JPH04150683A - Display/image pickup device - Google Patents

Abstract

PURPOSE:To unnecessiate a back light by executing the image pickup of a front object through a reflective type display. CONSTITUTION:A reflective type display device 10 is adopted, and all or the part of a reflective plate has a shutter mechanism of light. In a nondisplay period, the whole surface of a liquid crystal panel 11 is controlled in a transmission state, and when a dimmer glass 13 is also made transparent, as shown in a figure (b), incident light passes through two polarizing plates 12, the liquid crystal panel 11 and the dimmer glass 13 and reaches a television camera 2. Using this light, the image pickup of an object M is executed. Thus, the back light such as a transmission type display is unnecessitated, the power consumption of a display type is reduced, and a condition on a device design aiming at miniaturizing and thinning is reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a display/imaging device that combines a display device and an imaging device used in two-way video communication systems such as video telephones and video conferences. be.

[Conventional technology 1] In recent years, rapid advances in communication technology have made it possible to communicate video and video between remote locations.
2. Description of the Related Art Two-way video communications such as video conferences and video telephones connected via audio communication networks are rapidly becoming popular. FIG. 5 shows the basic configuration of a terminal used in such a system.

In FIG. 5, 1 is a CRT, 2 is a television camera, and 3 is a microphone. In addition, there is an audio/video interface, an encoding device, and a network control device, which are connected to the communication network. In such a terminal, the image of the subject M is captured by a television camera 2 installed above or to the side of the CRT monitor, but the subject M using the terminal is usually looking at the other person on the CRT monitor and the television camera 2 is installed on the top or side of the CRT monitor. 2 is not suitable. Therefore, the lines of sight of the communicators who meet each other via the system do not essentially match.

One method for aligning the lines of sight between communication parties is to use a transmissive display and capture an image from the back side of the display.

FIG. 6 shows an example of the configuration of a display/imaging device using a transmissive display.

In FIG. 6, 4 is a transmissive liquid crystal flat display (hereinafter simply referred to as a display), 5 is a backlight, and 6' is a scattering plate that scatters the light from the backlight 5 to provide a uniform surface light source. For example, a dynamic scattering type liquid crystal can be used. 23 is a television camera and a microphone as in FIG. In this case, the television camera 2 is placed on the back side of the display 4. The display 4 repeats display and non-display, and the scattering plate 6 repeats a scattering state and a transmitting state in a time-sharing manner. During the display period, the television camera 2 is not operated, but during the non-display period, the display 4 and the scattering plate 6 are in a transparent state, the backlight 5 is also turned off, and the subject in front of the display 4 is photographed through the transparent display 4 and scattering plate 6. M is imaged with a television camera 2. If each operation in the display period and non-display period is repeated quickly enough and the non-display period, that is, the imaging time is shortened, humans will not be conscious of the imaging by the television camera 2 on the back side of the display 4, and the display will be displayed. Only images that have been recorded will be recognized.

[Problems to be Solved by the Invention] However, as shown in FIG. 6, using the transmissive display 4 requires a backlight 5, and there is no problem if it is a stationary device. but,
In order to make it a portable, cordless type terminal, the main limiting factor is power consumption.

An object of the present invention is to reduce the size of the display/imaging device by using a reflective display in a display/imaging device used in a two-way video communication system such as a video phone, which achieves line-of-sight between communication parties. The aim is to reduce power consumption.

[Means for Solving the Problems] A display/imaging device according to the present invention employs a reflective display device, and all or a part of the reflecting plate has a light shutter function.

Further, the reflector is composed of a collection of minute movable reflectors, and an imaging device and a scattering plate are arranged between the liquid crystal panel and the movable reflectors.

[Operation 1] This invention enables imaging of a subject in front of a reflective liquid crystal display, and does not require a backlight.

In addition, the display becomes brighter when a small movable reflector is used.

[Example 1] The configuration of the first example of this invention is shown in Section 1 (a) and (b).
Shown below.

In FIG. 1, 11 is a liquid crystal panel, and 12 is a polarizing plate, which are arranged on the front and back sides of the liquid crystal panel 11. 13 is a light control glass, which is marketed by Nippon Sheet Glass as a product called LIMLI. With the above steps, the display device 10 is configured. 2 is a television camera placed on the back.

