Patent ID: 8406101

Claim:
An optical disk drive, comprising: a feeding device, comprising a spherical aberration (SA) lens and a stepping motor, wherein the SA lens is capable of correcting spherical aberration of a light beam emitted by a pickup head, and the stepping motor is capable of moving the SA lens according to a plurality of control signals; a power driver, coupled to the feeding device, capable of generating the control signals to drive the stepping motor to move the SA lens; and a controller, coupled to the power driver, capable of driving the stepping motor with only stable steps through the power driver during a driving excitation; wherein the stepping motor does not substantially rotate when there is no driving excitation; wherein when the feeding device is initiated for a first time, the controller directs the stepping motor to move the SA lens to a stepping motor stable point near a reference position, wherein the stepping motor is in the stable state without inducing step errors when the stepping motor moves the SA lens to the stepping motor stable point.