Patent · US Expired

Sound channel circuit for digital television receivers

US5202766A · kind A · utility

12Cited by

9References

6Claims

0Family size

Assignee

Deutsche ITT Industries, GmbH · DE

Inventors

Sonke Mehrgardt · March, DE
Heinrich Pfeifer · Denzlingen, DE
Thomas Hilpert · Denzlingen, DE

Key dates

Filing date	Sep 11, 1989
Grant date	Apr 13, 1993
Priority date	—
Expiry date	Sep 11, 2009

Classification

Technology area (CPC H)Electricity
CPC primaryH04N5/605
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

A circuit capable of handling all television sound transmission standards, including the "NICAM" standard. The circuit contains an analog antialiasing low-pass filter which is fed by the analog sound and video signal and followed by an analog-to-digital converter. The output of the latter is freed from the video signal by a filter circuit. The digital sound signal is applied to a phase splitter having a 0.degree. output and a 90.degree. output which are connected to a phase discriminator. An absolute-value output of the phase discriminator provides the amplitude-demodulated sound signal, while a phase-angle output feeds the DQPSK portion of a "NICAM" decoder and a differentiating stage, which delivers the frequency-modulated sound signal.

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