JPH11249237A - Screen, manufacture thereof, and multiprojector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of image blur at the mutual joint part of projected images or in its vicinity in a screen and make the screen large-sized in the case of arranging plural sets of rear projector units to constitute a multiprojector. SOLUTION: A screen projecting a large image plane is formed by sticking screen plates 7-1, 7-2 corresponding to each projection optical system, closely to each other to joint them on a large transparent reinforcing plate 6. The screen plates 7-1, 7-2 and the transparent reinforcing plate 6 are jointed by bonding them with an adhesive almost equal to the refractive index of both of them or fixing fine nails or the like piercingly into both of them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-projector in which a plurality of large-screen rear projector units are arranged in the vertical and horizontal directions so that a larger image can be viewed, and a screen used therefor.

[0002]

2. Description of the Related Art Conventionally, as a multi-projector, there have been ones described in JP-A-63-88976 and JP-A-62-6733.

In the technology described in Japanese Patent Application Laid-Open No. 63-88976, a projection lens having at least one optical path turning mirror is used, and the optical path of the projection light from the CRT is set to two.
A plurality of rear projector units, which are folded and project an image on a transmission screen (hereinafter, referred to as a rear screen), are closely arranged in the vertical and horizontal directions to obtain a super large screen.

In the technique described in Japanese Utility Model Application Laid-Open No. 62-6733, an image is projected onto each rear screen from two or more sets of projection optical systems. An optical member that substantially reduces the amount of transmitted light of each projection light by approximately half is provided at a seam portion where adjacent projected images obtained from each other overlap with each other, and the brightness of the projected image overlapping at the seam portion is changed to another projected image portion. And tried to be equivalent.

[0005]

SUMMARY OF THE INVENTION Among the above prior arts,
In the technique described in Japanese Patent Application Laid-Open No. 63-88976, the design of a multi-projector can be simplified by arranging a plurality of sets of rear projector units having the same projection optical system. However, there is a problem that there is a lot of wasted space in the cabinet, and the depth cannot be shortened sufficiently.

In the technique described in Japanese Utility Model Laid-Open No. 62-6733, there is a possibility that the brightness of a joint portion between adjacent projected images and the vicinity thereof can be made equal to the brightness of other projected image portions. However, no consideration has been given to the fact that a part of the projection light is scattered by the optical member installed to substantially reduce the amount of transmitted light by half, so that the image of the joint portion and the vicinity thereof is blurred.

Further, in the case of a multi-projector, a large rear screen is indispensable.
It is very difficult to obtain a large rear screen of 0 inches or more from a single plate in terms of screen production and cost. Therefore, we have to come up with a new method of forming such a large rear screen.
The above-mentioned Japanese Utility Model Application Laid-Open No. 62-6733 does not disclose any method for forming the same.

In general, in one set of rear projector units, when the luminance distribution of the screen on the rear screen is 10 at the center, about 3 at the periphery. The main reason is that, in the projection lens, the amount of light taken in at the peripheral portion is smaller than the amount of light taken in at the central portion.

Therefore, when a multi-projector is constructed by arranging a plurality of sets of such rear projector units, images obtained by the multi-projector have a luminance ratio between the central portion and the peripheral portion of 10: 3. , And even if there is no non-display portion between the projection images, luminance unevenness occurs in a 10: 3 cycle on the entire screen, and a large screen with high image quality is obtained. There was a problem that it was not possible.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the problem of blurring of the image at the joint between projected images and the vicinity thereof, and to increase the size of the screen. It is to make.

[0011]

In order to achieve the above-mentioned object, the present invention employs the following configuration. That is, in a screen for projecting light from the projection optical system, a plurality of screen plates are connected to each other on a transparent plate having a plane dimension larger than the individual screen plates.

In a multi-projector for displaying an image by projecting light from a plurality of projection optical systems onto a screen, the screen has a plurality of screen plates individually corresponding to the plurality of projection optical systems. The configuration is such that a plurality of screen plates are connected to each other on a transparent plate having a larger plane dimension than each screen plate.

In the above screen, a plurality of screen plates individually correspond to the plurality of projection optical systems, and the plurality of screen plates are connected to each other on a transparent plate having a larger plane dimension than the individual screen plates. The coupling surface is provided with means for preventing reflection and transmission of light.

In the screen, a plurality of screen plates individually correspond to the plurality of projection optical systems, and the plurality of screen plates are connected to each other on a transparent plate having a larger plane dimension than the individual screen plates. Then, the connecting portion is provided with a partition plate having a structure for preventing reflection and transmission of light.

In the above screen, a plurality of screen plates individually correspond to the plurality of projection optical systems, and the plurality of screen plates are connected to each other on a transparent plate having a larger plane dimension than the individual screen plates. The connecting portion has a configuration in which a partition plate having a configuration for preventing reflection and transmission of light is fixed to the concave portion.

In a screen for projecting light from a projection optical system, a front sheet formed by combining a plurality of sheets having a black stripe formed on the front side and a lenticular lens formed on the back side at the black stripe portion, A rear sheet formed by joining a plurality of sheets each having a Fresnel lens formed on the front side, wherein the front sheet and the rear sheet overlap with a black stripe of the front sheet and a joint of the rear sheet overlaps with the front sheet; A configuration is adopted in which the sheet is laminated so as to overlap with a black stripe different from the joint portion in the sheet.

