JP2002169227A - Rear projection display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rear projection display in which anisotropic diffusion is accomplished and excellent resolution and less reduction of contrast due to external light are ensured and which is well-balanced in terms of front luminance and an angle of visibility. SOLUTION: In consideration of the effect that a transmission loss is not increased in the case the diffusion angle of light made incident on a sheet of beads is within a specified extent even if the light made incident on the beads sheet is the diffused light, the anisotropic diffusion is accomplished by making the light from a projecting lens 3 incident on a screen 43 of beads after the light is diffused only in a horizontal direction through a lenticular lens 441. Then, the anisotropic diffusion is accomplished while utilizing such the properties of the beads sheet that the sheet is provided with a fine structure and an ability of eliminating the influence of the external light, then, the image display of improved resolution, high contrast even under a bright environment, and also, well-balanced in terms of the angle of visibility and the luminance is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear projection display. In particular, the present invention relates to a rear-projection display characterized by a rear-projection screen.

[0002]

2. Description of the Related Art In recent years, there has been an increasing need for large screens, mainly for TV receivers, and a rear projection display has attracted attention as a device suitable for large screen display.

[0003] The rear projection type display is a type in which a small high-luminance image is enlarged and projected by a projection lens, and the image is observed through a transmission screen. Conventionally, a system in which a monochromatic CRT of three primary colors is used as an image source, and a color image is formed by superimposing images on a screen by a projection lens, but recently, a system using a spatial modulation element such as a liquid crystal panel has been used. Is being developed. The method using a spatial modulation element is suitable for a multimedia display because it can display clear characters or graphics by dot matrix display, and is expected to be lighter and more compact. FIG. 6 schematically shows the basic configuration.

An image formed by spatially modulating light emitted from a lamp 1 by a liquid crystal panel 2 is enlarged and projected on a rear projection screen 4 by a projection lens 3. In an actual apparatus, three liquid crystal panels are generally used to realize color display. In this case, color separation optics that separates light from the lamp 1 into red, green, and blue components. The system has a complicated structure including a color synthesizing optical system for synthesizing light transmitted through three liquid crystal panels, but these are omitted here.

The same type of device using a spatial modulation device includes a device using a reflective liquid crystal display device as a modulation device, and a device using a device in which a number of fine mirrors whose angles can be varied are arranged. .

[0006] As shown in the figure, light diverging macroscopically from the center to the periphery and having extremely sharp directivity partially enters the screen 4 installed on the image plane. The screen 4 functions to appropriately distribute such projection light to enable good image recognition.

[0007] Even if a simple diffuser is used for the screen 4, the minimum image observation is possible. However, since the projection light diverges as described above, the peripheral portion has outward directivity. Therefore, when the screen is viewed from the front, the peripheral brightness becomes extremely dark compared to the center brightness, and when viewed from an oblique direction, the near end becomes bright and the far end becomes extremely dark, etc. It produces noticeable unevenness in screen brightness.

In order to eliminate such non-uniformity, it is common to arrange a Fresnel lens sheet 41 on the projection side of the diffusing means.

The Fresnel lens sheet 41 functions to convert the projection light divergently incident on the screen 4 from the projection lens 3 into parallel light whose main directivity is substantially perpendicular to the screen surface. In this way, if the main directional direction of light at each part of the screen is converted to a direction perpendicular to the screen surface and then diffused,
Irrespective of the viewing direction, almost uniform brightness can be realized over the entire screen.

Further, instead of using a simple isotropic diffusion plate as the diffusion means, a BS lenticular lens sheet 42 is used.
Is generally used.

As the observation range, good image recognition is required from various angles in the horizontal direction, while good image recognition is achieved in a limited range of standing and sitting in the vertical direction. I hope you can. Therefore, a bright image can be provided as a whole if light is effectively distributed to a necessary area by anisotropic diffusion. When a range of an observation angle (an angle formed with a normal line of the screen, hereinafter, this angle is referred to as a “β angle”) at which a luminance of 輝 度 of the luminance when the screen is observed from the front direction is set as a practical visual field range, It is appropriate that the β angle is about 40 ° to 50 ° in the horizontal direction and about 10 ° to 30 ° in the vertical direction. The BS lenticular lens sheet 42 realizes such anisotropic diffusion.

