Full motion video telephone system

• US 5,202,957 A
• Filed: 08/09/1990
• Issued: 04/13/1993
• Est. Priority Date: 08/09/1990
• Status: Expired due to Fees

• Current Assignee: Future Communications
• Original Assignee: Future Communications
• Inventors: Serrao, Thomas M.
• Primary Examiner(s): Dwyer, James L.
• Assistant Examiner(s): WOO, STELLA L
• Application Number:
  US07/565,579
• Time in Patent Office: 978 Days
• Field of Search: 379/53, 379/93, 379/96, 358/85, 358/134, 358/137
• US Class Current: 348/14.15
• CPC Class Codes: H04N 7/10 Adaptations for transmission by electrical cable H04N7/12 takes precedence
• CPC Class Codes: H04N 7/142 Constructional details of the terminal equipment, e.g. arrangements of the camera and the display

Abstract

A full motion video telephone system combines mechanical scanning from the early era of television with modern video and digital communications technology for operation over conventional loaded bandwidth limited telephone lines. A camera pickup mechanical disk scanner causes scanning of an object in picture frames with an image resolution in the range of 30-90 scan lines per frame and full motion resolution in the range of 15-30 frames per second. A photomultiplier sensor generates an analog serial scanning signal with a bandwidth within the analog frequency range of 0-90 kHz. The synchronous motor of the mechanical scanner is synchronized with a first clock signal generated from a reference clock standard. Analog to digital conversion permits transmission by a high speed modem on the telephone lines. The receiving station is similar permitting full motion image reproduction with acceptable resolution. The camera receiver mechanical scanner is synchronized with respect to the same reference clock standard so that the camera pickup and camera receiver are in phase.

Claims

1. A system for transmission and reception over bandwidth limited telephone lines of full motion video image information of an object in real time comprising:

a full motion video camera pickup comprising a first mechanical flying spot scanner means for causing light scanning of an object in picture frames with an image resolution in the range of approximately 30-90 scan lines per frame and full motion resolution in the range of approximately 15-30 frames per second, said mechanical flying spot scanner means comprising photomultiplier sensor means generating an analog serial scanning signal having an analog signal bandwidth within the analog frequency range of approximately 20-36 kHz kHz comprising full motion image information of the object in real time;

first clock means for generating a first clock signal at the camera pickup in synchronism with a selected reference clock standard;

first synchronous drive means operatively coupled to said first mechanical flying spot scanner means for driving said scanner means in synchronism with said first clock signal;

analog to digital (A/D) converter means converting said analog serial scanning signal to a digital signal for transmission of said digital signal;

a bandwidth limited telephone line and first modem coupling means at a first location coupling said digital signal to said telephone line for transmission over the bandwidth limited telephone line;

a digital to analog (D/A) converter means at a second location and second modem coupling means for coupling the digital signal transmitted over said bandwidth limited telephone line to the D/A converter means for digital to analog conversion, said D/A converter means substantially reproducing the analog serial scanning signal comprising full motion image information of the object in real time;

a full motion video camera receiver comprising a second mechanical flying spot scanner means for causing projection and mechanical scanning of light in picture frames in accordance with said analog serial scanning signal for reproducing full motion image information about the object in real time;

said camera receiver comprising an LED array light source having light output controlled by the reproduced analog serial scanning signal;

second clock means for providing a second clock signal at the camera receiver substantially in synchronism with the first clock signal;

and second synchronous drive means operatively coupled to said second mechanical flying spot scanner means for driving said scanner means in synchronism with the second clock signal to provide scan lines per frame and frames per second substantially in synchronism with said first mechanical flying spot scanner means thereby reproducing a full motion image of the object in real time;

said camera pickup and camera receiver each comprising a mechanical scanning disk formed with scanning hole apertures arranged in a scanning configuration for light scanning in picture frame scan lines upon rotation of the scanning disc, with the number of scanning hole apertures being in the range of approximately 30-90, said first and second synchronous drive means being constructed to drive and rotate said respective scanning disks in revolutions per minute in the range of approximately 900-1800 RPM'"'"'s.

2. The system of claim 1 wherein each scanning disk is formed with approximately 60 hole apertures arranged to provide approximately 60 scan lines per frame and wherein the first and second synchronous drive means drive and rotate the respective scanning disks at approximately 1200 RPM, thereby providing full motion resolution of approximately 20 frames per second.

3. The system of claim 1 wherein the camera receiver comprises a projector lens for projecting the reproduced full motion image information of the object in real time on a screen.

4. The system of claim 1 further comprising a video recorder optically coupled to the camera receiver for recording and reproducing the reproduced full motion image information of the object in real time on a TV screen or video monitor.

