Patent ID: 7551528

Claim:
An optical disc playback apparatus, the apparatus comprising: a) an optical pickup, the optical pickup operable to irradiate a recording surface of an optical disc with light and to output an electrical signal in response to light reflected from the recording surface; b) an error signal generating circuit operable to generate a tracking error signal indicating an error of the optical pickup with respect to the recording surface on the basis of the electrical signal from the optical pickup; c) a defect detecting circuit operable to detect a defect on the recording surface of the optical disc based on the electrical signal and to output a defect detection signal indicating the detected defect; d) a switch circuit operable to output a servo driving signal based on the tracking error signal when no defect is detected and to output a hold signal when a defect is detected, wherein the hold signal is the servo driving signal output prior to detecting the defect on the recording surface of the optical disc; e) a driving control circuit operable to control the optical pickup based on a signal output from the switch circuit; f) a correcting circuit operable to extract an oscillation component of the error signal when a defect is detected based on the defect detection signal and output a correction signal, the correcting circuit comprising: 1) an extracting circuit operable to extract a low-frequency signal from the tracking error signal, wherein the low-frequency signal is the oscillation component of the tracking error signal of the optical pickup; 2) a pulse generating circuit operable to generate a pulse signal having a constant pulse width, wherein the constant pulse width is based on a pulse width of the defect detection signal; and 3) an output circuit operable to output the low-frequency signal extracted by the extracting circuit as the correction signal for a period corresponding to the constant pulse width of the pulse signal; and g) an adding circuit operable to add the correction signal and the hold signal, and output the sum thereof to the driving circuit as a signal TD for a period corresponding to the constant pulse width of the pulse signal.