JPS57154606A - Processing circuit for time base of reproducing sound of variable speed reproducing device - Google Patents

Abstract

PURPOSE:To obtain a low-cost and high-practicality variable speed reproducing VTR device or stereo sound recording device, by processing a monaural signal, which is obtained by adding signals of channels L and R, in one time base compressing and expanding circuit in case of variable speed reproducing of a stereo signal. CONSTITUTION:Reproduced signals of two systems L and R from a sound reproducing circuit 1 through VTR reproducing heads PHl and PHr are inputted to an output switching circuit 2. The sound of the channel L is outputted to terminals 9 and 10 simultaneously by closing of contacts 3 and 4, and the sound of the channel R is outputted to terminals 9 and 10 simultaneously by closing contacts 6 and 7, and reprodued sounds of channels L and R are outputted to terminals 9 and 10 respectively by closing of stero contacts 5 and 8. A switch circuit 11 is closed, and normal open terminal sides of switches S3, S4, S5, and S6 are closed simultaneously with starting of the variable speed reproducing operation, and reproduced sounds of two systems are converted to a sum signal by a signal adder 22, and this sum signal has the time base compressed or expanded in a time base compressing and expanding circuit 23 in accordance with a speed signal from a tape speed detecting circuit 24 and is outputted.