JP2997588B2 - Multi-projection display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-projection type display device which forms a large screen by a plurality of projection type liquid crystal display devices.

[0002]

2. Description of the Related Art Heretofore, there has been commercialized a projection type liquid crystal display device in which image light is transmitted using a liquid crystal panel as a light valve and enlarged and projected on a screen by a projection lens. FIG. 15 is an explanatory diagram showing such a projection type liquid crystal display device (hereinafter, also referred to as a liquid crystal projector).

A high frequency (RF) signal induced in an antenna 8 is supplied to a tuner 6 to demodulate a signal of a predetermined channel. The demodulated video signal is video-processed in the video signal processing circuit 7, amplified, and supplied to the liquid crystal panel 3. The liquid crystal panel 3 has pixels divided into a large number in the vertical and horizontal directions, and a liquid crystal (not shown) in the liquid crystal panel 3 is controlled between a transparent state and a light-shielded state by an applied voltage supplied to electrodes corresponding to each pixel. I do. By supplying the video signal from the video signal processing circuit 7 as the applied voltage, the transparency of each pixel is based on the video signal, and the video can be projected on the liquid crystal panel 3.

On the other hand, a light beam 9 generated from the light source 1 is condensed by the reflector 2 and enters the liquid crystal panel 3. As the light source 1, a discharge lamp such as a metal halide having high efficiency, high luminance and high color rendering properties is employed. The light from the reflector 2 passes according to the transparency (transmittance) of each pixel of the liquid crystal panel 3 and is enlarged and projected on the screen 5 by the projection lens 4 as image light. Thus, a multi-screen image is formed on the screen 5.

[0005] In recent years, powerful large-screen images have been oriented, and display devices have been increasing in size. The liquid crystal projector can project a large screen image by increasing the projection distance and increasing the projection magnification. However, if the projection distance is increased, the size of the device increases. Further, when the enlargement ratio is increased, the conspicuousness of pixels becomes remarkable, so that it is necessary to use a liquid crystal panel with higher definition.

Therefore, a plurality of liquid crystal projectors are used, a part of the screen (small screen) is displayed on each liquid crystal projector, and the small screens are connected to form a single parent screen (multi-screen). Multi-projection display devices have been commercialized. FIG. 16 is an explanatory diagram for explaining a conventional multi-projection display device. FIG. 17 is an explanatory diagram showing the configuration of a conventional multi-projection display device.
17A is a front view, FIG. 17B is a side view, and FIG. 17C is a top view.

As shown in FIG. 16, a multi-screen 12 displayed on a screen 11 is formed by joining two small screens PL and PR. The small screens PL and PR are displayed by optical boxes (projectors) 13a and 13b. The optical boxes 13a and 13b have the same configuration as the liquid crystal projector shown in FIG.
a, 4b, etc. Optical boxes 13a, 13b
Is an optical axis 15 passing through the center of each liquid crystal panel 3a, 3b.
In a state where a and 15b are parallel to each other, they are horizontally arranged in a line in a housing 16 as shown in FIG. The screen 11 is mounted on the front of the housing 16, and the optical box 13a,
By projecting the projection lights 14a and 14b from the screen 13b from the back side of the screen 11, a projected image can be observed from the front side of the screen 11. Each optical box 13
a and 13b are arranged such that the projection lights 14a and 14b are continuously projected on the screen 11 without any gap. Also,
In some cases, the adjacent small screens PL and PR are slightly overlapped and displayed.

In the conventional multi-projection display device having the above-described configuration, the projection magnification of each of the optical boxes 13a and 13b can be set to a relatively small value. Therefore, the projection distance from each of the projection lenses 4a, 4b to the screen 11 can be reduced, the device can be reduced in size, and the noticeable pixels can be suppressed. In FIG. 17, video light is projected in parallel in the horizontal direction by the optical boxes 13a and 13b, and an image having a size twice as large in the horizontal direction as a single screen can be obtained at the same projection magnification.

In general, the aberration of a lens is worse at the periphery than at the center. In addition, the amount of light in the peripheral portion of the lens is lower than that in the central portion in accordance with the cosine fourth law of the aperture efficiency. FIG. 18 is an explanatory diagram for explaining a problem due to these effects. FIG. 19 is a graph showing the cosine fourth law, with the horizontal axis representing the angle ω with respect to the optical axis and the vertical axis representing the efficiency.

