JPH05328336A - Display/image pickup device - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a videophone and a videoconference terminal capable of line-of-sight matching without increasing the size of the device or degrading the display resolution. [Structure] The image pickup device 13 is arranged so as to look into the display surface 14, and a hologram 12 that reflects only light of a specific wavelength and focuses it on the image pickup device 13 is arranged in front of the display surface 14. Of the light reflected by the transmitter 11, only the specific wavelength is reflected by the hologram 12 and enters the image sensor 13. On the other hand, the light emitted from the display surface 14 displaying the listener is
The hologram 12 reflects a specific wavelength, but other wavelengths pass through the hologram 12 and reach the sender 11. [Effect] The transmitter / receiver can talk while looking at the face of the other party from the front. Since the hologram is a thin film and has no visible shape, the display resolution does not deteriorate, and the hologram can be miniaturized.

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 such as a video telephone and a video conference terminal.

[0002]

2. Description of the Related Art With the development of communication technology, demands for videophones and videoconferences capable of face-to-face communication are increasing. Up to now, as a means for realizing this kind of face-to-face communication, as shown in FIG. 7, a videophone having a display surface 72 for displaying the face of the listener and an image pickup device 73 for picking up the face of the talker 71, has been used. Video conference terminal devices are commercially available. However, in these devices, the image sensor 73 makes the speaker 71 looking into the screen of the display surface 72 obliquely (see FIG.
Since it was taken from above), there was a fundamental drawback in that the face of the listener could not be seen from the front. Generally, a state in which a transmitter / receiver can talk with the other person's face from the front is called a line-of-sight match state.

Conventionally, as a display / imaging device for a videophone / videoconference which realizes line-of-sight matching, a half mirror 8 tilted at 45 ° in front of a display surface 82 as shown in FIG.
4, the image pickup element 83 and the display surface 82 are placed on the half mirror 8
There is a configuration in which they are arranged in the direction of 45 ° with respect to 4, respectively. However, this configuration requires a large space in front of the display surface 82, and has a drawback that the device cannot be downsized. As a method of solving this, as shown in FIG. 9, a configuration has been proposed in which a half mirror 94 obtained by dividing the half mirror 84 of FIG. 8 into strips is attached to a display surface 92. With this configuration, the size of the device can be reduced, but the presence of the split half mirror 94 on the display surface 92 causes
There is a problem that the display resolution deteriorates.

[0004]

As described above, the conventional display / imaging devices such as videophones and videoconference terminals capable of face-to-face communication cannot perform videophones / videoconferences that are basically line-of-sight. Or even if I could,
There is a problem that the device becomes large or the display resolution deteriorates.

An object of the present invention is to provide a display / imaging device which solves all the problems of the prior art.

[0006]

In order to achieve the above object, the display / imaging apparatus of the present invention arranges an image pickup device so as to look into the display surface, and provides the image pickup device with a single or a plurality of specific wavelengths. That is, the hologram for reflecting and condensing the light is arranged in front of the display surface.

Further, in the display / imaging device of the present invention, the wavelength of the display material used on the display surface may be different from the wavelength of the light reflected by the hologram.

Further, in the display / imaging device of the present invention, the hologram arranged in front of the display surface may be a laminated body of holograms for reflecting and condensing single or plural wavelengths.

[0009]

The structure having a fine multi-layer structure having a light wavelength level and having a refractive index difference between layers reflects light having a specific wavelength determined by the interlayer pitch. This is a structure used in a Lippmann type hologram to obtain a stereoscopic image, and is beginning to be applied as a hologram optical element that causes a light condensing action in addition to a stereoscopic image. In this Lippmann type hologram, a reflection action occurs in a narrow wavelength range near a specific wave, and the remaining wavelengths can be made transparent.

In the present invention, by utilizing such a property of the hologram, of the light reflected by the speaker, only a specific wavelength is reflected by the hologram and is incident on the image pickup device, while it is emitted from the display surface. Of the lights, those other than the specific wavelength are passed through the hologram to reach the talker. As a result, a videophone / videoconference that matches the line of sight can be realized, and conversation can be performed in a natural environment. Further, since the hologram can be formed into a thin film and has no visible shape, the display resolution is not deteriorated and the device can be further downsized.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing an outline of a display / imaging device of the present invention. In FIG. 1, 11 is a talker, 12 is a film hologram, 13 is an image pickup device such as a CCD, and 14
Is a display surface such as a liquid crystal display. Hologram 12
Are arranged by pasting them on the display surface 14, and
3 is arranged so that the display surface 14 is seen.

