JPH09281885A - Video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video display device capable of freely setting an angle of at a low cost using a concave mirror having high accuracy in the angle of visibility suitable for a simulator and an amusement. SOLUTION: The image display device provided with at least a screen 5, an image projection part 4 for displaying an image on the screen 5, an image source 19 for generating the image supplied to the image projection part 4 and the concave mirror 6 for turning back the image displayed on the screen 5 to an observing side, is constituted so that a display range changing means 20 for adjusting a display period for the image from the image source 19, with respect to a horizontal scanning cycle of the image projection part 4 is provided to change the horizontal width of the image displayed on the screen. By such a constitution, a horizontal observing angle for the image reflected by the concave mirror 6 and observed at an eys's point position 1 can be mode a desired value, the distortion of the observed image is made extremely little and accuracy in the angle of visibility for observing is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A screen, an image projection unit for displaying an image on the screen, an image source for generating an image supplied to the image projection unit, and an image displayed on the screen. A concave mirror that folds back to the viewing side, at least, and relates to a video display device configured to allow a viewer to view an image projected on a screen through the concave mirror, a simulator, a game device that provides a particularly realistic image,
The present invention relates to a video display device suitable for VR (virtual reality) equipment and the like.

[0002]

2. Description of the Related Art Due to the recent downsizing and cost reduction of personal computers and workstations, and the improvement of the output performance of image information signals, the realistic images realized by conventional large-scale industrial flight simulators can be reproduced on a small scale. It has come to be offered to fields such as various games and simulators.

As described above, in order to obtain a realistic image, it is important to improve the output performance of the video information signal and to display the video information device.

Conventionally, various image display devices have been proposed in order to display a realistic image. Above all,
The image display device that views the image displayed on the screen through the concave mirror that folds back to the viewing side allows the viewer to feel the image with a sense of depth. It has been put to practical use in flight simulators for large-scale flight training that pursues sexuality.

Such a large-scale image display device is disclosed in Japanese Examined Patent Publication No. 55-13031, which will be described with reference to a vertical plane sectional view of FIG. However, this figure is a side view of the main part, where 1 is the viewpoint position, 4 is the projection unit, and 5 is the projection unit.
Is a screen, 6a is an elliptical concave mirror, 22 and 23 are outgoing rays, 24 and 25 are transmitted rays, and 26 and 27 are reflected rays.

In FIG. 1, outgoing light rays 22 and 23 emitted from a projection lens (not shown) of the projection unit 4 are screened.
By illuminating the screen 5, the image output from this projection unit is enlarged and displayed, and the transmitted light rays 24 and 25 that have passed through the screen 5 are reflected by the elliptic concave mirror 6a,
The reflected light rays 26 and 27 travel toward the viewpoint position. As a result, the viewer at the viewpoint position 1 can view the displayed image from the viewing direction F.

Here, the screen 5 has a convex shape when viewed from the projection device 4, and is arranged substantially on the focal plane of the elliptic concave mirror 6a.

In the image display device thus arranged, since the screen 5 is located substantially on the focal plane of the elliptical concave mirror 6a, the transmitted rays 24 and 25 from the screen 5 are reflected by the elliptic concave mirror 6a. The reflected light rays thus obtained become substantially parallel light rays, and a virtual image is viewed at infinity with respect to the viewer 1 at the viewpoint position 1, and as a result, the viewer feels a deep image.

Further, according to the above-mentioned publication, one image projection device is used. However, for example, when the left and right viewing angles are widened to about 60 degrees or more, a plurality of image projection devices are provided, for example. As disclosed in Japanese Patent Laid-Open No. 301331, there is one in which a plurality of projection units display an image with a wide viewing angle on a screen and try to widen the viewing angle of the image by viewing through a concave mirror. .

[0010]

As described above, the image display device using the concave mirror can display an image with a realistic sensation. However, the concave mirror is formed by vacuum molding, and its substrate is vacuum coated with a reflective film. Therefore, it is difficult to obtain a uniform surface shape and reflection characteristics over the entire surface of the concave mirror.
It is necessary to form a diffusion layer after forming a spherical shape, but it is difficult to apply a uniform shape and uniform coating over the entire surface, and the optical arrangement dimensions such as the viewpoint position, concave mirror, screen, etc. should be adjusted to the predetermined positions. Even if they are arranged, the image viewed by the viewer from a predetermined viewpoint position has a problem that it looks distorted.

