# US 4,400,725 A · Picture display-image pickup apparatus

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- Number: US 4,400,725 A
- Document ID: US4400725A
- Status: Granted
- Kind: A
- Application number: 06/346,602
- Filed: 1982-02-08
- Granted: 1983-08-23
- Earliest claimed: 1980-01-25
- Inventors: Suzuyo Tanigaki
- Web page: https://patentgrep.com/patent/US4400725A

## CPC

- H04N 7/144: {camera and display on the same optical axis, e.g. optically multiplexing the camera and display for eye to eye contact}
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A picture display-image pickup apparatus for visual communication includes a picture display device and an image pickup device. The display device and pickup device are arranged on a substantially common optical axis directing to a talker.

## Claims

### Claim 1

A picture display-image pickup apparatus for visual communication comprising a display element made of a transillumination controllable material, the transparency and opaqueness of which may be controlled in accordance with an applied electric field, used in a picture display device which is arranged to face a talker, said picture display device further comprising an image pickup device, said image pickup device being arranged inside of and on the common optical axis of said display device.

### Claim 2 (depends on 1)

An apparatus according to claim 1, wherein a condensing lens is interposed between said picture display device and said image pickup device.

### Claim 3 (depends on 1)

The apparatus of claim 1 wherein said image pickup device is a vidicon.

### Claim 4 (depends on 1)

The apparatus of claim 1 wherein said material is a liquid crystal.

### Claim 5 (depends on 1)

The apparatus of claim 1 wherein said material is PLZT.

### Claim 6 (depends on 1)

The apparatus of claim 1 wherein said material is EC.

### Claim 7 (depends on 1)

An apparatus according to claim 1, wherein the image pickup device is a solid state image sensing element of the class comprising an array of individual sensing elements arranged in an X-Y matrix.

### Claim 8 (depends on 7)

An apparatus according to claim 7, wherein a condensing lens is interposed between said picture display device and said solid state image sensing element.

### Claim 9 (depends on 7)

An apparatus according to claim 7, wherein said picture display device and said solid state image sensing device are made to contact each other thereby to form a unitary structure.

### Claim 10 (depends on 7)

The apparatus of claim 7 wherein said elements are CCDs.

### Claim 11 (depends on 7)

The apparatus of claim 7 wherein said elements are BBDs.

### Claim 12 (depends on 7)

The apparatus of claim 7 wherein said elements are photodiodes.

### Claim 13 (depends on 7)

The apparatus of claim 7 wherein said image pickup device is an image orthicon tube.

### Claim 14 (depends on 1, 7)

An apparatus according to claim 1 or 7, wherein said picture display device includes two transparent plates, a liquid crystal sandwitched in between and a plurality of transparent electrodes formed horizontally and vertically on the inner sides of said transparent plates, respectively.

### Claim 15 (depends on 1, 7)

An apparatus according to claim 1 or 7, wherein said apparatus includes control means for controlling said picture display device and image pickup device such that said display device turns transparent after said transillumination controllable material is controlled into opaque to display a picture and the talker's image passes through said transparent display device to reach said pickup device which is operated during the transparent condition of said display device.