| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disc initialization method which facilitates a focus pull-in operation without providing a special region on an optical disc. SOLUTION: An initialization object phase changing disc 11 is turned by a spindle motor 12 at a constant revolution. A laser source which emits a laser beam with a wavelength of α×λ(0.95>α>0.70) wherein λ denotes a wavelength most suitable for recording/reproducing/erasing is used as a laser source 13 for initializing the amorphous state of a recording film into the crystalline state of the film. The laser beam emitted from the laser source 13 is converted into a parallel light by a collimator lens 14 and converged by an object lens 15 having an actuator for focus servo so as to keep a certain beam shape on the recording film of the initialization subject phase changing disc 11. By employing the laser beam with a wavelength of α×λ, the recording film can be initialized by a laser beam whose reflectivity is large in an amorphous state. |