The BS lenticular lens sheet 42 has a lenticular lens array whose longitudinal direction is perpendicular to the plane of incidence, in which light diffusing particles having a refractive index slightly larger than the refractive index of the base material are dispersed. Have been. The projection light converted into substantially parallel light by the Fresnel lens sheet 41 is diffused in a relatively wide range in the horizontal direction by the refraction of the lenticular lens 421 and the synergistic action of the light diffusion particles, and in the vertical direction. Is diffused in a relatively narrow range only by the action of the above, and the anisotropic diffusion is realized.

Further, the light transmitting portion of the light exiting surface is limited by the light condensing action of the lenticular lens 421 provided on the incident side, so that the light absorbing layer 422 can be provided in the light non-transmitting portion. Since the light absorbing layer 422 is formed in a black stripe shape, it is called a black stripe or BS for short, and has an effect of greatly reducing the diffuse reflection of external light by a screen in a bright environment to reduce contrast deterioration. Demonstrate.

Thus, the BS lenticular lens sheet 4
2 is an extremely rational structure that simultaneously performs a plurality of functions such as diffusion of projection light and absorption of external light. However, the BS lenticular lens sheet 42 has some limitations in improving the performance of the rear projection display.

The first problem is the problem of fine pitch.
As is clear from FIG. 6, since the exit surface needs to be provided near the focal point of the incident-side lenticular lens 421, the ratio t / p between the thickness t of the lenticular lens sheet 42 and the arrangement pitch p of the lenticular lenses 421 is constant. It is about 1.3.

The BS lenticular lens sheet 42 is usually formed by hot press or roll extrusion using a pair of molds on the entrance side and the exit side. In order to ensure a wide viewing angle, it is preferable to form the lenticular lens surface on the incident side deeply. However, the lenticular lens sheet is easily broken, and the minimum thickness of the lenticular lens sheet that can be realized by the above method is about 0.7 mm. If the thickness is smaller than this, the yield is rapidly deteriorated and production becomes difficult. Therefore, the minimum achievable arrangement pitch p is about 0.5 mm from 0.7 / 1.3.
It is.

[0017] In recent years, as the definition of an image is progressing, as represented by Hi-Vision, the miniaturization limit of the BS lenticular lens sheet becomes a problem because the resolution limit of the screen is limited.

The second problem is a limit in reducing the influence of external light. The black stripe 422 needs to be provided in the light-impermeable region of the exit surface, and the incident surface and the exit surface need to be accurately aligned, but there is a limit in mechanical accuracy. In general, a land for black stripe printing is formed on the emission surface, and a side surface of the land needs to be tapered (inclined). The taper occupies a certain area in the in-plane direction of the emission surface, and this portion forms an ineffective region from which the projection light is not emitted. By ensuring a margin for these alignment errors and generating an ineffective area due to the taper, the lenticular lens 421
There is an upper limit on the ratio of the width of the black stripe 422 to the arrangement pitch (BS ratio), and the limit is about 50%. For this reason, there is a limit to the effect of preventing black stripes 422 from lowering contrast when external light enters the screen. In order to realize high contrast in a bright environment, a screen having higher external light absorbing ability is desired.

As shown in FIG. 7, a method using a bead sheet 43 in place of the BS lenticular lens sheet 42 has been proposed to realize a high resolution and a high external light absorbing ability by a fine structure.

FIG. 8 shows an enlarged sectional structure of the bead sheet 43. The transparent beads 432 are arranged adjacent to each other on the transparent base material (base sheet) 431 by the light absorbing material (opaque binder) 433. At this time, by adjusting the pressing force of the transparent beads 432 against the transparent base material 431, an opening (light transmitting part) 434 in which the light absorbing material 433 is not interposed is provided in a portion where the transparent beads 432 and the transparent base material 431 are in contact.

