JPH0750820A - Display image pickup device - Google Patents

Abstract

PURPOSE:To realize alignment of visual line and to improve the picture quality of a display screen in the display image pickup device used for a video telephone system or a video conference system. CONSTITUTION:An optical deflection element 3 whose transparent state or reflecting state is selected with respect to an incident light is arranged in front of a display device 1 and an image pickup device 2 in a way that the display device 1 is observed in the transparent state and the image pickup device 2 picks up the image of the user M in the reflecting state. Either of the two states of the optical deflection element 3 is switched in time division at a shorter interval than one frame period by a controller 5 and the image pickup device 2 is controlled in the reflecting state to pick up an image of the user M. Thus, it is possible to pick up the image of the user M from the direction of observing the display and a picture in which visual lines of the users are aligned is displayed and picked up. Furthermore, since the display is observed in the transparent state, no picture quality deterioration of the display screen is caused and the method adopts the display device of any kind.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display / image pickup device in which a display device and an image pickup device used in a TV telephone or a TV conference system are combined.

[0002]

2. Description of the Related Art In recent years, two-way video communication such as a TV telephone and a TV conference system in which remote locations are connected by a video / audio communication network has rapidly spread due to the development of communication technology such as image coding technology. . In the future, it is expected that a more realistic video service can be provided by enhancing the ISDN network and increasing the bandwidth of the transmission network.

FIG. 6 shows a display / imaging device currently used for two-way video communication. The image pickup device 2 is on the upper surface or the side surface of the display device 4 such as a CRT display, and picks up an image of the user M. However, since the user M who uses such a device normally looks at the display device 4, the user M does not turn his / her sight line toward the image pickup device 2 even if the image pickup device 2 takes an image. . Therefore, there is a drawback in that even if it is possible to transmit a highly realistic image, it becomes an unnatural conversation in which the line of sight of the interlocutors do not match.

[0004] By switching the light transmission / scattering state of the display screen at a high speed, a method of making the lines of sight of the interlocutors coincident with each other and capable of supporting a large screen display used in a TV conference system and the like is time-shared. There is a method (see Japanese Patent Laid-Open No. Hei 2)
-228893). In this method, as shown in FIG. 7, the display screen 4 having the above-mentioned functions, the projection display device 1 including a projection device, the imaging device 2, and the light transmission / scattering state of the display screen 4 are switched at high speed. And a control device 5 for controlling display and imaging in a time-divisional manner. When the display screen 4 is in a scattering state,
The projection type display device 1 displays the screen projected, and in the transmissive state, the user M, who is a subject, is imaged by the imaging device 2 through the display screen 4, thereby achieving line-of-sight matching.

[0005]

However, since the display screen having such a function is inferior in performance of displaying a projection image as compared with the original projection screen, the display and the image pickup are performed in a time division manner. The conventional method has a drawback that the display quality is deteriorated. For example, in this method, since the Fresnel lens cannot be inserted between the display screen 4 and the projection display device 1, the central portion of the display image projected on the display screen 4 is bright, but the peripheral portion is extremely dark. There are drawbacks. Furthermore, at the time of image pickup, that is, when the display screen 4 is in the transmissive state, the user M directly sees the projection light of the projection display device 1, so that a large bright spot corresponding to the projection port of the projection display device 1 is displayed on the display screen. Has a drawback.

The present invention has been made to solve the above problems, and an object of the present invention is to improve the image quality of a display screen in a display / imaging device used in a TV phone, a TV conference system or the like. It is an object of the present invention to newly provide a display / imaging device that realizes line-of-sight matching by a time division method.

[0007]

In order to achieve the above-mentioned object, a display / imaging device of the present invention is a display / imaging device comprising a display means and an imaging means, in front of the display means and the imaging means. An optical element capable of outputting incident light by switching the incident light to an arbitrary outgoing direction, and providing control means for time-divisionally switching the outgoing direction from the optical element to the display means and the imaging means. Is characterized by.

[0008]

In the display / imaging device of the present invention, the light path is changed by time-divisionally switching the emitting direction of the incident light of the display device and the optical element installed in front of the imaging device to the display means and the imaging means. Instead, the display is made visible to the user in the direction of the display means, and the user can be imaged from the direction in which the display is viewed in the direction of the image pickup means, thereby achieving line-of-sight matching. In this way, by not using a special display screen, deterioration of display quality is prevented. That is, by changing the light path at the time of display and at the time of image pickup by the optical element, for example, the display is not seen as a bright spot at the time of image pickup, and the image quality of the display image is reduced only by changing the direction of the display light at the time of display. Hold down,
Furthermore, make it visible regardless of the type of display means,
Enables measures to reduce the brightness of the peripheral area.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

