JPH0934014A - Screen for projection type display device and projection type display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely correct unevenness of screen surface which is generated owing to the deflection, etc., of a screen shape due to machining strain, etc., improve the screen surface into an ideal shape, and prevent distortion of an image and deterioration in picture quality by adjusting the surface shape of a screen main body to a plane shape by adjusting the quantity of forward- backward movement of a screen holding means. SOLUTION: The outer peripheral part 21a of the screen main body 21 is clamped with plural pressure plates 25 fitted slidably to a fitting plate 22 and fixed with fixing screws 28, so that the screen main body 21 is fixed to the fitting plate 22. This fitting plate 22 is fixed to a base frame 23 and then the screen main body 21 is fitted to the base frame 23 while being energized toward the outer periphery with a coil spring 26. Further, the fitting plate 22 is fitted with an adjusting screw 24 for fitting angle adjustment, and the fitting angle between the base frame 23 and fitting plate 22 is adjusted according to the clamping state of the adjusting screw 24, thereby adjusting the surface shape of the screen main body 21 to have a plane shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display device for enlarging and projecting an image on a screen by using an image display device such as a liquid crystal panel, and a screen thereof.

[0002]

2. Description of the Related Art Among projection type display devices, a screen made of resin such as acrylic resin is usually used as a screen of a rear projection type display device having a large screen.

For example, as shown in FIG. 14, the screen has a resin screen main body 41 and a mounting bracket 4 attached thereto.
2 to fix it to the base frame 40, or to use a screw 43 on the base frame 40 as shown in FIG.
The one in which 1 is directly fixed is generally used.

As described above, if the screen body 41 is fixed to the base frame 40 directly or by using the mounting brackets 42, the screen body 4 changes due to changes in temperature and humidity.
1 may be distorted.

Conventionally, as a means for preventing this problem, FIG.
As shown in FIG. 6, the four sides of the screen body 41 are attached to the base frame 40 in a state in which a tensile force is urged outward using the coil springs 44 and the like, and the expansion and contraction of the screen body 41 due to changes in temperature and humidity are absorbed. The method of doing is proposed.

By the way, since the screen body 41 of the projection display device is made of a resin material such as acrylic whose thickness is very thin compared to its size, the expansion and contraction due to the temperature and humidity changes described above. Instead, the flatness of the screen surface is impaired due to processing distortion during manufacturing, and the screen is finished in a concave or convex shape with respect to the center, as shown in FIG.

A conventional projection display device, for example,
In a projection display device for enlarging and projecting an image of one liquid crystal projector onto a screen, even if the flatness of the screen surface is impaired to some extent and the shape is deformed such as a bend, the image quality is not significantly affected. It was

In recent years, a projection display device such as a pixel superposition display device or a stereoscopic display device has been developed which uses a plurality of liquid crystal projectors or a plurality of projection lenses to display projected images side by side on a screen.

[0009]

However, in a projection type display device using a plurality of liquid crystal projectors or a plurality of projection lenses, high precision is required for the shape and alignment of each projected image, such as screen processing distortion. The deterioration of the plane accuracy caused by the above-mentioned problem is that the image quality is deteriorated due to image distortion such as focus shift between the center part and the peripheral part of the screen.

Further, in order to improve the plane accuracy of the screen, it is necessary to eliminate the manufacturing variations of the screen and the deformation of the screen during transportation, and there is a cost problem in realizing these.

On the other hand, even in the screen using the coil spring 44 shown in FIG. 16, it is not possible to correct and absorb the unevenness of the screen surface caused by the processing distortion. Also,
Although it is effective in the width direction even with expansion and contraction due to temperature and humidity, it is outward (width direction) with respect to expansion and contraction in the thickness direction.
I couldn't handle it enough because I was just urging it with a pulling force.

The present invention has been made in order to solve the above-mentioned conventional problems, and it is possible to freely correct the unevenness of the screen surface caused by the distortion of the screen shape due to processing distortion, etc., and to make the screen surface ideal. The objective is to improve the shape of the image and prevent distortion of the image and deterioration of the image quality.

[0013]

A screen for a projection display apparatus according to the present invention is provided with a plurality of holding means that are movable back and forth with respect to the direction of the viewing surface of the screen. It is characterized in that the screen body is fixed to the base frame and the plane shape of the screen body is adjusted by adjusting the amount of movement of the holding means in the front and rear.

