JPH04178685A - Display and image pickup device - Google Patents

Abstract

PURPOSE:To align the line of sight and to miniaturize a device by using a liquid crystal display composed of a liquid crystal panel and a polarizing plate installed on the rear of it and providing a half mirror having a function controlling the transmission and reflection of incident light according to the polarized state of the incident light. CONSTITUTION:In light from an object in the front of a polarizing beam splitter (PBS)2, only S-polarized light is reflected by the PBS 2. When this reflected light is imaged by this image pickup device 3, it is similar to that the imaging is carried out from the position of a display device. On the other hand, the PBS 2 has the function as a kind of polarizing plate because the PBS 2 transmits only P-polarized light, so that when the liquid crystal panel is used as the display device 1, the number of the polarizing plates 6 composing the liquid crystal display can be reduced. On the other hand, the PBS 2 has the function for serving both as the half mirror and the polarizing plate, so that reduction in a light transmitting quantity can be suppressed, and the reduction in the brightness of a display screen can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] 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, etc. The present invention relates to a display/imaging device that is capable of reducing the size of the device and improving image quality.

[Prior Art and Problems to be Solved by the Invention] In recent years, with the development of communication technology such as image coding, two-way video communications such as video telephones and video conference systems that connect remote locations using video and audio communication networks have rapidly increased. It is becoming popular. In the future, I
It is expected that the enhancement of the SDN network and the increase in the bandwidth of the transmission network will make it possible to provide video services that are even more immersive.

FIG. 5 is a diagram showing a schematic configuration of a display/imaging device currently used for two-way video communication. This shows that images are taken.

However, when using such a device, the user usually looks at the display device, so even if the image capture device captures an image, the user does not have to turn his/her line of sight toward the image capture device, which creates a sense of realism. Even if video transmission became possible, there was a drawback that the interlocutors could not see each other and it was difficult to have a natural conversation.

One method of aligning the line of sight between interlocutors is to use a semi-transparent mirror. FIG. 6 is a diagram showing a schematic configuration of a display/imaging device using a semi-transparent mirror and a liquid crystal panel as a display device. show what will happen. Here, a semi-transparent mirror 2 is installed in front of the display device 1, and an image from the subject is reflected by the semi-transparent mirror 2 and is imaged by an imaging device 3 located above the semi-transparent mirror 2. The same effect as taking an image from position 1 can be obtained.

As a result, the user's line of sight is directed toward the display device 1, so that the lines of sight between one party and the other party displayed on the display screen match.

However, in the case of the configuration shown in FIG. 6, as the screen size of the display device 1 increases, the size of the semi-transparent mirror 2 also increases, resulting in an increase in the depth d, and the display/imaging device itself becomes larger. The disadvantage was that it was too large.

An object of the present invention is to provide a display/imaging device having a configuration that can solve the problems of the prior art described above, achieve line-of-sight alignment, reduce the size of the device, and improve image quality. It is about providing.

[Means for Solving the Problems] The above object is to provide an imaging device that is configured of a display device, an imaging device, and a semi-transparent mirror, and is installed around the semi-transparent mirror to capture an object in front of the semi-transparent mirror as a reflected image from the semi-transparent mirror. In a display/imaging device that captures an image, a liquid crystal display consisting of a liquid crystal panel and a polarizing plate installed behind the liquid crystal panel is used as the display device, and the semi-transparent mirror changes the transmission of incident light depending on the polarization state of the incident light. , a semi-transparent mirror with the function of controlling reflection (
Polarizing beam splitter: Polarizing Bea
This can be achieved by using a display/imaging device configured as an m-Splitter (hereinafter referred to as PBS).

Further, by using a combination of a plurality of micro PBSs as the PBS, it is possible to downsize the device and to reduce the number of polarizing plates constituting the liquid crystal display. Furthermore, by utilizing the wavelength selectivity of PBS, color display can be performed without a color filter.

[Example] Hereinafter, the display/imaging device of the present invention will be specifically described using an example.

Embodiment 1 FIG. 1 is a diagram showing a schematic configuration of an embodiment of the display/imaging device of the present invention, in which a display device 1, a semi-transparent mirror 2 consisting of a PBS, an imaging device 3, a liquid crystal panel 5, and a rear part of the liquid crystal panel 5 are shown. It is shown that it consists of a polarizing plate 6 and a backlight 7 provided. Note that θ in the figure indicates the angle of inclination of the reflective surface in the PBS.

Here, the light from the subject in front of PBS 2 is
Therefore, only the S-polarized light is reflected, and if this reflected light is imaged by the imaging device 3, it is equivalent to capturing the image from the position of the display device. In addition, since the PBS 2 transmits only P-polarized light, it has a function as a kind of polarizing plate. Therefore, when a liquid crystal panel is used for the display device l as shown in the figure, the polarizing plate 6 that constitutes the liquid crystal display can reduce the number of

In a display/imaging device with a conventional configuration, the amount of light transmitted is reduced by about 30% by the polarizing plate 6 and by about 50% by a semi-transparent mirror, resulting in a decrease in the brightness of the display screen, but in the device with the configuration of this embodiment, Since the PBS 2 functions as both a semi-transparent mirror and a polarizing plate, it is possible to suppress a decrease in the amount of transmitted light and prevent a decrease in the brightness of the display screen.