The surface on the incident side of the transparent beads 432 functions as a lens, and condenses and transmits the projection light to the opening 434 while diffusing it.

In this method, the arrangement pitch of the transparent beads 432 is approximately the same as the bead diameter, and by using beads having a particle diameter of about 10 μm, miniaturization can be achieved as compared with the case of using the lenticular lens sheet 42 with BS shown in FIG. Will be possible. Further, since the openings 434 are scattered in a lattice point shape,
In the lenticular lens sheet with BS 42, the light absorbing material provided in a stripe shape can be formed in a planar shape, and the upper limit of the area ratio of the light absorbing material to the screen surface is about 50% in the case of a black stripe. 9
It can be increased to about 0%, and external light reflection can be greatly reduced.

As described above, the use of the bead sheet enables miniaturization and high external light absorption performance.

[0024]

However, in the system using the bead sheet 43, the diffusion of the projected light is isotropic,
Anisotropic diffusion that effectively distributes light cannot be performed. As a result, when the practical viewing range is set to a wide viewing angle required in the horizontal direction, for example, at a β angle of 45 °, the gain is reduced and the front luminance is insufficient, and conversely, a narrow viewing angle is required in the vertical direction. ,
For example, when the β angle is set to 30 °, the gain becomes high and luminance in the front direction can be obtained, but the viewing angle in the horizontal direction is insufficient.

The present invention solves the above-mentioned problems, and enables anisotropic diffusion while utilizing the characteristics of a bead sheet having a high ability to reduce external light reflection with a fine structure, thereby achieving excellent resolution.
It is an object of the present invention to provide a rear-projection display in which the contrast is hardly reduced due to external light and which has an excellent balance between front luminance and viewing angle characteristics.

[0026]

To achieve the above object, the present invention has the following arrangement.

A first rear projection type display according to the present invention comprises: an image display device for displaying an image in response to an input signal; an image projection unit including a projection lens for enlarging and projecting an image on the image display device; A rear projection type screen that projects an image projected by a projection unit, wherein the rear projection type screen emits macroscopically divergently from the center to the periphery of the screen in order from the projection side to the observation side. A Fresnel lens sheet having a circular Fresnel lens that converges light macroscopically and converts it into substantially parallel light, a lenticular lens sheet that has a lenticular lens array whose vertical direction is the longitudinal direction, and diffuses light in the horizontal direction, Microbeads made of a transparent material are arranged on the projection side of a base sheet made of a transparent material, Characterized in that it comprises a bead seat on the face of the projection side of said base sheet other than the light transmitting portion is covered with an opaque binder between the microbeads.

Also, a second rear projection type display of the present invention comprises: an image display device for displaying an image in accordance with an input signal; and an image projection unit comprising a projection lens for enlarging and projecting an image on the image display device. A rear projection screen that projects an image projected by the image projection unit,
The rear projection screen, in order from the projection side to the observation side, the lenticular lens array having a vertical direction as a longitudinal direction, on the projection side, the projection light macroscopically divergently incident from the center of the screen toward the periphery of the screen. On the observation side, a circular Fresnel lens that converges on a macro and converts it into substantially parallel light is placed on the projection side surface of a Fresnel lens sheet that has each, and microbeads made of a transparent material on the base sheet made of a transparent material. A bead sheet in which the surface of the base sheet on the projection side other than the light transmitting portion between the base sheet and the microbeads is covered with an opaque binder.

