Patent ID: 8300670

Claim:
A method for deriving precise control over laser power of an optical pickup unit (OPU), the method comprising: providing an analog-to-digital converter (ADC) within an automatic power calibration (APC) circuit to derive a path gain and/or a path offset from the APC circuit; and selectively performing compensation according to the path gain and/or the path offset, in order to control the laser power by a target command, wherein the step of selectively performing compensation according to the path gain and/or the path offset further comprises: compensating the path gain when the path gain is derived; and canceling the path offset when the path offset is derived; wherein the OPU comprises a front-end PD output (FPDO) for outputting an FPDO value; and the method further comprises: applying a compensated target value as the target command, wherein the compensated target value is substantially equal to a product of the FPDO value and the path gain minus the path offset.