JPH08102899A - Projection multi-image display device - Google Patents

Abstract

PURPOSE: To obtain a projection multi-picture display device of a large screen which reduces the depth of the whole set remarkably. CONSTITUTION: The large screen consists of four small screens (four small screens 5-1 to 5-4) and four sets of projection type optical systems (image projection cathode-ray tubes 1G and projection lenses 2) are provided corresponding to each small screen. An optical system supposed to belong to the small screen 5-1 projects a picture on another small screen 5-2 by jumping over the small screen 5-1 and to the contrary, an optical system supposed to belong to the small screen 5-2 projects a picture on another small screen 5-1 by jumping over the small screen 5-2. Thus, projection distances (PQR and P'Q'R') are prolonged without increasing the depth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type multi-image display device for enlarging and projecting an image projected from a projection tube with a lens, and particularly to an ultrathin large screen of 100 inches or more, and It can be used as a projection-type television image receiving device that realizes low cost and high performance. The present invention can also be used as a large screen display device for displaying characters, figures, and the like.

[0002]

2. Description of the Related Art Conventionally, in a large-screen television receiver of about 100 inches, a technical report of the Institute of Television Engineers of Japan, Vol.
o. 29 (1982) IPD72-1 pp. 37 to 4
As discussed on page 2 and on pages 42 to 47 of IPD 72-2, the three projection tubes (cathode ray tubes) for blue, green, and red are set as one set, and the images on each projection tube are set in front. And enlarged on each lens, and projected on the same screen to obtain a large screen.

[0003]

In the above prior art, a screen having a size of 100 inches is used, so that a screen having a Fresnel shape (Fresnel) used in a home (approximately 50 inches) projection type television receiver is used. Screen) was technically difficult to use. That is, the Fresnel-shaped screen has to be produced by press molding with a mold. Therefore, it is necessary to process a mold with a size of 100 inches and molding using the mold, which is very difficult. In view of this, two lenticular screens that can be extruded and can easily realize a large size are used to emit light in the horizontal and vertical directions. Such a screen has a low light-collecting efficiency, so that it is difficult to secure a gain as compared with the above-mentioned Fresnel screen.
There was a problem that it was much darker than 0ft-L, compared to 300ft-L for home use.

In view of the magnification and the angle of concentration, the projection distance from the lens to the screen is 3000 to 4000 mm.
Therefore, there is also a structural problem that the depth of the entire set (image receiving device) becomes long, the weight becomes heavy and the price becomes high.

[0005] On the other hand, in the projection with only one set of three tubes, the screen becomes one.
Because of the size of 00 inches, there was also a performance problem that color shift and color unevenness were noticeable.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, to realize a bright and clear, high performance with greatly improved color shift and color unevenness, and to reduce the depth of the entire set to a home projection type. It is an object of the present invention to provide a projection type multi-image display device which can be used as a projection type television image receiving device which is significantly reduced in size to a size comparable to that of a television image receiving device, and at the same time is inexpensive.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to form a screen of about 100 inches by forming four screen-type image display apparatuses of about 50 inches in close connection with each other. This is achieved by using a linear Fresnel screen or an eccentric Fresnel screen for each of the four projection image display devices.

That is, one screen is composed of four small screens, and four sets of projection optical systems (an image projection tube such as a television receiver and a lens arranged on the front surface thereof) are provided for each small screen. However, when the arrangement positions of the four small screens are sequentially determined in the counterclockwise direction from the first quadrant to the fourth quadrant, for example, using the projection optical system located corresponding to the small screen in the first quadrant, the fourth quadrant is used. To the small screen in the own quadrant, for example, by projecting the screen on the small screen in the first quadrant using the projection optical system located corresponding to the small screen in the fourth quadrant. If the projection is performed toward a small screen in another quadrant instead of the projection screen, the projection distance for projecting the screen from the projection optical system to the small screen will increase even if the distance between the screen and the projection optical system is constant. Can be longer than when projecting on a small screen in a quadrant A longer projection distance leads to a smaller concentration angle and angle of view on the screen (screen), so that color shift and color unevenness seen on the screen are improved, and performance is improved.