Therefore, in the past, in order to obtain an image with less distortion, a method has been adopted in which the viewpoint position is mainly moved to obtain an image without distortion. If you make such adjustments,
Since the viewpoint moves, the horizontal image viewing angle of the viewer changes. The state will be described with reference to the horizontal plane sectional view of FIG. However, this figure is a top view of the main part of the image display device. 1, 1a is the viewpoint position, 4 is the projection unit, 5 is the screen, 6a is the elliptical concave mirror, 7, 7c, 8 and 8c are the outgoing rays, 11, Reference numerals 11c, 28, 12, 12c and 29 are transmitted light rays, and 13, 13c, 30, 14, 14c and 31 are reflected light rays.

In FIG. 1, outgoing rays 7 and 8 emitted from a projection lens (not shown) of the projection unit 4 are screened by a screen 5.
The image output from the projection unit is enlarged and displayed by being illuminated upward, and the transmitted light rays 11 and 12 that have passed through the screen 5 are reflected by the elliptic concave mirror 6a, and the reflected light rays 13 and 14 thereof. Moves toward the viewpoint position 1. As a result, the viewer at the viewpoint position 1 can view the image with the viewing angle of the angle θ in the horizontal viewing direction.

However, as described above, when the visual image is distorted due to various factors and the viewpoint is moved to solve it, for example, it is moved from the predetermined position to the visual position 1a in the direction of the concave mirror. In this case, the image is enlarged and displayed on the screen 5, and the transmitted light beam 2 transmitted through the screen 5
8 and 29 are reflected by the elliptic concave mirror 6a, and their reflected light rays 30 and 31 travel toward the viewpoint position 1a. This allows
The viewer at the viewpoint position 1a views an image having a viewing angle of θb in the horizontal viewing direction.

Specifically, when the radius of curvature of the concave mirrors on both ends has an error of about 20% in the concave mirror, from a predetermined position to obtain an image without distortion, about 15% of the radius of curvature of the concave mirror is the viewpoint position. Had to be moved to the concave mirror side. As a result, the horizontal viewing angle was increased by about 10%. This means that the angle you want the viewer to see is 10
It shows that there is an error of%, which is an unacceptable level as a simulator.

Therefore, in order to reduce this error, in the prior art, a method of shortening the projection distance of the projection unit to reduce the image on the screen is adopted. This will be described with reference to FIG. When the projection unit 4 is brought close to the screen 5, the output light beams 7c and 8c emitted from the projection lens (not shown) are irradiated onto the screen 5 and the output image is smaller than that before the projection unit 4 is brought closer. Is displayed. The screen 5
The transmitted rays 11c and 12c that have passed through are reflected by the elliptical concave mirror 6a.
And the reflected light rays 13c and 14c travel toward the viewpoint position 1a.

As a result, the viewer at the viewpoint position 1a can view the image with the viewing angle of the angle θc in the horizontal viewing direction. At this time, the error of the viewing angle can be corrected by bringing the projection unit 4 closer until the viewing angle θc coincides with θ. Since such correction is performed by trial and error, it is a complicated work, and the workability is extremely poor because the projection unit is heavy.

Further, the housing (not shown) for fixing the projection section and the screen at a predetermined position needs to have a mechanism for moving and firmly fixing the projection section in advance, so that the structure is complicated. It was expensive and expensive in terms of resources.

Further, when displaying a wide viewing angle image on a screen by a plurality of image projection devices as disclosed in Japanese Patent Laid-Open No. 6-301331, the projection unit is set to the screen as in the prior art. However, there is a problem that it is difficult to sufficiently correct the projection distance because there is a limitation in shortening the projection distance because the projection portions interfere with each other.

Therefore, an inexpensive image display device suitable for a simulator with a high viewing angle of view could not be realized because the distortion of the viewed image was small.

Further, in order to freely set the viewing viewing angle of the image display apparatus according to the purpose of use, it is necessary to use a special projection lens suitable for the viewing angle in the prior art. Since a special projection lens is not a general-purpose part, it is technically possible, but it is industrially inefficient and it was difficult to realize an image display device.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an image display device which is inexpensive, can set a viewing angle freely, and has a high viewing angle accuracy.

[0022]

In order to solve the above-mentioned problems, according to the present invention, an image source for one horizontal scanning period of an image emitted from a projection lens of a projection unit of an image display device and output on a screen. By adjusting the display period of the image from, to change the horizontal width of the image displayed on the screen, the horizontal viewing angle of the image reflected by the concave mirror and viewed at the viewpoint position can be set to a desired value. I was able to do it.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) A first embodiment of an image display device according to the present invention will be described below.

