 is 20%, 46f is n =
2 shows a luminance curve in each case where only 2.1 is used.

Table 3 shows that the refractive index n is 2.1 and 1.9.
The peak gain, the gain at a bending angle of 30 °, and the bending angle of 20 when two types of transparent microspheres are used.
The simulation result about shading in ° is shown. In this case, when the peak gain is 2.4 or more, the mark at the bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more. Those are indicated by crosses.

[0079]

[Table 3]

As shown in Table 3, the refractive index n is 2.1
And 1.9, the screen using two types of transparent microspheres has a peak gain of 2.4 or more,
And the gain at a bending angle of 30 ° is 1 / the peak gain.
It can be seen that those satisfying the condition of 3 or more, that is, 33% or more, cannot be obtained.

FIG. 47 is a diagram showing a simulation result of screen luminance when two kinds of transparent microspheres having a refractive index n of 2.1 and 1.8 are used. In FIG. 47, a curve 47a uses n = 1.8 alone, 47b has n = 2.1 of 15%, n = 1.8 has 85%, and 47c has n of n.
= 2.1 is 20%, n = 1.8 is 80%, 47d is n =
2.1 is 44%, n = 1.8 is 56%, 47e is n =
2.1 is 60%, n = 1.8 is 40%, 47f is n =
2 shows a luminance curve in each case where only 2.1 is used.

Table 4 shows that the refractive indices n are 2.1 and 1.8.
The peak gain, the gain at a bending angle of 30 °, and the bending angle of 20 when two types of transparent microspheres are used.
The simulation result about shading in ° is shown. In this case, those having a peak gain of 2.4 or more and those having a gain at a bending angle of 30 ° that are 1/3 or more of the peak gain, that is, 33% or more, are marked with “○”, and those with less than each are indicated. It is shown with an x mark.

[0083]

[Table 4]

As shown in Table 4, the refractive index n was 2.1.
And 1.8, a screen using two types of transparent microspheres has a peak gain of 2.4 or more,
And the gain at a bending angle of 30 ° is 1 / the peak gain.
Those satisfying the condition of 3 or more, that is, 33% or more, are 16% to 44% of transparent microspheres of n = 2.1, and correspondingly, 84% of transparent microspheres of n = 1.8. ~ 5
It can be seen that a combination of 6% is obtained.

FIG. 48 is a diagram showing a simulation result of screen luminance when two kinds of transparent microspheres having a refractive index n of 2.1 and 1.7 are used. In FIG. 48, when n = 1.7 is used alone, the curve 48a has 20% of n = 2.1, 80% of n = 1.7, and 48c has n of 48c.
= 2.1 is 40%, n = 1.7 is 60%, and 48d is n =
2.1 is 60%, n = 1.7 is 40%, and 48e is n =
2.1 is 80%, n = 1.7 is 20%, 48f is n =
2 shows a luminance curve in each case where only 2.1 is used.

Table 5 shows that the refractive indices n are 2.1 and 1.7.
The peak gain, the gain at a bending angle of 30 °, and the bending angle of 20 when two types of transparent microspheres are used.
The simulation result about shading in ° is shown. In this case, those having a peak gain of 2.4 or more and those having a gain at a bending angle of 30 ° that are 1/3 or more of the peak gain, that is, 33% or more, are marked with “○”, and those with less than each are indicated. It is shown with an x mark.

[0087]

[Table 5]

As shown in Table 5, the refractive index n is 2.1
And the screen in which two types of transparent microspheres of 1.7 are used, the peak gain is 2.4 or more,
And the gain at a bending angle of 30 ° is 1 / the peak gain.
It can be seen that those satisfying the condition of 3 or more, that is, 33% or more, cannot be obtained.

FIG. 49 is a diagram showing a simulation result of screen luminance when two kinds of transparent microspheres having a refractive index n of 2.1 and 1.6 are used. In FIG. 49, the curve 49a uses n = 1.6 alone, 49b uses n = 2.1 at 20%, n = 1.6 at 80%, and 49c uses n = 1.6.
= 2.1 is 40%, n = 1.6 is 60%, and 49d is n =
2.1 is 60%, n = 1.6 is 40%, and 49e is n =
2.1 is 80%, n = 1.6 is 20%, and 49f is n =
2 shows a luminance curve in each case where only 2.1 is used.

Table 6 shows that the refractive index n is 2.1 and 1.6.
Peak gain, gain at a bending angle of 30 °, and bending angle of 20 ° when the two types of transparent microspheres are used.
4 shows simulation results for shading in FIG. In this case, the peak gain is 2.4 or more, and the gain at a bending angle of 30 ° is 1 peak gain.
も の or more, that is, 33% or more, are marked with a circle, and those below that are marked with a cross.

[0091]

[Table 6]

As shown in Table 6, the refractive index n is 2.1.
And the screen in which two types of transparent microspheres of 1.6 are used, the peak gain is 2.4 or more,
And the gain at a bending angle of 30 ° is 1 / the peak gain.
It can be seen that those satisfying the condition of 3 or more, that is, 33% or more, cannot be obtained.

FIG. 50 is a diagram showing a simulation result of screen luminance when two kinds of transparent microspheres having a refractive index n of 2.1 and 1.5 are used. In FIG. 50, when the curve 50a uses n = 1.5 alone, 50b is n = 2.1 at 20%, n = 1.5 is 80%, and 50c is n
= 2.1 is 40%, n = 1.5 is 60%, and 50d is n =
2.1 is 60%, n = 1.5 is 40%, 50e is n =
2.1 is 80%, n = 1.5 is 20%, 50f is n =
2 shows a luminance curve in each case where only 2.1 is used.