If the distance between the screen and the projection optical system itself is increased, the projection distance can be increased arbitrarily. In that case, however, the thickness of the set (receiver) increases and compactness cannot be maintained. It is desired to increase the projection distance while keeping the distance from the optical system constant, and the above-described device can be said to meet such a demand.

[0010]

With reference to FIGS. 5 and 6, the relationship between the above-described projection distance and color shift (uneven color) will be specifically described.

FIG. 5 shows a projection tube (cathode ray tube) 1B for projecting an image of each color of blue (B), green (G) and red (R).
FIG. 2 is a plan view showing a planar arrangement of 1G, 1R and a lens 2 arranged on the front surface of each. In a color projection type television receiver, these three projection tubes 1B, 1G, and 1R are usually used. At that time, a green projection tube 1G is used.
The blue and red projection tubes 1B and 1R are usually arranged on both sides of the projection tube.

FIG. 6A is a characteristic diagram showing the relationship between the relative luminance IR of red and the relative luminance IB of blue on the screen with respect to the concentration angle θ, and FIG. 6B is a graph showing the color shift ΔI,
FIG. 9 is a characteristic diagram showing the relationship between ΔI ′ and the concentration angle θ.

As can be seen from FIG. 5, the green projection tube 1G
When the angle formed by the optical axes of the blue projection tube 1B and the red projection tube 1R with respect to the optical axis of is the concentration angle θ, the following equation holds.

Θ ≒ 2 tan ^-1 (d / L1) (1) or θ ≒ 2 tan ^-1 (Wp / L2) (2) where d is the outer diameter of the lens 2 and Wp is the diameter of the projection tube. Width dimension,
L1 is the projection distance, and L2 is the optical path length.

Here, the smaller the width Wp of the projection tube or the lens outer diameter d, and the distance L from the lens 2 to the screen 5.
1 (projection distance) or distance L from phosphor screen to screen 5
As 2 (optical path length) increases, the concentration angle θ can be reduced.

The larger the concentration angle θ is, the more blue and red when the image is viewed from the front of the transmissive screen 5 are spread outward and emitted, and as a result, the eyes are moved leftward and rightward to see the image. For example, in FIG. 5, when viewed from the E direction, the blue (B) taste is stronger, and when viewed from the F direction, the red (R) taste is stronger, so that the white balance is lost and the so-called color shift increases. . That is, FIG.
As shown in (b), when the blue luminance distribution IB and the red luminance distribution IR are obtained, the smaller the luminance difference ΔI and ΔI ′ of each color when viewed from the E and F directions, the smaller the color shift. That is why. For this purpose, the smaller the concentration angle θ is, the better.

In the current 100-inch projection type television receiver, the concentration angle θ is about 3 to 4 °, whereas in the home projection type television receiver of about 50 inches, it is about 7 to 8 °. By using a two-screen Fresnel screen and a lenticular screen composed of a cylindrical lens group, the color shift is made equal to that of the above-described 100-inch projection television receiver.

On the other hand, in order to reduce the size of the projection type television receiver, in particular, to reduce the depth of the projection television receiver, a mirror is usually arranged in the middle of the optical path and the optical path is bent. However, even if a mirror is used, the use of only one mirror is predominant in terms of its reflection loss and optical adjustment.

FIG. 7 is an explanatory diagram showing the depth dimension D of the set and the center height H of the screen, and FIG. 8 is a characteristic diagram showing the relationship between the depth dimension D and the center height H of the screen when the projection distance is used as a parameter. . 4 is a mirror and 5 is a transmission screen.

In this case, the screen center height H
Is constant, the projection distance L1 is small,
If the projection distance L1 is constant, the depth D can be reduced as the screen center height H increases.

FIG. 9 is a schematic diagram for explaining the angle of view. As shown in FIG. 9, as the angle of view (2γ) from the lens 2 to the screen 5 increases, the light incident on the periphery of the screen 5 increases. Becomes small, and the reflection loss on the incident surface side of the screen 5 (the side with the lens) increases. Furthermore, when focusing on the same peripheral portion, the angles of incidence of blue, green, and red light are different from each other. Therefore, when the peripheral portion is viewed from the point P on the central axis of the screen 5, the white balance is lost and color unevenness occurs. When the size of the screen 5 is determined, the angle of view (2γ) increases as the projection distance L1 decreases, and the color unevenness further increases.