Further, the front sheet and the rear sheet are placed on the transparent plate such that a joint portion of the rear sheet overlaps a black stripe of the front sheet and another black stripe different from the joint portion of the front sheet. It was decided to adopt a laminated structure.

[0018] The front sheet and the rear sheet have a joint in the rear sheet having a light absorbing means, overlap a black stripe of the front sheet, and overlap with a black stripe different from the joint in the front sheet. A configuration in which the layers are stacked as described above is adopted.

In a multi-projector for displaying an image by projecting light from a plurality of projection optical systems onto a screen, the screen has a plurality of screen plates individually corresponding to the plurality of projection optical systems, and a front surface. A front sheet formed by combining a plurality of sheets on which a black stripe is formed on the side and a lenticular lens on the back side with the black stripe portion, and a plurality of sheets formed with a Fresnel lens on the front side are combined. A front seat and the rear seat,
The connecting portion of the rear sheet overlaps with the black stripe of the front sheet and is stacked so as to overlap with a black stripe different from the connecting portion of the front sheet.

The screen has a structure in which a plurality of Fresnel screen plates each having a Fresnel lens formed on one surface are connected, and a means for absorbing light is provided at the connection portion.

In a method of manufacturing a screen for projecting light from a projection optical system, a plurality of sheets having a black stripe formed on the front side and a lenticular lens formed on the back side are formed by a first connecting portion of the black stripe section. A front sheet is formed by combining the plurality of sheets having a Fresnel lens formed on the front side at a second connecting portion to form a rear sheet, and the front sheet and the rear sheet are connected to each other in the rear sheet. The second bonding portion is laminated so as to overlap with the black stripe of the front sheet and to overlap with a black stripe different from the first bonding portion of the front sheet.

[0022]

A large screen having sufficient strength can be easily obtained by joining a plurality of screen plates in close contact with each other on a large transparent plate. Further, on the transparent plate, by providing a light blocking partition plate for preventing reflection and transmission of light at a portion corresponding to a joint portion between the screen plates, an overscan portion of the projection light from each projection optical system is provided. Can be cut off, and the joint portion between adjacent projection images can be reduced. Accordingly, the image quality of the joint portion of the adjacent projected image and the image quality in the vicinity thereof become similar to the image quality of the other projected image portions, and an image without a sense of incongruity can be obtained.

When the position of the joint portion between the screen plates is viewed from the front side of the screen, the position of the black stripe formed on the front surface of the screen is matched to visually recognize the joint portion between the adjacent projected images. Can be difficult. As a result, it is possible to obtain image quality equivalent to that of a large-screen image having no seams, and to improve the image quality of the screen of the multi-projector.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Before that, in order to facilitate understanding of the embodiments of the present invention, a multi-projector based on the premise of the present invention will be described. The configuration will be described first.

FIG. 9 is a side view showing a main part of a multi-projector as a premise of the present invention. As shown in FIG. 9, the rear projector unit 1 includes a projection lens 1-
1, a projection optical system comprising a cathode ray tube 1-2, an optical path turning mirror 1-3, and a rear screen 1-4,
Further, the rear projector unit 2 also has a projection lens 2-
1, a projection optical system including a cathode ray tube 2-2, an optical path turning mirror 2-3, and a rear screen 2-4. The multi-projector in the present configuration example is configured by stacking the above-described rear projector unit 2 and rear projector unit 1 in two upper and lower stages.

Each of the rear projector units 2, 1
, The upper and lower projection lenses 2-1 and 1-1, the cathode ray tubes 2-2 and 1-2, the optical path turning mirror 2-3 and
1-3, and the rear screens 2-4 and 1-4 basically have the same performance as each other.

In FIG. 9, the projection lenses 2-1 and 1--1
1. Each of the CRTs 2-2 and 1-2 is displayed as a single unit. However, when three color images of red, green and blue are individually projected,
At least three or more projection lenses and cathode ray tubes are arranged in each rear projector unit.

In this example, as shown in FIG. 9, the mirror setting angle θ ₂ of the upper mirror 2-3 with respect to the surfaces of the rear screens 1-4 and 2-4 is changed to the lower mirror 1-
So the large 3 against the mirror set angle theta _1, each mirror 1-3 and 2-3, further projection lens 1-1,2-
1. CRTs 1-2 and 2-2 are arranged. In addition,
Usually, the neck portion 1-21 of the cathode ray tube 1-2 is arranged so as to be as close as possible to the extension of the screen surface of the rear screens 2-4 and 1-4.

By arranging as described above, the mirror 1-3 of the lower rear projector unit 1 can be brought as close as possible to the rear screen 1-4, so that the depth of the rear projector unit 1 can be made sufficiently short. It is possible to do.

The upper rear projector unit 2
In, by a mirror set angle theta ₂ of the mirror 2-3 and a mirror set angle theta ₁ is greater than an appropriate angle of the mirror 1-3, the upper portion of the projection lens 2-1, a mirror CRT 2-2 1-3 It becomes possible to arrange in space.