Table 7 shows that the refractive index n is 2.1, 1.5
The peak gain, the gain at a bending angle of 30 °, and the bending angle of 20 when two types of transparent microspheres are used.
The simulation result about shading in ° is shown. In this case, those having a peak gain of 2.4 or more and those having a gain at a bending angle of 30 ° that are 1/3 or more of the peak gain, that is, 33% or more, are marked with “○”, and those with less than each are indicated. It is shown with an x mark.

[0095]

[Table 7]

As shown in Table 7, the refractive index n is 2.1.
And a screen using two types of transparent microspheres of 1.5, the peak gain is 2.4 or more,
And the gain at a bending angle of 30 ° is 1 / the peak gain.
It can be seen that those satisfying the condition of 3 or more, that is, 33% or more, cannot be obtained.

FIG. 51 is a diagram showing a simulation result of screen luminance when two types of transparent microspheres having a refractive index n of 1.9 and 1.8 are used. In FIG. 51, when n = 1.8 is used alone for the curve 51a, n = 1.9 is 17%, n = 1.8 is 83%, and 51c is n.
= 1.9 is 20%, n = 1.8 is 80%, 51d is n =
1.9 is 50%, n = 1.8 is 50%, 51e is n =
1.9 is 69%, n = 1.8 is 31%, and 51f is n =
9 shows a luminance curve in each case where 1.9 is used alone.

Table 8 shows that the refractive indexes n are 1.9 and 1.8.
The peak gain, the gain at a bending angle of 30 °, and the bending angle of 20 when two types of transparent microspheres are used.
The simulation result about shading in ° is shown. In this case, those having a peak gain of 2.4 or more and those having a gain at a bending angle of 30 ° that are 1/3 or more of the peak gain, that is, 33% or more, are marked with “○”, and those with less than each are indicated. It is shown with an x mark.

[0099]

[Table 8]

As shown in Table 8, the refractive index n was 1.9.
And 1.8, a screen using two types of transparent microspheres has a peak gain of 2.4 or more,
And the gain at a bending angle of 30 ° is 1 / the peak gain.
Those satisfying the condition of 3 or more, that is, 33% or more, have n = 1.9 of 18% to 68%.
It can be seen that n = 1.8 is obtained in a combination of 82% to 32%.

FIG. 52 is a diagram showing a simulation result of screen luminance when two types of transparent microspheres having a refractive index n of 1.9 and 1.7 are used. In FIG. 52, when n = 1.7 is used alone for the curve 52a, n = 1.9 is 30%, n = 1.7 is 70%, and 52c is n.
= 1.9 is 70%, n = 1.7 is 30%, and 52d is n =
1.9 is 82%, n = 1.7 is 18%, and 52e is n =
1.9 is 90%, n = 1.7 is 10%, and 52f is n =
9 shows a luminance curve in each case where 1.9 is used alone.

Table 9 shows that the refractive indexes n are 1.9 and 1.7.
The peak gain, the gain at a bending angle of 30 °, and the bending angle of 20 when two types of transparent microspheres are used.
The simulation result about shading in ° is shown. In this case, those having a peak gain of 2.4 or more and those having a gain at a bending angle of 30 ° that are 1/3 or more of the peak gain, that is, 33% or more, are marked with “○”, and those with less than each are indicated. It is shown with an x mark.

[0103]

[Table 9]

As shown in Table 9, the refractive index n is 1.9.
And the screen in which two types of transparent microspheres of 1.7 are used, the peak gain is 2.4 or more,
And the gain at a bending angle of 30 ° is 1 / the peak gain.
Those satisfying the condition of 3 or more, that is, 33% or more, have n = 1.9 of 82% to 90%.
It can be seen that n = 1.7 is obtained in a combination of 18% to 10%.

FIG. 53 is a diagram showing a result of a simulation of screen luminance when two kinds of transparent microspheres having a refractive index n of 1.9 and 1.6 are used. In FIG.
Curve 53a is 53b when n = 1.6 is used alone.
Is 20% for n = 1.9 and 80% for n = 1.6, 53c is 60% for n = 1.9, 40% for n = 1.6, and 53d is n
= 1.9 is 95%, n = 1.6 is 5%, 53e is n =
1.9 is 97%, n = 1.6 is 3%, and 53f is n = 1.
9 shows a luminance curve in each case where 9 is used alone.

Table 10 shows that the refractive indexes n are 1.9 and 1.
6, the peak gain of the screen when using two types of transparent microspheres, the gain at a bending angle of 30 °, and the bending angle 2
The simulation result about the shading at 0 degree is shown. In this case, when the peak gain is 2.4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more,
Each was marked with a circle, and those below each were marked with a cross.

[0107]

[Table 10]

As shown in (Table 10), when the refractive index n is 1.
Regarding the screen using two types of transparent microspheres 9 and 1.6, the peak gain is 2.4 or more, and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33. % Satisfy the condition of not less than 96% and 97% for n = 1.9, and it can be seen that correspondingly, n = 1.6 is obtained in the combination of 4% to 3%.

