JPH04280582A - Display-image pickup device - Google Patents

Abstract

PURPOSE:To correct a picture distortion caused in the picked-up picture in the display.image pickup device in which the coincidence of line of sight is realized through the combination of plural small half-mirrors. CONSTITUTION:The display.image pickup device comprising a display device 1, a half mirror 5 comprising lots of small half mirrors 4 placed in front of the display device 1 and an image pickup device 2 is provided with an optical system magnifying or reducing the reflecting image from the half mirror 5 in the direction of correcting distortion before the image is picked up by the image pickup device 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display/imaging device that is a combination of a display device and an imaging device used in video telephones, video conference systems, and the like.

0002

[Background Art] In recent years, with the development of communication technologies such as image coding technology, two-way video communications such as video telephones and video conference systems that connect remote locations using video and audio communication networks have rapidly become popular. . In the future, it is expected that with the enhancement of ISDN networks and higher bandwidth transmission networks, it will be possible to provide video services with an even greater sense of reality.

FIG. 5 shows a display/imaging device currently used for two-way video communication. The imaging device 2 is located on the top or side of the display device 1 such as a CRT display, and the user M
image. However, since those who use such a device are looking at the normal display device 1, the user M does not turn his/her line of sight toward the imaging device 2 even when the imaging device 2 takes a picture. As a result, even if it becomes possible to transmit highly realistic images, there is a drawback that the conversation becomes unnatural because the interlocutors do not see eye to eye with each other.

[0004] Therefore, in order to construct a compact and inexpensive display/imaging device that achieves line-of-sight alignment, a method was devised to construct a semi-transparent mirror by combining multiple microscopic semi-transparent mirrors.
-273400).

FIG. 6 shows a sectional view of a semi-transparent mirror in which micro semi-transparent mirrors are combined. In this figure, numeral 3 indicates a transparent substrate, 4 indicates a micro semi-transparent mirror, and 5 indicates the entire semi-transparent mirror. θ in the figure indicates the inclination of the micro semi-transparent mirror 4. With such a configuration, a portion of the incident light will be reflected in the direction of a certain angle ψ, as shown in the figure. In this case, since the width W of the micro semi-transparent mirror 4 can be made small, the display/imaging device can be made more compact than the conventional method in which the semi-transparent mirror is installed at an angle.

[0006]

However, if an image is taken using a semi-transparent mirror 5 as shown in FIG. 6, the image taken will be distorted. For example, as shown in FIG. 7, when capturing an image from above the semi-transparent mirror 5, a circular object is compressed in the vertical direction, so that when the captured image is displayed on the monitor 6, it is not circular but elliptical. Furthermore, since the optical path length to the imaging device 2 is different between the upper and lower parts of the reflected image,
Another drawback is that rectangular objects become trapezoids with long upper sides, resulting in so-called trapezoidal distortion.

The present invention has been made to solve the above-mentioned drawbacks, and is a display/imaging device that realizes line-of-sight alignment by combining a plurality of microscopic semi-transparent mirrors used in video telephones, video conference systems, etc. It is an object of the present invention to easily correct image distortion that occurs in images.

[0008]

[Means for Solving the Problems] The present invention provides a display/imaging device using a semi-transparent mirror consisting of a large number of minute semi-transparent mirrors.
An optical system that expands or reduces the reflected image from a semi-transparent mirror only in the direction of correcting distortion, such as a beam expander optical system used to shape the beam shape of a laser. be.

[0009]

[Operation] According to the present invention, image distortion is corrected by passing the reflected image from the semi-transparent mirror through the optical system. The addition of such an optical system is a major difference from conventional display/imaging devices.

0010

Embodiment Embodiment 1 FIG. 1 shows the configuration of an embodiment of a display/imaging device according to the present invention. In this figure, the same reference numerals as in FIGS. 6 and 7 indicate the same things. The reflected image from the semi-transparent mirror 5 is
After passing through a beam expander optical system 7 composed of a cylindrical concave lens 8 and a cylindrical convex lens 9, the beam is imaged by the imaging device 2. The beam expander optical system 7 expands or reduces the image in a direction that corrects the distortion of the image, so that the reflected image compressed by the semi-transparent mirror 5 can be enlarged to correct the distortion of the image. Since the magnification or reduction rate of the reflected image depends on the focal length of the cylindrical lens and the distance x between the cylindrical concave lens 8 and the cylindrical convex lens 9,
By giving a distribution to the focal length and the distance x between the lenses, it is also possible to correct the trapezoidal distortion of the reflected image.