With this arrangement, the depth of the rear projector unit 2 may be slightly larger than the depth of the rear projector unit 1, but as a whole, the upper and lower parts which maximize the space utilization efficiency are used. A multi-projector having a two-stage configuration can be used, and the depth of the entire apparatus can be reduced and the apparatus can be made thin.

In the above structure, the cathode ray tube 2-
It is considered that the depth of the entire device can be reduced to the maximum by bringing the neck portion 2-21 of the second device as close as possible to the mirror 1-3.

In the above description, the mirror setting angles θ ₁ and θ ₂ for thinning the entire apparatus have been described.
Projection rays 1-5, 2 from each projection lens 1-1, 2-1
By defining the incident angles α ₁ and α ₂ when −5 is incident on the mirrors 1-3 and 2-3, it is possible to make the entire apparatus thinner.

That is, the rear projector units 1 and 2 are configured so that α ₁ <α ₂ . Again,
It is necessary to bring the neck portion 1-21 as close as possible to the extension of the screen surface of the rear screens 2-4 and 1-4, and to bring the neck portion 2-21 as close as possible to the mirror 1-3.

FIG. 10 is a front view schematically showing another example of the multi-projector on which the present invention is based. The multi-projector in this example is configured by arranging four sets of rear projector units vertically and horizontally.

With such a configuration, the rear screens 1-4 and 1- 1 of each rear projector unit are provided.
A large screen having a diagonal size twice the diagonal size of 4 ', 2-4, and 2-4' can be realized with a depth close to the depth of each rear projector unit alone.

FIG. 11 is a side view showing a main part of still another example of the multi-projector based on the present invention. As shown in FIG. 11, the multi-projector according to the present configuration example is configured by stacking three sets of rear projector units 5, 4, and 3 in three layers in the vertical direction.

At this time, in each of the rear projector units 3, 4, and 5, each mirror 3-3, 4-
The set angles θ ₃ , θ ₄ , θ ₅ of ₃ , 5-3 are θ ₃ <θ ₄
<A mirror setting angle that satisfies the relationship of θ _5. Thus, by satisfying the above relationship θ ₃ <θ ₄ <θ ₅ and arranging the projection optical systems in each rear projector unit as close as possible to each other, the entire apparatus can be made as thin as possible.

In the above configuration, each mirror 3-
Light projected on 3,4-3,5-3 3-5,4-5,5-
Even if the angles of incidence α ₃ , α ₄ , and α ₅ are set to satisfy the relationship α ₃ <α ₄ <α ₅ , the entire device can be made thinner.

Based on the above, FIG. 1 is a sectional view showing a section of a screen (specifically, a rear screen) in a multi-projector as a first embodiment of the present invention.

In the present embodiment, the rear screen for projecting a large screen is in close contact with and joining the respective screen plates 7-1 and 7-2 corresponding to the respective projection optical systems on one large transparent reinforcing plate 6. It is formed by this. Here, the connection between each of the screen plates 7-1 and 7-2 and the transparent reinforcing plate 6 is as follows.
It is conceivable that they are bonded by an adhesive material (not shown) having almost the same refractive index as that of the two, or that a thin nail (not shown) is penetrated and fixed to both. In this embodiment, the projection light beams 8-1 and 8-2 from the respective projection optical systems are connected to the screen plate 7-
It is necessary to give due consideration to the raster size of the cathode ray tube, the angles of the projected light beams 8-1 and 8-2, and the like so as not to be incident on 2,7-1.

When a large-sized transparent reinforcing plate cannot be obtained as the transparent reinforcing plate 6, a plurality of small-sized transparent reinforcing plates are firmly joined to each other to form one large-sized transparent reinforcing plate. It may be formed.

FIG. 2 is a sectional view showing a section of a main portion of a screen in a multi-projector according to a second embodiment of the present invention. The difference of the present embodiment from the first embodiment described above is that a concave portion 10 is formed on the transparent reinforcing plate 6 'at a portion facing the joint 9 of the screen plates 7-1 and 7-2. The point is that the partition plate 11 is fitted into the concave portion 10.

In this embodiment, among the projection light beams from the respective projection optical systems (not shown), the partition plate 11 is a projection light beam effective for projecting a projection image on the screen plates 7-1 and 7-2. 8'-1 and 8'-2 are directly incident on the rear screen, and unnecessary overscan rays 8'-11 and 8'-11.
8'-21 is cut off by the partition plate 11,
Formed and arranged.

As a result, in this embodiment, it is possible to prevent the projected light rays from each projection optical system (not shown) from being substantially incident on the adjacent screens 7-1 and 7-2. Joint 9 of screen plates 7-1 and 7-2
In, the joint between adjacent projection images can be reduced.

Here, when the present embodiment is specifically configured, the depth of the concave portion 10, the thickness of the partition plate 11,
It is necessary to sufficiently consider the surface condition of the partition plate 11, the light blocking performance of the partition plate 11, and the like.

In blocking the overscan rays 8'-11, 8'-21 at the partition plate 11, if the overscan rays 8'-11, 8 '
When -21 is reflected, flare light is generated, light is scattered, and the contrast of the projected image projected on the rear screen is reduced, and the projected image is blurred.