FIG. 54 is a diagram showing a simulation result of screen luminance when two kinds of transparent microspheres having a refractive index n of 1.9 and 1.5 are used. In FIG. 54, when the curve 54a uses n = 1.5 alone, the curve 54b has n = 1.9 of 20%, n = 1.5 of 80%, and 54c has n of
= 1.9 is 40%, n = 1.5 is 60%, 54d is n =
1.9 is 60%, n = 1.5 is 40%, and 54e is n =
1.9 is 80%, n = 1.5 is 20%, 54f is n =
9 shows a luminance curve in each case where 1.9 is used alone.

Table 11 shows that the refractive indices n are 1.9 and 1.
5, the peak gain of the screen when using two types of transparent microspheres, the gain at a bending angle of 30 °, and the bending angle 2
The simulation result about the shading at 0 degree is shown. In this case, when the peak gain is 2.4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more,
Each was marked with a circle, and those below each were marked with a cross.

[0111]

[Table 11]

As shown in (Table 11), when the refractive index n is 1.
Regarding the screen using two types of transparent microspheres 9 and 1.5, the peak gain is 2.4 or more, and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33. % Cannot be obtained.

FIG. 55 is a diagram showing a simulation result of screen luminance when two types of transparent microspheres having a refractive index n of 1.8 and 1.7 are used. In FIG. 55, when the curve 55a uses n = 1.7 alone, the curve 55b has n = 1.8 at 20%, n = 1.7 at 80%, and 55c has n at n = 1.7.
= 1.8 is 40%, n = 1.7 is 60%, and 55d is n =
1.8 is 60%, n = 1.7 is 40%, and 55e is n =
1.8 is 80%, n = 1.7 is 20%, and 55f is n =
18 shows a luminance curve in each case using 1.8 alone.

Table 12 shows that the refractive index n is 1.8 and 1.
7, the peak gain of the screen when using two types of transparent microspheres, the gain at a bending angle of 30 °, and the bending angle 2
The simulation result about the shading at 0 degree is shown. In this case, when the peak gain is 2.4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more,
Each was marked with a circle, and those below each were marked with a cross.

[0115]

[Table 12]

As shown in (Table 12), when the refractive index n is 1.
8 and 1.7, the screen has a peak gain of 2.4 or more, and a gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33. % Cannot be obtained.

FIG. 56 is a diagram showing a simulation result of screen brightness when two kinds of transparent microspheres having a refractive index n of 1.8 and 1.6 are used. In FIG. 56, when the curve 56a uses n = 1.6 alone, the curve 56b has n = 1.8 at 20%, n = 1.6 at 80%, and 56c has n at n.
= 1.8 is 40%, n = 1.6 is 60%, 56d is n =
1.8 is 60%, n = 1.6 is 40%, and 56e is n =
1.8 is 80%, n = 1.6 is 20%, 56f is n =
18 shows a luminance curve in each case using 1.8 alone.

Table 13 shows that the refractive indices n are 1.8 and 1.
6, the peak gain of the screen when using two types of transparent microspheres, the gain at a bending angle of 30 °, and the bending angle 2
The simulation result about the shading at 0 degree is shown. In this case, when the peak gain is 2.4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more,
Each was marked with a circle, and those below each were marked with a cross.

[0119]

[Table 13]

As shown in (Table 13), when the refractive index n is 1.
8 and 1.6, the screen has a peak gain of 2.4 or more, and a gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33. % Cannot be obtained.

FIG. 57 is a diagram showing simulation results of screen luminance when two types of transparent microspheres having a refractive index n of 1.8 and 1.5 are used. In FIG. 57, the curve 57a uses n = 1.5 alone, the curve 57b uses 20% for n = 1.8, the 80% uses n = 1.5, and the curve 57c uses n = 1.5.
= 1.8 is 40%, n = 1.5 is 60%, 57d is n =
1.8 is 60%, n = 1.5 is 40%, and 57e is n =
1.8 is 80%, n = 1.5 is 20%, and 57f is n =
18 shows a luminance curve in each case using 1.8 alone.

Table 14 shows that the refractive indexes n are 1.8 and 1.
5, the peak gain of the screen when using two types of transparent microspheres, the gain at a bending angle of 30 °, and the bending angle 2
The simulation result about the shading at 0 degree is shown. In this case, when the peak gain is 2.4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more,
Each was marked with a circle, and those below each were marked with a cross.

[0123]

[Table 14]

As shown in (Table 14), when the refractive index n is 1.
Regarding the screen using two types of transparent microspheres 8 and 1.5, the peak gain is 2.4 or more, and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33. % Cannot be obtained.

FIG. 58 is a diagram showing simulation results of screen luminance when two types of transparent microspheres having a refractive index n of 1.7 and 1.6 are used. In FIG. 58, when n = 1.6 is used alone, the curve 58a is 20% for n = 1.7, 80% for n = 1.6, and 58c is n for 58b.
= 1.7 is 40%, n = 1.6 is 60%, 58d is n =
1.7 is 60%, n = 1.6 is 40%, and 58e is n =
1.7 = 80%, n = 1.6 = 20%, 58f = n =
17 shows a luminance curve in each case using 1.7 alone.

Table 15 shows that the refractive indices n are 1.7 and 1.
6, the peak gain of the screen when using two types of transparent microspheres, the gain at a bending angle of 30 °, and the bending angle 2
The simulation result about the shading at 0 degree is shown. In this case, when the peak gain is 2.4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more,
Each was marked with a circle, and those below each were marked with a cross.

