Layer jump control for an optical drive

An optical drive for performing a layer jump process, wherein the layer jump process comprises a kicking process, a holding process, a braking process and a waiting process, the optical drive comprising:

• a pick up head having a lens and a voice coil motor, wherein the pick up head drives the voice coil motor in accordance with a driving force to vertically move the lens;
• a preamplifier for producing a focusing error signal;
• a controller for receiving the focusing error signal and producing a focusing control signal;
• a low pass filter for receiving the focusing control signal and producing a layer distance balancing signal;
• and
• a driving device for outputting the driving force;
• wherein:
• the driving device receives the focusing control signal to determine the driving force when the optical drive does not perform the layer jump process;
• the driving device receives a kicking signal and the layer distance balancing signal to determine the driving force when the optical drive performs the kicking process;
• the driving device receives a braking signal and the layer distance balancing signal to determine the driving force when the optical drive performs the braking process;
• the driving device receives the layer distance balancing signal to determine the driving force when the optical drive performs the holding process and the waiting process;
• the braking process is initiated when the focusing error signal reaches a first checking point, and is performed for a certain time;
• and
• the waiting process is performed after the braking process, and is completed when the focusing error signal reaches a second checking point.

A method of controlling an optical drive to perform a layer jump process, wherein the optical drive comprises a preamplifier, a controller, and a low pass filter, the method comprising the steps of:

• receiving a focusing error signal produced by the preamplifier in the controller to produce a focusing control signal;
• sending the focusing control signal to the low pass filter to produce a layer distance balancing signal;
• performing a kicking process to determine a driving force in accordance with a kicking signal and the layer distance balancing signal;
• performing a holding process to determine the driving force in accordance with the layer distance balancing signal;
• performing a braking process for a certain time, to determine the driving force in accordance with a braking signal and the layer distance balancing signal, wherein the braking process is initiated when the focusing error signal reaches a first checking point;
• and
• performing a waiting process to determine the driving force in accordance with the layer distance balancing signal, after the braking process and until the focusing error signal reaches a second checking point.