Therefore, in the present embodiment, the surface of the partition plate 11 is made black, for example, so that the partition plate 11 has a light absorbing function, and the overscan light beam 8'-
Most of 11,8'-21 are not reflected but absorbed. As a result, the projected image projected on the rear screen is not blurred.

FIG. 3 is a sectional view showing a section of a screen in a multi-projector as a third embodiment of the present invention. The main difference of this embodiment from the first and second embodiments described above is that the screen plates 7'-1, 7'-2 are joined without using the transparent reinforcing plates 6, 6 '. Thus, a large screen is formed. Moreover, in the present embodiment, the outer peripheral portion of the screen is fixed by a strong frame 12 in order to make the strength as the screen sufficient.

In this embodiment, the screen plate 7'-
At the junction 9 'of 1,7'-2, the projection light 13-
1 and 13-2, a concave portion 14 is provided on the incident side.
4, a light-blocking partition plate 15 is fitted. Thereby, similarly to the second embodiment, the screen plates 7'-1,
At the junction 9 'of 7'-2, the joint portion between adjacent projection images can be reduced.

At this time, a suitable adhesive (not shown) is applied to the concave portion 14 and the partition plate 15 is bonded to the screen plates 7'-1 and 7'-2, respectively. Since the bonding area of the screen plates 7'-1 and 7'-2 is larger than that in the case where no 15 is provided, the bonding strength of the screen plates 7'-1 and 7'-2 can be increased.

FIG. 4 is a sectional view showing a section of a main portion of a screen in a multi-projector according to a fourth embodiment of the present invention. This embodiment is similar to the third embodiment in that the screen plate 7 ″ -1 does not use the transparent reinforcing plates 6, 6 ′ used in the first and second embodiments. ,
7 ″ -2 are joined to form a large screen, and the difference is that the screen plates 7 ″ −1,
The concave portion 14 'provided at the 7 "-2 joint 9" is made sufficiently wider than the concave portion 14 in the third embodiment, and of the partition plate 15' fitted into the concave portion 14 '. The surface of only the light blocking portion 15'-3 is made black, for example, and the other fitting portion 15'-1 and its vicinity 1
5′-2 is a point made transparent.

In FIG. 4, in order to make the boundary between the fitting portion 15'-1 and its neighboring portion 15'-2 easier to understand,
For convenience, a broken line is added. In this embodiment, the partition plate 15 '
Is provided, as in the second and third embodiments, it is possible to reduce the joint portion between adjacent projection images at the joint 9 ″ of the screen plates 7 ″ -1, 7 ″ -2. it can.

Further, as described above, since the concave portion 14 'is wide, the width of the fitting portion 15'-1 of the partition plate 15' is also larger than the thickness of the light blocking portion 15'-3. Therefore, an appropriate adhesive (not shown) is applied to the concave portion 14 ', and the fitting portion 15'-1 of the partition plate 15' is changed to the screen plate 7 "-1, 7"-. 2 respectively, the bonding area of the screen plates 7 "-1, 7" -2 is further increased as compared with the case of the third embodiment, so that the screen plates 7 "-1, 7"-
2 can further increase the bonding strength.

In the partition plate 15 ', the fitting portion 1
When setting the shape and area (that is, the area to be made transparent) of 5′-1 and its neighboring portion 15′-2, the projection angles of the projection rays 13′-1 and 13′-2, It is necessary to calculate and set the projection angles and the like of '-11, 13'-21.

FIG. 5 is a perspective view showing a main portion of a screen in a multi-projector according to a fifth embodiment of the present invention. In this embodiment, the screen firstly joins two front sheets 16-1 and 16-2 each having a black stripe BS on the front surface and a lenticular lens 18 for expanding the horizontal viewing angle on the back surface, and , Fresnel lens on front (not shown)
Are joined to each other, and the joined front sheets 16-1 and 17-2 are joined together.
1, 16-2 and the rear seats 17-1, 17-2 are fixed to each other.

At this time, the front seats 16-1, 16-1,
16-2 and the rear seats 17-1, 17-2
Are arranged so that the positions thereof coincide with each other when viewed from the front of the screen and are located at the center of the black stripe BS.

At the joint 20 of the rear seats 17-1 and 17-2, the recess 19 is fitted into the fitting portion 19 of the partition plate 19.
-1 is fitted, an appropriate adhesive (not shown) is applied to the concave portion, and the fitted portion 19-1 of the partition plate 19 is bonded to the rear sheets 17-1 and 17-2, respectively. 4, the rear seats 17-1 and 17-1
-2 The bonding strength is further increased. The shape and the like of the partition plate 19 conform to the contents described in the fourth embodiment.

In this embodiment, by providing the partition plate 19, the joint portion between the adjacent projected images at the joints 20 and 21 can be reduced to about 1 mm or less.

Moreover, since the joints 20 and 21 are arranged so as to be at the center of the black stripe BS when viewed from the front of the rear screen, it is possible to make it difficult to visually recognize the above-mentioned joint. Therefore, according to the present embodiment, it is possible to obtain image quality equivalent to a large-screen image having no joints, and to improve the image quality of the screen of the multi-projector. In addition, on the screen of the 100 type class,
When the BS width is set to about 0.5 to 1 mm, a high resolution of 1000 or more horizontal resolutions is possible.