[0127]

[Table 15]

As shown in (Table 15), when the refractive index n is 1.
7 and 1.6, the screen has a peak gain of 2.4 or more, and a gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33. % Cannot be obtained.

FIG. 59 is a diagram showing simulation results of screen luminance when two types of transparent microspheres having a refractive index n of 1.7 and 1.5 are used. In FIG. 59, when curve n = 1.5 is used alone, curve 59a has n = 1.7 at 20%, n = 1.5 at 80%, and curve 59c has n = 1.5.
= 1.7 is 40%, n = 1.5 is 60%, 59d is n =
1.7 is 60%, n = 1.5 is 40%, 59e is n =
1.7 is 80%, n = 1.5 is 20%, and 59f is n =
17 shows a luminance curve in each case using 1.7 alone.

Table 16 shows that the refractive indices n are 1.7 and 1.
5, the peak gain of the screen when using two types of transparent microspheres, the gain at a bending angle of 30 °, and the bending angle 2
The simulation result about the shading at 0 degree is shown. In this case, when the peak gain is 2.4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more,
Each was marked with a circle, and those below each were marked with a cross.

[0131]

[Table 16]

As shown in (Table 16), when the refractive index n is 1.
Regarding a screen using two types of transparent microspheres 7 and 1.5, the peak gain is 2.4 or more, and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33. % Cannot be obtained.

FIG. 60 is a diagram showing a simulation result of the luminance of the screen when two kinds of transparent microspheres having a refractive index n of 1.6 and 1.5 are used. In FIG. 60, when n = 1.5 alone is used for the curve 60a, 60b is for n = 1.6 at 20%, n = 1.5 is at 80%, and 60c is for n.
= 1.6 is 40%, n = 1.5 is 60%, 60d is n =
1.6 is 60%, n = 1.5 is 40%, 60e is n =
1.6 is 80%, n = 1.5 is 20%, 60f is n =
The luminance curve in each case using 1.6 alone is shown.

Table 17 shows that the refractive index n is 1.6 and 1.
5, the peak gain of the screen when using two types of transparent microspheres, the gain at a bending angle of 30 °, and the bending angle 2
The simulation result about the shading at 0 degree is shown. In this case, when the peak gain is 2.4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more,
Each was marked with a circle, and those below each were marked with a cross.

[0135]

[Table 17]

As shown in (Table 17), when the refractive index n is 1.
Regarding the screen using two types of transparent microspheres 6 and 1.5, the peak gain is 2.4 or more, and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33. % Cannot be obtained.

FIGS. 41 to 60 described above and (Table 1)
To (Table 17) are summarized in the following (Table 18).

[0138]

[Table 18]

In Table 18, the refractive index n is 1.
5, 1.6, 1.7, 1.8, 1.9, 2.1 transparent microspheres are combined in any two types to form a screen. Although the gain is 2.4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more, the ratio (%) to each of the mixed transparent microspheres is shown.

As is clear from Table 18, the refractive index n
1.5, 1.6, 1.7, 1.8, 1.9, 2.1
When two types of transparent microspheres are combined at a predetermined ratio to form a screen, a screen having excellent peak gain and gain at a bending angle of 30 ° can be obtained.

The present invention is not limited to the case where two kinds of transparent microspheres having different refractive indices are used for the transparent microspheres 12 constituting the transparent microsphere arrangement layer 14 as described above. Even in the case where more than two kinds are combined, an excellent flat lens and a screen for a rear projection type projector can be realized.

FIG. 61 shows that the refractive index n is 1.7,
It is a figure which shows the simulation result of the brightness | luminance of a screen when three types of 1.8 and 1.9 transparent microspheres are used. In FIG. 61, the curve 61a is 20 when n = 1.9.
%, N = 1.8 is 75%, and n = 1.7 is 5%. Curve 61b shows that n = 1.9 is 30% and n = 1.9.
1.8 is 30%, n = 1.7 is 40%, and curve 61c is n
= 1.9 is 60%, n = 1.8 is 35%, n = 1.7 is 5%, and curve 61d is 70% for n = 1.9, 20% for n = 1.8, and n = 1. 0.7 is 10%, and curve 61e is n = 1.9.
, 90%, n = 1.8, 5%, and n = 1.7, 5%, respectively.

Table 19 shows that each of the refractive indices n was 1.
The simulation results about the peak gain of the screen, the gain at a bending angle of 30 °, and the shading at a bending angle of 20 ° when three types of transparent microspheres of 7, 1.8, and 1.9 are used are shown. In this case, those having a peak gain of 2.4 or more and those having a gain at a bending angle of 30 ° that are 1/3 or more of the peak gain, that is, 33% or more, are marked with “○”, and those with less than each are indicated. It is shown with an x mark.

[0144]

[Table 19]

As shown in Table 19, for a screen using three types of transparent microspheres having a refractive index n of 1.7, 1.8, and 1.9, respectively, the peak gain was 2. A screen that satisfies the condition that the gain at 4 or more and the gain at a bending angle of 30 ° is 1/3 or more of the peak gain, that is, 33% or more, is preferably a transparent microsphere having a refractive index n = 1.7, n = 1.8 transparent microspheres and n = 1.9 transparent microspheres at 5:35:
It can be seen that the mixture was in the range of 60 to 10:20:70.

