JPH09211412A - Multiimage display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multiimage display device free from joints. SOLUTION: Plural projecting units are longitudinally and transversely arranged and light is supplied from light sources to the respective projecting units 20a, 20b by using optical fibers. A screen 1 is composed of plural partial Fresnel lenses 11a, 11b disposed in correspondence to the plural projecting units, one sheet of a transparent spacer 12 and one sheet of a diffusion plate 13 including diffusion elements so that the images from the respective projecting units are continuously connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-sized multi-image display device for displaying one image in a divided manner by using a plurality of liquid crystal panels or for connecting and combining a plurality of images for display. is there.

[0002]

2. Description of the Related Art Conventionally, as a device for displaying a large multi-image, a plurality of CRTs (cathode ray) as shown in FIG. 14 is disclosed in the catalog of DIA RayX (registered trademark) of Mitsubishi Rayon Co., Ltd. -There was a display device that uses a tube) and divides it into, for example, four partial screens and displays the images by connecting them. FIG. 15 shows its internal structure. Divided partial screen 1a-
1d corresponding to the projection lenses 2a to 2d and C, respectively.
RTs 3a to 3d are provided. The distributor 4 receives the image signal I, divides the image signal into quarters, and outputs the divided image signals Ia to Id to the CRTs 3a to 3d. However, boundaries (also referred to as joints) L1 and L2 exist between the partial screens 1a to 1d. Border L
1 and L2 are designed so that the joint between the CRTs is about 1 mm so as to be as inconspicuous as possible, but since the projected image is displayed over this joint, it is possible to obtain an image with no boundary (joint). I could not do it.

[0003] FIG. 16 is a Japanese Patent Laid-Open Publication No. 62-250.
It is a figure which shows the cross-sectional structure of the rear projection type display apparatus which expands and projects a plurality of images on a screen using the liquid crystal panel shown by 474. A plurality of images projected from the projectors 5a and 5b including a liquid crystal panel, an irradiation light source and a projection lens are combined on the screen 1. The screen 1 is composed of one diffusive transmissive screen, and has a drawback that the boundary (joint) of a plurality of images can be seen when the projection image is viewed obliquely because of its directivity.

FIG. 17 is a cross-sectional structure of the screen shown in "Color Liquid Crystal Display" (Display Technology Series, Shunsuke Kobayashi, Sangyo Tosho, P205) in order to improve the characteristics of the single-panel screen used in FIG. It is a figure. In the projection units 20a and 20b, the illumination optical unit 21
a, 21b, liquid crystal panels 22a, 22b, projection lens 2
3a and 23b are provided. Illumination optics 21a, 2
1b is for irradiating the liquid crystal panel, and the projection lenses 23a and 23b are used for the exit pupil 2 to project the image of the liquid crystal panel.
A lens for projecting on the screen 1 via 4a and 24b. The screen 1 includes a plurality of partial Fresnel lenses (also simply referred to as Fresnel lenses) 11a and 11b and one diffuser plate 13 or a lenticular plate,
The Fresnel lens and the diffusion plate or the lenticular plate are in close contact with each other.

FIGS. 18 and 19 are for explaining the action of the Fresnel lens by taking as an example the case where there are two projection units. In FIG. 18, the image of the liquid crystal panel by the projection unit 20a is enlarged and projected on the portion A of the diffusion plate 13 to generate a projected image 30A. on the other hand,
Similarly, the image of the liquid crystal panel by the projection unit 20b is enlarged and projected on the portion B of the diffusion plate 13, and the projected image 3
Generates 0B. Pixels of projected image 30A and projected image 30
The boundary of the pixel of B is the projection unit 2 corresponding to each.
It is assumed that they are connected seamlessly by adjusting 0a and 20b. In FIG. 18, when the observer M is located in the approximate center of the projected image 30A and looks at the projected image 30A and the projected image 30B at the same time, he pays attention to the boundary portion between the projected image 30A and the projected image 30B. As shown in FIG.
If there is no Fresnel lens, the projection image 30A and the projection image 30B are diffused by the diffusion plate, respectively, but the light flux projected by the projection unit has a spread, so the projection image 30A and the projection image 30B are diffused respectively. It is not evenly diffused by the plate. Observing the boundary between the projected image 30A and the projected image 30B from the observer M,
The amount of direct light indicated by arrows F and G from the projection units 20a and 20b is larger than the amount of light indicated by arrow K diffused by the diffusion plate, and the brightness of the projected image 30B is higher than that of the projected image 30A. It becomes bigger and more like shadows, and the boundary can be seen. As shown in FIG. 19, when there is a Fresnel lens, the light flux having a spread from each projection unit is converted into a substantially parallel light flux by the Fresnel lens and enters the diffuser plate. Since the incident light flux on the diffuser plate is substantially perpendicular to the diffuser plate, the incident light flux is uniformly diffused at any place on the diffuser plate as indicated by arrow K. Therefore, the projected image 30A and the projected image 30B
The brightness at the boundary part of is almost the same, and the shadow becomes small.