The holding means that can be moved back and forth with respect to the direction of the observation surface of the screen can be obtained by adjusting the fixed angle of the holding means with respect to the base frame holding the screen.

The holding means can be realized, for example, by fixing the outer peripheral portion of the screen with a plurality of mounting plates and fixing the mounting plates to the base frame so that the fixed angle can be adjusted. The deflection of the screen shape can be corrected by adjusting the angle of the mounting plate with respect to the base frame.

Further, the holding means may be provided with a biasing means for biasing the screen body toward the base frame.

Further, it is preferable that the holding means is further provided with a biasing means capable of expanding and contracting in the direction of the observation surface of the screen.

FIG. 1 is a schematic diagram showing the principle of screen shape correction according to the present invention. The screen in this figure is composed of a plurality of mounting plates 12 for fixing the outer peripheral portion of the screen body 11, a base frame 13 for fixing the mounting plates 12, and a means for adjusting the fixing angle of the mounting plate with respect to the base frame 13. There is.

FIG. 1A shows a case where the screen body 11 itself has a flat surface shape. From this state, as shown in FIG. 2B, when the mounting plate 12 is tilted toward the viewer side, that is, in the direction A in the figure (movement of the screen toward the viewing surface side), the surface shape of the screen body 11 is changed from the viewing surface. It deforms into a convex shape when viewed. On the contrary, as shown in FIG. 3C, when the screen is tilted in the direction opposite to the observer, that is, in the direction B in the figure (movement in the direction opposite to the observation surface of the screen), the surface shape of the screen body 11 is observed. It deforms into a concave shape when viewed from the surface.

Using this principle, when the screen body 11 itself has a concave surface shape, the surface shape of the screen body 11 can be corrected to a flat surface or a convex surface by inclining the mounting plate 12 in the A direction. Conversely, when the surface shape of the screen opposite 11 itself is convex, the surface shape of the screen body 11 can be corrected to a flat surface or a concave surface by tilting the mounting plate 12 in the B direction. In this way, by adjusting the inclination angle of the mounting plate 12 with respect to the base frame 13 according to the surface shape of the screen body 11, it is possible to eliminate the distortion of the surface shape of the screen body 11.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

The screen according to the first embodiment of the present invention will be described with reference to FIGS. 2 is a plan view showing the screen of the first embodiment of the present invention viewed from the direction opposite to the viewing surface, and FIG. 3 is the state of the screen of the first embodiment of the present invention viewed from the viewing surface direction. FIG. 4 is a cross-sectional view taken along the line AA ′ of FIG. 2, and FIG. 5 is a plan view showing essential parts of the mounting plate and the pressing plate.

As shown in FIGS. 2 to 5, the pressing plate 2
A plurality of pressing plates 25 ... Are slidably attached to the mounting plate 22 by attaching the pressing plate 25 to the mounting plate 22 with the screws 29 through the long holes 29a provided in the mounting plate 22. A coil spring 26 is stretched between the pressing plates 25 ... And the mounting plate 22, and the pressing plates 25 are urged in the outer peripheral direction.

The mounting plate 22 in this embodiment is formed such that the position where the pressing plate 25 is mounted is slightly inclined in the direction opposite to the observation surface. Also, the screen body 2
Three holding plates 25 are attached to the mounting plates 22 attached to the upper and lower sides of the unit 1, and two holding plates 25 are attached to the mounting plates 22 attached to the left and right sides. In this way, by attaching the mounting plate 22 to the base frame 23 by preliminarily inclining the mounting plate 22 and adjusting the fixing angle between the base frame 23 and the mounting plate 22, the direction of the force applied to the screen main body 21 can be changed. You are operating.

Then, the outer peripheral portion 21a of the screen main body 21 in which a diffusion plate (including a sheet-shaped one) is attached to a resin plate such as an acrylic plate is slidably attached to an attachment plate 22. The screen body 21 is fixed to the mounting plate 22 by being sandwiched by the pressing plate 25 and fixed by the fixing screw 28. In this embodiment, two mounting plates 22 are fixed on the upper, lower, left and right sides of the screen body 21, and a total of eight mounting plates 22 are mounted on the screen body 21.

