JPH11249071A - Projection type three-dimensional display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a device and to enable an appreciater to secure wide appreciation area by transmitting at least one plural image signals, which are projected on a screen, through a semitransparent mirror and reflecting the other signal on the semitransparent mirror at least. SOLUTION: This projection type three-dimensional display device is composed of two image projecting means 3 for right and left eyes and a directional screen 1. A semitransparent mirror 2 is installed between the directional screen 1 and the image projecting means 3, the image signal projected from one image projecting means 3 is transmitted and the image signal from the other image projecting means is reflected and projected on the screen 1 later. Thus, even when the respective image projecting means 2 are larger than the interval between both the eyes in horizontal direction, two image projecting means 2 can be installed at the interval of both the eyes in horizontal direction and the same height in vertical direction. Thus, an image projector consisting of the projection three-dimensional display device is miniaturized and wide appreciation areas can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type display device which enables stereoscopic viewing using binocular parallax.

[0002]

2. Description of the Related Art Conventionally, projection display devices which provide independent images to the right and left eyes of a viewer and enable stereoscopic viewing using binocular parallax have been realized by various methods. For example, a projection type stereoscopic display of a type that performs stereoscopic vision by wearing special glasses such as a filter glasses type or a time-division stereoscopic type (basic of three-dimensional images, supervised by Takehiro Izumi 138-143)
Page). In addition, a projection-type stereoscopic display device that enables stereoscopic vision using a special screen without wearing special glasses (Basics of 3D video, supervised by Takehiro Izumi, 1
48-160 pages, 3D image engineering, Takataka Ohkoshi, 83-
97 pages).

The dedicated screen used here is, for example, a reflective or transmissive directional screen using a lenticular screen, a two-sided orthogonal mirror, or the like as shown in FIG. 7, and is projected onto the screen from image projection means. The image signal can be viewed only from a limited field of view. Therefore, even without glasses, stereoscopic viewing is possible by supplying independent image signals to the left and right eyes of the viewer. Such a directional screen and three or more image projecting means are configured as shown in FIG. 8, and each image projecting means projects an image signal corresponding to a corresponding visual field, so that the viewer can move right and left. There has been obtained a projection type three-dimensional display device capable of appreciating the wraparound.

[0004]

The above-mentioned prior art projection type three-dimensional display device comprises a screen and at least two image projection means for the right and left eyes. In order to reduce the distortion of the image projected on the screen, it is preferable that the plurality of image projecting means be arranged close to the exit lens position.

In particular, in a projection type stereoscopic display apparatus using a lenticular sheet or a two-sided orthogonal mirror or the like and performing a stereoscopic view with a directional screen as shown in FIG. It is necessary to arrange them so that the distance between the eyes is about (about 6.5 cm) in the horizontal direction, and the vertical positions are preferably matched.

However, in an actual apparatus, such an arrangement is difficult due to the size of the image projection means. Further, in a projection type stereoscopic display using a reflective directional screen, as shown in FIG. 5, since the position of the image projection means overlaps with the position of the viewer, a device for securing a wide viewing area is required. An object of the present invention is to overcome the above problems of the projection type stereoscopic display device by devising an optical system, to reduce the size of the device, and to secure a wide viewing area for a viewer.

[0007]

In order to solve the above-mentioned problems, in a projection type stereoscopic display device comprising a plurality of image projection means and a screen, at least one of a plurality of image signals projected from a plurality of image projection means onto a screen. This can be realized by allowing a person to transmit through the semi-transparent mirror and at least one reflecting the semi-transparent mirror.

[0008]

FIG. 1 is a schematic top view of a projection type stereoscopic display apparatus according to an embodiment of the present invention. The projection type three-dimensional display device comprises two image projection means 3 for the right eye and the left eye, and a directional screen 1. A semi-transparent mirror 2 is provided between the directional screen 1 and the image projecting means 3, and an image signal projected from one of the image projecting means is transmitted, and an image signal from the other is reflected and projected on the screen. With this configuration, even when each image projection unit is larger than the binocular distance in the horizontal direction, two image projection units are optically installed at the same distance in the horizontal direction and between the both eyes. I can do it.

Here, the semi-transparent mirror is obtained by depositing chromium or a dielectric material on the surface of a light-transmitting substrate such as glass or plastic. However, reflection also occurs from the surface opposite to the surface on which the semi-transparent mirror is deposited, and the screen is doubled due to the optical path difference from the surface.

In order to prevent this screen duplication, FIG.
It is preferable to apply an anti-reflection coating to the back surface of the translucent substrate on which the semi-transparent mirror is deposited as shown in FIG. The anti-reflection coat can be obtained by a method such as depositing a dielectric material having a different refractive index from the translucent substrate.