In the above example, the transparent microspheres 12
In this case, the refractive index of the transparent substrate 11 is changed to correct the transmitted light of the planar lens 10 or the screen 10S.
In one or more of the first, the absorbance or the spectral absorbance is changed gradually or stepwise between the center and the periphery of the lens, or any one of the transparent layers 15, 25, 26, etc., simultaneously or alternatively. Above the layers, the absorbance or spectral absorbance can be changed gradually or stepwise between the center and the periphery of the lens, for example to substantially uniform or aggressively produce the required distribution of the emitted light. .

In the above-described rear projection display device using the screen according to the present invention, that is, in the projector,
In the optical system of the projection unit 1, a zoom mechanism is configured or the distance between the screen and the projection unit 1 is changed so that the projection image is enlarged or reduced continuously or intermittently. be able to. By the way, in such a configuration, in the screen using the conventional lenticular lens, it is necessary to set the optical system, the distance between the screen and the image projection unit, etc. to a fixed state based on the design due to the problem of moire. However, according to the configuration of the present invention, the resolution can be improved because of the arrangement of the transparent microspheres and the fine arrangement of the microspheres.

Also, as an example of a rear projection type display device using a screen according to the present invention, by setting the central light illuminance on the image projection side to 500 [lx] or more, the central luminance is 200 [cd / m ² ] or more, and the central angle of the conical area where 50% or more of the central luminance is obtained in front of the screen, that is, on the observation side, is 45.
° or more.

Next, an example of a method for manufacturing the above-described flat lens or screen according to the present invention will be described. For example, in the case of forming a flat lens or a screen having the configuration shown in FIG. 1 and the basic configuration thereof, an adhesive or sticky material capable of fixing the transparent microspheres 12 on a sheet-like or rigid transparent substrate 11. The above-described colored layer 13 having a property is applied and formed, that is, coated, and the transparent microspheres 12 are arranged by close-packing to form a transparent microsphere arrangement layer 14.

In FIG. 2 and each structure having the basic structure, first, a transparent layer 15 having an adhesive property or a tacky property capable of fixing the transparent microspheres 12 is formed on the same base material 11. That is, it is coated, and the above-mentioned colored layer 13 having an adhesive or tacky property capable of fixing the transparent microspheres 12 in the same manner as described above is formed thereon, that is, coated with the transparent microspheres 12. To form a transparent microsphere arrangement layer 14.

The above-mentioned colored layers 13 can be formed of the above-mentioned colored coating material having the required coloring in the coating material. However, in the coating, a colorless or white coating having adhesiveness or tackiness is used. It can be done by using a material and coloring it after its coating.

The transparent microsphere placement layer 14 formed by filling the transparent microspheres 12 has the adhesive or sticky colored layer 13, or the transparent microspheres 12 on the colored layer 13 and the transparent layer 15. And embedded in a single particle layer, that is, one layer, to a required depth and thickness in close proximity to or in contact with the layer.

The formation of the transparent microsphere arrangement layer 14 is performed, for example, by using the apparatus and method proposed in Japanese Patent Application No. 7-344488 filed by the present applicant, entitled “Microbody Arrangement Apparatus and Microbody Arrangement Method”. Can be applied. That is, a supply nozzle of the transparent microsphere 12 used in the finally formed transparent microsphere placement layer 14 is provided, and the amount of the transparent microsphere 12 placed in the finally formed transparent microsphere placement layer 14 is provided. A sufficiently large amount is supplied onto the colored layer 13, and the transparent fine spheres 12 are densely arranged on the entire surface by squeezing. The sphere 12 is inserted into the colored layer 13 or the colored layer 13 and the transparent layer 15 under the colored layer 13 so as to embed the emission end side thereof. The transparent microspheres 12 and the transparent microspheres 12 whose embedding amount does not reach the required amount, and thus have a small fixing strength, are removed by suction. By doing so, the intended transparent microspheres in which only the colored layer 13 or the transparent microspheres 12 embedded and embedded in the colored layer 13 and the transparent layer 15 thereunder are arranged at a required depth The arrangement layer 14 can be configured.

In some cases, for example, when manufacturing the planar lens 10 having the structure shown in FIG. 2, for example, the colored layer 13 having an adhesive property or an adhesive property is formed on the transparent substrate 11.
To form On the other hand, a transfer sheet (not shown) is coated with a transparent layer 15 having an adhesive or tacky property, and the transparent layer 15 is arranged by, for example, the above-described method by finely filling the transparent microspheres 12. The transfer sheet is pressed against the colored layer 13 on the transparent substrate 11 on the side on which the transparent microspheres 12 are arranged so that the transparent microspheres reach the transparent substrate in the colored layer or almost. In this state, the transparent microspheres together with the transparent layer are peeled off from the transfer sheet and transferred to the transparent substrate side, so that the transparent microsphere placement layer 14 is placed on the transparent substrate 11.
Can be manufactured.

In manufacturing a flat lens or a screen having the structure shown in FIGS. 3 and 4,
The transparent protective layer 25 is coated on the transparent microsphere arrangement layer 14 of FIGS. 1 and 3 formed by the above-described method by the above-described methods.