FIG. 2 shows another example of the configuration of the display/imaging device according to the present invention, which is also equipped with an optical system using a cylindrical lens. The reflected image from the semi-transparent mirror 5 is passed through the beam expander optical system 7 as in FIG. 1, but unlike in FIG.
A total reflection mirror 10 is installed in front of the expander optical system 7, and the image pickup device 2 captures an image reflected from the total reflection mirror 10. In FIG. 1, the image for capturing the reflected image from the semi-transparent mirror 5 is horizontally inverted, but according to the configuration of FIG. No horizontal reversal occurs. (Embodiment 2) FIG. 3 shows a configuration diagram of a display/imaging device using a curved mirror as an optical system. The semi-transparent mirror 5 has a micro semi-transparent mirror 4 configured so that an image is reflected upward, and the reflected image is reflected by a curved mirror 11 installed above the semi-transparent mirror 5, and is installed above the display device 1. The image is captured by an image capturing device 2. Although the reflected image from the semi-transparent mirror 5 is magnified in the vertical direction, this distorted image can be corrected by using a cylindrical convex mirror as the curved mirror 11. The curved mirror 11 used here has a function that is a combination of a cylindrical lens and a mirror. Furthermore, since the magnification/reduction ratio of the reflected image by the curved mirror 10 depends on the curvature of the curved mirror 11, the side view, front view, and plan view are shown in FIGS. By providing a certain distribution in the curvature of the curved mirror 11, trapezoidal distortion can also be corrected. Furthermore, compared to the configuration described in the first embodiment, there is an advantage that the optical system can be configured with a simple optical system including only one curved mirror 11, so that the display/imaging device can be made smaller and lower in price.

Furthermore, although the above embodiment shows the case where a cylindrical convex mirror is used, it goes without saying that the same effect can be obtained even if a cylindrical concave mirror is used to reduce the reflected image from the semi-transparent mirror 5 in the horizontal direction. Nor.

[0013]

Effects of the Invention As explained above, the present invention improves the reflected image produced by the semi-transparent mirror by adding an optical system such as a beam expander optical system that expands or reduces the image in the direction of correcting distortion. distortion can be easily corrected.

Furthermore, by using a curved mirror as an optical system for enlarging or reducing an image in the direction of correcting distortion, image distortion can be corrected without constructing a complicated optical system. As a result, the device can be made smaller and cheaper.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of a display/imaging device according to the present invention.

FIG. 2 is a configuration diagram of a display/imaging device showing another embodiment according to the present invention.

FIG. 3 is a configuration diagram showing still another embodiment of the display/imaging device according to the present invention.

FIG. 4 is a diagram showing an example of a curved mirror having a curvature distribution used in the present invention.

FIG. 5 is a configuration diagram showing an example of a conventional display/imaging device.

FIG. 6 is a cross-sectional view of a semi-transparent mirror that is a combination of a plurality of micro semi-transparent mirrors proposed previously.

FIG. 7 is a configuration diagram of the previously proposed display/imaging device in which a semi-transparent mirror is constructed by combining a plurality of micro semi-transparent mirrors shown in FIG. 6;

[Explanation of symbols]

1 Display device 2 Imaging device 3 Transparent substrate 4 Microscopic semi-transparent mirror 5 Semi-transparent mirror 7 Beam expander optical system 8 Cylindrical concave lens 9 Cylindrical convex lens 10 Total reflection mirror 11 Curved mirror

Claims (2)

[Claims] 1. A display device, an imaging device, and a semi-transparent mirror including a large number of micro semi-transparent mirrors, the semi-transparent mirror is installed in front of the display device, and a subject in front of the display device is photographed through the semi-transparent mirror. In a display/imaging device that captures an image as a reflected image using the imaging device installed around the display device, the reflected image from the semi-transparent mirror is enlarged or reduced in a direction to correct distortion before being captured by the imaging device. A display/imaging device characterized by being provided with an optical system that performs. 2. The display/imaging device according to claim 1, wherein a curved mirror is used in the optical system.