Patent ID: 7420906
Filing Date: 2008-09-02
Classification: G11B

Abstract:
1. An automatic power calibration method comprising: obtaining two or more pairs of first reference signal values, or values of reference signals of first channel signals, which are input to an optical emission unit driving unit, the optical emission unit driving unit driving an optical emission unit, and first output signal values obtained by measuring outputs of the optical emission unit resulting from the first channel signal values, using an optical detection unit; obtaining two or more pairs of second channel signal values, which are input to the optical emission unit driving unit, the optical emission unit driving unit driving the optical emission unit, and second output signal values obtained by measuring outputs of the optical emission unit resulting from the second channel signal values, using the optical detection unit; storing the pairs of signal values obtained in the obtaining the first reference signal values and the obtaining the second channel signal values; determining the first reference signal value S inputting in the optical emission unit driving unit the first channel signal value S wherein the obtaining two or more pairs of first and second channel signal values are operations obtaining the pairs of signal values within a period where a relation between the signal values exhibits a linear function, and wherein a read power channel signal is applied to the optical emission unit driving unit along with a write power channel signal and an overdrive power channel signal.