Patent · US Expired

Digital flutter reduction system

US3938184A · kind A · utility

11Cited by
2References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 21, 1975
Grant dateFeb 10, 1976
Priority date
Expiry dateMar 21, 1995

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K5/1534
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A digital flutter reduction system which corrects for a varying time base ror in FM recordings on magnetic tape. Pulse transitions from the outputs of a reference oscillator and a reference tone on a first tape track are compared by a flip-flop whose output is a pulse having a width corresponding to the time base error. The output pulse enables a first counter to provide a digital output which is loaded into a second counter. Pulse transitions from a second tape track containing recorded data advance the second counter over a number of counts indicative of a correction factor. The pulse transitions of the recorded data are delayed in accordance with the correction factor thereby reducing the time base error.

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