Further, a third rear projection type display of the present invention comprises: an image display device for displaying an image in accordance with an input signal; and an image projection unit comprising a projection lens for enlarging and projecting an image on the image display device. A rear projection screen that projects an image projected by the image projection unit,
The rear-projection screen includes a circular Fresnel lens that sequentially converges macroscopically projected light that is divergently incident from the center of the screen toward the periphery from the projection side toward the observation side and converts the light into substantially parallel light. Having a Fresnel lens sheet and a laminated diffusion function sheet, wherein the laminated diffusion function sheet has a lenticular lens array having a longitudinal direction perpendicular to the projection side surface, and a lenticular that diffuses light in the horizontal direction. The lens sheet is placed on the projection side, and the microbeads made of a transparent material are arranged on the projection side surface of the base sheet made of a transparent material, and the base other than the light transmitting portion between the base sheet and the microbeads The observation side is provided with a bead sheet in which the projection side of the sheet is covered with an opaque binder, and the lenticular lens sheet and the bead sheet are provided. And bets, and characterized by being integrally bonded by a transparent adhesive layer.

That is, the rear projection type display of the present invention uses a rear projection type screen configured so that light diffused only in the horizontal direction by the lenticular lens array having the vertical direction as the longitudinal direction is incident on the bead sheet. Features.

With such a configuration, it is possible to realize anisotropic diffusion by using a bead sheet having a fine structure and a high ability to eliminate the influence of external light, thereby achieving excellent resolution.
Even in a bright environment, it is possible to realize an image display with high contrast and an excellent balance between viewing angle and brightness.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the individual embodiments of the rear projection type display of the present invention, the study results on which the present invention is based will be described.

In the bead sheet, since a light absorbing material is formed on the emission side of the transparent beads, an absorption loss occurs for obliquely incident light. Therefore, conventionally, the ray trajectory 5 in FIG.
As shown in FIG. 01, it is advantageous from the viewpoint of efficiency that light with high parallelism is incident from the normal direction of the bead sheet surface as much as possible. It was common practice to avoid insertion.

However, the present inventors have found that even if light is incident at an angle with respect to the normal direction of the bead sheet surface, if the incident angle is within a specific range as shown by a ray trajectory 502 in FIG. It has been found that no absorption loss occurs.

FIG. 4 shows the results of measuring the light transmittance when parallel light was incident on the prototype bead sheet while changing the incident angle. The horizontal axis is the incident angle with respect to the normal direction of the bead sheet surface, and the vertical axis is the relative transmittance standardized by the transmittance of light rays incident from the normal direction.

As shown in the figure, even if the light is incident obliquely, if the incident angle is within ± 10 °, almost no absorption loss by the light absorbing material provided on the bead sheet occurs, Through the bead sheet with the same transmittance as the light incident from the.

FIG. 5 shows an average relative transmittance calculated from the measurement results shown in FIG. 4 when diffused light having a uniform intensity distribution in a specific angle range is incident on the bead sheet in the normal direction. It is. Even if diffused light is uniformly diffused in a specific angle range, if the diffusion angle range is within ± 15 °, the average transmittance is almost equal to that when light with high parallelism is incident from the normal direction, and the diffusion angle Even if the range is ± 20 °, it shows an average relative transmittance of 90% or more.

The above measurement example is for a bead sheet which does not originally assume the incidence of diffused light. The opening width W (see FIG. 8) where no light absorbing material is formed is about 30% of the particle diameter of the transparent beads. Although the area aperture ratio is about 9%, the transmission efficiency for obliquely incident light can be further improved by increasing the aperture width. If the opening width is increased, there is a concern that the ability of the light absorbing material to reduce the reflection of external light may be reduced. However, even if the opening width is increased to about 40% of the particle size, the area aperture ratio is about 16%. Even if the transmittance of the projection light is increased in this manner, the area ratio of the region occupied by the light absorbing material can be secured to 80% or more, and this value is the upper limit when a black stripe is provided on the lenticular lens sheet. Much larger than 50%. That is, if the opening width of the conventionally used bead sheet is appropriately set, a screen that does not reduce the transmittance for obliquely incident light or diffused light and does not reduce the contrast when external light is incident. Can be configured.

An embodiment of the rear projection display of the present invention using such a bead sheet will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a horizontal sectional view showing the configuration of a rear projection display according to Embodiment 1 of the present invention.