In the configuration shown in FIGS. 1 to 4, the transparent base material 11 is arranged on the light emitting side. However, as shown in FIGS. In the case of being disposed on the incident side, for example, the transparent substrate 11
An adhesive or sticky transparent layer 26 is formed thereon, and an adhesive or sticky colored layer 13 is formed on a transfer sheet (not shown), or the adhesive layer is formed under the colored layer 13. Or a transparent layer 15 having an adhesive property, and the colored layer 13 or the colored layer 13 and the transparent layer 15 formed thereunder are buried in the transparent microspheres 12 by, for example, the above-described method. The transfer sheet is placed on the transparent layer 26 on the transparent substrate 11 with the side on which the transparent microspheres 12 are disposed.
A transparent microsphere 12 in this state, together with the colored layer 13 or the colored layer 13 and the transparent layer 15.
By peeling off the transfer sheet and transferring it to the transparent substrate 11 side, a flat lens or a screen in which the transparent microsphere arrangement layer 14 is formed on the transparent substrate 11 can be manufactured.

Further, in order to manufacture a flat lens or a screen having the structure shown in FIGS. 7 and 8, the above-described method for manufacturing a flat lens or a screen having the structure shown in FIGS. 1 to 6 is applied. A protective transparent substrate 41 made of a sheet-like or rigid substrate is bonded to the opposite side of the transparent substrate 11 through an adhesive layer or using, for example, the adhesiveness or tackiness of the transparent layers 26 and 15. can do.

The method for obtaining the flat lens or screen according to the present invention is not limited to the above-mentioned methods, but may be various methods and combinations.

According to the above-described flat lens according to the present invention and the screen for a rear projection type projector using the same, it is possible to solve various problems in the case of the lenticular lens described at the outset.

That is, according to the present invention, as described above, stray light of external light can be effectively avoided, so that the contrast of an image can be improved. In addition, since the disposition of a smoke plate or the like can be avoided, a decrease in luminance can be avoided, and accordingly, the use of a light source that consumes a large amount of power can be avoided, and power saving, reduction of heat measures, and cost increase can be avoided.
Further, according to the configuration of the present invention, since the light is diffused widely in both the horizontal and vertical directions, the range in which a clear image can be observed is extended, and partial non-uniformity can be avoided. Further, as compared with the lenticular lens, the manufacturing is easy, the handling is simple, and the cost is avoided. Further, the resolution is improved as compared with the case where a lenticular lens is used. Correction of the illuminance distribution can be easily performed to obtain a desired luminance distribution. Multiple reflections between the Fresnel lens and the lenticular lens as in the combination of the Fresnel lens and the lenticular lens can be avoided. Further, since moiré is less likely to occur, design constraints in, for example, configuring a rear projection type projector or the like are reduced, and a zoom mechanism or the like can be easily provided.

[0161]

As described above, according to the present invention, the contrast is improved, the brightness is improved, the power consumption is reduced, the power consumption is reduced, the heat measures are reduced, the cost is increased, and both the horizontal and vertical directions are improved. Can provide many effects such as observation of a clear image, expansion of the observation range, simplification of handling, improvement of resolution, improvement of moire, etc.

According to the present invention, a screen having a high peak gain and a relatively high gain even at a bending angle of 30 ° is formed by combining transparent microspheres having different refractive indices at a preferable ratio. We were able to.

The transparent microspheres made of glass have a refractive index n of 1.5, 1.6, 1.7, 1.8, 1.9, 2.1.
Can be produced, but n is 1.5, 1.9, 2..
Since the transparent microspheres 1 are mass-produced industrially, they are generally available at a low cost.
1.6, 1.7, and 1.8 are relatively expensive, which is disadvantageous in terms of cost. On the other hand, according to the present invention, two or more types of inexpensive transparent microspheres are arbitrarily combined to form a screen, or inexpensive transparent microspheres are mainly used and only a small amount of expensive transparent microspheres are used. By forming the screen by arbitrarily combining two or more kinds, a screen with an excellent gain curve could be produced at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic cross section of an example of a flat lens or a screen according to the present invention.

FIG. 2 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 3 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 4 is a schematic cross section of another example of the planar lens or the screen according to the present invention.

FIG. 5 is a schematic cross section of another example of the planar lens or the screen according to the present invention.

FIG. 6 is a schematic cross section of another example of the planar lens or the screen according to the present invention.

FIG. 7 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 8 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 9 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 10 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 11 is a schematic cross section of another example of the planar lens or the screen according to the present invention.

FIG. 12 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 13 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 14 is a schematic cross section of another example of the planar lens or the screen according to the present invention.

FIG. 15 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 16 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 17 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 18 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 19 is a schematic cross section of another example of the flat lens or screen according to the present invention.

FIG. 20 is a schematic cross section of another example of the planar lens or the screen according to the present invention.

FIG. 21 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 22 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 23 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 24 is a schematic cross section of another example of the flat lens or the screen according to the present invention.

FIG. 25 is a configuration diagram of an example of a rear projection type projector using a screen according to the present invention.

FIG. 26 is a configuration diagram of another example of a rear projection type projector using a screen according to the present invention.

FIG. 27 is a curve showing viewing angle dependence of a screen gain with respect to a refractive index of a transparent microsphere used for describing the present invention.

FIG. 28A is a distribution diagram of projection illuminance on a flat lens or a screen. B is a distribution diagram of a lens or a screen gain. C is a luminance distribution diagram of a lens or a screen.

FIG. 29 is a diagram showing a refractive index distribution in a flat lens or a screen according to the present invention.

FIG. 30 is a diagram showing a refractive index distribution in a flat lens or a screen according to the present invention.

FIG. 31A is a diagram showing a diffusion mode in a flat lens or a screen according to the present invention. B is a diagram showing the spread angle of diffusion at the center. C is a diagram showing a spread angle of diffusion in a peripheral portion thereof.