A projection lens 4 is provided between the liquid crystal panel 3 and the screen 5. Image light from liquid crystal panel 3
10 enters the projection lens 4 and projects the projection light 14 on the screen 5. A projection image 17 indicated by oblique lines is formed on the screen 5 by the projection light 14. In this case, the light that has passed through the center a, left b and right c of the projection lens 4 is projected onto the center a ', right c' and left b 'on the screen 5, respectively. The distortion of the projected image 17 is greater at the peripheral portions b 'and c' than at the central portion a 'due to the influence of aberration.

As shown in FIG. 19, as the angle ω between the optical axis 15 and the projection light 14 increases, the efficiency decreases.
That is, the light quantity of the projected image 17 on the screen 5 decreases from the central part a 'intersecting the optical axis 15 to the peripheral parts b' and c '. As described above, the peripheral portion of the projection image 17 has a larger distortion and a lower light amount than the central portion.

FIG. 20 and FIG. 21 are explanatory diagrams for explaining the problem of the multi-screen display.

The projection light from each optical box is screened.
Each of the small screens PR and PL is projected by projecting from the back side of 11. As described above, as the distance from the center of the optical axis of each projection light decreases, the amount of light and the distortion of the projection image formed by each projection light increase. For this reason, as shown in FIG.
The vicinity of each central portion (portion surrounded by a broken line) 18a, 18b of each of the small screens PR, PL becomes higher in brightness than each peripheral portion (hatched portion). If the area near the center of the screen is brighter than the periphery, such as on a single screen,
The change in brightness is not so noticeable to the observer. However, as shown in FIG.
When it occurs at two places relatively distant from the center in the horizontal direction of 11, the change in brightness is conspicuous, the connection between the small screens PR and PL becomes unnatural, and the deterioration of the image quality is remarkably recognized. Problem.

Further, distortion is large in the peripheral portion of the projected image of each of the small screens PR and PL. The broken line in FIG. 21 indicates the distortion of the projected image, and the matching at the connection between the small screens PR and PL is extremely poor. Moreover, since the small screens PR and PL are connected at the left and right central portions of the multi-screen 11, there is a problem that the quality of the multi-screen is significantly deteriorated.

FIG. 22 is an explanatory diagram showing a conventional multi-projection display device using four liquid crystal projectors. 22 (a) is a front view, FIG. 22 (b) is a left side view, FIG. 22 (c) is a right side view thereof, and FIG. 22 (d) is a top view thereof.

The multi-screen 22 on the multi-screen 21 is composed of four small screens PRD, PRU, PLD, PLU connected vertically, horizontally and vertically.
Formed by The optical boxes 13a to 13d are shown in FIG.
The liquid crystal projector has the same configuration as that of the liquid crystal projector described above, and is disposed adjacent to the upper, lower, left, and right in the housing 23. The small screens PRD, PLD, PRU, and PLU are formed by the projection lights 14a to 14d projected from the projection lenses 4a to 4d, respectively.

FIGS. 23 and 24 are explanatory views for explaining the display on the multi-screen in FIG.

As described above, each of the optical boxes 13a to 13a
The images projected by the projection lights 14a to 14d from 13d have large distortion at the periphery and low peripheral light amount. Therefore, as shown in FIG. 23, small screens PRD, PLD, PRU, PRU
The portions 24a to 24d near the center of the LU (portions surrounded by broken lines) are brighter than the peripheral portions (shaded portions). That is, the brightness distribution of the multi-screen is not uniform, and bright portions are generated at four locations. For this reason, it becomes easy for an observer to recognize the image as having a lot of uneven brightness.

As shown by the broken line in FIG. 24, since the distortion of the peripheral portion of the projected image of each of the small screens PRD, PLD, PRU, and PLU is large, the connection among the small screens PRD, PLD, PRU, and PLU is large. In some parts, the matching deteriorates, and the quality of the multi-screen deteriorates significantly.

By the way, as a screen, a Fresnel screen having a Fresnel lens formed on the exit surface side is employed in order to focus the projection light on an observer in front of the screen. FIG. 25 is an explanatory diagram for describing a Fresnel screen used in a four-screen multi-screen.

