| 摘要 |
PROBLEM TO BE SOLVED: To measure characteristics of a tracking actuator in an optical disk apparatus with high precision, and to set an optimal tracking jump drive current. SOLUTION: A tracking servo is turned OFF and the drive currents for track jumps toward an inner circumferential side and an outer circumferential side are alternately applied to the tracking actuator every time a rotation angle of an optical disk has a predetermined rotation phase. A tracking error signal during each track jump is detected at two predetermined time points t1 and t2. The absolute values ¾ΔEi(N)¾ and ¾ΔEo(N)¾ of differences between each signal level are stored. These values correspond to moving speeds of a light beam spot during the respective track jumps. An average value ¾ΔEav¾ corresponds to a gain Gtr of the tracking actuator. By setting a waveform of the track jump drive current, depending on the gain Gtr, tracking characteristics can be adjusted with high precision even if there is a variation in the characteristics of the tracking actuator. COPYRIGHT: (C)2006,JPO&NCIPI
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