As described above, the projection angle L1 determines the concentration angle θ and the angle of view (2γ), and as a result, the color shift and the color unevenness are determined. According to the present invention, in particular, FIGS.
As in the embodiment shown in FIG. 1, while achieving a significantly compact set (small back dimension), the projection distance L1 can be increased, so that the concentration angle and the angle of view can be reduced, and as a result, color shift and color unevenness are greatly reduced. Can be improved. Further, since the blue, green, and red projection tubes 1B, 1G, and 1R are arranged in a vertical inline manner, horizontal color shift for each small screen can be completely eliminated, and as a result, there is no color shift as a whole. A projection type multi-image display device that can be used as a large-screen projection type television receiver can be realized.

On the other hand, a projection optical system (a small screen) which is composed of a projection tube, a lens, a mirror, and a screen, which is a set of three of R, G, and B, can be obtained by itself. (Projection blocks) are combined to form a television receiver capable of obtaining a large screen of about 100 inches. However, if a small screen is obtained for each projection block as it is, the center of the optical axis of the screen, especially the Fresnel screen, is generally smaller. Because it is located at the center of the screen and the peripheral light amount ratio of the lens is usually about 30%, for a large screen of about 100 inches composed of four small screens, the center of the large screen (4 The point where two small screens touch each other, that is, the corners of each small screen, is darkest, which is inconvenient.

Therefore, in the present invention, a linear Fresnel screen is newly added to the screen, or an eccentric Fresnel screen in which the Fresnel center of the Fresnel screen is eccentric is used, so that it is possible to obtain The center of the large screen can be made to have practical brightness. Further, the projection block described above may be used as it is as a home projection television receiver of about 50 inches, so that it is possible to easily realize a thin type and a low cost.

Further, since a large screen of four times the size can be obtained while maintaining the resolution N obtained in each projection block as it is, the resolution can be substantially doubled (2N), and a high resolution can be realized.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIGS. 1 to 3 are explanatory views of a projection type multi-image display device, which can also be used as an ultrathin type large screen projection type television image receiving device, as an embodiment of the present invention, as seen from the front. . One screen that constitutes a large screen when viewed from the front is 4
The small screen is divided into four small screens, and the small screen on the upper right is set as the first quadrant, and each small screen is sequentially set in the second quadrant and the third quadrant in the counterclockwise direction.
When a quadrant and a fourth quadrant are set, a projection tube image arranged as a set of blue, green, and red arranged in an arbitrary quadrant is enlarged by a lens arranged in front of the projection tube image and arranged in another quadrant. The small screen of the other quadrant is formed by projection using the mirror and the transmission screen thus formed, and the projection distance is increased while keeping the distance between the projection tube and the screen constant.

The four small screens formed in this way are gathered to realize one large screen as a whole. For example, if the screen size of the small screen in each quadrant is 50 inches in diagonal dimension, a large screen of 100 inches can be realized by collecting four small screens.

The details will be described below. FIG. 1 is a front view showing the first embodiment of the present invention as described above. In FIG.
B, 1G, and 1R are blue, green, and red projection tubes, 2 is a lens, 3-1 to 3-4 are optical blocks, 4-1 to 4-
4 is a mirror, 5-1 to 5-4 are transmission screens. still,
In the following embodiments, the same components are denoted by the same reference numerals, and description thereof is omitted. The blue, green, and red projection tubes 1B, 1G, and 1R are vertically arranged in-line with each other, and a lens 2 is disposed in front of each projection tube. If one independent optical block 3-1 is 3-1. And

The optical block 3 having the same construction
2,3-3,3-4 are provided. The light beam emitted from the optical block 3-1 belonging to the first quadrant is bent by the mirror 4-2 belonging to the second quadrant to form a transmission screen 5- in the second quadrant.
2 to form a small screen, and the light flux emitted from the optical block 3-2 belonging to the second quadrant is reflected by the mirror 4 in the first quadrant.
It is bent at -1 and projected on the transmission screen 5-1 in the first quadrant to form a small screen.