An image formed by spatially modulating the light emitted from the lamp 1 by the liquid crystal panel 2 is enlarged and projected by the projection lens 3. As shown in the figure, light diverging macroscopically from the center to the periphery and having extremely sharp directivity is partially incident on the screen 4 provided on the image forming surface.
In an actual rear projection display, the projection lens 3 is used.
In general, a compact device is realized by projecting the projection light from the mirror 4 onto the screen 4 via a mirror, but the main part is shown as an expanded view in the figure.

The Fresnel lens sheet 41 macroscopically converges the projected light by the action of the circular Fresnel lens 411 provided on its exit surface and converts it into substantially parallel light whose direction is the normal to the screen surface. A lenticular lens array 441 having a vertical direction as a longitudinal direction is provided on the incident side of the lenticular lens sheet 44, and diffuses the substantially parallel light only in a horizontal direction within a specific angle range. The bead sheet 43 has a configuration basically similar to that shown in FIG. 8, and further diffuses the light diffused in the horizontal direction even more and also diffuses the light in the vertical direction.

In the above configuration, since the bead sheet 43 has a sufficient external light rejection function, the lenticular lens sheet 44
There is no need to provide a black stripe on the surface. for that reason,
A fine pitch of several tens of μm is possible.

By the above operation, anisotropic diffusion relatively wide in the horizontal direction and narrow in the vertical direction is realized.

For example, by using an isotropic diffusion bead sheet having a β angle of about 30 ° alone and a front gain of about 2.2 and a lenticular lens sheet having a horizontal diffusion range of about 20 °, a β angle of 45 in the horizontal direction can be obtained. °, vertical β angle 30
And a front gain of about 1.3 can be realized.

When the isotropic diffusion bead sheet is used alone, the isotropic diffusion bead sheet having a β angle of about 30 ° results in a short viewing angle in the horizontal direction as a display. In order to obtain a good horizontal viewing angle, it is necessary to use a bead sheet having a β angle of about 45 °.
About. According to the above-described example using the configuration of the present invention, a bright rear-projection display is realized by increasing the gain by about 1.3 times while maintaining a practical viewing angle substantially equal to the case where a bead sheet having a β angle of 45 ° is used. it can. Further, the characteristics of high resolution and small reduction in contrast to external light when using the bead method are not impaired.

(Embodiment 2) In a system in which the projection distance is somewhat longer than the screen size and the maximum angle of incidence on the Fresnel lens sheet is not so large, or when the anisotropy is set to be small, it is more reasonable. Configuration becomes possible.

FIG. 2 is a horizontal sectional view schematically showing a rear projection display according to the second embodiment of the present invention.

In the configuration shown in FIG. 1, the lenticular lens sheet 44 is provided as an independent member, and the lenticular lens array 441 is provided on the incident surface. In FIG. 2, the Fresnel lens sheet 41 is used without using the lenticular lens sheet 44. Lenticular lens array 4 on the incident side of
12 are provided.

With this configuration, light diffused only in the horizontal direction is incident on the bead sheet 43 and anisotropic diffusion can be realized as in the first embodiment.

When the above configuration is used in a system in which the projection distance is shorter than the screen size and therefore the maximum incident angle of the projection light on the Fresnel lens sheet 41 is large, if the diffusion range of the lenticular lens array 412 is increased, the Fresnel lens 411 is increased. Although the reflection loss may occur on the surface, if such reflection loss is within an allowable range, the configuration in which the lenticular lens array 412 is formed on the incident surface of the Fresnel lens sheet 41 as described above can reduce the number of sheets. The efficiency can be improved by reducing the number of reflection interfaces, and the cost can be reduced, which is more effective.

(Embodiment 3) FIG. 3 shows the configuration of still another embodiment of the rear projection display of the present invention.

In this embodiment, the lenticular lens sheet 451 and the bead sheet 452 provided independently in the first embodiment are joined by the transparent adhesive layer 453 to form the laminated diffusion function sheet 45. The basic configurations of the lenticular lens sheet 451 and the bead sheet 452 are the same as the lenticular lens sheet 44 and the bead sheet 43 described in the first embodiment except for the following points.