As described above, since the coil spring 26 is provided between the pressing plate 25 and the mounting plate 22,
By fixing the mounting plate 22 fixed to the screen main body 21 to the base frame 23, the screen main body 21 is urged by the coil spring 26 in the outer peripheral direction so that the base frame 23
Attached to. Therefore, the expansion and contraction of the screen body 21 due to changes in temperature and humidity are absorbed.

In this embodiment, the mounting plate 22 is attached to the base frame 23 by the fixing screw 28, and the mounting plate 22 is further provided with the adjusting screw 24 for adjusting the mounting angle. The mounting angle between the base frame 23 and the mounting plate 22 is adjusted depending on the tightened state of. As described above, since the mounting plate 22 is provided with the inclination, the angle adjusting screw 24
As is tightened, the state in which the force acts in the direction opposite to the observation surface changes from the state in which no force acts on the screen to the state in which the force acts on the observation surface side.

In this embodiment, when the mounting plate 22 is fixed to the base frame 23 with the fixing screw 28 without tightening the adjusting screw 24 at all, as shown in FIG. A force acts in the direction, and the screen surface of the screen body 21 is in a concave state. From the state of FIG. 5A, loosen the fixing screw 28 and then the fixing angle adjusting screw 2
4 is tightened, as shown in FIG.
When the inclined surface of No. 2 is in a vertical state, no force acts on the screen, and when the adjusting screw 24 is further tightened, a force acts on the observation surface side as shown in FIG. 5C. .

Next, referring to FIG. 6, the screen body 2
The correction when the screen surface on the observation surface side of No. 1 is deformed into a concave surface will be described. As shown in FIG. 6A, the screen body 2 is in a state where no force is applied to the screen body 21, that is, when the inclined surface of the mounting plate 22 is vertical.
The screen surface of 1 is distorted to be concave. From this state, first, the fixing screw 28 is loosened, the adjusting screw 24 of the mounting plate 22 is tightened to adjust the mounting angle, and the adjusting screw 24 is tightened.
As shown in, the mounting plate 22 is inclined, and a force in the right direction in the drawing acts on the screen main body 21 to correct the distortion of the concave surface. In this state, the fixing screw 28 is tightened to fix the angle of the mounting plate 22. As a result, the screen surface shape on the observation surface side of the screen body 21 which is originally concave can be corrected to a flat surface.

Next, with reference to FIG. 7, description will be given of correction when the screen surface on the observation surface side of the screen main body 21 is deformed into a convex surface. As shown in FIG. 7A, when no force acts on the screen main body 21, that is, when the inclined surface of the mounting plate 22 is vertical, the screen surface of the screen main body 21 is distorted into a convex surface. From this state, first, the fixing screw 28 is loosened, and then the adjusting screw 24 of the mounting plate 22 is loosened so that the mounting angle can be adjusted, and the adjusting screw 24 is loosened.
As shown in (b), the mounting plate 22 is tilted, and a force in the left direction in the drawing acts on the screen main body 21 to correct the distortion of the convex surface. In this state, the fixing screw 28 is tightened to fix the angle of the mounting plate. As a result, the screen surface shape on the viewing surface side of the screen body 21 which is originally convex can be corrected to a flat surface.

In the second embodiment of the present invention shown in FIG. 8, the mounting plate 22 has an inclined surface, whereas the mounting plate 22 has an inclined surface in the above-described embodiment.
2 is formed in a flat plate shape. In this embodiment, when the mounting plate 22 is fixed to the base frame 23 with the adjusting screw 24 not tightened and the mounting plate 22 is fixed with the fixing screw 28, as shown in FIG. A force acts in the direction and the screen becomes concave. When the fixing screw 28 is loosened and then the fixing angle adjusting screw 24 is tightened from the state of FIG. 8A, when the mounting plate 22 is in the vertical state as shown in FIG. When the force is not applied and the adjusting screw 24 is further tightened, the force is applied to the observation surface side as shown in FIG. 8C.

Since the operation and the adjusting method in this embodiment are the same as those in the above-mentioned embodiment, the description thereof will be omitted here to avoid duplication of description.

In the third embodiment of the present invention shown in FIG. 9, the mounting plate 22 is swingably mounted on the base frame 23 by a hinge 29, and the hinge 29 is sandwiched between the pair of adjusting screws 2 to be mounted.
4, 24 are provided, and the mounting angle between the base frame 23 and the mounting plate 22 is adjusted by the tightened state of the adjusting screws 24, 24.