Further, similarly, the light beam emitted from the optical block 3-4 belonging to the fourth quadrant is reflected by the mirror 4-3 in the third quadrant.
And the light flux emitted from the optical block 3-3 belonging to the third quadrant is bent by the mirror 4-4 in the fourth quadrant, and the transmission screen in the fourth quadrant is bent. Each of the images is projected onto 5-4 to form a small screen. Then, each small screen is connected by electrical processing to obtain one large screen as a whole.

FIG. 4 is a sectional view taken along the line AA 'of FIG. 1. FIG. 4 schematically shows the relative positional relationship among the projection tube, lens, mirror, and transmission screen. As shown in FIG. 4, the optical block that should belong to the transmissive screen 5-1 jumps over the screen 5-1 to the transmissive screen 5-2, and vice versa.
The optical block that should belong to the transmissive screen 5-2 jumps over the screen 5-2 and projects onto the transmissive screen 5-1. Therefore, the projection distance (PQR and P'Q'R ') can be increased.

The dotted line in FIG. 4 shows the positions of the lens and the projection tube in the conventional home-use projection television receiver.
Projection distance in inches class, screen width (W _S) are both approximately 1000 mm. Therefore, according to the present embodiment, even when the projection is performed on the same 50-inch screen, the projection distance is set to W.
_{Even if the} length is increased by an amount corresponding to _S , that is, the length is increased to about 2000 mm, the depth D ′ does not increase, and
Can be 800 mm. That is, despite the super-large screen of 100 inches, an ultra-thin shape with a depth of 600 to 800 mm comparable to a 50-inch home-use projection television receiver can be realized.

FIGS. 2 and 3 are front views of the second and third embodiments, respectively. FIG. 4 shows a main part of a cross section BB'CC '. In the second embodiment shown in FIG. 2, the blue, green, and red projection tubes 1B, 1G, and 1R are arranged laterally in-line with each other, and the optical blocks 3-1 and 3-are arranged in the same manner as described with reference to FIG.
2,3-3,3-4 are formed.

Then, the light beam emitted from the optical block 3-1 belonging to the first quadrant is bent by the mirror 4-4 in the fourth quadrant to project one small screen on the transmission screen 5-4 in the fourth quadrant. And an optical block 3-2 belonging to the second quadrant.
Is projected by a third quadrant mirror 4-3 on a transmissive screen 5-3 in the third quadrant.

Similarly, the light beam emitted from the optical block 3-3 belonging to the third quadrant is bent by the mirror 4-2 in the second quadrant, and is bent on the transmission screen 5-2 in the second quadrant.
The light beam emitted from the optical block 3-4 belonging to the quadrant is bent by the mirror 4-1 in the first quadrant and projected on the transmissive screen 5-1 in the first quadrant to form one small screen each. Then, the small screens are connected by electrical processing to obtain one large screen as a whole.

On the other hand, the third embodiment shown in FIG. 3 has a configuration in which the positions of the optical block, the mirror, and the transmission screen in the second embodiment shown in FIG. The same parts are given the same numbers.

The second embodiment shown in FIG. 2 is suitable for reducing the width of the whole set, and the third embodiment shown in FIG. Can be further reduced, and the characteristics of improving color shift and color unevenness are further improved. Further, the third embodiment has a feature that the operation and effect of the linear Fresnel screen shown in FIGS.

Also in the first to third embodiments, it is needless to say that the eccentric Fresnel screen and the linear Fresnel screen shown in FIGS.

FIG. 10 is a perspective view showing the appearance of one embodiment of the present invention.

The ultra-thin projection type television receiver as one embodiment of the present invention shown in FIG.
Are arranged in combination with each other. This arrangement is such that the projection block 6 of FIG. 11 is arranged as it is in the fourth and second quadrants of FIG. 10, and the projection block 6 of FIG. 11 is inverted in the first and third quadrants. I do.

FIG. 12 is a sectional view taken along the line AA of the entire structure of FIG. 10, and FIG.
1 shows a state in which one projection block 6 is arranged.

