Abstract: A system and method for controlling operation of a motor system that addresses the design challenges for the small form factor optical disk system. The control system can be operable to read a physical sector address (PSA) from an optical medium, calculate a table index based on the PSA, enter a lookup table module to acquire reference data, and maintain a constant data rate transfer from the optical medium for a range of PSAs.

Abstract: 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.

Abstract: A system for controlling focus in an optical disc drive for optical media with a premastered area that cannot be overwritten and a user-writeable area that can be overwritten includes instructions for turning focus on and off; and for acquiring focus on the optical media in response to a command to acquire focus. The actuator arm is moved according to a sinusoidal ramp function to prevent exciting resonances in the actuator arm. The amount of push-away force used while moving the actuator arm can be adjusted to avoid overshoot. The integrity of a focus error signal is determined and an attempt to re-acquire focus is made if the focus error signal indicates a bad focus status.

Abstract: A system, method, and apparatus for coordinating tasks in a control system for 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 optical disc drive includes a first processor operable to communicate with a second processor, wherein the first processor includes instructions for performing non-time-critical tasks, and the second processor includes instructions for performing time-critical tasks, such as reading from and writing to optical media in the disc drive. The first processor monitors the status of the time critical tasks in the second processor and transmits commands to perform operations in the second processor. The first processor also controls power mode, manages recovery from errors, controls focus, tracking/seeking, spin, physical sector address (PSA), a laser, adjusts gains, and monitor cartridge load/eject.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A calibration for a tracking error signal offset in a tracking servo system of an optical disk drive is presented. In some embodiments, the tracking error signal offset is adjusted for best servo function by, for example, adjusting the center of a tracking error signal when the tracking servo system is open to zero. In some embodiments, the tracking error signal offset is adjusted for best read function by, for example, adjusting the tracking error signal offset until the data jitter is minimized. Data jitter can be determined by reading data from the optical media and measuring the data error rate.

Abstract: A system for determining whether a focus servo system is in focus or out of focus (i.e. open) is disclosed. A sum signal can be compared with a threshold value. If the sum signal is below the threshold value, then a focus open condition (i.e., out-of-focus) can be indicated. In some embodiments, a focus open condition is indicated where the sum signal remains below the threshold value for a predetermined period of time.

Abstract: A control system for an optical disc for optical media with a premastered area that cannot be overwritten and a user-writeable area that can be overwritten, comprises a first processor operable to communicate with a second processor via a status register. The first processor sequences and monitors functions performed in the second processor and the second processor issues an interrupt when an error condition is detected in the second processor. The first processor detects the interrupt, and disables detecting further interrupts until the interrupt is serviced. Servicing the interrupt includes recording the error state and changing focus and tracking parameters based on the error condition detected.

Abstract: A servo system that calibrates a cross-talk gain parameter in a tracking error signal to focus error signal crosstalk correction is provided. The cross-talk gain parameter can be optimized such that the effects of a perturbation applied to the tracking servo loop on an adjusted focus error signal, i.e. a focus error signal that has been corrected for crosstalk, is minimized. The optimized cross-talk gain, then, can be set to the cross-talk gain of a set of cross-talk gains that results in the lowest value of a frequency component of the adjusted focus error signal while a perturbation at the frequency is being applied to the tracking servo loop.

Abstract: A system and method for handling events issued as a result of error conditions in the operation of an optical disc drive include suspending processing of commanded operations in the disc drive while attempting to recover from the error condition. The recovery attempt can include increasing levels of recovery effort, such as dynamically recalibrating various components in the disc drive. The system can also determine whether a previous notice was received for the same error condition. If so, the system can determine whether excessive recovery attempts have been initiated based criteria such as the time between the notices, and/or the number of notices, for the same error condition. The recovery attempts are aborted when they become excessive. If the recovery attempt is successful, the interrupted operation is resumed at the point where the processing was suspended, such as during a write or read command.

Abstract: 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.

Abstract: A notch filter that filters a focus error signal during a multi-track seek operation is presented. The notch filter has a center frequency that relates to the seek reference velocity of a multi-rack seek algorithm. During the multi-track seek operation, a focus control signal is calculated from the filtered focus error signal from the notch filter.

Abstract: 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.

Abstract: An anti-skate algorithm in a tracking servo system of an optical disk drive is described. The anti-skate algorithm prevents skating during close of the tracking servo system by allowing the tracking servo system to close on a tracking error signal with an appropriate slope.

Abstract: A calibration for a tracking error signal gain in a tracking servo system of an optical disk drive is presented. The calibration determines the peak-to-peak tracking error signal when the tracking servo system is open, calculates a gain factor in response to the peak-to-peak tracking error signal, and calculates a new tracking error signal gain based on the tracking error signal gain and the gain factor. New tracking error signal gains are calculated until the gain factor is approximately one.

Abstract: A calibration of a loop gain in a digital servo system is presented. The loop gain can be calibrated measuring the response in a control signal generated by the digital servo system when the control signal is replaced by a sum of the control signal and a sinusoidal disturbance. The loop gain can be set to provide a desired gain, for example unity, between the control signal and the sinusoidal disturbance at a cross-over frequency.

Abstract: A system and method for controlling operation of a motor system that addresses the design challenges for the small form factor optical disk system. The control system can include a first module for providing a period error, a proportional gain (Kp) and an integration gain (Ki); a second module for operating on the Ki and Kp to provide an output; and a third module for commutating the motor in response to the output.

Abstract: A system and method for controlling operation of a motor system that addresses the design challenges for the small form factor optical disk system. The control system can be operable to obtain digital feedback from a spin motor. The present invention includes detecting data representing a position on an optical medium and determining a detection rate; comparing the detection rate to a reference rate to provide an error rate; generating an output command in response to the error rate to provide a drive output which commands a voltage applied to a spin motor to adjust the spin speed of said spin motor.