Abstract: In a method of controlling data reproduction in an optical disk drive, when a decoding error occurs, decoding is performed by changing a servo parameter. Thus, the decoding errors are reduced while playability is improved. The method of controlling data reproduction in an optical disk drive for reading data stored on an optical disk is performed by monitoring whether a decoding error occurred at a host part, if a decoding error occurred, changing a servo parameter for adjusting balance and/or offset of error signal which input to servo system, and rereading a portion on the optical disk medium where the decoding error occurred using the changed servo parameter and performing decoding.

Abstract: This tilt correcting method includes the step of monitoring jitter values while adjusting a turntable or guide rail after a wobble disc is placed on the turntable. Thereafter, it is determined whether the depths of valleys of monitored jitter values are different, it is determined that the reference tilt is a radial tilt if it is determined that the depths of valleys of the monitored jitter values are different, and the radial tilt is corrected. If it is determined that the depths of valleys of the monitored jitter values are not different, it is determined whether the heights of peaks of the monitored jitter values are different, it is determined that the reference tilt is a tangential tilt if it is determined that the heights of peaks of the monitored jitter values are different, and the tangential tilt is corrected.

Abstract: In a method of controlling data reproduction in an optical disk drive, when a decoding error occurs, decoding is performed by changing a servo parameter. Thus, the decoding errors are reduced while playability is improved. The method of controlling data reproduction in an optical disk drive for reading data stored on an optical disk is performed by monitoring whether a decoding error occurred at a host part, if a decoding error occurred, changing a servo parameter for adjusting balance and/or offset of error signal which input to servo system, and rereading a portion on the optical disk medium where the decoding error occurred using the changed-servo parameter and performing decoding.

Abstract: This tilt correcting method includes the step of monitoring jitter values while adjusting a turntable or guide rail after a wobble disc is placed on the turntable. Thereafter, it is determined whether the depths of valleys of monitored jitter values are different, it is determined that the reference tilt is a radial tilt if it is determined that the depths of valleys of the monitored jitter values are different, and the radial tilt is corrected. If it is determined that the depths of valleys of the monitored jitter values are not different, it is determined whether the heights of peaks of the monitored jitter values are different, it is determined that the reference tilt is a tangential tilt if it is determined that the heights of peaks of the monitored jitter values are different, and the tangential tilt is corrected.

Abstract: This tilt servo control method includes the step of reading a first jitter value “A”. Thereafter, a second jitter value “B” is read after an angle of an objective lens is moved by a predetermined step. If “A” is equal to or smaller than “B”, the angle of objective lens is optimized by performing the tilt servo while the angle of objective lens is moved. If “A” is larger than “B”, a third jitter value “C” is read after the angle of objective lens is moved by predetermined step. If “A” is equal to or smaller than “C”, the angle of objective lens is optimized by performing the tilt servo while the angle of objective lens is moved. If “A” is larger than “C”, the angle of objective lens is optimized while the angle of objective lens is moved by half of the predetermined step.