As shown in FIG. 10 in which one large-sized projection television receiver is constructed by arranging four projection blocks as described above, the operation panel 7 such as a tuner and the speaker 28 are arranged to be ultra-thin. The whole of the projection type television receiver is constituted. The operation of the entire configuration of FIG. 10 will be described below with reference to other drawings.

In the projection block 6 of FIG. 11, the lenses 2 are arranged on the front surfaces of the three projection tubes 1R, 1B and 1G for red, blue and green, respectively, to form the optical block 3 and the entire housing 8
The magnified image is accommodated in the projection tube 1R, 1B, 1G by a lens 2, and the magnified image (not shown) is reflected by a mirror 4, thereby the magnified image is transmitted through the transmission screen 5.
-1.

The viewer sees an enlarged image formed on the transmissive screen 5-1 by the projection block 6 of FIG. 11 configured as described above.
It is necessary to provide the following relationship between -1 and the viewer.

FIG. 12 is a sectional view taken along the line AA of FIG. 10, and FIG. 13 is a partially enlarged view showing the configuration of the transmission screen 5-1 of FIG. In FIG. 13, the transmission screen 5-
1 is sequentially from the mirror 4 side of FIG.
Fresnel screen 11, Linear Fresnel screen 1
2, and the lenticular screen 13 are arranged to constitute the whole.

The Fresnel screen 11 is made of a transparent plate, and has a lenticular surface 14 formed on one side and a concentric Fresnel lens surface 15 formed on the other side. An enlarged image from the optical block 3 in FIG. 13, the lenticular surface 14 allows the transmission screen 5-1 viewed from the viewer side.
The field of view is widened in the vertical direction of ５−5-4. The Fresnel lens surface 15 plays a role of condensing the enlarged image from the optical block 3 toward the viewer by passing the image through the Fresnel lens surface 15.

Further, the lenticular screen 13 is
Cylindrical lens groups 16 and 17 are provided on both sides to widen the magnified image from the optical block 3 in the left-right direction of the screens 5-1 to 5-4 viewed from the viewer side.
As described above, the enlarged image from the optical block 3 in FIG. 12 is condensed in the direction of the viewer 9 ′ by the Fresnel screen 11 and the lenticular screen 13 in FIG. The viewer 9 ′ who views at the center of −1 to 5-4 can see a bright and sharp image at the center of the screen.

However, the viewer 9 located at the center of the screen of the ultra-thin projection television receiver shown in FIG. 12 has the transmission screens 5-1 to -5 to move by the distance I to the viewer 9 '. The central portion of the large screen screen 18 obtained by combining four -4 planes becomes dark, and the image is not sharp. To solve this, the linear Fresnel screen 12 of FIG. 13 was inserted between the Fresnel screen 11 and the lenticular screen 13 to form the projection block 6. FIG. 14 illustrates the operation of the linear Fresnel screen.
From FIG.

FIG. 14 shows that a large screen screen 18 of 100 inch size is formed by arranging four transparent screens of 50 inch size, and viewers 9 and 9 'view the large screen image. It is a state diagram, and the distance between the large screen screen 18 and the viewer 9, 9 'is set to 10000 mm. The position of the viewer 9 ′ is the optimum position when the linear Fresnel screen 12 in FIG. 13 is not used, and the optimum position for viewing the large screen screen 18 in FIG. 14 using the linear Fresnel screen 12 is the viewer. 9 position.

This linear Fresnel screen 12 is shown in FIG.
As shown in FIG. 5, a large-screen linear Fresnel screen 19 is constituted by arranging four screens facing each other. FIG. 1 is a diagram showing a cross-section BB in the diagonal direction of the linear Fresnel screen 12 of FIG.
It is 6.

In FIG. 16, when the center of the large-screen linear Fresnel screen 19 shown in FIG. 15 is set to the position zero and the x-axis is taken diagonally, the angle δ of the linear Fresnel screen 20 of the linear Fresnel screen 12 is obtained. Needs to be set as: n sin δ = sin ｛δ + tan ⁻¹ (x / 10000)｝ (3) Here, the refractive index of the linear Fresnel screen is n. FIG. 17 is a graph of the above equation (3), and shows the relationship between the diagonal position x of the linear Fresnel screen and the angle δ of the linear Fresnel surface when n = 1.5.

