SIGNAL PROCESSING DEVICE FOR OPTICAL DISC, INTEGRATED CIRCUIT, OPTICAL DISC DEVICE AND OPTIMUM RECORDING FOCUS POSITION DETECTING METHOD

摘要

A signal processing device for an optical disc is provided with a focus position determining unit for determining the optimum recording focus position based on recording quality in a region of test records on an optical disc when the test records have been carried out by changing a plurality of kinds of focus positions. The focus position determining unit is provided with a recording state measuring unit for measuring recording quality at every focus position in the region of the test records on the disc and a judging unit for judging, by using the recording quality at every focus position obtained by the recording state measuring unit, whether or not laser power at the test records is suitable for determining the optimum record focus position in accordance with a prescribed judging standard. When the judging unit judges that the laser power at the test records is not suitable for determining the optimum record focus position, the signal processing device for the optical disc controls an optical pickup so that test record is carried out again by changing laser power.