JP2882809B2 - Multi-plane multi-rear projector - Google Patents

Description

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

[Conventional technology]

Conventionally, as a multi-plane multi-rear projector,
Japanese Unexamined Patent Publication No. 88976 and Japanese Unexamined Utility Model Publication No. Sho 62-6733.

In the technique described in JP-A-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 bent twice.
A rear projector unit that projects images on a transmissive screen (hereinafter referred to as a rear screen)
A plurality of sets are closely arranged in the left-right direction to obtain a super large screen.

In the technology described in Japanese Utility Model Application Laid-Open No. 62-6733, an image is projected from two or more pairs of projection optical systems onto each rear screen, and the rear side of each rear screen is obtained from an adjacent projection optical system. An optical member that substantially reduces the amount of transmitted light of each projection light to approximately half is provided at a joint portion where the adjacent projected images overlap each other, and the brightness of the projected image overlapping at the joint portion is equal to that of the other projected image portions. I was trying.

[Problems to be solved by the invention]

Among the above conventional techniques, in the technique described in JP-A-63-88976, it is possible to simplify the design of a multi-plane multi-rear projector by arranging a plurality of sets of rear projector units having the same projection optical system. You can,
As a whole device of the multi-surface multi-rear projector, there is a problem that there is a lot of wasted space in the cabinet and the depth cannot be shortened sufficiently.

According to the technology described in Japanese Utility Model Application Laid-Open No. 62-6733, it is possible that the brightness of the joint portion between adjacent projected images and the vicinity thereof may be equal to the brightness of other projected image portions. A part of the projection light is scattered by the optical member that halves the transmitted light amount,
No consideration has been given to the fact that the image of the seam portion and its vicinity is blurred.

Also, in the multi-plane multi-rear projector, a large rear screen is indispensable, for example, to obtain a large rear screen with a diagonal dimension of 100 inches or more in a single plate, in the manufacture of the screen, It is also very difficult in terms of price. Therefore, a method of forming such a large rear screen must be newly devised. However, the above-mentioned Japanese Utility Model Application Laid-Open No. 62-6733 does not disclose any method of forming the rear screen.

Generally, in one set of rear projector units, the luminance distribution of the screen on the rear screen is centered.
When it is set to 10, the peripheral portion is about 3. 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-plane multi-rear projector is configured by arranging a plurality of such rear projector units,
The resulting image is configured by arranging a plurality of projection images in which the luminance ratio between the central part and the peripheral part is 10: 3, so that there is no non-display part between each projection image. However, there is a problem that luminance unevenness occurs in a 10: 3 cycle over the entire screen, and a high-quality large screen cannot be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problem of the prior art described above, in particular, to solve the problem that a large amount of wasteful space in a cabinet as a whole device of a multi-plane multi-rear projector could not be reduced in depth, and as a whole device, An object of the present invention is to provide a multi-plane multi-rear projector which has a short depth, is thin, and has a configuration in which useless space in a cabinet is eliminated.

[Means for solving the problem]

In order to achieve the above object, the present invention employs any of the following configurations.

(1) In a multi-plane multi-rear projector for projecting light from a plurality of projection optical systems onto a screen and displaying an image,
One of the projection optical systems in the adjacent projection optical system forms a mirror that reflects the light from the projection lens toward the screen, and an extension of the mirror surface intersects the screen surface of the screen and the mirror surface intersects the mirror surface. An arrangement is made such that the angle formed by the screen surface is smaller than that of the other projection optical system.

(2) In a polyhedral multi-rear projector in which a plurality of projection optical systems each having a mirror for reflecting light from the projection lens in the direction of the screen are arranged adjacent to each other, the optical path length from the tip of the projection lens to the mirror is L1, When the optical path length from the mirror to the screen is L2, the first projection optical system satisfies L1> L2, and the second projection optical system disposed adjacent to the first projection optical system is L2> L1 was satisfied.

(3) In a polyhedral multi-rear projector in which a plurality of projection optical systems each having a mirror for reflecting light from the projection lens in the direction of the screen are arranged adjacent to each other, an optical path length from the projection lens to the mirror is L1, and the mirror is When the optical path length from the first projection optical system to the screen is L2, at least the first projection optical system in the first and second projection optical systems adjacent to each other satisfies L1> L2, and the mirror has a mirror surface. Of the screen intersects with the screen surface of the screen, and the angle between the screen and the screen surface is made smaller than in the case of the second projection optical system.