The Fresnel lens 25 has the effect of a protruding lens formed by concentric grooves formed on the screen exit surface, and has the effect of condensing light in the peripheral portion (dark portion) to brighten the entire screen. I have. Therefore, Fresnel lens 25
Needs to be formed in a shape corresponding to the brightness distribution of the screen. As shown in FIG. 25, the four-screen multi-screen 21 is formed in a concentric shape centered on the light portion of each of the small screens PRD, PLD, PRU, and PLU. are doing. That is, the Fresnel lenses 25 are formed by being dispersed at four positions of the multi-screen 21.
With the current screen manufacturing technology, it is extremely difficult to form a Fresnel lens by dispersing it in four places on one screen, and therefore, the four screens 21a to 21d on which the Fresnel lens 25 is formed are joined together to form a Fresnel lens. Since a plurality of multi-screens 21 are formed, the productivity is extremely poor.

[0022]

As described above, in the above-described conventional multi-projection display device, the luminance on the screen is reduced due to the distortion at the peripheral portion of each projected image by a plurality of liquid crystal projectors and the decrease in the amount of projected light. There is a problem that the unevenness and the consistency of the connection portion of each small screen are deteriorated, and the screen quality is significantly deteriorated. In addition, since the bright portion is dispersed at the center of each small screen, there is a problem that a multi-screen in which a plurality of screens each having a Fresnel lens formed thereon are joined must be used.

According to the present invention, there is provided a multi-projection display device capable of improving the screen quality of a multi-screen by improving the luminance unevenness and distortion characteristics, and improving the productivity by forming the multi-screen with one screen. The purpose is to provide.

[0024]

A multi-projection display device according to the present invention comprises a plurality of projection lenses for enlarging and projecting each incident light on a multi-screen to form each small screen, and a light from a light source device. Is converted into image light, and the image light is emitted from the emission surface to the plurality of projection lenses as the incident light, and passes through the center of the multi-screen to each optical axis of the projection lens. A plurality of liquid crystal light valves in which the center of each emission surface is shifted in a parallel axis direction,
Thus, a plurality of optical boxes are formed, and these optical boxes are appropriately arranged on the multi-screen to display a multi-screen connecting the small screens on the multi-screen.

[0025]

In the present invention, the center of the exit surface of the liquid crystal light valve passes through the center of the multi-screen and is shifted in the axial direction parallel to each optical axis of the projection lens. Therefore, the optical box constituted by the liquid crystal light valve and the projection lens can project the projection light deviated from the optical axis. That is, one side near the optical axis of each projection light has a larger projection light amount and smaller distortion than the other side. By projecting one side of each projection light on the center side of the multi-screen, it is possible to increase the luminance of the projection light image near the center of the multi-screen and reduce distortion. Thereby, the screen quality of the multi-screen is improved.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing one embodiment of an optical system of a multi-projection display device according to the present invention. This embodiment is 2
This is applied to a two-plane multi-projection device using two projectors.

Light from a light source (not shown) is applied to a liquid crystal panel 31.
a, 31b. The liquid crystal panels 31a and 31b are supplied with video signals from a video signal processing circuit (not shown), and convert incident light into video lights 34a and 34b by changing the transmittance of each pixel based on the video signals. The light exits from the exit surface. Image lights 34a and 34b from the liquid crystal panels 31a and 31b are incident on the projection lenses 4a and 4b, and the projection lenses 4a and 4b project the projection lights 32a and 32b from the exit surface onto the multi-screen 33.

In this embodiment, the liquid crystal panels 31a, 31b
Is an optical axis 15 passing through the centers of the projection lenses 4a and 4b, respectively.
a, 15b in the direction in which the center of the exit surface approaches each other, that is, through the center of the multi-screen 33, the optical axis 15b.
a and 15b are shifted in the axial direction parallel to the positions. FIG. 2 is an explanatory diagram for explaining the arrangement of the liquid crystal panel and the projection lens with respect to the optical axis. FIG. 2 shows only one optical system composed of the liquid crystal panel 31a and the projection lens 4a, but the configuration of the other optical system composed of the liquid crystal panel 31b and the projection lens 4b is the same.

