Patent · US Expired

Digital video modulation and demodulation system

US3993861A · kind A · utility

110Cited by
8References
18Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 24, 1975
Grant dateNov 23, 1976
Priority date
Expiry dateMar 24, 1995

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N5/0675
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

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 these 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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.