(4) In a polyhedral multi-rear projector in which a plurality of projection optical systems each having a mirror for reflecting light from the projection lens in the direction of the screen are arranged adjacent to each other, the optical path length from the tip of the projection lens to the mirror is L1, When the optical path length from the mirror to the screen is L2, the first projection optical system satisfies L2 <L1, and the angle of incidence of light on the mirror is adjacent to the projection optical system. The projection optical system is configured to be smaller than the incident angle of light of the projection optical system.

(5) In a polyhedral multi-rear projector in which a plurality of projection optical systems each having a mirror for reflecting light from the projection lens in the direction of the screen are arranged adjacent to each other, the optical path length from the tip of the projection lens to the mirror is L1, When the optical path length from the mirror to the screen is L2, the first projection optical system satisfies L2 <L1, and the second projection optical system disposed adjacent to the first projection optical system includes: A configuration is provided in which L2> L1 is satisfied and the angle of incidence of light on the mirror is made larger than that in the first projection optical system.

(6) A multi-plane multi-rear projector that projects light from a plurality of projection optical systems onto a screen to display an image,
One of the adjacent projection optical systems forms a mirror that reflects light from the projection lens toward the screen and reflects the light from the projection lens so that an extension of the mirror surface intersects the screen surface of the screen and forms the screen surface. The angle is made smaller than in the case of the other projection optics, and
A configuration is also provided in which the angle of incidence of light on the mirror surface is also made smaller than that of the other projection optical system.

[Action]

By adopting any of the above-described configurations, it is possible to reduce a useless space occupying the entire apparatus of the projection optical system, to make the entire apparatus compact, and to shorten the depth, that is, to reduce the thickness.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side view showing a main part of a multi-plane multi-rear projector as a first embodiment of the present invention.

As shown in FIG. 1, the rear projector unit 1
Is a projection optical system including a projection lens 1-1, a cathode ray tube 1-2, and an optical path turning mirror 1-3, and a rear screen 1-4.
And the rear projector unit 2 also has
It comprises a projection optical system comprising a projection lens 2-1, a cathode ray tube 2-2, and an optical path turning mirror 2-3, and a rear screen 2-4. The multi-plane multi-rear projector according to the present embodiment is configured by stacking the above-described rear projector unit 2 and rear projector unit 1 in two upper and lower stages.

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

Also, in FIG. 1, the projection lens 2-1 and 1-1 and the cathode ray tube 2-2 and 1-2 are displayed as one each.
When individually projecting images of three colors of green and blue, three or more projection lenses and cathode ray tubes are arranged in each rear projector unit.

In the present embodiment, as shown in FIG. 1, the upper mirror 2-
3 so that the mirror setting angle θ ₂ of the third mirror is larger than the mirror setting angle θ ₁ of the lower mirror 1-3.
-3, projection lens 1-1, 2-1 and CRT 1
−2 and 2-2 are arranged. Normally, a CRT 1
-2 neck portion 1-21, rear screen 2-4, 1-4
To be as close as possible to the extension of the screen surface.

By arranging as described above, it is possible to bring the mirror 1-3 of the lower rear projector unit 1 as close to the rear screen 1-4 as possible.
The depth of the rear projector unit 1 can be made sufficiently short.

In the upper rear projector unit 2,
By the 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 projection lens 2-1, a mirror CRT 2-2 1-3
Can be arranged in the upper space.

Further, in FIG. 1, when the optical path length from the tip of the projection lens 1-1 to the mirror 1-3 is L1, and the optical path length from the mirror 1-3 to the screen 1-4 is L2, the first rear projector In the unit 1, L1> L2, and in the second rear projector unit 2 disposed adjacent to the first rear projector unit 1, L2> L1.

By arranging in this manner, the depth of the rear projector unit 2 may be slightly larger than the depth of the rear projector unit 1. And the depth of the entire apparatus can be reduced and the apparatus can be made thin.

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

By the way, in the above description, the mirror setting angles θ ₁ , θ ₂ and the optical path lengths L 1, L ₂ for thinning the entire apparatus have been described, but the projection light rays 1-5, from each of the projection lenses 1-1, 2-1. 2−
The angle of incidence α ₁ when 5 enters the mirrors 1-3 and 2-3,
By defining α ₂ , the entire device can be made thinner.

That is, the rear projector units 1 and 2 are configured so that α ₁ <α ₂ . Also at this time, the neck part 1-21
Is required to be as close as possible to the extension of the screen surface of the rear screens 2-4 and 1-4, and the neck portion 2-21 should be as close as possible to the mirror 1-3.