[Embodiment 1] FIG. 1 shows a block diagram of a first embodiment of a display / imaging device according to the present invention. In this embodiment,
As shown in FIG. 1, in front of the display device 1 and the image pickup device 2, a light deflection element 3 capable of switching the outgoing direction of outgoing light with respect to incident light (in the present embodiment, corresponds to the optical element of the present invention. Have been installed. The control device 5 electrically changes the emission direction of the light incident on the light deflection element 3. In the case of the illustrated example, the direction of the change is when the display light from the display device 1 is directly emitted to the direction of the user M (display state).
And two directions when the light from the user M is emitted toward the imaging device 2 (imaging state). In the display state, the user M can see the display device 1 through the light deflection element 3, and in this state, the light deflection element 3 is in a transparent state in principle, so that the display screen is not deteriorated. In the image pickup state, the user M will see the image pickup apparatus 2. That is, the image of the user M can be taken by the imaging device 2 under the control of the control device 5. However, the periphery of the image pickup device 2 needs to be dark. This is because the user M looks at the image pickup device 2 as described above at the time of image pickup, and the display image quality at the time of display deteriorates unless it is kept dark. In addition, at the time of imaging, the display device 1 is used by the user M.
Since it is not visible from the user, the display may be continued as it is, but in order to eliminate the possibility of the display being reflected on the imaging device 2, the display of the display device 1 may be stopped by the control of the control device 5 at the time of imaging. It is also possible to do so.

By switching between these two states in a time-division manner at intervals shorter than one frame period, it is possible to display and capture an image in which the lines of sight of the users are matched. In the present embodiment, since the display screen for switching the light transmission / scattering state at high speed is not used for realizing the line-of-sight matching, the display quality does not deteriorate as in the conventional case. For example,
Since the light path is changed between the image pickup state and the display state, the display becomes invisible at the time of image pickup, and the projection type display device does not appear as a bright spot at the time of image pickup unlike the conventional case. Further, at the time of display, the image displayed on the display device 1 is displayed on the light deflection element 3 in a transparent state.
Therefore, the deterioration of the quality of the display image can be suppressed. Further, since the type of the display device 1 is not limited, a display unit that does not have a brightness reduction in the peripheral portion of the display screen or has a measure against the brightness decrease can be used.

FIG. 2 shows a sectional view of an example of the structure of the optical deflecting element 3 used in this embodiment. In this structural example, the low-refractive index layers 6 and the high-refractive index layers 7 are alternately laminated at an angle θ with respect to the surface direction of the optical deflector 3. In such a structure, the incident light is totally reflected by the low refractive index layer 6 by appropriately selecting θ. here,
The high refractive index layer 7 is made of a material whose refractive index can be electrically controlled, for example, liquid crystal, and by applying a voltage to the high refractive index layer 7, the same refractive index as that of the low refractive index layer 6 can be obtained. To configure. As shown in FIG. 2, when a voltage is applied, the low-refractive index layer 6 and the high-refractive index layer 7 have the same refractive index, so that the incident light goes straight in the order of A → O → a in the figure. And emit. On the other hand, when no voltage is applied, the incident light is totally reflected at the point O, so that it is emitted in a certain angle φ direction by following the path of A → O → a '. Therefore, the configuration shown in FIG. 1 can be realized by installing the display device 1 in the normal line direction of the light deflection element 3 and the imaging device 2 in the φ direction from the normal line direction. Here, the relationship between φ and θ is φ = 2θ, and θ is the ratio (n ₆ / n of the refractive index of the low refractive index layer 6 and the high refractive index layer 7 to the following conditional expression derived from the total reflection condition: ₇ ) Substitute and decide.

Θ ≧ sin ⁻¹ (n ₆ / n ₇ ) [Embodiment 2] FIG. 3 shows a second display / imaging device according to the present invention.
The block diagram of the Example of FIG. In this embodiment, the optical deflecting element 3 in which θ in FIG. 2 is set to 0 ° is used, and the optical deflecting element 3 is a dielectric multi-layer mirror formed by stacking a low refractive index layer 6 and a high refractive index layer 7. ing. However, when a voltage is applied to this laminated structure as described in Example 1, the low refractive index layer 6 and the high refractive index layer 7 have the same refractive index, and thus are optically transparent. Such a light deflection element 3 is provided in front of the display device 1 and the image pickup device 2, in the transmission direction of the incident light from the user M with respect to the display device 1, and in the reflection direction with respect to the image pickup device 2. So that

In such a structure, if the light deflection element 3 is electrically switched between the transparent and reflective states at high speed under the control of the control device 5 as in the first embodiment, the display of the display device 1 can be seen in the transparent state. In the reflective state, the image pickup device 2 can pick up the image of the user M from the direction in which the display is viewed. That is, as in the case of the first embodiment, it is possible to display and capture an image in which the line of sight of the users are matched, and a display screen that switches the light transmission / scattering state at high speed is not used for realizing the line of sight. There is no deterioration in display quality as in the past.