FIG. 6 is a perspective view showing a main portion of a screen in a multi-projector according to a sixth embodiment of the present invention.

In this embodiment, the screen first
A plurality of front sheets 38-1, 38-2, 38-3,... Each having a black stripe BS on the front surface and a lenticular lens 18 for expanding the horizontal viewing angle on the back surface.
Are joined together, and then a Fresnel lens (not shown) is formed on the front surface, and four rear sheets 39-1 and 39 provided corresponding to four sets of projection optical systems (not shown), respectively.
-2, 39-3, and 39-4 are joined together, and the joined front and rear seats are fixed to each other.

At this time, the front seats 38-1,
38-2, 38-3,... Joints 40-1, 40-2,.
And the joining portion 41-1 of the rear seats 39-1, 39-2.
The joining portion 41-2 of the rear seats 39-3 and 39-4 is
When viewed from the front of the screen, the positions are arranged so as to be different from each other, and each is arranged so as to be the center of the black stripe BS.

In this embodiment, the rear seat 3
9-1, 39-2, 39-3, 39-4 each joint part 41
In -1, 41-2, 41-3, 41-4, partition plates 42, 42 'are provided on the incident side of the projected light beam (not shown), and further, each of the joint portions 41-1, 41-2, 41-3,
For example, by blackening the joining surface of 41-4, for example, each joining portion 41-1, 41-2, 41-3, 41-.
4 has a light absorbing function.

As described above, in the fifth embodiment, the joining portion 20 of the front seats 16-1 and 16-2 is used.
The joint 21 of the rear sheets 17-1 and 17-2 is arranged so as to be at the center of the black stripe BS when viewed from the front of the screen, and in many cases, a joint portion between adjacent projected images is visually recognized. It was difficult to do.

However, the positions of the joints 20 and 21 coincide with each other when viewed from the front of the screen.
There is a problem that when the projected image on the screen is viewed, such as when both of them are incomplete, the joints 20, 21 are emphasized and visually recognized.

Therefore, in this embodiment, as described above, the front seats 38-1, 38-2, 38-3,.
And the rear seat 39-
1, 39-2, a joint portion 41-1, a rear seat 39-3,
When viewed from the front of the screen, the bonding portions 41-2 of 39-4 are arranged so that their positions are different from each other.
.. And the joints 41-1, 41-2,... And the joints 41-1, 41-2 when the projected images on the screen are viewed.
-2 became difficult to visually recognize. Therefore, according to the present embodiment, it is possible to view a better image as compared with the fifth embodiment.

In this embodiment, the partition plate 4
By providing 2, 42 ', of the projection light beams (not shown) from the respective projection optical systems (not shown), unnecessary overscan light beams (not shown) are cut off and do not enter the adjacent rear sheet. You can do so.

Furthermore, even if a part of the overscanning light beam (not shown) cannot be blocked by the partition plates 42 and 42 ', in this embodiment, each of the joints 4
Since each of 1-1, 41-2, 41-3, and 41-4 has a light absorbing function, each of the joints 41-1, 41-2, and 41-4.
At -3 and 41-4, the overscan rays (not shown) can be absorbed, so that unnecessary overscan rays (not shown) are not completely incident on the adjacent rear sheet. it can.

Therefore, according to the present embodiment, each joint 41
-1, 41-2, 41-3, and 41-4 do not have the light absorbing function,
Image quality degradation near -3, 41-4 can be further prevented.

In manufacturing a front sheet, it is generally easier to manufacture a front sheet that is long in the vertical direction than to manufacture a front sheet having a wide width. As shown in FIG. 6, the front seat 38 has no joint in the longitudinal direction.
It is better to use 1, 38-2, 38-3,.

However, a front seat having a joint in the vertical direction may be used as the front seat. In this case, the joint in the vertical direction of the front seat and the joint 41-1 of the rear sheets 39-1 and 39-4 are also used. 3. By arranging the joints 41-4 of the rear seats 39-2 and 39-3 so that the positions thereof are different from each other when viewed from the front of the screen, the joints are formed when the projected image on the screen is viewed. The portions 41-3 and 41-4 can be made hard to visually recognize.

Next, FIG. 7 is a cross-sectional view showing, as a reference example, a cross section of a projection lens suitable for a multi-projector as a premise of the present invention. That is, the projection lens in this reference example is used in a rear projector unit constituting a multi-projector together with a cathode ray tube.

As shown in FIG. 7, the projection lens in this embodiment is a large-curved first lens 23, a light-impermeable plate 27, and a slightly convex first lens 23 arranged in order from the face plate 22 side of the CRT. A second lens 24 having a convex shape, a third lens 25 having a convex shape, and a fourth lens 26 disposed on the light exit side.

Here, the light partially opaque plate 27 is formed by the light non-reflection / light non-transmission object 27-1 at the optical axis and the vicinity thereof, and the other part is formed by the light transmission body 27-2. I have. Further, between the first lens 23 and the face plate 22 of the cathode ray tube, the fluorescent screen 2 of the cathode ray tube is provided.
A liquid 29 is filled to efficiently dissipate the heat generated in 8.