As shown in FIG. 2, the center a of the projection lens 4a is located on the optical axis 15a. The liquid crystal panel 31a is disposed such that the center of the emission surface is located at a position shifted from the optical axis 15a, and both ends of the liquid crystal panel 31a face the leftmost part b and the right part c of the projection lens 4a, respectively. . Video light 34a
Is incident between the leftmost part b and the right part c of the projection lens 4a. As a result, the projection light 32a from the projection lens 4a forms an image between the right part c 'and the left part b' on the multi-screen 33 to form a projection light image 35 indicated by oblique lines.

Since the range of the image light 34a incident on the projection lens 4a is not symmetrical with respect to the optical axis 15a and is shifted leftward when viewed from the screen 33 side, the image forming range of the projection light image 35 is multi-screen 33. Are not symmetrical with respect to the intersection of the screen 33 and the optical axis 15a, and are formed so as to be shifted to the right as viewed from the front side of the screen 33. Similarly, a projection light image (not shown) by the projection light 32b from the projection lens 4b is formed shifted to the left of the optical axis 15b when viewed from the front side of the multi-screen 33.

FIG. 3 is a top view showing a multi-projection type display device having a pair of optical boxes incorporating these optical systems. In FIG. 3, a conventional multi-projection display device is indicated by a broken line.

The front surfaces of the pair of housings 36a and 36b are open, and the multi-screen 33 is attached to the opening.
Optical boxes 37a, 37b are provided on the rear side of each housing 36a, 36b.
Is arranged. The optical box 37a includes a light source (not shown), the liquid crystal panel 31a shown in FIG. 1, the projection lens 4a, and the like. Similarly, the optical box 37b includes a light source (not shown) and the liquid crystal panel 31b and the projection lens 4b shown in FIG.
And so on. Whereas the conventional optical boxes 13a and 13b (see FIG. 16) indicated by broken lines are disposed at positions substantially corresponding to the centers of the left and right small screens PR and PL of the multi-screen 33, respectively, in this embodiment, , Optical box
37a and 37b are arranged at positions corresponding to the vicinity of the center of the multi-screen 33.

Although the image forming range of the projection light image by the conventional optical boxes 13a and 13b is symmetric with respect to the optical axis, as described above, the projection light 32 from the optical box 37a of this embodiment is used.
The image formation range of the projection light image by a is shifted to the right side with respect to the optical axis when viewed from the front side of the screen 33, and the image formation range of the projection light image by the projection light 32b from the optical box 37b is
It is shifted leftward with respect to the optical axis when viewed from the front side of the screen 33. For this reason, by arranging the optical boxes 37a and 37b so as to face each other near the center of the multi-screen 33,
The small screens PR and PL by the projection lights 32a and 32b are connected to the left and right centers of the multi-screen 33 to form a multi-screen on the entire surface of the screen 33.

Next, the operation of the embodiment configured as described above will be described with reference to FIGS. 2, 4 and 5. FIG. 4 and 5 show the display on the multi-screen 33. FIG.

In FIG. 2, the image forming range of the projection light image 35 is shifted to the right with respect to the intersection between the screen 33 and the optical axis.
That is, the image forming position b 'on the screen 33 corresponding to the right portion c of the projection lens 4a is relatively close to the intersection between the optical axis 15a and the screen 33. Further, the image forming position c 'corresponding to the leftmost portion b of the projection lens 4a is relatively far from the intersection between the optical axis 15a and the screen 33. Therefore, in the vicinity of the image forming position b ', the projection light amount is large and the distortion is small. Similarly,
The imaging position of the projection light image from the left side of the projection lens 4b is the optical axis.
It is relatively close to 15b, and the amount of projection light in the vicinity is large, and the distortion is small.

That is, the portion where the projection light images by the projection lights 32a and 32b from the projection lenses 4a and 4b are connected, that is, the vicinity of the portion where the small screens PR and PL are connected by the optical boxes 37a and 37b (enclosed by a broken line in FIG. 4). (A shaded portion) 39, the brightness becomes higher than that of the peripheral portion (shaded portion). As described above, the high-luminance portion of the projection light image appears at one location substantially at the center of the multi-screen 33. It is a relatively natural brightness distribution where the center of the multi-screen 33 is bright and the periphery is dark,
Screen quality is improved.