Next, the operation will be explained.

During the display period, the light control glass 13 serving as a reflection plate is controlled to be opaque as shown in FIG. Some of it is transmitted and some of it is reflected. Therefore, the incident light is modulated by the two polarizing plates 12 and the liquid crystal panel 11 according to the image displayed, is reflected by the light control glass 13, and is reflected again by the polarizing plates 12. LCD panel 1
1. The image passes through the polarizing plate 12 and reaches the eyes of the subject M (at this time, the television camera 2 is not operated.

During the non-display period, the entire surface of the liquid crystal panel 11 is controlled to be in a transparent state. Further, the light control glass 13 is also made transparent. Then, as shown in FIG. 1(b), the incident light passes through two polarizing plates 1.
2, the liquid crystal panel 11 and the light control glass 13 to reach the television camera 2. This light is used to capture an image of the subject M.

If each operation of the display period/non-display period is repeated quickly enough and the non-display period, that is, the imaging time is shortened, the human being will not be conscious of the imaging and will only recognize the displayed image. As shown in FIG. 1(a), the light scattered by the opaque light control glass 13 is both reflected and transmitted, but since it is used as a reflector, the brightness of the display increases as the ratio of reflected light increases. becomes brighter. Therefore, the light control glass 13 needs to be sufficiently opaque during the display period.

However, in general, the light control glass 13 has a large transmittance (,
Its function as a reflector is insufficient. Therefore, as shown in FIG. 2(a), the back surface of the light control glass 13 can be
In this case, the light scattered and transmitted by the light control glass 13 is further reflected, and the reflectance can be increased. However, the amount of light reaching the television camera 2 when capturing images during the non-display period decreases, but this can be controlled by adjusting the transmittance of the semi-transmissive mirror 14 and by increasing the sensitivity of the television camera 2. It is possible. Furthermore, with such a configuration, as shown in FIG. 2(b), the reflected light from the semi-transmissive mirror 14 may enter the television camera 2 and affect imaging during the non-display period. This problem can also be solved by covering the television camera 2 with a case 15 that is integrated with the light control glass 13 as shown in FIG. 3(C). here,
Although there is no mention of whether the liquid crystal panel 11 is color or black and white, the above explanation fully corresponds to the case of black and white display. In addition, in the case of color display using a filter, even if the liquid crystal panel 11 and the light control glass 13 of the reflector become transparent during the non-display period, the color filter is still present, so images must be taken through the filter. , the amount of transmitted light decreases and the image becomes dark. However, since the focal point of the television camera 2 is sufficiently in front of the display device 10 and the size of the filter for each pixel is sufficiently small, the red light passes through the filter.

The green and blue lights are mixed and reach the television camera 2, and images can be captured without color bias, etc., as in the previous example.

[Embodiment 2] The configuration of the second embodiment of this invention is shown in FIGS. 3(a) and 3(b).
Shown below. Here, reference numeral 16 denotes a reflector consisting of a collection of minute movable reflectors, and is realized, for example, by integrating minute metal pieces on a silicon wafer using LSI microfabrication technology. Such a structure has already been developed by Texas Instruments as a deformable mirror (DM) for application in printers.
D) (Nikkei Sangyo Shimbun, July 23, 1990), and the mirror tilts up to 10 degrees by applying a voltage of 5 cm. During the display period, the reflection plate 16 is tilted toward the scattering plate 17, as shown in FIG. 3(a). Then, as shown in the figure, the incident light passes through the reflection plate 16 and the scattering plate 1.
7 and is modulated by the polarizing plate 12 and liquid crystal panel 11 to display an image. At this time,
Since the reflectance of incident light is higher than in Example 1, the display becomes brighter. Also, during this time, the television camera 2 is not operated.

During the non-display period, the reflector 16 is tilted toward the television camera 2, as shown in FIG. 3(b). At this time,
The incident light is reflected by a reflecting plate 16 and reaches the television camera 2 as shown in the figure. With this light, it is possible to image the subject M on the entire surface of the display device 10. The repetition of each operation during this display period/non-display period is the same as in the case of the first embodiment.