FIG. 2 is a schematic top view of a projection type stereoscopic display apparatus according to another embodiment of the present invention. In this embodiment,
In addition to the previous embodiment, the image signal transmitted through the semi-transparent mirror is configured to be reflected by a total reflection mirror disposed between the semi-transparent mirror and the image projection means.

In a three-dimensional display using a reflective directional screen, the viewing position matches the position of the exit lens of the image projection means as shown in FIG. As such a directional reflection screen, there is a screen using a lenticular sheet shown in FIG. In such a projection type stereoscopic display device, in the embodiment of FIG. 1, the image projecting means on the side where the image signal transmits through the semi-transparent mirror is a factor for limiting the image viewing position. This embodiment shown in FIG.
It is preferable that the viewing position limiting factor is alleviated by the arrangement of the total reflection mirror, and a sufficient viewing area can be secured for the viewer.

Further, it is sufficient to provide a total reflection mirror between the semi-transparent mirror and the screen as shown in FIG. 3 so that all image signals projected from the plurality of image projection means onto the screen are reflected. A large viewing area can be ensured, and further, the entire three-dimensional display device can be easily integrated in a small size. Also, all image signals in this structure are reflected an even number of times before emitting the image projection means and reaching the screen. Therefore, an image similar to that obtained when the image is directly projected onto the screen from the image projecting means is obtained, and it is preferable that the image is not converted by an electric engineering method or the like. Further, when all the image signals are reflected an odd number of times before emitting from the image projecting means and reaching the screen, all the image projecting means may be configured to project the left-right inverted image. It is a target.

An optical system using these semi-transparent mirrors and total reflection mirrors can be similarly applied to a case where there are three or more image projection means as shown in FIG. It is needless to say that the apparatus can be miniaturized and integrated even if it is applied to a projection type stereoscopic display that requires special glasses such as a filter glasses system or a time-sharing system. In this case, it is preferable that the position of the exit lens coincide between the right-eye image projection device and the left-eye image projection device.

[0015]

According to the present invention, it is possible to reduce the size of the image projection device constituting the projection type stereoscopic display device and to secure a wide viewing area.

[Brief description of the drawings]

FIG. 1 is a schematic top view of a projection type stereoscopic display device according to an embodiment of the present invention.

FIG. 2 is a schematic top view of a projection type stereoscopic display device according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a projection type stereoscopic display device according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of a semi-transparent mirror constituting the projection stereoscopic display device of the present invention.

FIG. 5 is a schematic top view of a conventional projection type stereoscopic display device.

FIG. 6 is a schematic top view of a projection stereoscopic display device according to one embodiment of the present invention.

FIG. 7 is an explanatory diagram of a directional reflection screen suitable for carrying out the present invention.

FIG. 8 is a schematic view of a projection type stereoscopic display device of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Screen, 2 ... Semi-transparent mirror, 3 ... Image projection means.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroki Kaneko 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside Central Research Laboratory, Hitachi, Ltd.

Claims (7)

[Claims] In a projection type stereoscopic display apparatus comprising a plurality of image projection means and a screen, at least one of a plurality of image signals projected from the plurality of image projection means onto a screen is transmitted through a semi-transparent mirror, and A projection type three-dimensional display device wherein one member reflects a semi-transparent mirror. 2. The projection type three-dimensional display device according to claim 1, wherein said semi-transparent mirror is formed on a surface of a light-transmitting substrate, and a back surface of said light-transmitting substrate is coated with an anti-reflection coating. Projection type stereoscopic display device. 3. A projection type stereoscopic display apparatus according to claim 1, wherein, among a plurality of image signals projected from a plurality of image projection means onto a screen, an image signal transmitted through a semi-transparent mirror is projected onto the semi-transparent mirror. A projection type three-dimensional display device characterized by being reflected by a total reflection mirror disposed between the means. 4. The projection type stereoscopic display device according to claim 1, wherein all images projected on the screen from a plurality of image projection means by a total reflection mirror disposed between the semi-transparent mirror and the screen. A projection type stereoscopic display device, wherein a signal is reflected. 5. An image projection apparatus according to claim 3, wherein all image signals projected onto the screen from the plurality of image projection means are reflected an even number of times by a semi-transparent mirror or a total reflection mirror. Projection type stereoscopic display device. 6. An image projection apparatus according to claim 3, wherein all image signals projected from said plurality of image projection means onto said screen are reflected an odd number of times by a semi-transparent mirror or a total reflection mirror. Projection type stereoscopic display device. 7. A three-dimensional display device according to claim 1, wherein the screen is a directional reflection screen.