Importance

Loading Importance Indicators...

Abstract

A digital data recovery circuit for recovering digital data recorded on a magnetic record medium along with still-image video signals in a frequency mulitplexed relationship employs two phase-control-loops, in which the first loop corrects absolute or DC phase errors and the second phase-control-loop corrects AC phase errors evidenced as abrupt phase shifts of the digital data signal caused by changes in rotation of the magnetic record by using a horizontal synchronization signal derived from the video signal, and in which the outputs of loop filters included in the first and second phase-control loops, respectively, are combined to provide a control signal for a voltage controlled oscillator that provides a demodulating carrier signal so that a synchronous detector can detect the digital data signal, thereby to cause the synchronous detector to lock onto even abrupt phase shifts in the carrier of the digital data signal.

Loading the Abstract Image...

First Claim