FIG. 1 shows an external view of a first embodiment of a video display device according to the present invention. FIG. 2 is a sectional view of the video display device of FIG. 1 taken along a horizontal plane, and FIG. 3 is a video display according to the present invention. The explanatory view explaining the state of is shown.

Next, the structure of the image display device according to the present invention will be described with reference to the drawings.

Reference numeral 1 denotes the viewpoint position of the viewer, which is the origin of the x, y, z coordinate system. A projection type cathode ray tube 2 is composed of a red projection type cathode ray tube 2a, a green projection type cathode ray tube 2b, and a blue projection type cathode ray tube 2c. A projection lens 3 is composed of a red projection lens 3a, a green projection lens 3b, and a blue projection lens 3c.

Reference numeral 4 denotes a projection unit in which the projection type cathode ray tube 2 and the projection lens 3 are mechanically and optically coupled by a coupler, and further fixedly integrated in a state where they have a predetermined positional relationship with each other. is there. Reference numeral 5 is a transmissive screen having a substantially spherical shape, 6 is a concave mirror, and a synthetic resin sheet is heated and softened, and compressed air is introduced or air is passed between a die having a fixed peripheral edge of the sheet and the sheet. The sheet is formed into a substantially spherical crown shape by suction of, and the formed base material is cut into a substantially spherical band shape, and a reflective layer is formed on at least one surface of one of the plurality of cut base materials. After that, a layer for protecting the reflective layer is formed.

Reference numerals 7, 8, 9, and 10 denote rays emitted from the projection lens 3, 11, 12, 15, and 16 denote transmitted rays from the screen 5, and 13, 14, 17, and 18 denote transmitted rays 1.
Reference numerals 1, 12, 15, and 16 are reflected light rays reflected by the concave mirror 6 and viewed by the viewer. Reference numeral 19 denotes an image source that generates an image supplied to the projection unit 4, and 20 is a display range changing unit that changes the display range of the image output from the image source. The image output from the image source 19 is projected by the projection unit 4 It is a down converter or a graphic board having a function of adjusting the display range of a personal computer, which has a function of adjusting the image display period of the image source with respect to one horizontal scanning period with reference to the horizontal synchronizing signal. It should be noted that the circuits for driving the projection unit 4 and the chassis for fixing each member are not shown.

The image output from the image source 19 is adjusted to a predetermined image range by the display range changing means 20 and supplied to the image section 4, and the projection section 4 receives this image signal and the projection type cathode ray tube. An image is displayed by the light emitted from the second fluorescent surface (not shown). Here, by the display range changing means 20, during one horizontal deflection period of the projection unit 4, a period during which the image of the image source 19 is displayed, a non-display period during which the image of the image source 19 is not displayed, and a dark black display and a blanking line are displayed. Make a period.

Corresponding to this signal, the image of the image source 19, the dark black display during the non-display period, and the dark black display during the blanking period are displayed on the fluorescent surface of the projection cathode ray tube 2 in one horizontal period. Perform. The displayed image passes through the projection lens 3 and the dark black color at both ends of the image becomes emitted light beams 7 and 8 which are enlarged and projected on the screen 5 and are transmitted through the screen 5 and transmitted light beam 1 is transmitted.
1 and 12 are reflected by the concave mirror 6 to become reflected light rays 13 and 14, and reach the viewer 1. The viewer 1 views the dark black display of the horizontal viewing angle θa, but cannot recognize it as an image because of the dark black display. Then, the image of the image source 19 passes through the projection lens 3 to become the outgoing light rays 9 and 10, which are enlarged and projected on the screen 5 and are transmitted through the screen 5, and the transmitted light rays 15 and 16 are transmitted.
Is reflected by the concave mirror 6 to become reflected rays 17 and 18, and the viewer 1 perceives an image having a horizontal viewing angle θ by observing the bundle of the reflected rays.

As described above, since the horizontal viewing angle of the image viewed by the viewer 1 can be adjusted by adjusting the image display period of the image source with respect to the horizontal scanning period, even if the viewpoint position is moved horizontally. An arbitrary horizontal viewing angle can be realized within the range of the angle θa in the viewing direction.

