Objective lens actuator and optical pickup unit employing the same

An optical pickup unit, comprising:

• a light source for generating a light beam;
• an objective lens for focusing the light beam to an optical disk;
• an optical detector for receiving a return light beam reflected from the optical disk;
• and
• an objective lens actuator configured for driving the objective lens, the objective lens actuator comprising:
• a lens holder for holding the objective lens;
• a first micro-actuator connected to the lens holder, the first micro-actuator being configured for driving the objective lens along a substantially radial direction of an optical disk;
• and
• a second micro-actuator connecting to the lens holder, the second micro-actuator being configured for driving the objective lens along a direction substantially perpendicular to the optical disk;
• wherein the first and second micro-actuators each comprise at least one inactive portion and at least one active portion, the at least one active portion is movably received in the corresponding at least one inactive portion;
• the at least one inactive portion is comb-shaped with a plurality of slots therein, and the at least one active portion includes a shaft and a plurality of comb fingers extending from a circumference of the shaft.

An optical pickup unit for reading information recorded in an optical disk, the optical pickup unit comprising:

• a light source configured to generate a light beam;
• an objective lens configured to focus the light beam to the optical disk;
• an optical detector configured to receive a return light beam reflected from the optical disk;
• and
• an objective lens actuator configured to drive the objective lens, the objective lens actuator comprising:
• a lens holder configured to hold the objective lens, the lens holder comprising:
• a first surface;
• and
• a second surface, the second surface extending substantially perpendicular to the first surface;
• a first micro-actuator attached to the first surface, the first micro-actuator capable of being actuated to apply a first force to the lens holder, so as to drive the lens holder to move along a radial direction with respect to the optical disk;
• and
• a second micro-actuator attached to the second surface, the second micro-actuator capable of being actuated to apply a second force to the lens holder, so as to drive the lens holder to move along a direction substantially perpendicular to the optical disk;
• wherein the first and second micro-actuators each comprise at least one inactive portion and at least one active portion, the at least one active portion is movably received in the corresponding inactive portion.