In FIG. 1, regarding the optical path length L1 from the tip of the projection lens 1-1 to the mirror 1-3 and the optical path length L2 from the mirror 1-3 to the screen 1-4, in the rear projector unit 1, L2 <L1, and the incident angle alpha ₁ of light into the mirror 1-3 is smaller than the incident angle alpha ₂ of the light of the rear projector unit 2 arranged adjacent to the rear projector unit 1.

In FIG. 1, regarding the optical path length L1 from the tip of the projection lens 1-1 to the mirror 1-3 and the optical path length L2 from the mirror 1-3 to the screen 1-4, in the rear projector unit 1, L2 <L1. In the rear projector unit 2 disposed adjacent to the rear projector unit 1, L2
> L1 and the incident angle alpha ₂ of the light to the mirror 2-3, are larger than the alpha ₁ in the case of the rear projector unit 1.

In FIG. 1, one of the rear projector units 1 in adjacent rear projector units 1 and 2
A mirror 1-3 that reflects the light from the projection lens 1-1 toward the screen 1-4 and reflects the light through an angle θ _{1 at} which an extension of the mirror surface intersects the screen surface of the screen and forms the screen surface. Is smaller than that of the other rear projector unit 2 (θ ₂ ), and the angle of incidence α ₁ of light on the mirror (1-3) surface is also smaller than that of the other rear projector unit 2. If it (α ₂ )
Is smaller than.

Here, the rear projector unit 1 is one of a plurality of projection optical systems included in the multi-plane multi-rear projector, and is one of the projection optical systems disposed at the end of the multi-plane multi-rear projector. It will be understood from the figure that the projection lens 1-1 is at the end of the screen (2-4, 1-4) with respect to the mirror 1-3.

FIG. 2 is a front view schematically showing a multi-surface multi-rear projector as a second embodiment of the present invention.

The multi-plane multi-rear projector in the present embodiment
A set of rear projector units is arranged vertically and horizontally.

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

FIG. 3 is a side view showing a main part of a multi-plane multi-rear projector as a third embodiment of the present invention.

As shown in FIG. 3, the multi-plane multi-rear projector according to the present embodiment includes three rear projector units 5, 4,
3 are vertically stacked in three stages.

At this time, the projection optical path length of the lowermost rear projector 3 is set as follows. That is, the projection optical path length from the tip of the projection lens 3-1 to the optical path turning mirror 3-3.
L1 ′ is turned from the optical path turning mirror 3-3 to the rear screen 3
The projection optical path length up to −4 is L2 ′ or more. In each of the rear projector units 3, 4, and 5, the set angles θ ₃ , θ ₄ , and θ ₅ of the mirrors 3-3, 4-3, and 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 3-3, 4-3, 5-3
Angles α ₃ , α ₄ , α of the projected light beams 3-5, 4-5, 5-5
_{Even if 5} is set so as to satisfy α ₃ <α ₄ <α ₅ , the entire device can be made thinner.

FIG. 4 is a cross-sectional view showing a cross section of a rear screen suitable for use in the multi-plane multi-rear projector according to the present invention as a reference example.

In this embodiment, the screen that projects the large screen is:
Each of the screen plates 7-1 and 7-2 corresponding to each of the projection optical systems is adhered and bonded on one large transparent reinforcing plate 6. Here, each screen plate 7-1,
7-2 and the transparent reinforcing plate 6 are bonded by an adhesive (not shown) having substantially the same refractive index as the two, or a thin nail (not shown) is penetrated and fixed to both. It is conceivable that they are joined by a method such as the following. In this reference example, the projection light rays 8-1, 8-2 from each projection optical system are used.
However, in order not to enter the screen plates 7-2 and 7-1 adjacent to each other, the raster size of the cathode ray tube and the projected light beam 8-
It is necessary to give full consideration to the angle of 1, 8-2.

In the case where a large-sized tread is not 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. You may do it.

FIG. 5 is a cross-sectional view showing, as a reference example, a cross section of a main part of another rear screen suitable for use in the multi-rear projector according to the present invention.

The difference of this embodiment from the embodiment of FIG. 4 described above is that the screen plates 7-1 and 7-7 are provided on the transparent reinforcing plate 6 ′.
2 is that a concave portion 10 is formed in a portion facing the joint portion 9, and a partition plate 11 is fitted into the concave portion 10.

In the present reference example, the partition plate 11 is one of the screen plates 7-1 and 7-7 among the projected light beams from each projection optical system (not shown).
-2, a projection ray 8 'effective for projecting a projected image on
1, 8'-2 is incident on the rear screen as it is, and unnecessary overscan rays 8'-11, 8'-21 are formed and arranged so as to be blocked by the partition plate 11.

