| 摘要 |
PROBLEM TO BE SOLVED: To actualize fast initialization by an optical system which is simple and inexpensive by making the intensity distribution of a laser beam small and securely holding a reflectivity and reflectivity variation within specific standards. SOLUTION: A YAG laser is made incident as laser light R on a polygon mirror 2 which rotates time sequentially, the laser light is made incident on a f.θ lens 3 from a polygon mirror 2, and further made incident on a galvanomirror 1 which varies the angle of the reflecting surface from an f.θ lens 3 time sequentially; while the optical disk D is stopped, the entire disk surface of the optical disk D is irradiated with the laser light R. |
