Patent ID: 6661757
Filing Date: 2003-12-09
Classification: G11B

Abstract:
A power control circuit for an optical disk drive, the optical disk drive having a diode driving circuit, a light emitting diode and a photo diode, wherein the diode driving circuit is used for outputting a driving signal to the light emitting diode, the light emitting diode generates an optical signal corresponding to the driving signal, and the photo diode is used for sensing the optical signal to generate a power sampling signal correspondingly, the power control circuit comprising:an erase-period sample-and-hold circuit, for receiving the power sampling signal, and then outputting an erase-period sample-and-hold signal to the diode driving circuit; a peak envelope acquiring circuit, for receiving the power sampling signal and outputting a peak envelope signal; a bottom envelope acquiring circuit, for receiving the power sampling signal and outputting a bottom envelope signal; a write-period sample-and-hold circuit, for receiving the peak envelope signal, and outputting a write-period sample-and-hold signal to the diode driving circuit; and a bias-period sample-and-hold circuit, for receiving the bottom envelope signal, and outputting a bias-period sample-and-hold signal to the diode driving circuit; wherein the diode driving circuit alters the driving signal according to the erase-period sample-and-hold signal, the write-period sample-and-hold signal, and the bias-period sample-and-hold signal so that power of the optical signal is adjusted.