| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a coma aberration correcting method for correcting coma aberration that occurs due to the displacement in the signal track direction of an objective lens incorporated in an optical pickup. <P>SOLUTION: Whenever the level of an aberration correction signal to be supplied to an aberration collection element 18 is changed, the spot diameter of laser beams in a radial direction is detected. When the spot diameter becomes minimum, the level of the aberration correction signal is set as aberration correction reference data, displacement distance to the signal track direction from the reference position of the objective lens incorporated in the optical pickup is calculated, and the aberration correction element 18 is controlled by a control signal generated with the aberration correction reference data as reference on the basis of the calculated distance to thereby correct coma aberration. <P>COPYRIGHT: (C)2007,JPO&INPIT |
