Patent ID: 6744705
Filing Date: 2004-06-01
Classification: G11B

Abstract:
An apparatus for recording and reproducing data for an optical disc, the apparatus driving an objective lens in a direction of an optic axis, irradiating a light beam on the optical disc through the objective lens, and actuating a focus servo to drive the objective lens in response to a focus error signal generated based on reflected light from a recording plane of the optical disc, to reproduce data recorded on the optical disc, the apparatus comprising:a gain setter that sets a gain for the focus error signal; and a disc discriminator that determines whether the optical disc is loaded in the apparatus and, when the optical disc is loaded, determines whether the optical disc is a recordable type or a read only type; wherein the gain setter sets the gain for the focus error signal to a first gain, corresponding to the recordable type optical disc, before the loaded optical disc is determined to be one of the read only type or the recordable type by the disc discriminator, and switches the gain of the focus error signal to a second gain, corresponding to the read only type optical disc, when the optical disc is determined to be the read only type by the disc discriminator; and wherein, while the objective lens is moving toward a focus position, the disc discriminator detects a level of the focus error signal and a peak of the focus error signal before focus is obtained, and compares the detected level with a first reference level and a second reference level, the disc discriminator determining that the optical disc is the recordable type when the focus error signal level exceeds the first reference level and reaches the peak without exceeding the second reference level, and that the optical disc is the read only type when the focus error signal level exceeds the second reference level.