FIG. 20 is a diagram showing a boundary portion of a Fresnel lens when a plurality of Fresnel lenses are used. The optical paths of the outermost luminous fluxes F and G must be adjusted so that the outermost luminous fluxes F and G are incident just near the boundary between the Fresnel lenses 11a and 11b. Further, even when the outermost light fluxes F and G are adjusted so as to be incident near the boundary between the Fresnel lenses 11a and 11b, the Fresnel lenses 11a and 11b are adjusted.
The outermost luminous fluxes F and G may not be continuously displayed on the screen 1 due to the presence of the adhesive or the bonding agent between them. Alternatively, if the manufacturing accuracy of the Fresnel lens is not high, a gap may occur between the Fresnel lenses 11a and 11b, and images of the outermost light fluxes F and G may not be continuously formed on the screen.

FIG. 21 shows an example of a projected image. In this example, the 2 × 2 portion of the central portion of the 4 × 4 image is shown. A space is generated at the boundary portion of the projected image, and it is impossible to continuously connect the pixels at the same pitch inside each projected image at the boundary portion of the projected image. As described above, even if there is a Fresnel lens, it is difficult to connect the images completely and seamlessly, and there is a defect that a boundary is formed in the projected image.

FIG. 22 is a front view of a Fresnel lens in the case where a plurality of Fresnel lenses integrated as a result of temperature change expands and contracts. When the temperature changes, the center of the Fresnel lens moves diagonally. For example, if the Fresnel lens is made of acrylic, its linear expansion coefficient is
6 × 10 ^{−5 to} 8 × 10 ⁻⁵ , and assuming that the entire diagonal dimension of the integrated Fresnel lens is 60 inches, when the temperature changes by 20 °, the entire diagonal direction expands or contracts by about 2 mm. The center and the boundary of the Fresnel lens move according to this expansion and contraction. For example, the center of the Fresnel lens moves from point C to point S. Further, the boundary of the Fresnel lens moves from the line P to the line Q. FIG. 23 shows a screen cross section for explaining the movement of a light beam in the vicinity of an adjacent Fresnel lens when the Fresnel lens expands or contracts due to temperature change or the like. When the Fresnel lens expands or contracts due to temperature changes, etc., the boundary position of the Fresnel lens moves, so the conventional screen has the drawback that the projected image wraps around the adjacent Fresnel lens, causing crosstalk between the projected images. It was For example, in the drawing, the light indicated by T is the light to be incident on the Fresnel lens 11a, but the boundary position of the Fresnel lens is from line P to line Q.
The figure shows the case where crosstalk has occurred because the light has entered the Fresnel lens 11b due to the movement to. T
The light indicated by is changed in angle by the Fresnel lens 11b, the verticality is rather deteriorated with respect to the diffusion plate, and the light is incident.

[0009]

The display device using a plurality of CRTs shown in FIGS. 14 and 15 has a drawback that boundaries (joints) L1 and L2 are formed on the divided partial screens 1a to 1d. there were.

The display device using a single-plate screen using a plurality of liquid crystal panels shown in FIG. 16 has a drawback that the boundary (joint) of the plurality of images is visible when the projected image is viewed obliquely because of the directivity of the single-plate screen. was there.

In the conventional screen shown in FIG. 17, it is difficult to connect the pixels at the boundary between the projected image 30A and the projected image 30B without a break, and there is a drawback that the projected image has a boundary.

Further, the conventional screen shown in FIG. 22 has a drawback that the projected image wraps around the adjacent Fresnel lens, which causes crosstalk between the projected images.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a multi-image display device capable of generating a large image without joints or crosstalk. .