FIG. 18 shows another embodiment of the present invention, in which four projection blocks 6 in FIG. 11 are arranged sideways by 90 °. Lenticular screen 13 and linear Fresnel screen 1 shown in FIG.
2 and the lenticular screen 11 are also turned over by 90 ° in this embodiment, so that the image itself viewed by the viewer is exactly the same as in the previous embodiment.

As described in detail above, by using the linear Fresnel screen according to the present invention in combination with a Fresnel screen and a lenticular screen, a viewer who views the large screen of the ultra-thin projection type television receiver can be obtained as follows. A bright and sharp image at the center of the screen can be viewed.

Next, FIG. 19 is a screen cross-sectional view relating to the eccentricity of the Fresnel screen described above. Figure 1 above
In FIGS. 3, 10 and 18, the diagonal cross section of the main part of the screen is shown, and particularly, only the Fresnel screen 14 'is shown. As described above, in order to make the image brightest and sharpest when viewed from the viewer 9, the following means is provided.

That is, the screen center axis I of the entire set
If the lens 2 with respect to I ', apart axes W _C systems of projection tube 1G, said system is arranged with a distance L0 away from the screen, whereas the viewer may see the screen at a distance of L,
Fresnel screen 14 'by Δh determined by the following equation (4)
Eccentric center a.

Δh≈L0 · W _C / (L + L0) (4) For example, when the diagonal length of the Fresnel screen 14 ′ is 50 inches (about 1270 mm), W _C ≈635 mm, L = 10
000mm, L0 = 1500mm
From the equation (4), the entire set is decentered along the diagonal line in the direction of the center axis II 'of the screen by Δh 線 80 mm.

In the above equation (4), when Δh exceeds the value given on the right side, the brightness at the center of the large screen becomes brighter, but the periphery becomes darker, and a uniformly bright image cannot be obtained. On the other hand, as Δh becomes smaller than the value given on the right side, the periphery of the screen becomes brighter, but the center of the screen becomes darker, and a uniform bright image cannot be obtained.

FIG. 20 is a partial cutaway view from the front when the eccentric Fresnel screen shown in FIG. 19 is used in an ultra-thin large-screen projection television receiver. Reference numeral 14 'denotes an eccentric Fresnel screen, and the entire set is formed by combining the above-described projection block 6 (FIG. 11) in the same manner as described with reference to FIG.

FIG. 21 is a view showing another embodiment according to the present invention. As in the previous embodiment, a bright and clear image is projected on the viewer side. That is, the projection tubes 1G-1, 1G-
2, 1G-3, 1G-4 and the optical axes m _{1 to} m _{4 of the} lens 2
The projection tubes 1G-1 to 1G-4 and the lens 2 are arranged so as to intersect at a single point as an optimum condition so that the lens faces the viewing position 9.

The blue and red projection tubes 1B and 1R are also arranged at a predetermined angle with respect to the projection tubes 1G-1 to 1G-4. Such a screen is shown in FIGS.
It is more effective by using the Fresnel screen of the embodiment in FIGS.

[0062]

According to the present invention, a 100-inch large-screen television set is constituted by four television receivers of about 50 inches, so that the image performance is about 50 inches despite the large screen of 100 inches. And a 100-inch large screen can improve resolution and brightness and reduce color shift and color unevenness as compared with the conventional one.

The main components such as a cathode ray tube, a lens, a mirror, and a screen of a 100-inch large-screen television receiver can be shared with a small-screen television set of about 50 inches. Nevertheless, the depth of the set can be made the same as a small screen TV set of about 50 inches, and the cost and weight are 5
Cost reduction equivalent to four 0-inch TV sets.

Further, since four 50-inch televisions each having a large screen of 100 inches divided by 1/4 can be separated, a set of 1/4 screens can be transported separately.
Despite the large inch screen, it can be easily transported.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a front view showing an embodiment of the present invention.

FIG. 3 is a front view showing one embodiment of the present invention.

FIG. 4 is a sectional view taken along the line AA ′ in FIG. 1;

FIG. 5 is a plan view showing a planar arrangement of blue (B), green (G), and red (R) projection tubes (cathode ray tubes) and lenses arranged on the front surfaces thereof.

