Servo circuit for disc reproducer

Abstract

Abstract PURPOSE:To prevent skipped tracking and out of focus due to the failure of a disc, by controlling the tracking or focusing, based on a detection signal being amplitude-limited which is obtained at a limiter restricted with an output voltage of a low pass filter. CONSTITUTION:A limiter 22 amplitude-limiting a detection signal VA is inserted between a subtractor 6 to obtain the tracking error detection signal VA and a servo amplifier 7. A low pass filter 21 picking up a low frequency component of the detection signal VA is connected to an output side of the subtractor 6 and an output voltage Vc of the filter 21 is applied to a voltage follower 25 of the limiter 22. Thus, the signal VA including noise is amplitude-controlled within a range where the output voltage Vc of the filter 21 is added or subtracted with a voltage drop of a diode array 24. That is, a tracking error detection signal VB including the suppressed noise is given to a driving means 8 via an amplifier 7.

Inventors

• 👤 Tadao Yoshida
• 👤 忠雄 吉田

Bibliographic Details