[ 54 ] DIGITAL VIDEO MODULATION AND DEMODULATION SYSTEM
[ 75 ] Inventor: Ralph H. Baer, Manchester, N. H.
[ 73 ] Assignee: Sanders Associates, Inc., South Nashua, N. H.
[ 22 ] Filed: Mar. 24, 1975
[ 21 ] Appl. No.: 561,131
[ 52 ] U. S. Cl.178/5.6; 178/DIG. 1
[ 51 ] Int. Cl.2H04N 7/00
[ 58 ] Field of Search178/5.6, DIG. 1, DIG. 23, 178/DIG. 35, DIG. 38
[ 56 ] References Cited
UNITED STATES PATENTS
| 3,369,073 | 2/1968 | Scholz | 178/5.6 |
| 3,493,674 | 2/1970 | Houghton | 178/5.6 |
| 3,663,937 | 5/1972 | Bolner | 178/DIG. 1 |
| 3,728,480 | 4/1973 | Baer | 178/DIG. 1 |
| 3,737,566 | 6/1973 | Baer et al. | 178/5.8 R |
| 3,743,767 | 7/1973 | Bitzer et al. | 178/DIG. 23 |
| 3,891,792 | 6/1975 | Kimura | 178/5.6 X |
| 3,900,887 | 8/1975 | Soga et al. | 178/DIG. 23 |
Primary Examiner–Richard Murray
Assistant Examiner–Aristotelis M. Psitos
Attorney, Agent, or Firm–Louis Etlinger; Richard I. Seligman
[ 57 ] ABSTRACT
In a television system, a digital video system permits the transmission of data along with the usual television picture. The television picture field includes one or more selectively addressable areas and the data is imprissed on these areas as digital, binary-coded brightness modulations at rates greater than the vertical field rate. At the receiving end of the system, the viewer positions one or more light sensors opposite those screen areas. The light sensors respond to the binary-coded brightness modulations by developing corresponding binary-coded digital electrical signals. The data stream from a light sensor can then be decoded by a demodulator/decoder operated by the viewer.
18 Claims, 6 Drawing Figures
_-_p30.png)
–28–