FIG. 6A shows a relative luminance IR of red on a screen.
And (b) is a characteristic diagram showing the relationship between the relative brightness IB of blue and the concentration angle θ. FIG.
FIG. 4 is a characteristic diagram showing a relationship with the above.

FIG. 7 is an explanatory diagram showing a depth dimension of a set and a screen center height.

FIG. 8 is a characteristic diagram showing a relationship between a depth dimension and a screen center height when a projection distance is used as a parameter.

FIG. 9 is a schematic diagram illustrating an angle of view.

FIG. 10 is a perspective view showing the appearance of an embodiment of the present invention.

FIG. 11 is a perspective view showing a configuration of a projection block.

FIG. 12 is a sectional view taken along line AA of FIG. 10;

13 is a partially enlarged view showing the configuration of the transmissive screen of FIG.

FIG. 14 is a perspective view showing a viewing state of a large screen.

FIG. 15 is a perspective view showing a configuration of a large-screen linear Fresnel screen.

FIG. 16 is a sectional view taken along line BB of FIG. 15;

FIG. 17 is a characteristic diagram showing the relationship between the diagonal position of the linear Fresnel screen and the angle of the linear Fresnel surface.

FIG. 18 is a front view showing an embodiment of the present invention.

FIG. 19 is a sectional view of a Fresnel screen.

FIG. 20 is a partial cross-sectional view of an eccentric Fresnel screen.

FIG. 21 is a perspective view showing one embodiment of the present invention.

[Explanation of symbols]

1G, 1R, 1B ... Projection tube, 2 ... Lens, 3, 3-
1-3-4: Optical block, 4,4-1 to 4-4 ...
Mirror, 5,5-1 to 5-4 ... Transparent screen, 6 ... Projection block, 11 ... Fresnel screen, 12 ... Linear Fresnel screen, 13 ... Lenticular screen, 18 ... Large screen screen, 20 ... ... Linear Fresnel surface, 14 '... Eccentric Fresnel, D ... Depth dimension, θ ... Concentration angle, γ ... Half angle of view, δ ... Fresnel surface angle, a ... Fresnel center

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Koji Hirata, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Home Appliances Research Laboratory, Hitachi, Ltd. (72) Inventor Masayuki Muranaka, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Home Appliances Research Laboratory, Hitachi, Ltd. (72) Kiyoshi Wada, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Home Office, Home Appliances Research Laboratory, Hitachi, Ltd. (72) Teru Maruyama 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa House number Incorporated company Hitachi, Ltd. Home Appliances Research Laboratory (72) Inventor Masamichi Takeshita 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Address House Company Hitachi Ltd. Home Appliances Research Laboratory (72) Inventor Hiroki Yoshikawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Banchi Co., Ltd. Home Appliance Research Laboratory, Hitachi, Ltd.

Claims (11)

