Patent ID: 7529173
Filing Date: 2009-05-05
Classification: G11B

Abstract:
1. An optical disk device which reproduces a wobble signal, i.e., information about wobbling of tracks, from an optical disk that has information-recording tracks formed spirally from inner radius to outer radius of the disk, wobbling periodically, characterized by comprising: mark forming means which forms marks on the tracks by laser irradiation according to recording data; a split-type optical sensor which outputs multiple systems of signals by detecting return beams from the marks as well as from spaces between the marks; first sampling means which samples, in mark segments, the signals outputted from the split-type optical sensor and outputs the sampled signals; second sampling means which samples, in space segments, the signals outputted from the split-type optical sensor which outputs sampled signals; first amplitude adjusting means which justifies amplitudes of the signals sampled and outputted by the first sampling means; second amplitude adjusting means which justifies amplitudes of the signals sampled and outputted by the second amplitude adjusting means; selection means which alternately selects and outputs the signals outputted by the first and second amplitude adjusting means by alternatively selecting the signal outputted from the first amplitude adjusting means in the mark segments and the signal outputted from the second amplitude adjusting means in the space segments; and reproducing means which adds the multiple systems of signals that have been subjected to a series of processes by the first sampling means, the second sampling means, and the selection means, in predetermined combinations, finds differences among the added signals after justifying amplitudes of the added signals, and thereby reproduces the wobble signal.