Thereby, in the present embodiment, the projection light beams from each projection optical system (not shown) are transmitted to the screen 7-7 adjacent to each other.
Since it is possible to prevent light from being substantially incident on the screens 1 and 7-2, it is possible to reduce a seam portion where adjacent projected images overlap each other at the joint 9 of the screen plates 7-1 and 7-2.

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

When the overscan rays 8'-11, 8'-21 are blocked by the partition plate 11, if the overscan rays 8'-11, 8'-21 are reflected, flare light is generated. Then, light scattering occurs, and the contrast of the projected image projected on the rear screen is reduced, and the projected image is blurred.

Therefore, in the present reference example, by making the surface of the partition plate 11 black, for example, the partition plate 11 has a light absorbing function,
Most of the overscan rays 8'-11 and 8'-21 to be blocked are not reflected but absorbed. As a result, the projected image transferred onto the rear screen is not blurred.

FIG. 6 is a sectional view showing, as a reference example, a section of still another rear screen suitable for use in the multi-plane multi-rear projector according to the present invention.

The main difference between the present embodiment and the above-mentioned embodiment shown in FIGS. 4 and 5 is that the screen plates 7'-1, 7'-2 do not use the transparent reinforcing plates 6, 6 '. In that a large rear screen is formed. Moreover, in the present reference example, the outer peripheral portion of the rear screen is fixed by a strong frame 12 in order to make the strength as the rear screen sufficient.

Further, in this reference example, the screen plates 7'-1, 7'-2
A concave portion 14 is provided on the incident side of the projected light beams 13-1 and 13-2, and a light blocking partition plate 15 is provided on the concave portion 14.
Is inserted. As a result, as in the reference example of FIG. 5, at the joint 9 'of the screen plates 7'-1 and 7'-2, the overlapping seam between the adjacent projected images can be reduced.

At this time, an appropriate adhesive (not shown) is applied to the concave portion 14, and the partition plate 15 is attached to the screen plate 7'-1,
By adhering to the 7'-2, the partition plate 15
Screen plates 7'-1, 7'-
2 becomes large, the screen plate 7 '
The joining strength of -1,7'-2 can be increased.

FIG. 7 is a cross-sectional view showing, as a reference example, a cross-section of still another rear screen suitable for use in the multi-plane multi-rear projector according to the present invention.

The common point of this embodiment with the embodiment of FIG. 6 is that the transparent reinforcing plates 6, 6 'used in the embodiment of FIG. 4 and the embodiment of FIG.
The screen plates 7 "-1,7" -2 are joined to form a large-sized rear screen without using the screen plates 7 "-1,7" -2. The concave portion 14 'provided at the "-2 joint 9" is sufficiently wider than the concave portion 14 in the reference example of FIG.
Of the partition plate 15 'fitted into 14', the light blocking portion 15'-
3, only its surface is made black, for example, and the other fitting portions 15 '
-1 and its vicinity 15'-2 are transparent.

In FIG. 7, the fitting portion 15'-1 and its vicinity 1
In order to make the boundary with 5′-2 easy to understand, a broken line is added for convenience.

In this embodiment, the partition plate 15 'is provided so that the screen plate 7 "-1, 7" -2 is joined at the joining portion 9 "similarly to the embodiment shown in FIGS. The overlapping seam portions of the projected images can be reduced.

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 sufficiently larger than the thickness of the light shielding portion 15'-3. Therefore, an appropriate adhesive (not shown) is applied to the concave portion 14 ', and the fitting portions 15'-1 of the partition plate 15' are respectively attached to the screen plates 7 "-1, 7" -2. By bonding, the bonding area of the screen plates 7 "-1,7" -2 is further increased as compared with the case of the reference example of FIG. 6, so that the bonding of the screen plates 7 "-1,7" -2 is performed. Strength can be further increased.

In setting the shape and area (that is, the area to be made transparent) of the fitting portion 15 -1 and the vicinity 15 ′-2 of the partition plate 15 ′, the projection light beams 13 ′ 1,
13'-2 projection angle, overscan ray 13'-11,1
It is necessary to calculate and set the 3'-21 projection angle and the like.

FIG. 8 is a perspective view showing a main part of another rear screen suitable for use in the multi-plane multi-rear projector according to the present invention, which is shown as a reference example.