[0014]

A multi-image display device according to the present invention synthesizes a plurality of projection units for generating partial images forming a part of an image and partial images generated by the plurality of projection units. In the multi-image display device having a screen for displaying the same, the screen is composed of a plurality of partial Fresnel lenses provided corresponding to the plurality of projection units, and one diffusing plate containing a diffusing material. A space of a certain length is provided between the plurality of partial Fresnel lenses and the diffusion plate.

One transparent spacer is provided between the plurality of partial Fresnel lenses and the diffusing plate.

The transparent spacer and the diffusion plate are integrated.

It is characterized in that the plurality of partial Fresnel lenses are integrated.

The plurality of partial Fresnel lenses, the transparent spacer and the diffusing plate are integrated.

An antireflection film is provided on all or part of the plurality of partial Fresnel lenses, the transparent spacers, and the diffusion plate.

The integrated Fresnel lens is fixed at the center of each side of the integrated Fresnel lens.

The length of the space is set so that the plurality of images generated from the plurality of projection units enter only the corresponding Fresnel lenses.

It is characterized in that the projection unit is provided with an adjusting mechanism for a plurality of axes.

The adjusting mechanism includes an optical axis of the projection unit,
The optical axis of the projection unit is controlled so that the optical axis of the partial Fresnel lens corresponding to the projection unit coincides.

[0024]

1 is a perspective view showing an example of a multi-image display device of the present invention when viewed from the front,
FIG. 2 is a perspective view when viewed from the back. 1 and 2 show a state in which the screen 1 is removed to display the internal structure. When an image is actually displayed, the screen 1 covers the entire front surface of the multi-image display device 100. In the example shown in FIGS. 1 and 2, the projection units 20 are arranged in a 4 × 4 array.
0s are arranged in the cabinet 101 by the adjustment stage 150. The projection unit 20 inputs an image signal from the control unit 160. Projection unit 20
The image from is projected from behind the screen 1 via the reflecting mirror 40. Further, in this example, the illumination light is supplied to the projection unit by the optical fiber 41 from the light source provided in the lamp box (not shown).

FIG. 3 shows an example of the screen 1 according to the present invention. Projection units 20a, 20b
Include illumination optics 21a, 21b, liquid crystal panel 22a,
22b and projection lenses 23a and 23b are provided.
The illumination optical units 21a and 21b are for illuminating the liquid crystal panel, and the projection lenses 23a and 23b are lenses that project an image from the liquid crystal panel onto the screen 1 via the exit pupils 24a and 24b. The screen 1 includes a plurality of partial Fresnel lenses (also simply referred to as Fresnel lenses) 11 a, 11 b, a transparent spacer 12, and a diffusion plate 13.
It is composed of The focus positions of the Fresnel lenses 11a and 11b are the exit pupils 24 of the projection lenses 23a and 23b.
It is assumed to be near a and 24b. Projection lens 23a,
The projection image from 23b may be emitted as a divergent light beam from the exit pupils 24a and 24b. Exit pupil 2
The divergent light fluxes from 4a and 24b are the Fresnel lens 11
By entering the light beams a and 11b, they are converted into substantially parallel light beams, pass through the transparent spacer 12, and form an image on the diffusion plate.

