| 摘要 |
PROBLEM TO BE SOLVED: To provide a head and laser spot varying method for writable optical disk drive with which information can be completely erased from various kinds of optical disks while using a spatial filters having holes for deciding the size of a laser spot corresponding to the size of a diameter. SOLUTION: This writable optical disk drive is provided with a laser diode 1, optical system 2 and photodiode 3 and arranges a spatial filter 4 between a collimator lens 20 and a beam splitter 21 of the optical system 2. Thus, since the size of the laser spot, with which an optical disk 100 is irradiated, in the direction of tracking corresponds to the size of a rectangular hole 40 of the spatial filter 4 in a lateral direction (b), by using various kinds of spatial filters 4 having the different sizes of the lateral side (b) while switching them, the complete erasure and write of information can be performed to various kinds of optical disks. |
