Abstract: An optical recording/reproducing apparatus and method to determine a type of disk including a photodetector divided into at least two light receiving sections in a radial direction. A radial subtractor generates a radial push-pull signal from a difference between light receiving signals from a disk and received by the at least two light receiving sections, where the disk includes one of a first disk and a second disk. An upper envelope detector detects an upper envelope signal from the radial push-pull signal and a lower envelope detector detects a lower envelope signal from the radial push-pull signal. A phase comparator detects a phase difference between the upper envelope signal and the lower envelope signal. A type of disk determiner distinguishes the first disk from the second disk according to a magnitude of the phase difference and outputting a signal indicative thereof, where the second disk includes a density higher than the first disk.

Abstract: A device for automatically controlling a sled loop gain in an optical disc drive having a sled motor.

Abstract: A disc reproduction apparatus and method to reproduce an optical disc using a constant linear velocity (CLV) method. The disc reproduction apparatus includes an equalizer to receive a signal read from the optical disc and equalizing the received signal according to an equalization control signal, and a wide-capture range phase-locked loop (wide PLL) to perform a phase lock operation with regard to the received equalized signal based on a phase lock control signal. An automatic adjuster selects one of predetermined phase lock control value, according to a type of an optical disc to be used and reproduction velocity determined during initial operation, and a desired target position to read the data from the optical disc, and generates a phase lock control signal having the selected value.

Abstract: A track zero cross signal generation apparatus for use in an optical disk system receives a tracking error signal acquired when traversing tracks on a recording medium and generates a track zero cross signal. The track zero cross signal generation apparatus includes a booster which receives the tracking error signal, low-pass-filters the received tracking error signal, and amplifies the low-pass-filtered tracking error signal having a predetermined high frequency band in a pass band for low-pass-filtering. The booster outputs the low-pass-filtered tracking error signal whose signal level in a predetermined high frequency band is amplified, to a comparator.

Abstract: A track zero cross signal generation apparatus for use in an optical disk system receives a tracking error signal acquired when traversing tracks on a recording medium and generates a track zero cross signal. The track zero cross signal generation apparatus includes a booster which receives the tracking error signal, low-pass-filters the received tracking error signal, and amplifies the low-pass-filtered tracking error signal having a predetermined high frequency band in a pass band for low-pass-filtering. The booster outputs the low-pass-filtered tracking error signal whose signal level in a predetermined high frequency band is amplified, to a comparator.