OPTICAL RECORDING AND REPRODUCING DEVICE

摘要: PURPOSE:To surely protect an actuator by checking a driving current to the at prescribed intervals and cutting off when number of times that is out set range exceeds times. CONSTITUTION:A difference signal outputs photodetectors 13 14 extracted subtractor 18 become track error St, which then amplified in amplifier 19, Ta 21 driven this output via detecting resistor 32 through relay 20. Consequently, 20 closed, device under state servo control. Each electric potential both ends inputted 33 Sc proportion current, impressed upon comparators 24a 24b compare with comparison levels VHR VRL, it limited these levels, limit H outputted. The checked CPU 25 for period time 1 sec interval 0.01 sec, 30 times, considered abnormal, hence cut off. By method, burning, etc., can be prevented.