Tracking servo unit in information read-out unit

Abstract

Abstract PURPOSE:To enable to close the servo loop surely and stably at the start of operation of the tracking servo unit, by detecting the change in the phase relation between the tracking servo signal and reproduced RF signal. CONSTITUTION:In the tracking servo unit on the track Y of recording media with the information from the read-out means, the servo control spots E and F is produced for the error signal C corresponding to the distance from the center line of the track through the detection of the optoelectro converters 5, 6. The information read-out spot G is detected with the optoelectro converter 1 being RF signal and detected with the envelope detector 2. The output of envelope detection and the said error signal are detected for the phase difference and when the polarity of the phase difference is changed, the instruction signal which closes the servo loop of the tracking servo means is produced.

Inventors

• 👤 Takashi Okano
• 👤 Yoshio Inamoto

Bibliographic Details