Accordingly, when the radius of curvature of the concave mirror on both ends has an error of about 20% in the concave mirror as described in the prior art, in order to obtain an image without distortion, the radius of curvature of the concave mirror is set to 15 from the predetermined position. Even if the viewpoint position is moved to the concave mirror side, a substantially predetermined viewing angle can be provided because the horizontal viewing angle is arbitrarily adjusted. (Embodiment 2) Hereinafter, a second embodiment of the image display device according to the present invention will be described. To do.

FIG. 4 shows an external view of a second embodiment of the image display device according to the present invention. FIG. 5 is a sectional view taken along a horizontal plane of the image display device of FIG. 4, and FIG. 6 is an image display according to the present invention. The explanatory view explaining the state of is shown.

Next, the structure of the image display device according to the present invention will be described with reference to the drawings.

Reference numeral 1 is the position of the visual point of the viewer, which is x, y, z.
The origin of the coordinate system. Reference numeral 4 mechanically and optically couples the projection cathode ray tube and the projection lens with a coupler, and further,
The projection units are fixedly integrated in a state where they have a predetermined positional relationship with each other. In this embodiment, two sets are used so that the chief rays of the image lights intersect at an intersection point 21 so that they do not interfere with each other on the xz plane. It is provided. Reference numeral 5 is a transmissive screen, and 6 is a concave mirror.

7a, 7b, 8a, 8b, 9a, 9b, 1
0a and 10b are light rays emitted from the projection lens 3, and 15a and
15b, 16a and 16b are transmitted rays from the screen 5, and 17a, 17b, 18a and 18b are transmitted rays 15
Reference numerals a, 15b, 16a, and 16b are reflected light rays reflected by the concave mirror 6 and viewed by the viewer.

Reference numerals 19a and 19b denote image sources for generating the image supplied to the projection unit 4, and 20a and 20b are display range changing means for changing the display range of the image output from the image source. The image sources 19a and 19b. The image output from the projector 4 has a function of adjusting the image display period of the image source for one horizontal scanning period with the horizontal synchronizing signal of the projection unit 4 as a reference, for example, a function of adjusting the display range of a down converter or a personal computer. Such as a graphic board to have. It should be noted that the circuits for driving the projection unit 4 and the chassis for fixing each member are not shown.

The images output from the image sources 19a, 19b are adjusted to a predetermined image range by the display range changing means 20a, 20b and supplied to the projection unit 4, which receives the video signal. An image is displayed by the light emitted on the fluorescent surface (not shown) of the projection cathode ray tube 2. Here, by the display range changing means 20a, 20b, a period during which the images of the image sources 19a, 19b are displayed during one horizontal deflection period of the projection unit 4 and a dark black that does not display the images of the image sources 19a, 19b are displayed. Create a display period and a blanking period.

Corresponding to this signal, the image of the image sources 19a and 19b, the dark black display during the non-display period, and the dark black during the blanking period are displayed on the fluorescent surface of the projection cathode ray tube 2 in one horizontal period. Is displayed. The displayed image passes through the projection lens 3 and the dark black color at both ends of the image indicates the outgoing rays 7a, 7b,
8a and 8b, which are enlarged and projected on the screen 5. Since this image is dark black, even if the image passes through the screen 5 and is reflected by the concave mirror 6 to reach the viewer 1, the viewer 1
I can see the black display, but I cannot recognize it because it is a dark black display.

Next, the images of the image sources 19a and 19b pass through the projection lens 3 and exit rays 9a, 9b, 10a and 10 are emitted.
The transmitted light rays 15a, 15b, 16a, 16b that have become b and are enlarged and projected on the screen 5 and have passed through the screen 5 are
The light rays 17a, 17b, 18a reflected by the concave mirror 6 are reflected.
At 18b, the viewer 1 perceives a video by observing the bundle of reflected light rays.

As described above, the horizontal viewing angle of the image viewed by the viewer 1 can be adjusted by adjusting the image display period of the image source with respect to the horizontal scanning period. The horizontal viewing angle of can be realized.

As a result, when the radius of curvature on both ends of the concave mirror has an error of about 20% in the concave mirror as described in the prior art, in order to obtain an image without distortion, the radius of curvature of the concave mirror is set to 15 from a predetermined position. Even if the viewpoint position is moved to the concave mirror side by about%, it is possible to easily provide a substantially predetermined viewing angle because the horizontal viewing angle is arbitrarily adjusted.

Further, since it is not necessary to bring the projection unit 4 closer to the screen direction by adjusting the viewing angle, there is no problem that the projection units 4a and 4b interfere with each other.

Further, when the images from the two projection sections are connected to one image on the screen, the display width of each image can be adjusted, so that the images can be easily connected.