The structural features of this embodiment are as follows.
The point is that the light partially opaque plate 27 is provided inside the projection lens. That is, in the present reference example, the light partially opaque plate 2
7, the effective light rays emitted from the fluorescent screen 28 of the cathode ray tube and passing through the projection lens
By blocking a part of the effective light rays emitted from the central part 30 of the rear projector 8 and its vicinity, the brightness of the central part of the screen and its vicinity can be suppressed on a screen (not shown) in the rear projector unit.

Here, the effective light means the first to fourth lenses 22 out of the light emitted from the fluorescent screen 28 of the cathode ray tube when the light partially impermeable plate 27 is not provided.
26 through 26, and emitted from the exit surface of the fourth lens 26.

In FIG. 7, the space between the central part 30 of the fluorescent screen 28 and the outer peripheral part 35 of the fluorescent screen 28 is divided into five equal parts, and each of the dividing points is divided into a dividing point 31 and a dividing point 32 in order from the central part 30 side. ,
The division point 33 and the division point 34 are set. Further, among the effective light rays from the central portion 30, the division points 31, 32, 33, and 34, and the outer peripheral portion 35, the central ray is defined as 30-1, 31-1, and 32-.
1, 33-1, 34-1, 35-1, the upper limit ray is 30-
2,31-2,32-2,33-2,34-2,35-
2. Lower limit rays are 30-3, 31-3, 32-3, 33-
3, 34-3 and 35-3.

By arranging the light partially opaque plate 27 as shown in FIG. 7, the central ray 30-1 from the central portion 30 of the fluorescent screen 28 and the vicinity of the central ray 30-1 in the non-reflective / non-transparent object 27-1 Light beam, dividing point 3 of 20% from central part 30 of fluorescent screen 28
A part of the effective ray from 1 and a part of the effective ray from the 40% split point 32 are blocked. Therefore, on the screen of the rear projector unit, about 50% from the central portion of the screen and the peripheral portion toward the peripheral portion.
At the point (2), the luminance is lower than when the light partially impermeable plate 27 is not provided.

Therefore, as described in the prior art, for example, in the projection lens, the amount of light taken in the peripheral portion is smaller than the amount of light taken in in the central portion. Even if the luminance of the peripheral part is lower than the luminance of the central part, the luminance of the central part of the screen can be reduced by providing the partially opaque plate 27 in the projection lens. Can be made uniform.

Accordingly, if a multi-projector is constructed by arranging a plurality of sets of rear projector units each having such a projection lens and having a cathode ray tube capable of providing a high-luminance screen, an image obtained by the arrangement is ,
A large screen with high image quality can be obtained without causing uneven brightness on the entire screen.

The degree of luminance reduction at the center of the screen on the screen of the rear projector unit is controlled by the position of the light partially opaque plate 27, the size of the light non-reflection / light non-transmission object, and the like. be able to.

Further, the light non-reflection / light non-transmission object 27-1 is formed on the lens surface of the first lens 23 or the second lens 24 without installing the light partially opaque plate 27 alone.
It may be used instead of the light partially opaque plate 27.
The same effect as when the light partially opaque plate 27 is provided can be sufficiently obtained, and in this case, the structure of the projection lens can be simplified.

FIG. 8 is an explanatory diagram for explaining, as a reference example, a luminance distribution of a cathode ray tube suitable for a multi-projector, which is a premise of the present invention. That is, the cathode ray tube in the present reference example is used together with a projection lens and the like in a rear projector unit constituting a multi-projector.

The cathode ray tube according to the present embodiment is such that a thin film made of a low refractive index material and a thin film made of a high refractive index material are alternately laminated between the fluorescent screen 28 and the glass of the face plate 22 shown in FIG. The optical multi-layer film (not shown) having the above configuration has directivity.

For example, the luminance distribution 36 in the peripheral portion 35 of the fluorescent screen 28 is such that the luminance 36-1 in the range of about 20 degrees from the normal direction of the fluorescent screen 28 is reduced, and the luminance distribution 36 in the range of about 20 degrees to about 70 degrees. The distribution has an increased luminance 36-2. In addition, the luminance becomes zero above about 70 degrees.

On the other hand, a substantially circular luminance distribution 37 indicated by a broken line
Is a luminance distribution in a normal CRT without directivity. The absolute values of the luminous flux of a normal CRT and the luminous flux of a directional CRT are basically substantially equal. That is, the area of the portion surrounded by the curve indicating the luminance distribution 36 and the area of the portion surrounded by the substantially circular curve indicating the luminance distribution 37 are basically substantially equal.

The effective rays 35-1, 35-2, 35 shown in FIG.
As can be seen from -3, in the peripheral portion 35 of the fluorescent screen 28, the effective rays 35-1, 35-2, 35-3 fall within a range of 20 to 70 degrees with respect to the normal to the fluorescent screen 28. Therefore,
In the present reference example, the luminance distribution in the peripheral portion 35 of the phosphor screen 28 is represented by the luminance distribution 36 shown in FIG.
The brightness in the range of up to 70 degrees is set to be large. By doing so, it is possible to increase the brightness of the peripheral portion of the screen on the screen of the rear projector unit.

In this embodiment, in addition to the peripheral portion 35 of the fluorescent screen 28, the luminance distribution in the central portion and the portion between the central portion and the normal portion of the fluorescent surface 28 as shown in the luminance distribution 36 shown in FIG. The luminance in the range of 20 to 70 degrees is large,
The brightness in the range of degrees is reduced. By doing so, it is possible to reduce the luminance at the center of the screen on the rear screen of the rear projector unit.

