JP2606671B2 - Video display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video display device,
In particular, the present invention relates to an image display device that synthesizes an image using a half mirror.

[0002]

2. Description of the Related Art Conventionally, in this field, there is a technique for synthesizing a background passing through a half mirror and an image reflected by the half mirror. This is schematically shown in FIG. In the figure, 1 indicates an image, for example, C
A display device such as an RT, 2 is its image display surface,
Reference numeral 3 denotes a half mirror installed at an angle of 45 degrees with the image display surface 2. The half mirror is a mirror having a property of reflecting a part of the light incident on the mirror surface and transmitting the other part.

Next, a description will be given of the path of light emitted from the image display surface 2 in the prior art with reference to FIG. FIG. 5 is a view seen from the direction of the cross section of the half mirror. The light 5 emitted from the image display surface 2 is split by the half mirror 3 into reflected light 5a and straight traveling light 5b. The observer can see the image reflected by the half mirror 3 by looking at the half mirror from the side of the inclination of the half mirror 3, that is, from the direction of arrow A. Here, for the sake of simplicity, it is assumed that the light 5 is emitted perpendicular to the image display surface 2, but it is sufficient that the light 5 is reflected by the half mirror 3 and emitted in a direction reaching the observer.

On the other hand, light from an object in the direction opposite to the inclination of the half mirror 3 also reaches the observer as light 61 reduced by the half mirror 3.

Accordingly, the half mirror 3 is moved in the direction of the arrow A.
Can see the image from the image display device and the background over the half mirror in a superimposed manner.

[0006]

In the above-mentioned prior art,
When observed from the direction of the inclination of the half mirror, the image from the image display device and the background over the half mirror can be viewed in an overlapping manner. However, the direction opposite to the inclination of the half mirror, that is, the direction of arrow B in FIG. There is a drawback in that when viewed from above, only the light rays 6r from the background can be seen.

It is an object of the present invention to provide an image display device capable of superimposing an image on a background even when viewed from either side of a half mirror.

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, an image display device of the present invention has a total reflection mirror at a position facing an image display surface, and is provided between the image display surface and the total reflection mirror. An image display device having a half mirror interposed therebetween and forming a predetermined inclination angle with respect to the image display surface, is characterized in that an optical attenuator is provided on an inclined side of the half mirror.

Further, another image display device of the present invention is characterized in that the transmittance of the optical attenuator is set to a value obtained by subtracting the reflectance of the half mirror from 1.

Further, another image display device of the present invention has a first half mirror at a position facing the image display surface,
A second half mirror is provided between the video display surface and the first half mirror and forms a predetermined inclination angle with respect to the video display surface.

[0011]

[0012]

[0013]

[Function] The image light reflected by the total reflection mirror installed at the position facing the image display surface is further reflected by the half mirror, so that the image can be viewed from the direction opposite to the inclination of the half mirror. Will be possible.

[0014] Further, by reducing the light advancing to the side of the inclination of the half mirror by the optical attenuator, it is possible to view an image of equal luminance from any side of the half mirror.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an image display apparatus according to the present invention.

FIG. 1 is a conceptual diagram showing a configuration of a video display device according to one embodiment of the present invention. In the figure, 1 is a display device for displaying an image, for example, a CRT, 2 is its image display surface, 3 is a half mirror installed at an angle of 45 degrees with the image display surface 2, and 4 is an image. This is a total reflection mirror installed in parallel with the display surface 2 and with the mirror surface facing the image display surface. The image display device 1 displays an image on the image display surface 2. The half mirror 3 is a mirror having a property of reflecting a part of incident light from any surface and transmitting the other part.

Next, referring to FIG. 2, the path of light emitted from the image display surface 2 in this embodiment will be described. FIG.
FIG. 3 is a diagram viewed from the direction of the cross section of the half mirror 3. The light 5 emitted from the image display surface 2 is split by the half mirror 3 into reflected light 5a and straight traveling light 5b. Half mirror 3
The light 5a reflected by the half mirror reaches the observer who views the half mirror 3 from the side of the inclination of the half mirror 3, that is, from the direction of the arrow A in FIG. You can see the picture above. Here, for the sake of simplicity, it is assumed that the light 5 is emitted perpendicular to the image display surface 2, but it is sufficient that the light 5 is reflected by the half mirror 3 and emitted in a direction reaching the observer. On the other hand, light from an object in a direction opposite to the inclination of the half mirror also reaches the observer as light 61 reduced by the half mirror 3. Therefore, an observer who views the half mirror 3 from the side of the arrow A can see the image from the image display device 1 and the background over the half mirror in a superimposed manner.

