Samsung Electronics Co., Ltd.

Sang Yeal Park

Kab Kyun Jeong

Kwan Joon Kim

An optical disc apparatus and a focusing method for the same prevent a focusing start error of an optical pickup when using a ring-shaped lens to handle multiple wavelengths, and allow the optical pickup to start focusing at the correct starting time. To write and/or read data to and/or from an optical disc, an optical pickup in the optical disc apparatus emits a laser beam to the disc through an objective lens, and reads a reflected beam to output a read signal. The optical pickup outputs a signal based on the read reflected beam. An actuator controls the position of the objective lens so that the laser beam is focused on a surface of the disc. A focusing controller performs focusing operations on the actuator using a focus error signal generated from the signal outputted from the optical pickup. A focusing start time detector processes the read signal used to generate the focus error signal and detects when to start the focusing control of the focusing controller.

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Suwon-si, South Korea

Sang Yeal Park