FIG. 4 is for explaining the function and effect of the transparent spacer 12 in the structure of the screen 1 according to the present invention. By providing the transparent spacer 12 between the Fresnel lenses 11a and 11b and the diffusing plate 13, the outermost light fluxes F and G that form the projection image incident on the Fresnel lenses 11a and 11b are provided to form a plurality of images. It becomes possible to guide the outermost light fluxes F and G to the continuous positions of the diffusion plate 13 without being incident on the borders between the adjacent plurality of Fresnel lenses 11a and 11b that are adjacent to each other. The outermost light fluxes F and G have a width W on the Fresnel lenses 11a and 11b.
Incident. Fresnel lens 11a, 11b,
The outermost light fluxes F and G are converted into substantially parallel light fluxes, but in the present embodiment, instead of utilizing perfect parallel light fluxes, as shown by light F1 and G1 indicated by arrows, they are completely parallel light fluxes. Utilizes unconverted light. Lights F1 and G1 have a width U
Is output from the Fresnel lenses 11a and 11b. Light F output from the Fresnel lenses 11a and 11b
Similarly, 2 and G2 are not perfect parallel light fluxes and are emitted in directions approaching each other. Light F2 applied to the diffusion plate 13
And G2 will have a width V. If this width V is the same as the pitch for displaying pixels, images can be displayed continuously. The transparent spacer 12 is for making the lights F2 and G2 have a width V. That is, the transparent spacer 12
The width V can be adjusted by changing the thickness D. The transparent spacer 12 includes the Fresnel lens 11a,
The output width U of 11b is converted into the pixel width V displayed on the diffusion plate 13. By adjusting the thickness D of the transparent spacer 12, the conversion rate from the width U to the width V can be adjusted.
As a result, the width W at which the outermost light fluxes F and G are incident can be adjusted. That is, by providing the transparent spacer 12, the irradiation position of the outermost light fluxes F and G is changed to the Fresnel lens 11
It is not necessary to make the incident just near the boundary between a and 11b. As described above, by providing the transparent spacer 12, a margin for image formation can be provided between the emission surface of the Fresnel lenses 11a and 11b and the diffusion plate. In addition, the outermost light fluxes F and G do not enter just near the boundary between the Fresnel lenses 11a and 11b, and it is possible to eliminate joints generated from the joint portion of the Fresnel lenses. Then, by adjusting the positions of the projection units 20a, 20b and the projection lenses 23a, 23b, the positions between adjacent projected images can be easily adjusted.

The Fresnel lenses 11a and 11b are lenses that convert a divergent light beam into a substantially parallel light beam. In this embodiment, the Fresnel lenses 11a and 11b cannot completely convert the divergent light beam into a parallel light beam. The feature is that it is positively utilizing not converting. FIG.
Lights F1 and G1 shown in FIG.
In the above, the divergent light flux is not converted into a parallel light flux or is not converted into a parallel light flux. As described above, the transparent spacer 12 is provided in order to display continuous pixels by using light that is not converted into a perfect parallel light beam or is not converted. An adhesive or a bonding agent exists between the Fresnel lenses 11a and 11b. Also, Fresnel lens 11
If the manufacturing precision of a and 11b is not high, a space may be generated between the Fresnel lenses 11a and 11b. That is, the boundary between the Fresnel lenses 11a and 11b is considered to be a portion that does not function as a Fresnel lens, and it is desirable to use the boundary between the Fresnel lenses 11a and 11b as little as possible. Also,
The positions of the projection unit and the projection lens must be adjusted accurately in order to allow the light to enter the border of the Fresnel lenses 11a and 11b. In this embodiment, the images can be continuously displayed on the screen without using the boundary portion between the Fresnel lenses 11a and 11b.

In this embodiment, as described above, the light that is not converted into a parallel light beam is positively utilized, so that the Fresnel lenses 11a and 11b of this embodiment are used.
It is preferable to convert the light incident on the boundary portion into a parallel light flux rather than converting it into a parallel light flux, rather than converting it into a parallel light flux, such as the lights F1 and G1 shown in FIG. Fresnel lenses 11a and 11b of this embodiment
May be manufactured in advance in this way. That is, the Fresnel lenses 11a and 11b of this embodiment
May be manufactured so as to simply change the optical path, instead of converting the light incident on the peripheral portion into a parallel light flux. Alternatively, the Fresnel lenses 11a and 11b are manufactured and placed in the same manner as in the conventional case so as to convert a divergent light flux into a parallel light flux, and the exit pupils 24a and 24 of the projection lenses 23a and 23b are positioned more than the focal positions of the Fresnel lenses 11a and 11b.
b may be placed at a position close to the Fresnel lens 11a, 11b side. The exit pupils 24a, 24a of the projection lenses 23a, 23b are located farther than the focal positions of the Fresnel lenses 11a, 11b.
When 24b is near the Fresnel lenses 11a and 11b, the divergent light flux emitted from the exit pupils 24a and 24b is
The Fresnel lenses 11a and 11b convert the light beam into a light beam whose divergence angle is weakened. Therefore, as shown in FIG. 4, the outermost light fluxes F and G are emitted from the Fresnel lenses 11a and 11b as divergent light fluxes whose optical paths have been slightly changed, and the same operation as that of the above-described embodiment. Have an effect.

FIG. 5 shows an example of a projected image according to the present invention. In this example, the 2 × 2 portion of the central portion of the 4 × 4 image is shown. By providing the transparent spacer 12, the pixels forming the adjacent images of the projected image 1 to the projected image 4 can be continuously connected at the same pitch.