[Embodiment 31 The configuration of a third embodiment of the present invention is shown in FIG. 4. In this embodiment, as shown in FIG. 4(a), an optical distance is provided between the liquid crystal panel 11, the polarizing plate 12, and the reflecting plate 18, and the television camera 2 is mounted on a part of the reflecting plate 18. Unify. Here, instead of the light control glass 13, the reflection plate 18 is made of a material that totally reflects and scatters the incident light, such as a metal plate with a roughened surface.

The operation is similar to the embodiment shown in FIG. 1, but the display becomes brighter because almost all the light passing through the two polarizing plates 12 during the display period is scattered and reflected. Figure 4(a)
Although light is not scattered or reflected by the lens part of the television camera 2, since there is a distance between the reflector 18 and the liquid crystal panel 11, each display point on the liquid crystal panel 11 is illuminated by the reflector 18. Since scattered light from all directions reaches the lens, the display in front of the lens is unlikely to be affected.

Further, as shown in FIG. 4(b), a reflector plate 18 having holes 19 may be used. Although no light is reflected in the part of the hole 1, since light from all directions scattered by the reflector 18 reaches each display point of the liquid crystal panel 11, if the hole 19 is small, it will be reflected at a specific point. The impact is incomparable. During the non-display period, the hole 19 of the reflective plate 18
If the liquid crystal at the front of the screen becomes transparent, images can be taken through it, and there is no need to make the entire surface transparent. therefore,
During the repetition of the display period/non-display period, only a part of the liquid crystal panel 11 changes, so there is little disturbance in the image even if the repetition period is not too fast (the image is displayed without the human being being conscious of it). Only images that have been recorded will be recognized.

Although the case where there is one hole 19 has been explained here, the same effect can be applied even if there are multiple holes 19. Also, instead of installing the television camera 2 directly behind the hole 19, as shown in FIG. 4(C), It is also possible to guide light to the television camera 2 through the fiber 2o to take an image.

In this case, it is possible to install the television camera 2 at a certain arbitrary position, and it is also possible to reduce the thickness of the entire device.

[Effects of the Invention] As explained above, in this invention, the display device is a reflective liquid crystal display, and the whole or a part of the reflector has a light shutter function. , it is possible to match the line of sight between the parties. Therefore, since a backlight like a transmissive display is not required, the power consumption of the display type is significantly reduced, and there are fewer restrictions on device design aimed at miniaturization and thinning.

In addition, the reflector is composed of a collection of small movable reflectors, and the imaging device and scattering plate are placed between the liquid crystal panel and the movable reflector, so the display is displayed using the reflected light from the reflector and the scattering plate. Since the image is captured using the reflected light from only the reflector, the display has the advantage of being brighter.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, and is an explanatory diagram of an example of the configuration of a display/imaging device using a reflective liquid crystal display using a light control glass as a reflector, and FIG. An explanatory diagram of a configuration example when glass and a semi-transmissive mirror are combined, FIG.
FIG. 4 is an explanatory diagram of a configuration example of a display/imaging device using a reflective liquid crystal display using a reflective plate with holes. FIG. 5 is a perspective view showing the basic configuration of a conventional two-way video communication system terminal. FIG. 6 is an explanatory diagram of an example of the configuration of a display/imaging device that also uses a transmissive display to achieve line-of-sight alignment. Throughout the country, 1 is a CRT, 2 is a TV camera, 3 is a microphone, 10 is a display device, 11 is a liquid crystal panel, 12 is a polarizing plate, 13 is a light control glass, 14 is a semi-transparent mirror, 15 is a case, 16.18 1 is a reflecting plate, 17 is a scattering plate, and 19 is a hole. (a) Figure] j Light training power゛Two people Figure Figure Figure (a)] S Pa Figure Figure

Claims (2)

[Claims] (1) Consisting of a display device and an imaging device placed on the back side thereof, the display device is time-divisionally driven into a period in which an image is displayed and a non-display period in which nothing is displayed. A display/imaging device that images a subject in front of the display device through the display device, wherein the display device is a reflective liquid crystal display, and the entire or part of the reflector has a light shutter function. . (2) The reflector is composed of a collection of minute movable reflectors, and an imaging device and a scattering plate are arranged between the liquid crystal panel and the movable reflector, and the display is displayed using the reflected light from the reflector and the scatterer. The display/imaging device according to claim 1, wherein the image is captured using reflected light from only the reflecting plate.