Patent ID: 7746735

Claim:
A laser focus controlling method for controlling a focus position of a laser beam on an optical disk in an optical disk apparatus by irradiating said laser beam upon the optical disk and obtaining a reflection light therefrom, the method comprising: performing a pre-process for detecting an electric signal, which is obtainable upon basis of reflection lights reflected from the optical disk loaded in the optical disk apparatus, including unnecessary lights detected at a disk surface and between said disk surface and a recording surface from the optical disk, while executing a focus sweep operation of gradually approaching the laser beam to a recording surface of the optical disk, at an unnecessary light detection gain set higher than a normal operation gain, thereby counting a number of signals generated due to the unnecessary lights; and performing a focus drawn-in process for detecting the electric signal, which is obtainable upon basis of the reflection lights reflected from the optical disk loaded in the optical disk apparatus, and conducting a focus drawing-in, by considering an electric signal, which is generated after a number of signals detected thereof reaches to a counted number of signals generated due to the unnecessary lights, to be a necessary signal reflected from the recording surface of the optical disk.