Samsung Electronics Co., Ltd.

Je-kook Kim

Young-wook Jang

Suk-jung Lee

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.

Focus search apparatus and method

A frequency detector in a phase locked loop which generates a clock signal for reproducing a signal from a optical disc. 3 T information corresponding to an upper limit of the frequency of the Eight-to-Fourteen Modulation signal is compared with the oscillation clock of the VCO divided by three to reduce the oscillation frequency of the VCO. Additionally, 11 T information corresponding to a lower limit of the frequency of the Eight-to-Fourteen Modulation signal is compared with the oscillation clock of the VCO divided by eleven to increase the oscillation frequency of the VCO thereby providing a VCO which oscillates at a frequency corresponding to the frequency of the Eight-to-Fourteen Modulation signal.

Growing community of inventors

Kyungki-do, South Korea

Je-kook Kim