| 摘要 |
PROBLEM TO BE SOLVED: To suppress the deterioration of recording and/or reproducing characteristics due to out-of-focus by correcting the influence due to the astigmatic difference of a semiconductor laser. SOLUTION: The semiconductor laser emitting a light beam irradiating an optical disk is arranged so that the light beam emitted from the semiconductor laser irradiates the optical disk at an angle of about 30 deg. to 60 deg. between a surface perpendicular to the joint surface of the semiconductor layers of this semiconductor laser and the tangential direction of the recording track TR of the optical disk so as to correct asymmetry around the tangential direction based on the out-of-focus of a beam spot on the optical disk. |