FIG. 6 is a diagram showing another example of the screen according to the present invention. The difference between the configuration shown in FIG. 6 and the configuration shown in FIG. 4 is that a space is provided instead of inserting the transparent spacer 12 in order to make a gap between the Fresnel lenses 11a and 11b and the diffusion plate 13. . By providing this space, a plurality of Fresnel lenses 11a, 1a provided for forming a plurality of images are formed on the outermost light flux that forms a projection image that is incident on the Fresnel lens.
It is possible to guide the light to the continuous position of the diffusion plate 13 without making the light incident on the borders of the adjacent 1b.

FIG. 7 is a diagram showing another example of the screen according to the present invention. The difference between the configuration shown in FIG. 7 and the configuration shown in FIG. 4 is that the transparent spacer 12 and the diffusion plate 13 are integrated into a diffusion plate 15. The transparent spacer and the diffuser plate can be made of acrylic, for example. A transparent spacer and a diffuser plate can be integrally manufactured by forming a diffusing portion in which a diffusing agent is mixed in transparent acrylic and a transparent portion 15a that remains transparent. As described above, the transparent portion 1 is provided on the incident side of the diffusion plate 15.
By providing 5a, the outermost light flux that forms the projection image that enters the Fresnel lens does not enter the boundary between adjacent Fresnel lenses 11a and 11b that are provided to form a plurality of images. Diffuser 1
It becomes possible to lead to three consecutive positions.

FIG. 8 is a diagram showing another example of the screen of the present invention. The difference between the configuration shown in FIG. 8 and the configuration shown in FIG. 7 is that Fresnel lenses 11a and 11b are integrated with the transparent portion 15a of the diffusion plate 15 provided with the transparent portion 15a. As described above, by providing the transparent portion 15a on the incident side of the diffusion plate 15, the outermost light flux forming the projection image incident on the Fresnel lens is provided with the plurality of Fresnel lenses 11a provided for forming the plurality of images. , 1
It is possible to guide the light to the continuous position of the diffusion plate without making the light incident on the borders of the adjacent 1b. Further, by integrating the Fresnel lens, the transparent spacer, and the diffuser plate, it is possible to eliminate the two interfaces of the interface between the Fresnel lens and the transparent spacer and the interface between the transparent spacer and the diffuser plate, and to eliminate the reflection that occurs at these interfaces. be able to. Moreover, since the number of parts can be reduced by integrating, the screen can be made inexpensive.

By providing an antireflection film on both sides (total of 6 places) of each of the Fresnel lens, the transparent spacer and the diffusion plate constituting the above screen, a projected image with better contrast and less loss of light quantity can be obtained. .
Further, an antireflection film may be provided at two places on both sides of the screen or / and at two borders between the Fresnel lens, the transparent spacer and the diffusion plate. Alternatively, an antireflection film may be provided at any one position.

FIG. 9 is a diagram showing an example of the multiple Fresnel lens of the present invention. FIG. 10 is a diagram showing an example of manufacturing the one-dimensional Fresnel lens array of the present invention. Fresnel lenses are usually manufactured using a mold. For example, it is produced by pressing plastics using a mold, ultraviolet curing of liquid plastic, or the like. Since one Fresnel lens has a concentric sawtooth shape, it must be peeled from the periphery of the Fresnel lens when the Fresnel lens is removed from the mold. In the multiple Fresnel lens according to the present invention, as shown in FIG. 10, the molds are connected in the lateral direction to manufacture a strip-shaped one-dimensional Fresnel lens array integrally manufactured. Then, the strip-shaped one-dimensional Fresnel lens array produced integrally is bonded to form a two-dimensional array. When removing the Fresnel lens from the mold, as shown in FIG. 10, a force is applied in the direction of arrow H to peel it off. If the Fresnel lens is peeled from the mold by applying a force in the direction of arrow I, in the sawtooth region S,
Although it can be peeled off cleanly, it cannot be peeled off in the serrated portion R, which may damage the serrated teeth. Therefore, when the two-dimensionally arranged molds are used to manufacture the two-dimensionally arranged Fresnel lenses at one time, it becomes impossible to remove the Fresnel lenses from the mold. In this embodiment, FIG.
As shown in, since the molds are connected in the one-dimensional direction,
By applying force in the direction of arrow H, the Fresnel lens can be removed from the mold. The reason why the Fresnel lens is integrally molded in the horizontal direction and then bonded in the vertical direction to form a two-dimensional array is that the seams are more in the horizontal direction than in the vertical direction due to the visual characteristics of the eyes. Is hard to see,
This is because it can be a multi-image display device with small joints.

