Patent attributes
An optical disk drive includes a pickup head, a servo circuit, and a controller. An optical disk has a first area and a second area for which different tracking methods are to be used. The controller may cause the pickup head to make a seek for a target address in the first area from a position in this area that is farther from the boundary between the two areas than the address. If the controller cannot perform tracking servo control after the seek is made, and if the calculated address is located in a critical region, the controller immediately causes the pickup head to make a seek by a specified number of addresses toward the position farther from the boundary. After the seek is made, the controller performs tracking servo control again.