The image forming position c 'in FIG. 2 has a large distortion since it is relatively far from the intersection of the optical axis 15a and the screen 33, but the image forming position b' has a small distortion. FIG. 5 shows the distortion by a broken line. The distortion is large at the periphery of the multi-screen 33 corresponding to the imaging position c ', but small at the center of the multi-screen 33 corresponding to the imaging position b'. That is, since the distortion at the joint portion between the small screens PR and PL is small, a multi-screen with good matching can be formed.

As described above, in the present embodiment, the liquid crystal panels 31a and 31b are shifted from the optical axes 15a and 15b so that the image forming positions of the projection lights 32a and 32b are set to the optical axis. And the projected light 32a, 32b is connected near the optical axis.
One central portion of the multi-screen 33 has high brightness, and the distortion at the center of the multi-screen 33 is reduced to improve consistency. For this reason, a natural image can be obtained as compared with the related art, and the screen quality is improved. Also, as shown in FIG.
The optical boxes 37a and 37b can be arranged closer to each other than before, and the apparatus can be reduced in size.

FIG. 6 is an explanatory diagram for explaining a multi-projection display device according to another embodiment of the present invention. The present embodiment is applied to a four-surface multi-projection device using four optical boxes. FIG. 6 schematically shows the projection lenses 4a to 4d and the liquid crystal panels 31a to 31d viewed from four light sources (not shown).

An optical box 37a is constituted by the liquid crystal panel 31a and the projection lens 4a, etc., an optical box 37b is constituted by the liquid crystal panel 31b and the projection lens 4b, and an optical box 37c is constituted by the liquid crystal panel 31c and the projection lens 4c. , The liquid crystal panel 31d, the projection lens 4d and the like constitute an optical box 37d. The optical boxes 37a to 37d are arranged vertically and horizontally adjacent to each other in a housing (not shown), and are arranged on a multi-screen by each projection light.
Configure a multi-screen consisting of two small screens. FIG.
In the figure, an axis passing through the center of the multi-screen and parallel to the optical axes 15a to 15d is indicated by a double circle.

Each of the optical boxes 37a to 37d is arranged such that the optical axes 15a to 15d (marked by X in FIG. 6) are parallel, and the centers of the projection lenses 4a to 4d are the optical axes 15a to 15d.
Matches. In the present embodiment, the respective liquid crystal panels 31a to 31d are arranged such that the centers of the emission surfaces thereof are shifted from the optical axes 15a to 15d in the axial direction passing through the center of the multi-screen indicated by the mark ◎.

Next, the operation of the embodiment configured as described above will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 shows the luminance distribution of the multi-screen, and FIG. 8 shows the distortion of the multi-screen by a broken line.

The light projected from each of the optical boxes 37a to 37d is projected on the multi-screen 41, and the small screens PRD, PLD,
A multi-screen 42 composed of PRU and PLU is constructed. Each liquid crystal panel 31a to 31d is multi-screened from each optical axis 15a to 15d.
The projection light from each of the projection lenses 4a to 4d is displaced in the axial direction passing through the center of
It shifts to the peripheral side of the multi-screen 42 with respect to 15a to 15d. That is, when the multi-screen 42 is formed by connecting the projection light images of the respective projection lights in the vertical and horizontal directions, the optical axes 15a to 15d intersect the screen 41 near the center of the multi-screen 42. Therefore, the small screens PRD, PLD, PRU, and PLU formed by the optical boxes 37a to 37d have high brightness near the center of the multi-screen 42 (portion surrounded by a broken line). Multi screen
A relatively natural luminance distribution is obtained in which the vicinity of the center of 42 is bright and the periphery is dark, and the image quality is improved.

The screen 41 and each of the optical axes 15a to 15d
8, the projection light is connected to form the multi-screen 42, so that the distortion is small at the center of the multi-screen 42 and large at the periphery as shown by the broken line in FIG. Since the distortion at the center is reduced, each small screen PRD, PL
The consistency between D, PRU, and PLU is improved, and the screen quality is further improved.

It is clear that this embodiment can be made smaller than the conventional four-surface multi-projection device, as in the embodiment of FIG.

FIG. 9 is an explanatory diagram for explaining a multi-screen employed in this embodiment.

