JPS5641534A - Information recording and regenerative device - Google Patents

Abstract

PURPOSE:In case of waveform memory of the track distortion shape, to elevate the memory precision by making expansion of the dynamic range unnecessary, by removing its DC portion. CONSTITUTION:The DC value detection circuit 19 inputs the tracking control signal (j) into the window comparator 26 through the time constant filter 25 which can detect the DC portion to some extent, in a state that the final recording information track has been subject to retrieval tracking. The comparator 26 detects whether the DC portion of the signal (j) generated in the filter 25 exists in the regular width or not, and in case it exists in the regular width, the gate signal (p) is output immediately, and waveform memory is made as to the tracking control signal following the track shape distortion of the signal (j). On the other hand, in case the aforesaid DC portion does not exist in the regular width, the rotary angle, etc. of the moving means 24 are controlled by obtaining the signal (q) corresponding to the difference to its regular width through the moving and setting circuit 27 corresponding to the output of the comparator 26. As a result of the foregoing, expansion of the dynamic range becomes unnecessary, and therefore the memory precision can be elevated.