In the above embodiment, the image display device with two projection units has been described. However, the problems and means for solving the problems of the present invention do not change depending on the number of projection units, but depend on the number of projection units. It goes without saying that there is no such thing. Although the projection type cathode ray tube is used as the image display unit in the above description, another method may be used in which the projection lens is provided in another image display unit, for example, a liquid crystal panel provided with a backlight in close proximity. The effect does not change depending on the form of the image display unit.

Further, as the embodiment of the present invention, the description has been made by using the substantially spherical transmissive screen as the screen for displaying the image. However, the screen is not limited to the transmissive screen and, for example, a reflective screen may be used. , If the image on the screen can be viewed by the viewer through the concave mirror,
The same effect as the above embodiment is obtained.

[0047]

As described above, the two embodiments have been described. The screen is emitted from the projection lens of the projection unit of the image display device.
By adjusting the display period of the image from the image source for one horizontal scanning period of the image output on the screen and changing the horizontal width of the image displayed on the screen, it is reflected by the concave mirror and the viewpoint position is changed. The horizontal viewing angle of the image viewed with can be set to a desired value. As a result, since complicated work is not required to adjust the viewing angle to a desired value, workability is greatly improved. .

Further, the housing for fixing the projection section and the screen at a predetermined position does not require a mechanism for adjusting each viewing angle, and thus the housing may be simple in structure and inexpensive.

When displaying a wide viewing angle image on a screen with a plurality of image projection devices, a projection display device with a wide viewing angle can be easily realized without mutual interference of the projection sections.

Therefore, an inexpensive video display device suitable for a simulator with a high viewing visual angle accuracy can be realized with little distortion of the viewed video.

Further, when the viewing viewing angle of the image display device is freely set according to the purpose of use, it is not necessary to use a special projection lens suitable for the viewing angle.

[Brief description of drawings]

FIG. 1 is an external view of a first embodiment of an image display device according to the present invention.

FIG. 2 is a cross-sectional view of the first embodiment of the image display device according to the present invention taken along a horizontal plane.

FIG. 3 is an explanatory diagram illustrating a state of image display according to the first embodiment.

FIG. 4 is an external view of a second embodiment of a video display device according to the present invention.

FIG. 5 is a cross-sectional view of a second embodiment of an image display device according to the present invention taken along a horizontal plane.

FIG. 6 is an explanatory diagram illustrating a video display state according to the second embodiment.

FIG. 7 is a vertical plan sectional view of a conventional image display device.

FIG. 8 is a horizontal plane sectional view of a conventional image display device.

[Explanation of symbols]

1 Viewpoint position (viewer) 2 Projection type cathode ray tube 3 Projection lens 4 Projection part 5 Screen 6 Concave mirror 7,8,9,10,22,23 Outgoing light beam 11,12,15,16,24,25, 28,29 transmitted light rays 13,14,17,18,26,27,30,31 reflected light ray 19 image source 20 display range changing means 21 intersection of principal rays of two projection units

Front page continuation (72) Hideo Taniide, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Hitachi, Ltd. Multimedia System Development Division

Claims (5)

[Claims] 1. A screen, an image projecting unit for displaying an image on the screen, an image source for generating an image supplied to the image projecting unit, and an image for viewing the image displayed on the screen. A video display device including at least a concave mirror that is folded back to the side, further comprising display range changing means for adjusting a display period of a video image from a video source with respect to one horizontal scanning period of the video projection unit. Video display device. 2. The video display device according to claim 1, wherein the video projection unit includes a plurality of video projection units. 3. The video display device according to claim 2, wherein the video projection unit includes two sets of video projection units.
The chief ray of the image rays from the pair of image projection units is the screen.
An image display device in which image projection units are arranged so as to intersect with each other before being focused on a screen. 4. The image display device according to claim 1, 2 or 3, wherein the concave mirror is provided between a mold and a sheet in which a peripheral edge of the sheet is fixed after the synthetic resin sheet is heated and softened. The sheet is formed into a substantially spherical crown shape by inflowing compressed air or sucking air, and the formed base material is cut into a substantially spherical shape, and a reflective layer is formed on at least one surface of the cut base material. After that, the image display device is a concave mirror formed by forming a layer for protecting the reflection layer. 5. The image display device according to claim 1, wherein the image projection unit for displaying an image on the screen includes an image display unit and an image generated from the image display unit. And a projection lens for enlarging and projecting the image, which is fixedly integrated with a predetermined positional relationship with each other.