In the present reference example, the rear screen is formed by first joining two front sheets 16-1 and 16-2 each having a black matrix BM on the front surface and a lenticular lens 18 for expanding the horizontal viewing angle on the back surface. And two rear sheets 17 each having a Fresnel lens (not shown) formed on the front surface.
-1, 17-2 are joined to each other, and the joined front sheets 16-1, 16-2 and rear sheets 17-1, 17-2 are attached to each other by a thin nail (not shown). It is fixed and configured by penetrating. At this time, the front seat
When viewed from the front of the rear screen, the joint 20 of the 16-1, 16-2 and the joint 21 of the rear sheet 17-1, 17-2 have the same position, and are located at the center of the black matrix BM. It is arranged so that it becomes.

Also, at the joint 20 of the rear seats 17-1 and 17-2,
The fitting portion 19-1 of the partition plate 19 is fitted into the concave portion, an appropriate adhesive (not shown) is applied to the concave portion, and the fitting portion 19-1 of the partition plate 19 is attached to the rear sheets 17-1 and 17-1. The bonding strength of the rear sheets 17-1 and 17-2 is further increased as in the seventh embodiment. In addition,
The shape and the like of the partition plate 19 conform to the contents described in the seventh embodiment.

In the present reference example, by providing the partition plate 19, the overlapping portions of the adjacent projected images at the joints 20 and 21 can be reduced to about 1 mm or less.

In addition, since the joints 20 and 21 are arranged so as to be at the center of the brat matrix BM 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 the same image quality as a large-screen image having no seams, and to improve the image quality of the screen of the multi-plane multi-rear projector.

Note that the BM width is 0.5 to 1 m on the 100-type class screen.
When set to about m, a high resolution of 1000 or more horizontal resolutions is possible.

FIG. 9 is a perspective view showing a main part of still another rear screen suitable for use in the multi-plane multi-rear projector according to the present invention and showing the main part as a reference example.

In the present reference example, the rear screen first has a plurality of front sheets 38-1, 38-2, 38-3,... Each having a black matrix BM on the front and a lenticular lens 18 for expanding the horizontal viewing angle on the back. To each other, then
A Fresnel lens (not shown) is formed on the front surface, and four Fresnel lenses (not shown) are provided corresponding to the four sets of projection optical systems (not shown).
The rear sheets 39-1, 39-2, 39-3, 39-4 are joined to each other, and the joined front sheet and rear sheet are penetrated by a thin nail (not shown). Is fixed and configured.

At this time, the front seats 38-1, 38-2, 38-3, ...
Of the rear sheets 39-1 and 39-2, and the joint 41-2 of the rear sheets 39-3 and 39-4 from the front of the rear screen. When viewed, the positions are arranged so as to be different from each other, and they are arranged so as to be at the center of the black matrix BM.

Further, in this reference example, the rear seats 39-1, 39-2,
At the joints 41-1, 41-2, 41-3, 41-4 of 39-3, 39-4, partition plates 42, 4 are provided on the incident side of the projected light beam (not shown).
2 ′ are provided, and further, each of the joints 41-1, 41-2, 41-3, 41
For example, by making the joining surfaces of the joint portions -4 black, for example, the joint portions 41-1, 41-2, 41-3, and 41-4 have a light absorbing function.

As described above, in the reference example shown in FIG. 8, the joint 20 between the front seats 16-1 and 16-2 and the rear seat 17-
By arranging the joints 21 of 17-2 at the center of the black matrix BM when viewed from the front of the rear screen, in many cases, the overlapping seam portions of adjacent projected images are visually recognized. It was difficult to do.
However, when viewed from the front of the rear screen, the positions of the joints 20 and 21 coincide with each other.
When the projected image on the rear screen is viewed, for example, when the joint state of the joints 0 and 21 is incomplete at both joints 20 and 21, there is a problem that the joints 20 and 21 are emphasized and visually recognized. .

Therefore, in the present embodiment, as described above, the joints 40-1, 40-2,... Of the front seats 38-1, 38-2, 38-3,.
And the joint 41-1 between the rear seats 39-1 and 39-2, the rear seat
When viewed from the front of the rear screen, the joining portions 41-2 of 39-3 and 39-4 are arranged so that their positions are different from each other, and furthermore, they are arranged so that they are respectively located at the center of the black matrix BM. When the projected image on the rear screen is viewed, the joints 40-1, 40-2,.
Were hard to see. Therefore, according to the present embodiment, it is possible to view a better image as compared with the embodiment of FIG.

Further, in the present embodiment, by providing the partition plates 42 and 42 ', unnecessary overscan rays (not shown) among projection rays (not shown) from each projection optical system (not shown) are provided. It can be blocked so that it does not enter the adjacent rear seat. Moreover, even if the partition plates 42, 42 '
Even if a part of the overscan light beam (not shown) could not be blocked due to this, in the present embodiment, each of the joints 41-1, 41-2, 41-3, 41-4 has a light absorbing function. In each of the joints 41-1, 41-2, 41-3, 41-4,
These overscan rays (not shown) can be absorbed, so that unnecessary overscan rays (not shown) can be prevented from completely entering the adjacent rear sheet.

