| 摘要 |
PROBLEM TO BE SOLVED: To obtain an improved reproduction signal or the like for suppressing the influence of the adjacent track of a disk by reducing the change in the quantity of emitted light even if an objective lens moves in an optical pickup device for a mini disk. SOLUTION: The optical pickup device is provided with an objective lens 16 that can be moved for applying a beam spot onto the information recording surface of an optical disk 30, and a collimator lens 14 for guiding a laser beam that is emitted from a semiconductor laser to the objective lens 16 as parallel light. At the same time, reflection light that is reflected on the information recording surface is applied to a photo detector 20 via the objective lens 16 and the collimator lens 14 again, the radius direction of the optical disk 30 is matched to the direction of the electric field vibration of a semiconductor laser 11, and at the same time, a 1/2 wavelength plate 15 is arranged at a light path so that the direction of the wide distribution of the light of the laser beam of the semiconductor laser 11 can be matched with the radius direction of the optical disk 30. |