Therefore, as described in the prior art, for example, in the projection lens, the amount of light taken in the peripheral portion is smaller than the amount of light taken in in the central portion. Even if the luminance of the part is lower than the luminance of the central part, by using the cathode ray tube having the directivity as described above, it is possible to increase the luminance of the peripheral part of the screen and decrease the luminance of the central part, The luminance distribution on the screen can be made uniform.

Therefore, if a multi-projector is constructed by arranging a plurality of sets of rear projector units having such a cathode ray tube, an image obtained by the multi-projector is as follows.
A large screen with high image quality can be obtained without causing uneven brightness on the entire screen.

As described above, when the brightness in the range of 20 to 70 degrees with respect to the normal line of the fluorescent screen 28 is increased, the brightness in the other range inevitably decreases. Face 2
In the peripheral portion 35 of FIG.
Light rays emitted in directions other than the range of 0 to 70 degrees are not a problem because they do not become effective light rays necessary for displaying an image.

In the present embodiment, the luminance distribution at the center of the fluorescent screen 28 and the area between them is 20 to 20 with respect to the normal line of the fluorescent screen 28, similarly to the luminance area of the peripheral area 35.
Although the brightness distribution is increased in the range of 70 degrees, the brightness distribution of each part of the fluorescent screen 28 may be different.

When setting a range in which the luminance of each part should be increased (that is, setting a directional direction), the angular width is limited as much as possible according to the projection lens to be used, and the directivity is increased accordingly. It is better to
For example, at the peripheral portion 35 of the fluorescent screen 28, the angular width of the effective light beam emitted from the peripheral portion 35 (that is, the angle between the upper limit light beam and the lower limit light beam) depends on the projection lens used. It is considered to be about 10 to 30 degrees. Therefore, it is advantageous to make the luminance distribution of the screen uniform by limiting the angle width at which the luminance should be increased to about 10 to 30 degrees and increasing the luminance at that angle.

[0095]

As described above, according to the present invention,
The following effects can be expected.

By joining a plurality of screen plates in close contact with each other on a large transparent plate, a large screen having sufficient strength can be easily obtained. Also,
On the transparent plate, by providing a light blocking partition plate in a portion corresponding to the joint portion between the screen plates,
An overscan portion of the projection light from each projection optical system can be blocked, and a joint portion between adjacent projection images can be reduced. Accordingly, the image quality of the joint portion of the adjacent projected image and the image quality in the vicinity thereof become similar to the image quality of the other projected image portions, and an image without a sense of incongruity can be obtained.

When a large screen is obtained by joining a plurality of screen plates without using a transparent plate, a joining plate between the screen plates is provided by providing a partition plate for blocking light at the joint between the screen plates. The intensity can be increased, the overscan portion of the projection light from each projection optical system can be blocked, and the joint between adjacent projection images can be reduced.

When the positions of the joints between the screen plates described above are viewed from the front side of the screen, they match the positions of the black stripes formed on the front surface of the screen, so that the joints between the adjacent projected images can be obtained. This makes it difficult to see the portion. As a result, it is possible to obtain image quality equivalent to that of a large-screen image having no seams, and to improve the image quality of the screen of the multi-projector.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a section of a screen in a multi-projector as a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a cross section of a main part of a screen in a multi-projector as a second embodiment of the present invention.

FIG. 3 is a sectional view showing a section of a screen in a multi-projector as a third embodiment of the present invention.

FIG. 4 is a sectional view showing a section of a main part of a screen in a multi-projector as a fourth embodiment of the present invention.

FIG. 5 is a perspective view showing a main portion of a screen in a multi-projector according to a fifth embodiment of the present invention.

FIG. 6 is a perspective view of a main part of a screen in a multi-projector according to a sixth embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a cross section of a projection lens suitable for a multi-projector as a premise of the present invention as a reference example.

FIG. 8 is an explanatory diagram for describing, as a reference example, a luminance distribution of a cathode ray tube suitable for a multi-projector as a premise of the present invention.

FIG. 9 is a side view showing, as a reference example, a main part of a multi-projector as a premise of the present invention.

FIG. 10 is a front view schematically showing another example of the multi-projector as a premise of the present invention as a reference example.

FIG. 11 is a side view showing, as a reference example, a main part of still another example of the multi-projector as a premise of the present invention.

[Explanation of symbols]

1, 2, 3, 4, 5 ... rear projector unit, 1-
1, 1-2: Projection lens, 1-2, 2-2: CRT, 1-3, 2-3, 3-3, 4-3, 5-3: Optical path turning mirror, 1-4, 2-4 , 1-4 ', 2-4' ...
Screen (rear screen), θ ₁ , θ ₂ , θ ₃ , θ
₄ , θ ₅ … mirror setting angle, α ₁ , α ₂ , α ₃ , α ₄ ,
alpha ₅ ... incident angle of the projection light, 6 ... transparent reinforcing plate, 7-1,
7-2, 7'-1, 7'-2, 7 "-1, 7" -2 ... screen plate, 9, 9 ', 9 ", 20, 21, 41-1, 4
1-2, 41-3, 41-4 ... joint, 10, 14, 1
4 ': concave portion, 11, 15, 15', 19, 42, 4
2 ': Partition plate, 12: Frame, 16-1, 16-
2, 38-1, 38-2, 38-3 ... front seat,
17-1, 17-2, 39-1, 39-2, 39-3,
39-4: Rear seat, BS: Black stripe, 1
8: Lenticular lens, 22: Face plate,
27: light partially opaque plate, 27-1: light non-reflective / light non-transparent object, 28: fluorescent screen.