Therefore, according to the present reference example, each of the joints 41-1, 41-2, 41
As compared with a case where the light-absorbing function is not provided to −3, 41-4, it is possible to further prevent the image quality deterioration in the vicinity of the joints 41-1, 41-2, 41-3, 41-4.

When manufacturing a front seat, generally,
Because it is easier to manufacture a front seat that is long in the vertical direction than to manufacture a wide front seat,
As the front seat, as shown in FIG. 9, front seats 38-1, 38-2, 38-3, which have no joints in the vertical direction,
It is better to use ...

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 rear seat 39 may be used.
By arranging the joint 41-3 of -1,39-4 and the joint 41-4 of the rear sheets 39-2, 39-3 so that their positions are different from each other when viewed from the front of the rear screen, When viewing the projected image on the rear screen, the joints 41-3, 41-
4 can be hardly visually recognized.

Next, FIG. 10 is a sectional view showing, as a reference example, a section of a projection lens suitable for a multi-plane multi-rear projector according to the present invention.

That is, the projection lens in the present reference example is used in a rear projector unit constituting a multi-plane multi-rear projector together with a cathode ray tube.

As shown in FIG. 10, the projection lens in this embodiment is
Largely curved first lens 23, partially opaque plate arranged in order from the face plate 22 side of the Braun tube
27, a second lens 24 having a slightly convex shape, a third lens 25 having a concave shape, and a fourth lens 26 arranged on the light emitting side.

Here, the light partially opaque plate 27 is made of a light non-reflective / light non-transmissive object 27-1 at the optical axis and its vicinity, and the other part is made of a light transmissive body 27-2.
Also, the first lens 23 and the face plate 22 of the cathode ray tube
Between them, a liquid 29 is filled in order to efficiently diffuse the heat generated on the fluorescent screen 28 of the cathode ray tube.

By the way, the structural feature of this embodiment is that a light partially opaque plate 27 is provided inside the projection lens.

That is, in the present reference example, by providing the light partially opaque plate 27, of the effective light rays emitted from the fluorescent screen 28 of the CRT and passing through the projection lens, the effective light rays are emitted from the central portion 30 of the fluorescent screen 28 and the vicinity thereof. By blocking a part of the effective light beam, it is possible to suppress the luminance at the center of the screen and its vicinity on the rear screen (not shown) of the rear projector unit.

Note that, here, the effective light beam, in the case where the light partially opaque plate 27 is not provided, passes through all of the first to fourth lenses 22 to 26 among the light beams emitted from the fluorescent screen 28 of the CRT, The light emitted from the emission surface of the fourth lens 26.

In FIG. 10, 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 dividing point is divided into a dividing point 31, a dividing point 32, and a dividing point in order from the central part 30 side. A point 33 and a division point 34 are set. Also, of the effective rays from the central part 30, the division points 31, 32, 33, 34, and the outer peripheral part 35, the central ray is 30-1, 31-1, 32-1,
33-1, 34-1, 35-1, upper limit rays 30-2, 31-2, 32-2, 33
−2,34−2,35−2, lower limit ray is 30−3,31−3,32−3,33−
3,34-3,35-3.

By arranging the light partially opaque plate 27 as shown in FIG.
A central ray 30-1 from 30 and a ray in the vicinity thereof, a part of an effective ray from a dividing point 31 which is 20% from the central part 30 of the phosphor screen 28, 40
Part of the effective rays from the% split points 32 are respectively blocked. Therefore, on the rear screen of the rear projector unit, a part of the light-impermeable plate extends from the center of the screen and from that part to about 50% of the point toward the periphery.
The brightness is lower than when 27 is not provided.

Therefore, as described in the related 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 the central portion, and thus, on the rear screen of the rear projector unit, Even if the brightness is lower than the brightness at the center, the brightness at the center of the screen can be reduced by providing the partially opaque plate 27 in the projection lens, so that the brightness distribution of the screen is uniform. can do.

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

The degree of brightness reduction at the center of the screen on the rear screen of the rear projector unit can be 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. it can.

In addition, the light non-reflection / light non-transmission object 27-1 is formed on the lens surface of the first lens 23, the second lens 24, or the like without installing the light partially opaque plate 27 alone, and the light partially opaque plate 27 is formed. The transmissive plate 27 may be used in place of the transmissive plate 27. In this case, it is possible to obtain the same effect as when the light partially impermeable plate 27 is installed, and in that case, the structure of the projection lens is simplified. There is an effect that can be made.

