Patent attributes
In an optical disk apparatus and a disk rotation speed control method thereof, enabling to rotate a disk at high speed, with stability and certainty, irrespective of mass eccentricity thereof, detection is made on the greatest value and the smallest value on the signal after conducting a process of a band pass filter 511 on a lens error signal in a step response of a pickup, with using a wobble signal in the place of a tracking error signal and chaining an offset, when controlling the rotation speed of the apparatus by loading an optical disk therein, and thereafter, determination is made on whether the disk rotation speed be shifted to the high speed or not, upon basis of a value obtained through comparison of the maximum value (Max_spnup) and the minimum value (Min_spnup) obtained with the greatest value (Max_step) and said smallest value (Min_step) memorized, when shifting the disk rotation to the high speed.X=(Max—spnup−Min—spnup)/(Max_step−Min_step)
