| 摘要 |
PURPOSE:To eliminate the offset without complicating the structure of an optical head by detecting electrically the offset component of a tracking signal, which is generated with tracking control, and correcting it. CONSTITUTION:An output information signal 28 of an operating circuit 8 which generates the tracking signal is led to a binarizing circuit 9. A tracking signal 27 is inputted to a sampling and holding circuit 10 and is sampled and held at the timing of the output of the circuit 9. The signal 27 is inputted to an operating circuit 11 also, and this signal and the output signal of the circuit 10 are subjected to subtraction processing to correct the signal 27. The corrected tracking signal is supplied to a tracking element 13 through a driving circuit 12, and the element 13 moves a converging lens 5 in the radial direction of a disc 6 on a basis of this signal, thus performing the tracking control. |