Since the operation and the adjusting method in this embodiment are the same as those in the above-mentioned embodiment, the description thereof will be omitted here to avoid duplication of description.

In the above embodiment, the mounting plates 22 are arranged in the upper, lower, left and right directions, respectively, but the number of the mounting plates 22 is divided into a large number and mounted on the screen main body 21 and adjusted only in the direction A of FIG. It is also possible to alternately arrange possible elements and elements that can be adjusted only in the B direction and adjust the shape of the screen surface.

Next, referring to FIG. 1 of the fourth embodiment of the present invention.
It will be described with reference to FIGS. FIG. 10 is a perspective view showing the entire structure of the mechanism adopted in the fourth embodiment, and FIG.
Is a side view showing the adjusting mechanism, and FIG. 12 is an enlarged side view of the relevant part.

In the fourth embodiment, the screen body 2
The screen surface can be adjusted to have a concave-convex shape with the center of the screen as a fulcrum at the four side ends of 1, and an adjusting mechanism 30 for urging by a pulling force in the thickness direction is provided, and the four corners on the extension line are provided with coil springs in the outer peripheral direction of the screen. A biasing means 34 for biasing by a pulling force is provided, and its tip is fixed to the base frame 31.

A total of 12 adjusting mechanisms 30 were installed on each side of the screen body 21. 11 and 1
As shown in FIG. 2, the adjusting mechanism 30 includes a movable plate 32 that is swingably attached to a movable shaft 33 and a movable shaft 3.
It is composed of a control plate 35 connected to 3 and an adjusting screw 37 containing a coil spring 38.

The screen main body 21 and the movable plate 32 are fixed by screws 36, coil springs 34 ... Are attached to both ends of the movable shaft, and the coil springs 34 are attached to the base frame 31, so that the screen main body 21 is surrounded. Biased in the direction.

In this embodiment, by tightening the adjusting screw 37 containing the coil spring 38, the tip of the adjusting screw 37 comes into contact with the control plate 35 of the movable shaft 33, and
As shown in FIG. 2, the movable plate 32 fixed to the screen body 21 and the screw 36 moves in the rotation direction with the movable shaft 33 as a fulcrum. By making the direction of this movement opposite to the warp of the screen body 21, the function of eliminating the warp caused by the processing strain works and the screen surface of the screen body 21 can be made flat as in the above-described embodiment. Becomes

The adjustment amount corresponds by increasing the central portion of the screen main body 21 having the largest amount of warp and decreasing the adjustment amount at the end of the screen main body 21.

Further, due to the expansion / contraction characteristics of the coil spring 38 incorporated in the adjusting screw 37, expansion / contraction in the thickness direction of the screen main body 21 due to changes in temperature and humidity can be absorbed.

With respect to expansion and contraction in the outer peripheral (width) direction of the screen main body due to changes in temperature and humidity, expansion and contraction due to changes in temperature and humidity are corrected by the expansion and contraction characteristics of the coil spring 34 installed in the adjusting mechanism 30. There is no problem because it can be absorbed.

According to the above-described embodiment, since the warpage caused by the processing strain and the expansion and contraction due to the change in temperature and humidity can be corrected and absorbed, the screen surface can always be maintained in a flat shape.

FIG. 13 is a schematic view showing a projection type display device using the screen of the present invention. FIG.
The projection display device using two liquid crystal projectors uses the screen having the screen surface adjustment mechanism described in each of the above embodiments.

As shown in FIG. 13, when the observation surface of the screen 3 is flat (3a), the images from the liquid crystal projectors 1 and 2 are imaged in a state where the center a, the upper end b, and the lower end c are aligned. The images of the two liquid crystal projectors 1 and 2 match on the front side.

On the screen 3b in which the screen shape is not corrected and the observation surface of the screen is convex, the image of the liquid crystal projector 1 is connected to a1, b, and c of the screen 3b at the center, the upper end, and the lower end, respectively. The image of the liquid crystal projector 2 is formed at the center, the upper end, and the lower end on a2, b, and c of the screen 3b, respectively. For this reason,
At the upper end and the lower end, the images of both projectors 1 and 2 are imaged in a matched state, but the central portion is projected at the upper points a1 and a2, and the projected positions of the images do not match. Therefore, in such a convex screen, the screen surface may be adjusted as described above, the observation surface of the screen may be corrected to a flat state, and the projection positions from the liquid crystal projectors 1 and 2 may be matched. .