Embodiment 2 FIG. 2 is a sectional view showing a schematic configuration of a semi-transparent mirror of another embodiment of the present invention, that is, a display/imaging device using a combination of a plurality of micro PBSs as a semi-transparent mirror, and 4 is a micro PBS, θ indicates the angle of inclination of the reflective surface of the micro PBS 4.

By using a semi-transparent mirror having such a configuration, as shown in the figure, the S-polarized light of the incident light is reflected at a certain angle in the ψ direction, and the imaging device is installed in the ψ direction. With such a configuration, it is possible to reduce the width of the reflective surface of the micro PBS, and the thickness t of the semi-transparent mirror can be reduced.

Figure 3 is a diagram showing the configuration of a display/imaging device when the semi-transparent mirror shown in Figure 2 is used.
, an imaging device 3, a liquid crystal panel 5, a polarizing plate 6, and a backlight 7.

Unlike the case shown in FIG. 1, since the depth d can be significantly reduced, the device can be made smaller.

Embodiment 3 FIG. 4 is a diagram showing a cross-sectional configuration of a semi-transparent mirror 2 and a liquid crystal panel 8 of still another embodiment of the display/imaging device of the present invention, where 4 is a micro PBS and 8 is a color LCD shown in FIG. The figure shows a monochrome display liquid crystal panel obtained by removing the color filter from the liquid crystal panel of 1995, and R, G, and B indicate minute PBSs that transmit only red light, green light, and blue light, respectively.

Normal liquid crystal panels for color display use color filters to separate white light into wavelengths corresponding to red, green, and blue, and display color by controlling the transmittance of the light. Since the dielectric multilayer film is coated, P polarized light is transmitted through the multilayer film, while S polarized light is transmitted through the multilayer film.
Polarized light will be reflected. However, by appropriately determining the structure of the multilayer film, it is possible to control the transmission and reflection of light based on the polarization state as well as the difference in wavelength.

Therefore, in the liquid crystal display used in the display/imaging device of this example, by arranging a micro PBS in each pixel that transmits only red light, only green light, and only blue light, The structure is such that the minute PBS serves not only as a polarizing plate but also as a color filter.

With the configuration of this embodiment, since no color filter is used, the brightness of the display screen can be significantly improved.

[Effects of the Invention] As mentioned above, the problems of the prior art can be solved by using a display/imaging device configured according to the present invention for use in video telephones, video conference systems, etc. As a result, it was possible to provide a display/imaging device configured to achieve line-of-sight alignment, miniaturize the device, and improve image quality.

That is, by using PBS for the semi-transparent mirror, when a liquid crystal display is used as a display device, the number of polarizing plates constituting the liquid crystal display can be reduced, and as a result, the substantial brightness of the liquid crystal display can be increased. Furthermore, by combining multiple micro PBSs, it was possible to downsize the device. In addition, because the micro PBS has wavelength selectivity, color display can be performed without a color filter, and as a result, brightness can be significantly improved compared to ordinary color liquid crystal displays. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing a schematic configuration of one embodiment of the display/imaging device of the present invention, and FIG. 2 is a sectional view showing the schematic configuration of a semi-transparent mirror made of a micro PBS of another embodiment of the display/imaging device of the present invention. , FIG. 3 is a diagram showing the configuration of a display/imaging device using the semi-transparent mirror shown in FIG. 2, and FIG. 4 is a cross-section of the semi-transparent mirror and liquid crystal panel of still another embodiment of the display/imaging device of the present invention. A diagram showing the configuration,
Fig. 5 is a diagram showing a schematic configuration of a conventional display/imaging device, Fig. 6 is a diagram showing a schematic configuration of a display/imaging device using a semi-transparent mirror and a liquid crystal panel as a display device, and Fig. 7 is a color 1 is a diagram showing a schematic configuration of a liquid crystal panel of an LCD. DESCRIPTION OF SYMBOLS 1... Display device, 2... Semi-transparent mirror, 3... Imaging device, 4... Micro PBS, 5... Liquid crystal panel, 6... Polarizing plate, 7... Backlight, 8...・・・
LCD panel for black and white display. Patent applicant Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. Consisting of a display device, an imaging device, and a semi-transparent mirror, the semi-transparent mirror is installed in front of the display device, and a subject in front of the semi-transparent mirror is used as a reflected image from the semi-transparent mirror. In display/imaging devices that capture images using imaging devices installed around them,
A liquid crystal display consisting of a liquid crystal panel and a polarizing plate installed behind the liquid crystal panel is used as the display device, and the semi-transparent mirror is a semi-transparent mirror that has a function of controlling transmission and reflection of incident light depending on the polarization state of the incident light. A display/imaging device characterized by the following. 2. The display/imaging device according to claim 1, wherein the semi-transparent mirror is a semi-transparent mirror made up of a combination of a plurality of semi-transparent mirrors having the above functions. 3. The display/imaging device according to claim 2, wherein the semi-transparent mirror is a semi-transparent mirror having wavelength selectivity of light.