In the present embodiment, the bead sheet 4
At the interface between the transparent beads and the transparent adhesive layer 453 provided at 52, the light is refracted to diffuse the projected light, and the beads sheet 4
52, the refractive index of the transparent beads is changed to the transparent adhesive layer 45 so that the projection light is effectively incident on the opening provided on the observation side
It is necessary to make the refractive index larger than 3. The difference between the two refractive indexes is preferably 0.3 or more. For example, glass beads having a refractive index of about 1.9 can be used as the transparent beads, and a general acrylic adhesive (refractive index: about 1.5) can be used as the transparent adhesive for the transparent adhesive layer 453.

When the lenticular lens sheet 451 is made of PMMA having a refractive index of about 1.5, no reflection occurs at the interface between the lenticular lens sheet 451 and the transparent adhesive layer 453.

In the above configuration, an adhesion step is added as compared with the first embodiment, but there are some advantages that cannot be realized with the configuration of the first embodiment.

The first advantage is that the isotropic diffusion by the bead sheet 452 can be suppressed to be small, and a large diffusion anisotropy and, consequently, a high front luminance can be easily realized.

The basic idea of the present invention is to use an isotropic diffusion element, suppress the isotropic diffusion to a relatively small level, and secure a practically effective visual field range by combining it with a diffusion element only in the horizontal direction. The object is to realize high front luminance.

In the first embodiment, the isotropic diffusion by the bead sheet utilizes the refraction at the interface between the transparent beads and air (refractive index 1). Although the isotropic diffusion can be reduced, the lower limit of the refractive index of a general transparent material is about 1.5, and the difference in the refractive index at the interface is about 0.5.

On the other hand, in the present embodiment, a refractive index difference of about 0.4 can be easily realized by using a general material as in the above example. In addition, the transparent beads having a refractive index of about 1.9 in the above example are widely distributed as a material of the recursive reflection sheet, and the use of such beads is effective in suppressing the price.

The second advantage is that the transmission efficiency is improved as compared with the first embodiment.

In the first embodiment, the plane on the observation side of the lenticular lens sheet is in contact with air, and a reflection of about 5% occurs, whereas in the present embodiment, the refractive index of the lenticular lens sheet 451 and the transparency are different. The reflection at the interface between the lenticular lens sheet 451 and the transparent adhesive layer 453 can be made substantially zero by making the refractive index of the adhesive layer 453 substantially coincide with the refractive index. The difference in the refractive index between the lenticular lens sheet and the transparent adhesive layer is preferably 0.2 or less, more preferably 0.1 or less.

In the first to third embodiments, examples in which a transmissive liquid crystal display panel is used as an image display device have been described.
The image display device of the present invention is not limited to this, and known elements such as a reflective liquid crystal panel and a mirror device in which a number of fine mirrors whose angles can be varied are arranged can be used.

[0064]

As apparent from the above description, according to the rear projection display of the present invention, an anisotropic structure is obtained by using a bead sheet having a fine structure and a high ability to eliminate the influence of external light. Diffusion can be realized, image resolution is excellent, contrast is high even in a bright environment, and image display with an excellent balance between viewing angle and brightness can be realized.

[Brief description of the drawings]

FIG. 1 is a horizontal cross-sectional view of a rear projection display according to a first embodiment of the present invention.

FIG. 2 is a horizontal sectional view of the rear projection display according to the second embodiment of the present invention;

FIG. 3 is a horizontal sectional view of the rear projection display according to the third embodiment of the present invention;

FIG. 4 is a graph showing the incident angle dependence of the transmittance of a bead sheet.

FIG. 5 is a graph showing an average relative transmittance with respect to a diffusion angle range when diffused light in a specific angle range is incident on a bead sheet.

FIG. 6 is a horizontal sectional view showing the configuration of a conventional rear projection display.

FIG. 7 is a horizontal sectional view showing another configuration of the conventional rear projection display.