FIG. 32A is a distribution diagram of projection illuminance on a flat lens or a screen according to the present invention. B is a distribution diagram of a lens or a screen gain. C is a luminance distribution diagram of a lens or a screen.

FIG. 33A is a distribution diagram of projected illuminance on a flat lens or a screen according to the present invention. B is a distribution diagram of a lens or a screen gain. C is a luminance distribution diagram of a lens or a screen.

FIG. 34 is a configuration diagram of a conventional rear projection type video display device.

FIG. 35 is a perspective view of a screen of a conventional rear projection type video display device.

FIG. 36A is a distribution diagram of projection illuminance on a flat lens or a screen of a conventional rear projection type image display device. B is a distribution diagram of a lens or a screen gain. C is a luminance distribution diagram of a lens or a screen.

FIG. 37 is an explanatory diagram of a bending angle when a screen is observed.

FIG. 38 is an explanatory diagram of a bending angle when a screen is observed.

FIG. 39 shows a measurement diagram of the luminance of the screen of the present invention.

FIG. 40 shows a configuration diagram of an example of the screen of the present invention.

FIG. 41 shows a luminance curve when one type of transparent microsphere is used.

FIG. 42 shows a luminance curve when one type of transparent microsphere is used.

FIG. 43 shows a luminance curve when two types of transparent microspheres are used in a mixture of 8: 2.

FIG. 44 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.9 and 1.6 are mixed and used.

FIG. 45 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.9 and 1.6 are mixed and used.

FIG. 46 shows a luminance curve when two types of transparent microspheres having a refractive index of 2.1 and 1.9 are used in combination.

FIG. 47 shows a luminance curve when two types of transparent microspheres having a refractive index of 2.1 and 1.8 are mixed and used.

FIG. 48 shows a luminance curve when two types of transparent microspheres having a refractive index of 2.1 and 1.7 are used in combination.

FIG. 49 shows a luminance curve when two types of transparent microspheres having a refractive index of 2.1 and 1.6 are mixed and used.

FIG. 50 shows a luminance curve when two types of transparent microspheres having a refractive index of 2.1 and 1.5 are mixed and used.

FIG. 51 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.9 and 1.8 are mixed and used.

FIG. 52 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.9 and 1.7 are mixed and used.

FIG. 53 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.9 and 1.6 are mixed and used.

FIG. 54 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.9 and 1.5 are mixed and used.

FIG. 55 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.8 and 1.7 are mixed and used.

FIG. 56 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.8 and 1.6 are used in combination.

FIG. 57 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.8 and 1.5 are used in combination.

FIG. 58 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.7 and 1.6 are mixed and used.

FIG. 59 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.7 and 1.5 are used in combination.

FIG. 60 shows a luminance curve when two types of transparent microspheres having a refractive index of 1.6 and 1.5 are mixed and used.

FIG. 61 shows a luminance curve when three types of transparent microspheres having a refractive index of 1.7, 1.8, and 1.9 are used in combination.

[Explanation of symbols]

1 image projection unit, 2 transmission screen, 3 reflection mirror, 4 Fresnel lens, 5 lenticular lens,
10 flat lens, 10S screen for rear projection type projector, 11 transparent substrate, 12 transparent microsphere,
Reference Signs List 13 colored layer, 14 transparent microsphere arrangement layer, 15 transparent layer, 25 protective transparent layer, 26 transparent layer, 28 antireflection layer, 31 transparent substrate, 41 protective transparent substrate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ken Matsui 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Hirotaka Ito 6-35-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Shunichi Hashimoto 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (38)

