Patent · US Expired

Modulated sound reading system

US4085296A · kind A · utility

14Cited by
7References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 19, 1975
Grant dateApr 18, 1978
Priority date
Expiry dateDec 19, 1995

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B20/24
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A motion picture sound reading system employing a light emitting diode source which is modulated at a carrier frequency several times higher than the highest sound-track frequency for exciting the optical sound track and a carrier-demodulation signal processing system for deriving a high-quality audio signal from the photoelectrically detected optical sound track.

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