[Embodiment 3] FIG. 4 shows a block diagram of a display / imaging apparatus according to a third embodiment of the present invention. Example 1 of FIG.
Alternatively, the second embodiment of FIG. 3 is, so to speak, a transmissive type that controls transmitted light, whereas this embodiment is equivalent to a reflective type.
By controlling the reflection direction, the same effect as that of the first embodiment can be obtained. As the optical element used in this embodiment, the optical deflecting element 3 shown in FIG. This optical element is provided in front of the display device 1 and the imaging device 2, and when the light deflection element 3 is in a transparent state, the mirror 8 reflects the incident light from the user M to the display device 1 and the light deflection element 3 In such a case, it is arranged so as to be inclined at an angle such that the image is reflected by the image pickup device 2 in the reflection state.

In a state corresponding to the display state described in the first embodiment, the display light from the display device 1 is directly reflected by the mirror 8,
The user M will see this reflection image. Therefore, since the image displayed on the display device 1 is only reflected by the optical element, it is possible to suppress the deterioration of the display quality. Further, in the image pickup state, the light is totally reflected by the light deflection element 3, and the reflected light is directed to the image pickup apparatus 2, so that the image of the user M can be picked up from the direction in which the display is viewed, and the line-of-sight matching is realized. can do.

In this embodiment, the optical element of the present invention is constructed by combining the light deflecting element 3 and the mirror 8. However, instead of these optical elements, the angle of the reflecting surface can be set arbitrarily. Mirror array (LJ Hornbeck, "De
formable-mirror spatial l
light modulators ”, SPIE, 115
0,86 (1989)) can also be used. FIG. 5 shows a sectional view of an example of the structure of the micromirror array. In this structural example, the micromirrors 8'supported at the center by the support rods 9 are arranged in an array, and the electrodes 10a and 10b are installed on both sides of the support rods 9 below the micromirrors 8 '. When voltages of −V and + V are applied to the electrodes 10a and 10b, respectively, the inclination of the micromirror 8 ′ changes due to electrostatic force. For example, when no voltage is applied to the electrodes 10a and 10b, the micromirror 8'maintains horizontal, and the light incident from the A direction is reflected by the micromirror 8'and emitted in the A1 direction. On the other hand, when a voltage is applied to the electrodes 10a and 10b, the micromirror 8'is tilted and the reflection direction changes to the A2 direction.
Here, the display device 1 is in the A1 direction and the imaging device 2 is in the A2 direction.
By installing, the structure shown in FIG. 4 can be realized. In that case, needless to say, the light deflection element 3 and the mirror 8 are not necessary.

In each of the above embodiments, the case where the image pickup device 2 is installed below the display device 1 has been shown, but it goes without saying that it is possible to install the image pickup device 2 above or to the side by changing the configuration of the light deflection element 3. Yes. Further, it is obvious that the same effect can be obtained even if the positions of the display device 1 and the imaging device 2 are exchanged.

[0019]

As described above, according to the present invention,
By using an optical element that can control the incident light in an arbitrary outgoing direction, it is possible to realize and provide a display / imaging device that allows easy line-of-sight matching, and the image light displayed on the display means can be provided by this optical element. Since only the direction is changed, it is possible to suppress deterioration in the quality of the displayed image. Further, there is an advantage regardless of the type of display device used.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a display / imaging device (transmissive type) according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a structural example of an optical deflecting element used in an embodiment of the present invention.

FIG. 3 is a configuration diagram showing a display / imaging device (transmission type) according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a display / imaging device (reflection type) according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a structural example of an optical element using a micromirror array that can be used in the third embodiment.

FIG. 6 is a block diagram showing a conventional display / imaging device.

FIG. 7 is a configuration diagram showing a conventional display / imaging device that achieves line-of-sight matching by a time division method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Display device 2 ... Imaging device 3 ... Optical deflection element 5 ... Control device 6 ... Low refractive index layer 7 ... High refractive index layer 8 ... Mirror 8 '... Micromirror 9 ... Support rods 10a, 10b ... Electrodes

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sowa Date 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. A display / imaging device comprising a display means and an imaging means, wherein an optical element capable of switching incident light to an arbitrary outgoing direction and emitting the light is disposed in front of the display means and the imaging means. A display / imaging device comprising a control means for time-divisionally switching the output direction from the optical element to the direction of the display means and the imaging means.