With the configuration shown in FIG. 1, of the light reflected by the sender 11, only the specific wavelength can be reflected by the hologram 12 and incident on the image pickup device 13. On the other hand, the light emitted from the display surface 14 that displays the face of the listener, etc. does not reach the talker 11 because the specific wavelength is reflected by the hologram 12, but the other wavelengths pass through the hologram 12 and are transmitted. Person 1
Reach 1.

FIG. 2 shows the relationship between the hologram wavelength (λ) and the reflected light intensity (I). In the configuration of FIG. 1, when a hologram manufactured with a single wavelength is used as the hologram 12, as shown in FIG. 2A, light of a narrow specific wavelength (the wavelength of the laser light used for manufacturing the hologram is almost Since only the same) is reflected and condensed, the imaged image of the image sensor 13 is monochromatic. However, holograms were created by multiple exposure at multiple wavelengths, especially at the wavelengths containing the three primary colors.
A color image can be captured by using a hologram having a reflection characteristic as shown in (b). In this case, a laminated body of holograms having a single wavelength or a plurality of wavelengths may be used.

Further, in the configuration of FIG. 1, the image pickup device 13
The incoming light is the light reflected from the hologram 12, and the light reaching the speaker 11 from the display surface 14 is the remaining wavelengths reflected by the hologram 12. Therefore, in order to make the display screen of the display surface 14 bright, it is necessary to reduce the wavelength band width that is lost by being reflected by the hologram 12.
In order to obtain a bright imaging screen in 3, it is necessary to widen the wavelength band reflected by the hologram 12. When the image pickup screen is dark and the sensitivity of the image pickup device 13 is poor, a hologram having a large number of reflection wavelengths may be used as the hologram 12, as shown in FIG. In this case, the display screen becomes dark, but as shown in FIG. 2D, this can be prevented by making the wavelength of the display material used for the display surface 14 (broken line portion) different from the wavelength of the light reflected by the hologram (solid line portion). .. Also in the case of a color image, a display surface and an image pickup screen can be obtained that do not cause discomfort to the talker and the receiver if the display and the image pickup appropriately include the three primary colors.

FIG. 3 is a diagram for explaining a method of manufacturing a hologram used in the present display / imaging device. In the actual production, the film (dry plate) 31 is a silver salt emulsion film (S for ilford, which is generally used for producing a stereoscopic image hologram).
P673) was used. As the laser, a He-Ne laser was used.

FIG. 3A shows that a hologram is produced by the interference of the divergent laser beam 32 from the portion where the image pickup device is placed and the parallel laser beam 33 emitted from the back side of the film 31. The hologram is completed by developing the film 31 and bleaching silver. However, in this method, in FIG. 1, of the light reflected by the transmitter 11, only the light whose direction coincides with the parallel laser light used for manufacturing the hologram enters the image pickup device 13, so that the light collection efficiency is improved. bad.
In FIG. 3B, the film 3 is used to improve the light collection efficiency.
As the laser light to be radiated from the back side of the laser beam 1, the laser beam 3 that gently diverges instead of the parallel laser beam 33 of FIG.
4 is used. In this method, since the light is effectively collected, the amount of light entering the image sensor 13 is increased.
Further, in FIG. 3C, instead of the parallel laser light 33 of FIG. 3A, laser light 35 from multiple directions is irradiated from the back side of the film 31, and the light collection efficiency is further improved.

The hologram actually manufactured by the method of FIG. 3 was pasted on the front surface of the display surface of a full-color liquid crystal display having a diagonal of about 10 inches, and the CCD was placed at the light source position of the divergent laser light.
When the image pickup device of No. 3 was installed and the speaker was looked into from the front of the liquid crystal display, a red image of the talker was seen on the image pickup device. This is because only the wavelength of 633 nm of the He-Ne laser used for writing was selectively reflected and condensed and imaged. On the other hand, from the display surface of the liquid crystal display, light of 633 nm should be reflected by the hologram so that it cannot be seen by the transmitter, but other wavelength components are transmitted through the hologram, so that a display with no discomfort was obtained.

FIG. 4 shows another method of manufacturing a hologram used in the present display / imaging device. He-N shown in FIG. 4 (a) is shown as a divergent laser beam from a portion where an image sensor is placed.
4B and 4C as well as the light 42 from the e-laser
As shown, two wavelengths from an Ar laser (488 nm, 5
The film 41 is subjected to multiple exposure with light beams 43 and 44 (14.5 nm), and then a hologram is produced. Actually, when the hologram produced by this method was arranged in the same manner as described above, it was found that the He-Ne 633n
Reflected light of a total of three wavelengths of 488 nm and 514.5 nm of m laser and Ar laser was captured, and the captured image could be a color image. That is, the hologram having the reflection characteristic shown in FIG. 2B was obtained. On the other hand, although the transmission of these wavelength bands is obstructed by the hologram, the display screen was not as strange as on the left.