In the multi-screen 41, a Fresnel lens 45 for condensing light in the peripheral portion is formed concentrically on the exit surface side. As described above, the Fresnel lens needs to correspond to the luminance distribution of the multi-screen. For this reason, conventionally, it has been necessary to form concentric Fresnel lenses dispersed at a plurality of locations on a multi-screen. However, in the present embodiment, bright portions are concentrated at one central portion of the multi-screen. Therefore, the Fresnel lens may be formed concentrically around the center of the multi-screen, that is, the center of the multi-screen 41. Because of this, multi-screen
It becomes easy to form 41 with one screen, and the productivity is remarkably improved.

The single multi-screen can also be applied to the two-surface multi-projection apparatus of the embodiment shown in FIGS.

The liquid crystal panel used in each of the above embodiments employs, for example, a twisted nematic liquid crystal. FIG. 10 is an explanatory diagram for explaining the viewing angle characteristics of the twisted nematic liquid crystal panel used in these examples.

The twisted nematic liquid crystal panel has the following features.
A liquid crystal is sealed by a pair of glass electrodes, an alignment film having a rubbing direction (alignment direction) different from each other by 90 degrees is formed on each glass electrode, and liquid crystal molecules are arranged so as to be twisted by 90 degrees between the glass electrodes. It is. FIG. 10 shows the rubbing direction (orientation direction) of the pair of glass electrodes by solid arrows when the liquid crystal panel is viewed from a direction perpendicular to the incident surface. That is, in FIG. 10, the rubbing directions are the longitudinal direction (left-right direction) of the incident surface and the vertical direction (vertical direction). In this case, the liquid crystal panel has a wide viewing angle characteristic in an oblique direction, as indicated by a broken arrow in FIG.

FIG. 11 is an explanatory view showing an embodiment in which the liquid crystal panel of FIG. 10 is applied to the four-plane multi-projection display device of FIG.

The liquid crystal panels 51a to 51d have optical axes 15a to 15d, respectively, similarly to the liquid crystal panels 31a to 31d in FIG.
It is arranged so as to deviate from the (x mark) in the direction of the axis (marked with ◎) 54 passing through the center of the multi-screen and parallel to each optical axis (marked with ◎). The rubbing directions of the liquid crystal panels 51a to 51d are determined so that the wide viewing angle direction is a straight line connecting the center of the liquid crystal panels 51a to 51d and the axis 54, as indicated by the broken arrows in the figure. I have.

FIG. 12 is an explanatory diagram for explaining the viewing angle characteristics of the multi-screen in the apparatus shown in FIG.

The projection light from the projection lenses 4a to 4d is projected on the screen 52, and the small screens PRD, PLD, PRU, PLU
Is formed. LCD panel 51a-
Since the wide viewing angle direction of 51d is the direction of the center of the liquid crystal panels 51a to 51d and the axis 54 passing through the center of the multi-screen 53, the wide viewing angle direction of the multi-screen 53 is indicated by the dashed arrow in FIG. Is the diagonal direction of the multi screen 63. This allows the observer to obtain a high-quality image in a wide range.

FIG. 13 is an explanatory view showing a modified example in which a wide viewing angle characteristic is provided to the two-surface multi-projection display device of FIG.

The liquid crystal panels 55a and 55b have respective optical axes 15a and 15b.
In contrast to this, it is arranged so as to be deviated in the direction of an axis (marked by 58) 58 passing through the center of the multi-screen and parallel to the optical axes 15a and 15b. The rubbing directions of these liquid crystal panels 55a and 55b are determined such that the wide viewing angle direction is based on the center of the liquid crystal panels 55a and 55b and the axis 58 as shown by the dashed arrow in FIG. ing.

FIG. 14 is an explanatory diagram for explaining the viewing angle characteristics of the multi-screen in the apparatus shown in FIG.

The projection light from the projection lenses 4a and 4b is projected on a screen 56 to form a multi-screen 57 composed of small screens PR and PL. Since the directions of the wide viewing angles of the liquid crystal panels 55a and 55b are directions based on the centers of the liquid crystal panels 55a and 55b and the axis 58 passing through the center of the multi-screen 57, as shown by the broken arrows in FIG. The wide viewing angle direction is a horizontal direction passing through the center of the multi-screen. This allows the observer to obtain a high-quality image in a wide range.