5. The system of claim 1 wherein the mechanical flying spot scanner means comprises a light source and scanning disk constructed to provide a scanning window size of approximately 1"×

1" (2.5 cm×

2.5 cm).

6. The system of claim 1 wherein the analog to digital converter means is constructed to convert the analog serial scanning signal to a digital signal for transmission from the first location without interleaving and transmitting the first clock signal, and wherein the second clock means separately generates the second clock signal from said reference clock standard at the second location.

7. The system of claim 6 wherein the reference clock standard is a utility 60 Hz power supply available at the first and second locations.

8. The system of claim 1 wherein said first and second clock means for generating the first and second clock signals comprise clock circuits coupled to a standard utility 60 Hz power supply for separately deriving said first and second clock signals respectively from the standard utility 60 Hz power supply at said separate first and second locations.

9. The system of claim 1 wherein the modem coupling means are constructed to provide a transmission rate in the range of 2400-9800 baud.

10. The system of claim 1 wherein the camera pickup comprises said scanning disk, a light source on the side of the scanning disk opposite the object, and a photomultiplier tube detector on the same side of the scanning disk as the object.

11. The system of claim 1 wherein the camera pickup comprises said scanning disk, a light source on the same side of the scanning disk as said object illuminating said object, and a photomultiplier tube detector on the opposite side of the scanning disk from said object.

12. The system of claim 1 wherein the telephone line comprises a standard loaded telephone line with effective analog signal bandwidth in the range of approximately 0-4 kHz.

13. A system for transmission and reception over bandwidth limited telephone lines of full motion image information of an object in real time comprising:

a full motion image camera pickup comprising first mechanical scanning means for causing scanning pickup of light amplitude image information of an object in picture frames with an image resolution in the range of approximately 30-90 scan lines per frame and motion resolution in the range of approximately 15-30 frames per second for full motion image information, and photomultiplier light detector means generating an analog serial scanning signal encoding said light amplitude image information about the object with an analog signal bandwidth in the range of approximately 20-36 kHz;

first clock signal circuit means for generating a first clock signal in synchronism with a selected reference clock standard;

first synchronous motor drive means operatively coupled to the first mechanical scanning means for causing scanning pickup in synchronism with said first clock signal for preserving phase image information about the object;

A/D converter means converting said analog serial scanning signal to a digital signal;

a bandwidth limited telephone line and first modem coupling means at a first location coupling said digital signal to the telephone line for transmission to a second location;

D/A converter means for converting said digital signal transmitted over the telephone line to reproduce said analog serial scanning signal encoding the light amplitude image information about the object and second modem coupling means at the second location coupling said digital signal from the telephone line to the D/A converter means;

a full motion image camera receiver comprising second mechanical scanning means for causing scanning projection of the light amplitude image information encoded in said reproduced analog serial scanning signal;

said camera receiver comprising an LED array light source having light output controlled by the reproduced analog serial scanning signal;

second clock signal circuit means for generating a second clock signal in accordance with said selected reference clock standard;

and second synchronous motor drive means operatively coupled to the second mechanical scanning means for causing scanning projection in synchronism with said second clock signal and substantially in synchronism with the scanning pickup by the first mechanical scanning means of said full motion image camera pickup, thereby preserving the phase image information about the object for effective scanning projection of the light amplitude image information in said picture frames to reproduce a full motion image of said object in real time;

said camera pickup and camera receiver each comprising a mechanical scanning disk formed with scanning hole apertures arranged in a scanning configuration for light scanning in picture frame scan lines upon rotation of the scanning disc with the number of scanning hole apertures being in the range of approximately 30-90, said first and second synchronous drive means being constructed to drive and rotate said respective scanning disks in revolutions per minute in the range of approximately 900-1800 RPM'"'"'s.

14. The system of claim 13 wherein the bandwidth limited telephone line comprises a loaded telephone line with effective analog signal bandwidth in the range of approximately 0-4 kHz.

15. The system of claim 13 wherein the first mechanical scanning means causes scanning pickup with image resolution at the preferred spatial frequency of approximately 60 scan lines per frame, and with motion resolution at the preferred temporal frequency of approximately 20 frames per second.

16. The system of claim 13 wherein the analog to digital converter means is constructed to convert the analog serial scanning signal to a digital signal for transmission from the first location without interleaving and transmitting the first clock signal, and wherein the second clock means separately generates the second clock signal from said reference clock standard at the second location.

17. The system of claim 16 wherein the reference clock standard is a utility 60 Hz power supply available at the first and second locations.

18. The system of claim 13 wherein the image resolution is approximately 60 scan lines per frame, and the motion resolution is approximately 20 frames per second;

wherein the first and second coupling means comprise modems with a transmission rate of approximately at least 4800 baud; and

wherein the bandwidth limited telephone line comprises a loaded line with an analog signal bandwidth of approximately 0-4 kHz.