| 摘要 |
PURPOSE:To lower the price by decreasing the number of circuit parts by simplifying circuit constitution by using only one kind of reference signal for tracking control. CONSTITUTION:From a reproduced signal obtained through the pickup reproduction of a reproducing element, only one kind of reference signal for tracking control or one of two kind of reference signals for tracking control recorded periodically at a nearly intermediate part between track center lines of adjacent main tracks for every main track is discriminated and separated. The polarity of a signal obtained by detecting said reference signal by a detecting circuit 11 is inverted alternately every time a main track is reproduced. A tracking error signal obtained by processing the polarity inverted signal and a reference signal with a prescribed level through the differential amplification of a differential amplifier 15 is used to bring the reproducing element under tracking control. |