FIG. 11 is an explanatory diagram for describing, as a reference example, a luminance distribution of a cathode ray tube suitable for a multi-plane multi-rear projector according to the present invention.

That is, the cathode ray tube in this reference example is used in a rear projector unit constituting a multi-plane multi-rear projector together with a projection lens and the like.

The CRT in this reference example has a phosphor screen shown in FIG.
An optical multilayer film (not shown), which is formed by alternately laminating a thin film made of a low-refractive-index material and a thin film made of a high-refractive-index material between glass 28 and the face plate 22. Thus, it has directivity.

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

On the other hand, a substantially circular luminance distribution 37 shown by a broken line is a luminance distribution in a normal CRT having no 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.

As can be seen from the effective light rays 35-1, 35-2, and 35-3 in FIG. 10, the effective light ray 35 in the range of 20 to 70 degrees with respect to the normal to the fluorescent screen Enter -1,35-2,35-3. Therefore, in the present reference example, the peripheral portion 35 of the fluorescent screen 28
The luminance distribution at is similar to the luminance distribution 36 shown in FIG.
The luminance in the range of 20 to 70 degrees is set to be large. This makes it possible to increase the brightness of the peripheral portion of the screen on the rear screen of the rear projector unit.

In addition, in the present reference example, in addition to the peripheral portion 35 of the fluorescent screen 28, the luminance distribution in the central portion and the portion between them also has a luminance distribution 36 shown in FIG. 20-70
The luminance in the range of degrees is set to be large, and the luminance in the range of 0 to 20 degrees is set to be small. 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 related 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 the central portion, and thus, on the rear screen of the rear projector unit, Even if the brightness is lower than the brightness at the center, the brightness at the periphery of the screen can be increased and the brightness at the center can be reduced by using a cathode ray tube having the above directivity. The luminance distribution can be made uniform.

Therefore, if a multi-plane multi-rear projector is configured by arranging a plurality of sets of rear projector units having such a cathode ray tube, an image obtained by the multi-plane multi-rear projector does not generate uneven brightness on the entire screen and has high image quality. It can be a large 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. In the peripheral portion 35, there is no problem since light rays emitted in directions other than the range of 20 to 70 degrees with respect to the normal to the fluorescent screen 28 do not become effective light rays necessary for displaying an image.

Further, in the present reference example, the luminance distribution in the central portion of the fluorescent screen 28 and the portion between them also has a luminance in the range of 20 to 70 degrees with respect to the normal line of the fluorescent screen 28, similarly to the luminance portion of the peripheral portion 35. Is increased, but the luminance 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), it is preferable to limit the angular width as much as possible in accordance with the projection lens to be used, and to increase the directivity accordingly. Is good. For example, in 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. about
It is considered to be about 10 to 30 degrees. Therefore, limiting the angle width at which the luminance should be increased to about 10 to 30 degrees and increasing the luminance at that angle is more advantageous for making the luminance distribution on the screen uniform.

〔The invention's effect〕

As described above, according to the present invention, the depth of the entire multi-plane multi-rear projector can be reduced,
There is an advantage that it can be made thin.

[Brief description of the drawings]

FIG. 1 is a side view showing a main part of a multi-plane multi-rear projector as a first embodiment of the present invention, and FIG. 2 schematically shows a multi-plane multi-rear projector as a second embodiment of the present invention. FIG. 3 is a front view, FIG. 3 is a side view showing a main part of a multi-plane multi-rear projector according to a third embodiment of the present invention, and FIG. 4 is a cross section of a rear screen suitable for use in the multi-plane multi-rear projector according to the present invention. FIG. 5 is a cross-sectional view showing, as a reference example, a cross-sectional view of a main part of a rear screen suitable for use in the multi-plane multi-rear projector according to the present invention, and FIG. 6 is a multi-plane according to the present invention. FIG. 7 is a cross-sectional view showing a cross section of a rear screen suitable for use in a multi-rear projector as a reference example. FIG. 7 is a main part of a rear screen suitable for use in a multi-plane multi-rear projector according to the present invention. Sectional view showing a cross-section as a reference example,
FIG. 8 is a perspective view showing a main portion of a rear screen suitable for use in the multi-plane multi-rear projector according to the present invention and shown as a reference example, and FIG. 9 is a view suitable for use in the multi-plane multi-rear projector according to the present invention. FIG. 10 is a perspective view showing a main part of a rear screen cut out and shown as a reference example, and FIG. 10 is a cross-sectional view showing a cross section of a projection lens suitable for use in the multi-plane multi-rear projector according to the present invention as a reference example.
The figure is an explanatory diagram for describing, as a reference example, the luminance distribution of a cathode ray tube suitable for use in the multi-plane multi-rear projector according to the present invention. Description of reference numerals 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' ... rear _{screen, θ 1, θ 2, θ} 3, θ 4,
θ ₅ : mirror setting angle, α ₁ , α ₂ , α ₃ , α ₄ , α ₅ ... incident angle of projected light beam, 6 ... transparent reinforcing plate, 7-1, 7-2, 7'-1,
7'-2,7 "-1,7" -2 ... Screen plate, 9,9 ', 9 ", 20,
21,41-1,41-2,41-3,41-4 ... joint, 10,14,14 '...
Concave part, 11, 15, 15 ', 19, 42, 42' ... 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, BM: black matrix, 18: lenticular lens, 22: face plate, 27: partially opaque plate, 27-
1: light non-reflection / light non-transmission object, 28: fluorescent screen.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 5/66-5/74 G09F 9/00