FIG. 11 shows a method of fixing the Fresnel lens of the present invention. When a plurality of partial Fresnel lenses provided corresponding to a plurality of projection units are integrated, they are orthogonal to each other and pass through the center of the integrated Fresnel lens.
The integrated Fresnel lens is fixed on the reference lines C1 and C2 of the book. That is, the integrated Fresnel lens is fixed at the center of each side of the integrated Fresnel lens. The integrated Fresnel lens is provided with 103, which is 1
Reference line C1 and C from cabinet 101 to 03
Along axis 2, shaft 104 is engaged. FIG. 12 is a diagram showing the expansion and contraction state of the Fresnel lens when the integrated Fresnel lens is fixed on the reference lines C1 and C2. In this way, by fixing the Fresnel lens, even if the Fresnel lens expands or contracts due to temperature changes or the like, two orthogonal reference lines can be secured, so the position of the projected image in the central portion does not change. The center position of the Fresnel lens in the peripheral part moves due to temperature change, causing a deviation from the optical axis of the corresponding projection unit, and the projection image from the projection unit is obliquely incident on the Fresnel lens, but the angle is It is smaller than when there is a reference line in the peripheral part of the converted Fresnel lens, and the position change of the image projected on the diffusion plate can be ignored. For example, when the focal length of the Fresnel lens is 260 mm and the temperature change is 20 degrees, the change in projection angle is 3.7 mrad, and when the thickness of the transparent spacer is 1 mm, the amount of movement of the projected image is 3.
Only 7 μm. The amount of movement of this projection image is shown in FIG.
When the distance W between the outermost light fluxes F and G shown in (1) is 1/2 or less, for example, the outermost light flux F is not incident on the Fresnel lens 11b. Alternatively, the outermost light flux G does not enter the Fresnel lens 11a. That is, crosstalk does not occur. In this invention, since the transparent spacer is inserted between the Fresnel lens and the diffuser plate, it is not necessary to irradiate the outermost light fluxes F and G to the boundary of the Fresnel lens, and even if the Fresnel lens expands or contracts due to temperature change, Since the outermost light fluxes F and G are not emitted just near the boundary of the Fresnel lens, the projected image does not go around to the adjacent Fresnel lens. Further, by fixing the integrated Fresnel lens at the center of each side in this way, the amount of change is halved even if the temperature changes, so that a multi-image display without joints can be obtained.

FIG. 13 shows an adjusting mechanism of the projection unit according to the present invention. The projection unit is attached via an adjustment stage 150 attached to the cabinet 101, which is independently movable in the X-axis, Y-axis, and Z-axis, an attachment arm 151, and a goniometer stage 152 attached to the attachment arm. The adjustment stage 150, which can be independently moved in each of the X axis, Y axis, and Z axis, moves the projection image from the projection unit in parallel in the X and Y directions with respect to the surface of the screen 1, and moves back and forth in the Z direction. By doing so, the size of the projected image is set to a predetermined size. Gonio Stage 152
Has a function of rotating the projection image from the projection unit in the θ direction with respect to the optical axis L of the projection unit and rotating the projection image in the ψ direction with respect to the axis M perpendicular to the optical axis L. By adjusting the five axes X, Y, Z, L, and M, it is possible to connect a plurality of images projected on the screen 1 without joints.

Further, the adjusting stage 150 and the goniometer stage 152 are always operated by the sensor from the sensor (not shown) that senses the boundary between the adjacent projection images when the position of the Fresnel lens is moved due to temperature change. The optical axis of the Fresnel lens corresponding to the optical axis is controlled to match. In this way, by applying feedback control to the projection unit, even if the position of the Fresnel lens moves due to temperature change, joints are not generated at the boundary between adjacent images, and continuous multi-images can be obtained.

In the above embodiment, the liquid crystal panel 2 is used.
The case where only one 2a is arranged inside the projection unit has been described, but a case where a plurality of liquid crystal panels are arranged inside one projection unit is also possible. For example,
It does not matter even in the case of a projection unit in which liquid crystal panels are arranged for red, blue, and green, respectively, and these are combined to generate an image.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a multi-image display device of the present invention when viewed from the front.

