摘要:
A control system for controlling tracking and seeking in an optical disc drive for optical media with a pitted premastered area that cannot be overwritten and a grooved user-writeable area that can be overwritten. The control system determines whether an optical pickup unit is over the premastered or the writeable areas of the optical media by measuring peak to peak amplitude of a tracking error signal. Gains and calibration values are selected based on whether an optical pickup unit is over the premastered or the writeable areas of the optical media. Reading from and writing to the optical media is disabled while jumping tracks. Control of jumping tracks on the optical media includes controlling: jumping a single track on the optical media; jumping a specified number of tracks every specified number of revolutions of the optical media; auto jumpbacks, and jumping in forward or reverse directions. Parameters for controlling jumps include at least one of: jump type, number of tracks to jump, time delay between track jumps, number of revolutions of the optical media between jumps, and whether it is not safe to read from or write to the optical media. The control system performs long seeks by predicting whether the tracking actuator arm will be positioned over the premastered area or the writeable area at the end of the long seek, and to load calibration parameters corresponding to the type of media over which the tracking actuator arm will be positioned at the end of the long seek.
摘要:
A calibration method for an optical disk drive is presented. The operating parameters of an optical disk drive are initially calibrated when the disk drive is produced or during a repair step. The disk drive is then field calibrated during normal operation. Operating parameters can be field calibrated during power up. Further, operating parameters can be field calibrated when a new optical media is inserted into the optical disk drive. Additionally, operating parameters can be field calibrated during error recovery.
摘要:
A multi-zone calibration system is disclosed. The multi-zone calibration system calibrates the operating parameters of an optical disk drive over a plurality of zones over an optical media. The optical media, in addition, can have writeable and premastered portions. The operating parameters can be calibrated for each of the media types in each of the zones. Additionally, the operating parameters can be calibrated for each type of operation (e.g., read or write) in each zone.
摘要:
A method of storing calibrated optical parameters is presented. In some embodiments, calibrated optical parameters are stored in place of stored parameters. In some embodiments, averages between the calibrated operating parameters and stored optical parameters are stored. In other embodiments, the stored optical parameters are allowed to vary only by a maximum amount. In some embodiments, if the calibrated parameters vary by more than threshold values, then the calibrated parameters are not stored.
摘要:
A servo system with in an optical disk drive with an inverse non-linearity compensation is disclosed. An error signal calculated from signals received from an optical pick-up unit can be offset by an offset value and amplified by a gain in the early stages of a calculation of a control signal for controlling a position of the optical pick-up unit. The non-linearity compensation adjusts the gain based on the offset value so that the response of the servo system to changes in the error signal is substantially linear. The error signal can be the tracking error signal in a tracking servo system and can be the focus error signal in a focus servo system.
摘要:
A focus servo system with a focus close algorithm is disclosed. The focus close algorithm provides a bias control effort to the focus servo system when focus is closed. A method of closing focus includes positioning an optical pick-up unit at a first position away from an optical medium, moving the optical pick-up unit towards a second position by altering a focus control effort, monitoring a sum signal obtained from signals received from the optical pick-up unit, and setting the bias control effort to the focus control effort when a closure criteria is satisfied. In some embodiments, the closure criteria includes that a sum signal exceeds a threshold value. In some embodiments, the closure criteria includes that a focus error signal is below a FES threshold.
摘要:
A digital servo system with a biased feed-forward control is disclosed. The biased feed-forward control determines the low frequency component of a control signal from the digital servo system. The low frequency component can then be added to a future control signal to form an adjusted control signal. In some embodiments, the low frequency component is then removed from the future control signals. In some embodiments, a bias signal is incremented or decremented in response to the low frequency component, the bias signal being added to future control signals.
摘要:
A system and method for dynamically re-calibrating an optical disc drive during operation is provided. The optical media includes a pitted premastered area that cannot be overwritten and a grooved user-writeable area that can be overwritten. The system can attempt several increasing levels of effort to recalibrate the disc drive until the disc drive reaches a desired level of performance, or the recalibration effort levels are exhausted. During each level of recalibration effort, various calibration values are determined for the optical media and the servo actuator, along with a notch frequency for a notch filter; a focus actuator offset; a tracking actuator offset; a focus control loop gain; and a tracking control loop gain. The optical media disc is divided into zones, and zone calibration tables for each of the zones are generated. Each zone is recalibrated using the corresponding zone calibration table. The calibration values can be stored and used during subsequent recalibration efforts, such as adjusting the focus control loop gain and/or the tracking control loop gain.
摘要:
A calibration of input signal offset in an optical disk drive is presented. The input signal offsets the input signals received from an optical pick-up unit before digitization. In some embodiments, the input signal offset is set such that the digitized input signals are zero when laser power is off. Further, a thermal drift correction is presented.
摘要:
A head load algorithm for an optical disk drive is presented. On startup, the optical media can be spun up. Then an optical pick-up unit can be positioned at an extreme position, for example at the inner diameter, and focus can be closed. The optical pick-up unit then can be incrementally moved away from the extreme position while the tracking error signal is monitored to locate an area of the optical media with tracks. Once the area is located, a tracking servo system can close on one of the tracks.