Claims (8)

(57) [Claims] In a multi-plane multi-rear projector for projecting light from a plurality of projection optical systems onto a screen to display an image, one of the adjacent projection optical systems transmits light from a projection lens to the screen. The mirror reflecting in the direction is configured such that an extension of the mirror surface intersects the screen surface of the screen and the angle between the mirror surface and the screen surface is smaller than that of the other projection optical system. A multi-plane multi-rear projector, comprising: 2. The multi-plane multi-rear projector according to claim 1, wherein each of the adjacent projection optical systems is arranged vertically. 3. A multi-plane multi-rear projector in which a plurality of projection optical systems each having a mirror for reflecting light from a projection lens in the direction of a screen are arranged adjacent to each other, wherein an optical path length from the tip of the projection lens to the mirror is determined. L
1. When the optical path length from the mirror to the screen is L2, the first projection optical system satisfies L1> L2, and the second projection optical system disposed adjacent to the first projection optical system is L2> L1
A multi-plane multi-rear projector characterized by satisfying the following. 4. The multi-faceted optical system according to claim 3, wherein said first projection optical system is a projection optical system in which a projection lens is located at a screen end side with respect to a mirror among projection optical systems arranged at an endmost portion. Multi rear projector. 5. A multi-plane multi-rear projector in which a plurality of projection optical systems each having a mirror for reflecting light from a projection lens in the direction of a screen are arranged adjacent to each other, wherein an optical path length from the projection lens to the mirror is L1, When the optical path length from the mirror to the screen is L2,
At least the first projection optical system in the first and second projection optical systems adjacent to each other satisfies L1> L2, and the mirror intersects the mirror surface with an extended line of the mirror surface, and A multi-plane multi-rear projector having a configuration in which an angle between the screen and the screen is made smaller than in the case of the second projection optical system. 6. A multi-plane multi-rear projector in which a plurality of projection optical systems each having a mirror for reflecting light from a projection lens in the direction of a screen are arranged adjacent to each other, and an optical path from a tip of the projection lens to the mirror is provided. L for length
1. When the optical path length from the mirror to the screen is L2, one projection optical system satisfies L2 <L1, and
A multi-faced multi-layer system comprising a configuration in which an incident angle of light on the mirror is made smaller than an incident angle of light on a mirror of a projection optical system disposed adjacent to the projection optical system. Rear projector. 7. A multi-plane multi-rear projector in which a plurality of projection optical systems each having a mirror for reflecting light from a projection lens in a screen direction are arranged adjacent to each other, wherein an optical path length from a tip of the projection lens to the mirror is provided. L
1. When the optical path length from the mirror to the screen is L2, the first projection optical system satisfies L2 <L1, and the second projection optical system disposed adjacent to the first projection optical system is , L2>
L1 and the angle of incidence of light on the mirror is
A multi-plane multi-rear projector characterized by having a configuration designed to be larger than in the projection optical system. 8. A multi-plane multi-rear projector for projecting light from a plurality of projection optical systems onto a screen to display an image, wherein one of the adjacent projection optical systems transmits light from a projection lens to the screen. The mirror reflecting in the direction, the extension of the mirror surface intersects with the screen surface of the screen and the angle between the mirror surface and the screen surface is smaller than that of the other projection optical system, and
A multi-plane multi-rear projector, characterized in that the angle of incidence of light on the mirror surface is also made smaller than that of the other projection optical system.