[0059]

As described above, according to the present invention, the brightness unevenness and distortion characteristics are improved to improve the screen quality of the multi-screen, and the multi-screen is constituted by one screen to improve the manufacturability. And has an effect that good viewing angle characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of an optical system of a multi-projection display device according to the present invention.

FIG. 2 is an explanatory diagram for explaining an arrangement of a liquid crystal panel and a projection lens with respect to an optical axis.

3 is a top view showing an example of the configuration of the multi-projection display device of the embodiment shown in FIG.

FIG. 4 is an explanatory diagram for explaining the operation of the embodiment.

FIG. 5 is an explanatory diagram for explaining the operation of the embodiment.

FIG. 6 is an explanatory diagram for explaining a multi-projection display device according to another embodiment of the present invention.

FIG. 7 is an explanatory diagram for explaining the operation of the embodiment in FIG. 6;

FIG. 8 is an explanatory diagram for explaining the operation of the embodiment in FIG. 6;

FIG. 9 is an explanatory diagram for explaining a multi-screen adopted in the embodiment of FIG. 6;

FIG. 10 is an explanatory diagram for explaining viewing angle characteristics of a twisted nematic liquid crystal panel.

FIG. 11 is an explanatory diagram showing an embodiment in which the liquid crystal panel of FIG. 10 is applied to the four-surface multi-projection display device of FIG. 6;

FIG. 12 is an explanatory diagram for explaining a viewing angle characteristic of a multi-screen in the device of FIG. 11;

FIG. 13 is an explanatory view showing a modification in which a wide viewing angle characteristic is added to the two-surface multi-projection display device of FIG. 1;

FIG. 14 is an explanatory diagram for explaining viewing angle characteristics of a multi-screen in the device of FIG. 13;

FIG. 15 is an explanatory view showing a projection type liquid crystal display device.

FIG. 16 is an explanatory diagram for explaining a conventional multi-projection display device.

FIG. 17 is an explanatory diagram showing a configuration of a conventional multi-projection display device.

FIG. 18 is an explanatory diagram for explaining a conventional problem.

FIG. 19 is a graph showing a cosine fourth law, with the horizontal axis representing the angle ω with respect to the optical axis and the vertical axis representing efficiency.

FIG. 20 is an explanatory diagram for explaining a problem of multi-screen display.

FIG. 21 is an explanatory diagram for explaining a problem of displaying a multi-screen.

FIG. 22 is an explanatory diagram showing a conventional multi-projection display device using four liquid crystal projectors.

FIG. 23 is an explanatory diagram for explaining display on the multi-screen in FIG. 22;

FIG. 24 is an explanatory diagram for explaining display on the multi-screen in FIG. 22;

FIG. 25 is an explanatory diagram for explaining a Fresnel screen used in a four-screen multi-screen.

[Explanation of symbols]

4a, 4b: Projection lens, 15a, 15b: Optical axis, 31a, 31
b: liquid crystal panel, 32a, 32b: projection light, 33: screen

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-227238 (JP, A) JP-A-3-245687 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03B 21 / 00,21 / 10 G02F 1/13 H04N 5/74

Claims (3)

(57) [Claims] 1. A plurality of projection lenses for enlarging and projecting each incident light onto a multi-screen to form each small screen to form a multi-screen by each small screen, and light from a light source device to enter an image. The image light is converted into light, and the image light is emitted from the emission surface to the plurality of projection lenses as the incident light, and passes through the center of the multi-screen in an axial direction parallel to each optical axis of the projection lens. A multi-projection display device, comprising: a plurality of liquid crystal light valves in which the centers of the emission surfaces are shifted. 2. A plurality of optical boxes, each having a liquid crystal light valve and a projection lens, for emitting each projection light for forming each small screen while being deviated with respect to each optical axis, and a center thereof. A multi-screen for displaying a multi-screen by each of the small screens by forming a Fresnel lens in a concentric shape with a center as the center; and the plurality of optical boxes such that the respective optical axes intersect the multi-screen near the center of the multi-screen. A multi-projection display device, comprising: a predetermined support member for supporting the display. 3. The multi-projection display device according to claim 1, wherein the liquid crystal light valve determines a rubbing direction based on a shape of the multi-screen.