| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an aberration correcting method for an optical disk recording and reproducing device which records signals to an optical disk by a laser beam radiated from a laser diode incorporated in an optical pickup. <P>SOLUTION: A quantity of astigmatism is obtained from a variation of the diameter of a spot of a laser beam accompanied by the alteration of a defocus value of a focus servo circuit 21, and an aberration correcting element 18 is controlled according to the quantity of the obtained astigmatism to correct the astigmatism, and then a quantity of spherical aberration is obtained from a variation of a spot area of a laser beam accompanied by the alteration of the defocus value of the focus servo circuit 21, and the aberration correcting element 18 is controlled according to the quantity of the obtained spherical aberration to correct the spherical aberration. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