FIG. 2 is a perspective view showing an example of the multi-image display device of the present invention when viewed from the back side.

FIG. 3 is a diagram showing an example of a screen of the present invention.

FIG. 4 is a diagram for explaining the function and effect of the transparent spacer 12 in the configuration of the screen 1 according to the present invention.

FIG. 5 is a diagram showing an example of a projected image according to the present invention.

FIG. 6 is a diagram showing another example of the screen according to the present invention.

FIG. 7 is a diagram showing another example of a screen according to the present invention.

FIG. 8 is a diagram showing another example of a screen according to the present invention.

FIG. 9 is a diagram showing an example of a multiple Fresnel lens of the present invention.

FIG. 10 is a diagram showing a manufacturing example of the one-dimensional Fresnel lens array of the present invention.

FIG. 11 is a diagram showing a method of fixing the Fresnel lens of the present invention.

FIG. 12 is a diagram showing expansion and contraction of the Fresnel lens when the Fresnel lens fixing method of the present invention is used.

FIG. 13 is a diagram showing an adjusting mechanism of the projection unit of the present invention.

FIG. 14 is a diagram showing an image display device using a conventional CRT.

FIG. 15 is a diagram showing a multi-image display device using a conventional CRT.

FIG. 16 is a diagram showing a conventional multi-image display device using liquid crystal.

FIG. 17 is a diagram showing a conventional screen.

FIG. 18 is a diagram illustrating the operation of a Fresnel lens.

FIG. 19 is a diagram for explaining the operation of the Fresnel lens.

FIG. 20 is a diagram illustrating an operation when a Fresnel lens is used.

FIG. 21 is a diagram showing an example of a conventional projected image.

FIG. 22 is a front view of the Fresnel lens when the Fresnel lens expands and contracts due to temperature change and the like.

FIG. 23 is a diagram showing a screen cross section for explaining a movement of a light beam in the vicinity of an adjacent Fresnel lens when the Fresnel lens expands and contracts due to temperature change or the like.

[Explanation of symbols]

1 screen, 11 Fresnel lens, 12 transparent spacer, 13 diffuser plate, 14 space, 15 spacer integrated diffuser plate, 20 projection unit, 21 illumination optical part, 22 liquid crystal panel, 23 projection lens, 24 exit pupil, 100 multi-image display device , 101 cabinet, 150 adjustment stage, 151 mounting arm,
152 Gonio Stage.

Claims (10)

[Claims] 1. A multi-image display device comprising: a plurality of projection units for generating partial images forming a part of an image; and a screen for combining and displaying partial images generated by the plurality of projection units. The screen is composed of a plurality of partial Fresnel lenses provided corresponding to a plurality of projection units and one diffuser plate containing a diffusion material, and the plurality of partial Fresnel lenses and the diffuser plate are combined. A multi-image display device characterized in that a space of a certain length is provided between them. 2. The multi-image display device according to claim 1, wherein one transparent spacer is provided between the plurality of partial Fresnel lenses and the diffusion plate. 3. The multi-image display device according to claim 2, wherein the transparent spacer and the diffusion plate are integrated. 4. The multi-image display device according to claim 1, wherein the plurality of partial Fresnel lenses are integrated. 5. The multi-image display device according to claim 2, wherein the plurality of partial Fresnel lenses, the transparent spacer, and the diffusion plate are integrated. 6. The multi-image display device according to claim 2, wherein an antireflection film is applied to all or part of the plurality of partial Fresnel lenses, the transparent spacers, and the diffusion plate. 7. The multi-image display device according to claim 4, wherein the integrated Fresnel lens is fixed at the center of each side of the integrated Fresnel lens. 8. The length of the space is set so that the plurality of images generated from the plurality of projection units enter only the corresponding Fresnel lenses, respectively. The multi-image display device described in 1. 9. The multi-image display device according to claim 1, wherein the projection unit is provided with an adjusting mechanism in a plurality of axial directions. 10. The adjusting mechanism controls the optical axis of the projection unit so that the optical axis of the projection unit coincides with the optical axis of the partial Fresnel lens corresponding to the projection unit. 9. The multi-image display device according to item 9.