FIG. 8 is an enlarged sectional view in the thickness direction showing a schematic configuration of a bead sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp 2 Liquid crystal panel 3 Projection lens 4 Screen 41 Fresnel lens sheet 411 Fresnel lens 412 Lenticular lens array 42 BS lenticular lens sheet 421 Lenticular lens 422 Light absorption layer (black stripe) 43 Bead sheet 431 Transparent substrate (base sheet) 432 Transparency Beads 434 Opening (light transmitting portion) 433 Light absorbing material (opaque binder) 44 Lenticular lens sheet 441 Lenticular lens array 45 Stacked diffusion function sheet 451 Lenticular lens sheet 452 Bead sheet 453 Transparent adhesive layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H04N 5/74 H04N 5/74 C (72) Inventor Narita Yamagishi 1006 Odakadoma, Kazuma, Osaka Matsushita Electric F-term (reference) in Sangyo Co., Ltd. 2H021 BA24 BA27 BA29 2H042 BA02 BA14 BA19 BA20 5C058 BA08 BA25 BA31 EA01 EA12 EA32 EA36

Claims (4)

[Claims] 1. An image display device for displaying an image according to an input signal, an image projection unit including a projection lens for enlarging and projecting an image on the image display device, and a rear surface for projecting an image projected by the image projection unit A projection type screen, wherein the rear projection type screen converges macroscopically the projected light divergently incident from the center of the screen toward the periphery in order from the projection side to the observation side to substantially parallel light. A lenticular lens sheet having a circular Fresnel lens that converts the light into a light, a lenticular lens sheet having a lenticular lens array having a vertical direction as a longitudinal direction, and diffusing light in a horizontal direction, and a transparent material in which minute beads made of a transparent material are transparent. A light transmitting portion between the base sheet and the microbeads disposed on the projection side surface of the base sheet made of Rear-projection display characterized by comprising a bead seat on the face of the projection side of the base sheet is covered with an opaque binder. 2. An image display device for displaying an image in accordance with an input signal, an image projection unit comprising a projection lens for enlarging and projecting an image on the image display device, and a rear surface for projecting an image projected by the image projection unit A projection type screen, wherein the rear projection type screen has a lenticular lens array having a vertical direction as a longitudinal direction on the projection side, and diverges macro from the center of the screen toward the periphery in order from the projection side to the observation side. Projection of a Fresnel lens sheet having a circular Fresnel lens on the observation side that converges the incident light macroscopically and converts it into substantially parallel light, and a base sheet made of a transparent material with fine beads made of a transparent material A surface on the projection side of the base sheet other than the light transmitting portion between the base sheet and the microbeads, Rear-projection display characterized by comprising a bead seat which is covered with an opaque binder. 3. An image display device for displaying an image in accordance with an input signal, an image projection unit comprising a projection lens for enlarging and projecting an image on the image display device, and a rear surface for projecting the image projected by the image projection unit A projection type screen, wherein the rear projection type screen converges macroscopically the projected light divergently incident from the center of the screen toward the periphery in order from the projection side to the observation side to substantially parallel light. A laminated Fresnel lens sheet having a circular Fresnel lens for converting into a laminated diffused functional sheet, wherein the laminated diffused functional sheet has a lenticular lens array whose longitudinal direction is perpendicular to the projection side surface, and is horizontal. A lenticular lens sheet that diffuses light in the direction is placed on the projection side. Observe a bead sheet that is disposed on the projection side of the substrate sheet, and the projection side surface of the base sheet other than the light transmitting portion between the base sheet and the microbeads is covered with an opaque binder. A rear projection display, wherein the lenticular lens sheet and the bead sheet are integrated by bonding with a transparent adhesive layer. 4. The refractive index of the fine beads is 0.3 or more larger than the refractive index of the transparent adhesive layer, and the refractive index of the transparent adhesive layer is substantially equal to the refractive index of the lenticular lens sheet. 4. The rear projection display according to claim 3, wherein: