Abstract: Provided are a focus search apparatus and method for performing a focus search after moving an optical pickup to a focus-on point according to a signal output from a sine wave generator so that a stable and smooth focus search is performed. In the focus search method, a sine wave is generated in response to a focus search command. The focus search is performed using an optical pickup in response to the sine wave. The optical pickup is driven in response to an amplitude of the sine wave during the focus search and in response to a filtered focus error signal during a focus servo.

Abstract: Method and apparatus for controlling the light power of an optical disk system, and optical disk system having the same are provided. The optical disk system includes a microcontroller for controlling the operation of the optical disk system, a light power adjusting apparatus for generating a light quantity control signal for controlling the quantity of light emitted from the optical disk, and an optical pickup device for adjusting the quantity of light emitted from the optical disk in response to the light quantity control signal.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: A brake signal generating circuit and method for improving the efficiency of a lens brake in an optical disc reproducing system are provided.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: In an apparatus and a method for correcting asymmetry in an optical disk reproduction system, an analog RF signal is received from an optical diode and an asymmetry-corrected signal is output as a digital EFM signal. The apparatus includes envelope detectors for detecting upper and lower envelopes of the RF signal, a level controller for controlling the level of the sum of the upper envelope and the lower envelope and for outputting signal having the controlled level, and a comparator for comparing the level of the signal output from the level controller with the level of the RF signal and for outputting the comparison result as the digital EFM signal.

Abstract: A tracking servo control apparatus for muting a tracking error signal when a mirror signal is generated, in an optical disk system, such as a compact disk player or a digital video disk, compensates for tracking gain and phase according to the tracking error signal. The apparatus includes a mirror setting unit for receiving the generated mirror signal and for generating a mirror signal by defining the mirror signal to predetermined minimum and maximum time intervals, a switch for outputting a muted tracking error signal while the defined mirror signal is activated, and otherwise, outputting the tracking error signal, and a tracking gain/phase compensator for receiving the output signal from the switch and compensating for the tracking gain and phase. Thus, the system can be stabilized by muting a tracking servo loop according to a mirror signal whose pulse width is defined to a predetermined window section.

Abstract: An optical signal conversion apparatus in a compact disk player detects peaking in an RF signal read from a disk and compensates to reproduce a stable conversion signal, for example an EFM signal. In the optical signal conversion apparatus, a peaking prevention portion detects peaking of the RF input signal and outputs a predetermined reference voltage, if the peaking is detected, or alternately the input signal, if the peaking is not detected. A waveform processing portion extracts a high frequency component from the signal output from the peaking prevention portion, slices the extracted signal as a predetermined level, and outputs the sliced signal.

Abstract: An optical disk reading apparatus and method compensate for errors in the full period of an EFM signal. An RF amplifier converts an optical signal reflected from an optical disk into an analog electrical signal. A signal converter converts the analog signal into a digital signal which is modulated to provide an EFM signal. A full period compensating portion compensates for full period errors in the EFM signal and outputs the error compensated EFM signal. An error correcting portion corrects the errors of the compensated EFM signal using an error correction code. Image quality is improved by removing the full period errors.