| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical information recording and reproducing device in which stability of a focus control and a tracking control is secured even in recordings/reproductions by plural light spots and also interchangeability is attained even when substrate materials and track pitches of optical disks are different. SOLUTION: In this device, a luminous flux deflecting means which is constituted of a rotatable wedge shaped prism is provided in order to suppress the offset of a tracking error signal while reducing the positional deviation of a light spot on a detector and, moreover, with respect to the difference of substrate materials and track pitches of optical disks, a substrate discriminating circuit 16 and a track pitch discriminating circuit 17 are provided, and then, characteristics of a focus control circuit 6, tracking error detecting circuits 7, 9, a velocity detecting circuit 11 and a velocity instructing circuit 12 are changed over. As a result, stability of controls is secured even in recordings/ reproductions by plural light spots and also interchangeability is attained even with respect to the change of the optical disk and the positioning of the light spots to target tracks and recordings/reproductions/erasings are made possible. |