FIGS. 5 and 6 show an embodiment in which a hologram used in the present display / imaging device is constituted by a laminate of a plurality of holograms.

FIG. 5 shows a hologram 51 produced by a He-Ne laser as shown in FIG. 4A, and FIG. 4B and FIG. c)
Two kinds of holograms 52 prepared by the Ar laser as described above are prepared, and these are laminated to form the hologram 53. In this case, a silver salt emulsion film having optimum sensitivity to the laser wavelength used can be used for producing the holograms 51 and 52 (for example, I1for for a wavelength of 633 nm).
The SP53 manufactured by the d company, the SP672 manufactured by the company for wavelengths of 488 nm and 514.5 nm, etc.), and the hologram 53 in which these are stacked have three wavelengths reflected in a well-balanced manner, which has the effect of improving image quality.

FIG. 6 shows a hologram 61 in which the hologram produced as shown in FIGS. 3 and 4 is swollen in a solvent to shift the wavelength at which reflection occurs and the hologram 62 is not swollen.
The hologram 63 is laminated on the
There is an effect that the reflection wavelength is increased and the amount of light entering the image pickup device is improved to be bright.

The gist of the present invention is to introduce an image of a speaker who looks at the display surface into an image pickup device by using a hologra which reflects a specific single or a plurality of wavelengths and focuses the light at a specific place. , To match the line of sight of the listener. Therefore, it is obvious that other than the above-mentioned embodiment can be used within the scope of this gist. For example,
It is obvious that the hologram can be used in addition to the above-mentioned materials, and various films developed for the hologram can be used. As the laser light used for producing the hologram, various lasers other than the above can be used. For example, if a wavelength tunable laser such as a dye laser is used, writing at an arbitrary wavelength or multiplexing of an arbitrary number of wavelengths can be performed, and reflection / transmission wavelengths can be arbitrarily selected to improve image quality of a display surface and an imaging screen. It is obvious that the brightness can be adjusted to a desired level.

Further, it is obvious that various methods such as the setting of the laser light source in consideration of the position of the illumination to the talker can be made in the method of increasing the light collection efficiency by the multiple exposure in which the position of the laser light source is changed.

[0025]

According to the first aspect of the present invention, it is possible to realize a videophone / videoconference with line-of-sight matching, and to have a dialogue in a natural environment. Further, since the hologram has a thin film-like shape and has no visible shape, the display resolution is not deteriorated and the apparatus can be downsized.

According to the second aspect of the invention, all the light emitted from the display surface reaches the talker without being reflected by the hologram, so that, for example, the image pickup screen is dark and the sensitivity of the image pickup element is low, and a large number of reflection wavelengths are reflected. Even when using a hologram having, it is possible to prevent the display screen from becoming dark. Further, in the case of a color image, if the display and image pickup wavelengths appropriately include the three primary colors, a display screen and an image pickup screen can be obtained which will not cause discomfort to the sender and the receiver.

According to the third aspect of the present invention, the image quality can be improved by using a hologram in which each hologram is made of a film having the optimum sensitivity for the laser wavelength to be used and laminated. Alternatively, by using a laminate in which the produced hologram is swollen in a solvent and is not swollen in the solvent, the reflected wavelength is increased, and the captured image can be brightened.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a display / imaging device of the present invention.

FIG. 2 is a diagram illustrating a reflection wavelength of a hologram.

FIG. 3 is a diagram showing a method of manufacturing a hologram used in the present invention.

FIG. 4 is a diagram showing a method of manufacturing a hologram by multiple exposure.

FIG. 5 is a diagram showing an example of a multilayer hologram.

FIG. 6 is a diagram showing another example of a multilayer hologram.

FIG. 7 is a diagram showing an example of a conventional display / imaging device.

FIG. 8 is a diagram showing an example of a conventional display / imaging device that realizes line-of-sight matching.

FIG. 9 is a diagram showing an example of a conventional display / imaging device that realizes improved line-of-sight matching.

[Explanation of symbols]

 11 Speaker 12 Hologram 13 Image sensor 14 Display surface

Claims (3)

[Claims] 1. A display unit, an image pickup device arranged so as to look into the display surface of the display unit, and a light beam having a specific wavelength or a plurality of specific wavelengths arranged in front of the display face and reflected by the image pickup device. A display / imaging device comprising a hologram capable of condensing light. 2. The display / imaging device according to claim 1, wherein the wavelength of the display material used for the display surface is different from the wavelength of the light reflected by the hologram. 3. The display / imaging device according to claim 1, wherein the hologram comprises a laminated body of holograms that reflect and collect a single wavelength or a plurality of wavelengths.