[Claims] 1. A projection type multi-image display device for displaying different images projected on a plurality of unit screens as one combined image, wherein at least three images of red, green and blue are provided for each unit screen. A unit optical system including a projection tube that projects light, a lens that projects an image of the projection tube, and one mirror that reflects image light from the lens toward a corresponding unit screen, and Each unit optical system is arranged so that the optical path of the image light from the lens of a certain unit optical system to the mirror crosses the image optical path from the mirror of another unit optical system to the unit screen. A projection type multi-image display device characterized in that 2. The projection type multi-image display device according to claim 1, wherein four quadrants are constituted by four unit screens, and unit optics arranged corresponding to an arbitrary odd quadrant among the four quadrants. Projection images from the projection tube of the system are projected onto the unit screen of the unit optical system arranged corresponding to the other odd quadrants, while the unit arranged corresponding to any even quadrant of the four quadrants A projection type multi-image display device, wherein a projection image from a projection tube of an optical system is projected on a unit screen of a unit optical system arranged corresponding to another even quadrant. 3. The projection type multi-image display apparatus according to claim 1, wherein four quadrants are constituted by four unit screens, and a unit optical system arranged corresponding to a first quadrant of the four quadrants. The projection image from the projection tube of the unit optical system is projected on the unit screen of the unit optical system arranged corresponding to the second quadrant, and the projection image from the projection tube of the unit optical system arranged corresponding to the second quadrant is A projection image is projected on a unit screen of the unit optical system arranged corresponding to the first quadrant, and a projection image from a projection tube of the unit optical system arranged corresponding to the third quadrant is arranged corresponding to the fourth quadrant. Projects onto the unit screen of the unit optical system, and projects the projection image from the projection tube of the unit optical system arranged corresponding to the fourth quadrant on the unit screen of the unit optical system arranged corresponding to the third quadrant Projection multi-image display device characterized by Place. 4. The projection type multi-image display device according to claim 1, wherein four quadrants are constituted by four unit screens, and a unit optical system arranged corresponding to a first quadrant of the four quadrants. The projection image from the projection tube of the unit optical system arranged corresponding to the fourth quadrant on the unit screen of the unit optical system arranged corresponding to the fourth quadrant. The projection image is projected on the unit screen of the unit optical system arranged corresponding to the first quadrant, and the projection image from the projection tube of the unit optical system arranged corresponding to the second quadrant is arranged corresponding to the third quadrant. Projects onto the unit screen of the unit optical system and projects the projected image from the projection tube of the unit optical system arranged corresponding to the third quadrant on the unit screen of the unit optical system arranged corresponding to the second quadrant Projection multi-image display device characterized by Place. 5. The projection type multi-image display device according to claim 1, wherein the screen has a Fresnel screen having a Fresnel lens surface formed concentrically on at least one surface, and a plurality of cylindrical lens groups; A projection screen comprising a lenticular screen in which a diffusing material is mixed therein and a linear fresnel screen having a Fresnel lens surface arranged in a straight line inserted between the lenticular screen and the three-screen. Multi-image display device. 6. The projection type multi-image display device according to claim 2, wherein the screen has a Fresnel screen having a Fresnel lens surface formed concentrically on at least one side, and a plurality of cylindrical lens groups. And a lenticular screen having a diffusing material mixed therein, and a linear Fresnel screen having Fresnel lens surfaces arranged in a straight line inserted between the lenticular screen and the three-screen structure. Projection type multi-image display device. 7. The projection-type multi-image display device according to claim 6, wherein the Fresnel center of the Fresnel screen having a Fresnel lens surface concentrically formed on at least one surface is located on the Fresnel screen in the first quadrant. Diagonally downward to the left on the Fresnel screen, diagonally downward to the right on the Fresnel screen diagonal for the Fresnel screen in the second quadrant, and diagonally to the Fresnel screen diagonal for the Fresnel screen in the third quadrant. , Diagonally upward to the right, and for Fresnel screens in the fourth quadrant, diagonally upward to the left on the diagonal of the Fresnel screen,
A projection-type multi-image display device, characterized in that each of them is decentered. 8. The projection type multi-image display device according to claim 2, wherein a projection tube for projecting a red, blue, or green image of each unit optical system arranged corresponding to each quadrant, A projection type multi-image display device, comprising a projection tube in which three projection tubes are arranged in line with each other. 9. The projection type multi-image display device according to claim 8, wherein the optical axis of the projected image from the green projection tube of each unit optical system arranged corresponding to each quadrant is set in all four quadrants. At least a green projection tube of each unit optical system is attached at a predetermined angle with respect to the vertical and horizontal directions so as to intersect at any one point in front of the screen when one composite image is formed. Characteristic projection type multi-image display device. 10. The projection type multi-image display device according to claim 2, 3, 4, 5, 6, 7, 8 or 9, wherein a projection type optical system including a projection tube, a lens and a mirror is provided for each quadrant. A projection-type multi-image display device, characterized in that each is housed in one housing to form a projection block. 11. The unit type optical system according to claim 5, 6, or 7, wherein the viewing distance to the screen is L, and each quadrant is composed of a projection tube, a lens, and a mirror. When the lens included in is at a position away from the screen along the optical axis direction by a distance LO and a distance from the screen axis along a direction perpendicular thereto by a distance W _C , Δh≈LO · W _C / (L + LO ) A projection type multi-image display device characterized in that the Fresnel center of the Fresnel screen in each quadrant is decentered by Δh given by