Claims (11)

[Claims] 1. A screen for projecting light from a projection optical system, wherein a plurality of screen plates are combined with each other on a transparent plate having a plane dimension larger than each of the individual screen plates. 2. A multi-projector for projecting light from a plurality of projection optical systems onto a screen to display an image, wherein the screen has a plurality of screen plates individually corresponding to the plurality of projection optical systems, and A multi-projector, wherein the plurality of screen plates are connected to each other on a transparent plate having a larger plane dimension than each of the individual screen plates. 3. A multi-projector for displaying an image by projecting light from a plurality of projection optical systems onto a screen, wherein the screen has a plurality of screen plates individually corresponding to the plurality of projection optical systems, and A multi-projector, wherein the plurality of screen plates are coupled to each other on a transparent plate having a plane size larger than each individual screen plate, and the coupling surface is provided with means for preventing reflection and transmission of light. 4. A multi-projector for displaying an image by projecting light from a plurality of projection optical systems onto a screen, wherein the screen has a plurality of screen plates individually corresponding to the plurality of projection optical systems, and A plurality of screen plates which are connected to each other on a transparent plate having a plane size larger than that of the individual screen plates, and wherein the connection portion includes a partition plate having a configuration for preventing reflection and transmission of light. projector. 5. A multi-projector for displaying an image by projecting light from a plurality of projection optical systems onto a screen, wherein the screen has a plurality of screen plates individually corresponding to the plurality of projection optical systems, and The plurality of screen plates are connected to each other on a transparent plate having a plane size larger than the individual screen plates, and at the connection portion, a partition plate having a configuration for preventing reflection and transmission of light is fixed to the concave portion. A multi-projector. 6. A screen for projecting light from a projection optical system, wherein a front sheet is formed by combining a plurality of sheets having black stripes formed on the front side and lenticular lenses on the back side at the black stripe portion. And a rear sheet formed by combining a plurality of sheets each having a Fresnel lens formed on the front side thereof, wherein the front sheet and the rear sheet overlap with a black stripe of the front sheet at a joint portion of the rear sheet and A screen characterized in that the front sheet is laminated so as to overlap a black stripe different from the connecting portion in the front sheet. 7. A screen for projecting light from a projection optical system, wherein a front sheet is formed by combining a plurality of sheets having a black stripe formed on the front side and a lenticular lens on the back side at the black stripe portion. And a rear sheet formed by combining a plurality of sheets each having a Fresnel lens formed on the front side thereof, wherein the front sheet and the rear sheet overlap with a black stripe of the front sheet at a joint portion of the rear sheet and A screen characterized by being laminated on a transparent plate so as to overlap with a black stripe different from the connecting portion of the front sheet. 8. A screen for projecting light from a projection optical system, wherein a front sheet is formed by combining a plurality of sheets having a black stripe formed on the front side and a lenticular lens on the back side at the black stripe portion. And a rear sheet formed by joining a plurality of sheets each having a Fresnel lens formed on the front side, wherein the front sheet and the rear sheet have a light absorbing means at a joint portion in the rear sheet, and A screen characterized by being laminated so as to overlap with a black stripe of a sheet and to overlap with a black stripe different from a joint portion of the front sheet. 9. A multi-projector for displaying an image by projecting light from a plurality of projection optical systems onto a screen, wherein the screen has a plurality of screen plates individually corresponding to the plurality of projection optical systems, and A front sheet formed by combining a plurality of sheets on which a black stripe is formed on the front side and a lenticular lens on the back side with the black stripe portion, and a plurality of sheets on which a Fresnel lens is formed on the front side A rear sheet formed by combining the front sheet and the rear sheet such that a joint in the rear sheet overlaps a black stripe of the front sheet and a black stripe different from the joint in the front sheet. A multi-projector characterized in that the multi-projector has a configuration in which the multi-projector is stacked. 10. A multi-projector for displaying an image by projecting light from a plurality of projection optical systems onto a screen, wherein the screen is formed by combining a plurality of Fresnel screen plates each having a Fresnel lens formed on one surface. A multi-projector having a configuration in which a unit for absorbing light is provided in a unit. 11. A method of manufacturing a screen for projecting light from a projection optical system, wherein a plurality of sheets each having a black stripe formed on a front side and a lenticular lens formed on a back side are first joined to the black stripe portion. Parts to form a front sheet, and a plurality of sheets having a Fresnel lens formed on the front side are connected at a second connecting part to form a rear sheet, and the front sheet and the rear sheet are The screen according to claim 1, wherein the second joint portion on the rear sheet overlaps with the black stripe of the front sheet and overlaps with a black stripe different from the first joint portion on the front sheet. Manufacturing method.