The straight light 5b is totally reflected by the total reflection mirror 4, returns to the half mirror 3, and is split into the reflected light 5ba and the straight light 5bb. The light beam 5ba reflected by the half mirror reaches the observer who views the half mirror 3 from the side opposite to the inclination of the half mirror 3, that is, from the direction of the arrow B, so that the observer can display an image reflected by the half mirror. The image on plane 2 can be seen. On the other hand, light from an object in the direction of the inclination of the half mirror also reaches the observer as light 6r reduced by the half mirror 3. Therefore, the observer who looks at the half mirror 3 from the arrow B can also see the image from the image display device 1 and the background over the half mirror in an overlapping manner.

As described above, according to the present embodiment, the total reflection mirror 4 is installed above the half mirror 3 in parallel with the image display surface 2 so that the half mirror can be tilted and the half mirror can be tilted. Either way, it is possible to see the video and the background superimposed.

Although the total reflection mirror 4 is provided above the half mirror 3 in the present embodiment, a half mirror may be used instead of the total reflection mirror. In this case, an image on the image display surface 2 can be viewed also from above the image display surface 2, that is, from the arrow C in FIG.

When the image display surface 2 is made of glass or the like, the light beam 5b reflected by the total reflection mirror 4 is reflected by the image display surface 2 and further reflected by the half mirror 3. Observers can be reached. When reflection on the image display surface is not preferable, it is desirable that the image display surface 2 be subjected to non-reflection processing.

Further, in this embodiment, the half mirror 3 is set at 45 degrees to the image display surface 2 and the total reflection mirror 4 is set parallel to the image display surface 2 for simplicity. The angle formed with respect to the display surface 2 may be greater than 0 degree and less than 90 degrees, and the total reflection mirror 4 may be located at a position where light rays from the image display surface 2 are reflected in the direction of the half mirror 3. . These positional relationships can be arbitrarily adjusted depending on the position of the observer.

Next, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a conceptual diagram showing the configuration of a video display device according to a second embodiment of the present invention. In the figure, 1 display device, 2 image display surface, 3 half mirror, and 4 total reflection mirror all have the same configuration as FIG. Here, for the sake of simplicity, the reflectance of the half mirror is equal to x on both surfaces. x is greater than 0 and less than 1. 7
Is an optical attenuator, which has a property of transmitting a part of incident light. The transmittance is y. y is also greater than 0 and 1
Less than. The optical attenuator 7 is installed perpendicularly to the image display surface 2 on the side of the inclination of the half mirror.

In this embodiment, assuming that the intensity of the light 5 emitted from the image display surface 2 is 1, the intensities of 5a and 5b split by the half mirror 3 are x and 1-x, respectively. Therefore, the amount of light reaching the observer from the arrow A is reduced by the optical attenuator 7 to become x · y. On the other hand, the straight traveling light 5b is reflected by the total reflection mirror 4 and then split by the half mirror 3 again.
ba and 5bb are x · (1-x) and (1-
x) (1-x), the amount of light reaching the observer from arrow B is x · (1-x).

Therefore, if an optical attenuator satisfying y = 1-x is selected, the amount of light from the image display surface 2 becomes equal regardless of the observation from either side of the half mirror 3. Therefore, it is possible to adjust the luminance of the image display surface 2 so that the amount of light becomes appropriate for any observer.

In this embodiment, the optical attenuator 7 is installed perpendicularly to the image display surface 2. However, where the optical attenuator 7 is not on the path of the light ray 5 but on the path of the light ray 5a reflected by the half mirror 3, May be installed.

[0028]

As is apparent from the above description, according to the present invention, by installing the total reflection mirror above the half mirror in parallel with the image display surface, the half mirror has a tilted side and a side opposite to the tilted side. It is possible to see the video and the background in any of the above.

Further, by installing an optical attenuator on the side of the inclination of the half mirror, it is possible to select the luminance of the image display surface so that an appropriate amount of light is obtained for the observer on either side of the half mirror. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing paths of light rays from an image display surface in the first and second embodiments of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 4 is a schematic diagram showing a configuration of a conventional video display device.

FIG. 5 is a diagram showing a path of light rays from an image display surface in a conventional image display device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 display device 2 image display surface 3 half mirror 4 total reflection mirror 5, 5 a, 5 b, 5 ba, 5 bb Path of light exiting from image display surface 6 l, 6 r Path of background light 7 Optical attenuator

Claims (3)

(57) [Claims] 1. A total reflection mirror is provided at a position facing an image display surface, and a half mirror is provided between the image display surface and the total reflection mirror and forms a predetermined inclination angle with respect to the image display surface. An image display device, comprising: a light attenuator on an inclined side of the half mirror. 2. The image display device according to claim 1, wherein the transmittance of the optical attenuator is set to a value obtained by subtracting the reflectance of the half mirror from 1. 3. A first half mirror is provided at a position facing the image display surface, and is provided between the image display surface and the first half mirror and forms a predetermined inclination angle with respect to the image display surface. An image display device comprising a second half mirror.