[Claims] 1. A transparent substrate is disposed on a light emitting side or a light incident side, and transparent microspheres are mutually contacted on the transparent substrate in a two-dimensional arrangement with a single particle layer arrangement. Or a transparent microsphere arrangement layer which is arranged in close proximity and has at least a colored layer for exposing a part of the transparent microsphere to the outside on the light incident side, wherein the transparent microsphere arrangement layer is A flat lens having a configuration in which light transmittance is enhanced at a light emitting side end of a microsphere. 2. A transparent base material is disposed on a light emitting side or a light incident side, and transparent microspheres are brought into contact with each other on the transparent base material in a two-dimensional manner with adjacent transparent microspheres having a single particle layer arrangement. Or a transparent microsphere arrangement layer which is arranged in close proximity and has at least a colored layer for exposing a part of the transparent microsphere to the outside on the light incident side, wherein the transparent microsphere arrangement layer is A screen for a rear projection type projector, comprising: a flat lens having a configuration in which light transmittance is enhanced at an end of a light emitting side of a microsphere. 3. The flat lens according to claim 1, wherein a transparent layer is formed on the transparent microspheres between the transparent microsphere arrangement layer and the transparent substrate. 4. The screen for a rear projection type projector according to claim 2, wherein a transparent layer is formed on the transparent microspheres between the transparent microsphere arrangement layer and the transparent substrate. 5. The flat lens according to claim 1, wherein a protective transparent layer is formed on a side of the transparent microsphere arrangement layer opposite to a side having the transparent substrate. 6. The screen for a rear projection type projector according to claim 2, wherein a protective transparent layer is formed on a side of the transparent microsphere arrangement layer opposite to a side having the transparent base material. 7. The flat lens according to claim 1, wherein a protective transparent substrate is disposed opposite to the transparent substrate with the transparent microsphere disposed layer interposed therebetween. 8. The screen for a rear projection type projector according to claim 2, wherein a protective transparent substrate is disposed opposite to the transparent substrate with the transparent microsphere disposed layer interposed therebetween. 9. The flat lens according to claim 1, wherein a Fresnel lens is bonded to the light incident side of the transparent microsphere arrangement layer via a transparent layer. 10. The screen for a rear projection type projector according to claim 2, wherein a Fresnel lens is bonded to a light incident side of the transparent microsphere arrangement layer via a transparent layer. 11. The flat lens according to claim 1, wherein an anti-reflection layer is formed on one or one of the outermost light incident surface side and the light emission surface side. 12. The screen for a rear projection type projector according to claim 2, wherein an antireflection layer is formed on one or one of the outermost light incident surface side and the light emission surface side. 13. The flat lens according to claim 1, wherein a protective layer is formed on one or one of the outermost light incident surface side and the light emission surface side. 14. The rear projection type projector screen according to claim 2, wherein a protective layer is formed on at least one of the light incident surface side and the light emission surface side on the outermost side. 15. The transparent microspheres have a portion corresponding to at least 30% of the diameter of the transparent microspheres projecting from the light incident side of the colored layer, and the thickness of the colored layer is equal to the thickness of the transparent microspheres. 70% of diameter
2. A thickness corresponding to less than 1.
A flat lens according to item 1. 16. The transparent microspheres have a portion corresponding to at least 30% of the diameter of the transparent microspheres protruding from the light incident side of the colored layer, and the thickness of the colored layer is equal to the thickness of the transparent microspheres. 70% of diameter
3. A thickness corresponding to less than 2.
2. The screen for a rear projection type projector according to item 1. 17. The flat lens according to claim 3, wherein the absorbance or the spectral absorbance of at least one of the colored layer and the transparent layer on the light emission side is changed in the thickness direction. 18. The rear projection type projector according to claim 4, wherein the absorbance or the spectral absorbance of at least one of the colored layer and the transparent layer on the light emission side is changed in the thickness direction. screen. 19. The planar type according to claim 17, wherein at least one of the colored layer and the transparent layer on the light emitting side is formed by stacking a plurality of layers having different absorbances or spectral absorbances. lens. 20. The rear projection according to claim 18, wherein at least one of the colored layer and the transparent layer on the light emission side is formed by stacking a plurality of layers having different absorbances or spectral absorbances. Screen for projectors. 21. The diameter of the transparent microsphere is 100 μm.
2. The flat lens according to claim 1, wherein m is equal to or less than m. 22. The diameter of the transparent microsphere is 100 μm.
3. The screen for a rear projection type projector according to claim 2, wherein m is equal to or less than m. 23. The planar lens according to claim 1, wherein the distribution range of the diameter of the transparent microsphere is 10% or less of the average diameter. 24. The rear projection type projector screen according to claim 2, wherein the distribution range of the diameter of the transparent microsphere is 10% or less of the average diameter. 25. The transparent microsphere has a refractive index of 1.4.
2. The flat lens according to claim 1, wherein the size of the lens is larger than a member contacting the light incident side. 26. The refractive index of the transparent microsphere is 1.4.
3. The screen for a rear projection type projector according to claim 2, wherein the size of the screen is larger than a member which is in contact with the light incident side. 27. The flat lens according to claim 1, wherein the transparent microspheres of the transparent microsphere arrangement layer are constituted by two or more kinds of transparent microspheres having different refractive indexes. 28. The rear projection type projector according to claim 2, wherein the transparent microspheres of the transparent microsphere arrangement layer are formed of two or more kinds of transparent microspheres having different refractive indexes. For screen. 29. The transparent microspheres of the transparent microsphere arrangement layer are constituted by two or more kinds of transparent microspheres having different refractive indexes, and the peak gain of the flat lens is 2.4 or more. 2. The flat lens according to claim 1, wherein a gain at a curved angle of 30 ° of the flat lens is equal to or more than の of a peak gain. 3. 30. The transparent microspheres of the transparent microsphere arrangement layer are composed of two or more kinds of transparent microspheres having different refractive indices, and the flat lens has a peak gain of 2.4 or more. 3. The rear projection type projector screen according to claim 2, wherein a gain of the flat lens at a curved angle of 30 ° is equal to or more than の of a peak gain. 4. 31. The flat lens according to claim 1, wherein the refractive index of the transparent microsphere is changed gradually or stepwise between the center and the periphery of the lens. 32. The rear projection type projector screen according to claim 2, wherein the refractive index of the transparent microsphere is gradually or stepwise changed between the center and the periphery of the screen. 33. The flat lens according to claim 1, wherein the absorbance or the spectral absorbance of the transparent substrate is changed gradually or stepwise between the center and the periphery of the lens. 34. The rear projection type projector screen according to claim 2, wherein the absorbance or the spectral absorbance of the transparent substrate is changed gradually or stepwise between the center and the periphery of the screen. 35. The flat lens according to claim 1, wherein fine irregularities are formed on the surface of the transparent microsphere. 36. The screen for a rear projection type projector according to claim 2, wherein fine irregularities are formed on a surface of the transparent microsphere. 37. The flat lens according to claim 1, wherein one or both of an antireflection treatment and a water-repellent treatment are applied to the surface of the transparent microsphere. 38. The rear projection type projector screen according to claim 2, wherein one or both of an antireflection treatment and a water repellent treatment are applied to the surface of the transparent microsphere.