Further, in the screen 3c in which the observation surface of the screen in which the screen shape is not corrected is a concave surface, the image of the liquid crystal projector 1 is connected to a3, b, and c of the screen 3c at the center, the upper end, and the lower end, respectively. The image of the liquid crystal projector 2 is formed on a4, b, and c of the screen 3c at the center, the upper end, and the lower end, respectively. For this reason,
At the upper end and the lower end, the images of both projectors 1 and 2 are imaged in a matched state, but the central portion is projected at the upper points a3 and a4, and the projected positions of the images do not match. Therefore, in such a concave screen, the screen surface may be adjusted as described above, the observation surface of the screen may be corrected to a flat state, and the projection positions from the liquid crystal projectors 1 and 2 may be matched. .

[0049]

As described above, according to the present invention, even if the shape of the screen itself varies due to processing distortion or the like, the distortion of the screen shape can be freely corrected to make the screen shape an ideal shape. It is possible to improve.

Therefore, the deflection of the screen shape which leads to the deterioration of the image quality such as the resolution of the projection type display device which has the accuracy in adjusting the projection positions of a plurality of images and the projection shape,
It can be improved without imposing a burden on the screen manufacturing which leads to an increase in cost.

Further, according to the projection display apparatus of the present invention, since the screen surface is always kept flat, the image distortion caused by the screen distortion, which has been a problem in the past, is eliminated, and the projection apparatus with high image quality is eliminated. Can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the principle of the present invention.

FIG. 2 is a plan view showing a state in which the screen according to the first embodiment of the present invention is viewed from the direction opposite to the observation surface.

FIG. 3 is a plan view showing a state where the screen according to the first embodiment of the present invention is viewed from the viewing surface direction.

FIG. 4 is a sectional view taken along line A-A ′ of FIG. 2;

FIG. 5 is a plan view showing essential parts of a mounting plate and a pressing plate according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a corrected state of the screen according to the present invention, in which (a) shows a state in which the observation surface of the screen is deformed into a concave surface, and (b) shows the corrected state.

FIG. 7 is a cross-sectional view showing a corrected state of the screen according to the present invention, in which (a) shows a state in which the observation surface of the screen is deformed into a convex surface and (b) shows the corrected state.

FIG. 8 is a sectional view showing a second embodiment of the screen of the present invention.

FIG. 9 is a sectional view showing a main part of a third embodiment of the screen of the present invention.

FIG. 10 is a perspective view showing the overall structure of a mechanism adopted in a fourth embodiment of the present invention.

FIG. 11 is a side view showing an adjusting mechanism according to a fourth embodiment of the present invention.

FIG. 12 is an enlarged side view of a main part of an adjusting mechanism according to a fourth embodiment of the present invention.

FIG. 13 is a schematic view showing a projection display device of the present invention.

FIG. 14 is a perspective view showing a screen used in a conventional projection display device.

FIG. 15 is a perspective view showing a screen used in a conventional projection display device.

FIG. 16 is a perspective view showing a screen used in a conventional projection display device.

FIG. 17 is a perspective view showing a screen body used in a conventional projection display device.

[Explanation of symbols]

 11 Screen Main Body 12 Mounting Plate 13 Peripheral Base 21 Screen Main Body 22 Mounting Plate 23 Base Frame 24 Fixing Angle Adjusting Screw 25 Holding Plate 26 Coil Spring 28 Fixing Screws 1, 2 Liquid Crystal Projector 3 Screen

Claims (4)

[Claims] 1. A screen for a projection display device for forming a projected image, comprising a plurality of holding means movably back and forth with respect to a viewing surface direction of the screen,
A screen for a projection display device, characterized in that an outer peripheral portion of a screen body is fixed to a base frame by the holding means, and a surface shape of the screen body is adjusted to a flat shape by adjusting a front and rear movement amount of the holding means. 2. The screen for a projection display apparatus according to claim 1, wherein the holding means is provided with a biasing means for biasing the screen body toward the base frame. 3. The screen for a projection display apparatus according to claim 1, wherein the holding means is provided with a biasing means that is capable of expanding and contracting with respect to the viewing surface direction of the screen. 4. A projection type display device, wherein an image formed by an image display element is enlarged and projected on a screen according to claim 1 through a projection lens.