Abstract: A method for adjusting a control parameter is adopted in an optical disc drive server system, which has a compensator, a control loop and a parameter regulator. The control loop includes an optical pickup and outputs a first tracking error signal/focus error signal. The compensator adjusts the first tracking error signal/focus error signal to obtain a compensated signal for driving the optical pickup to read/write the optical disc. The parameter regulator generates a first sinusoidal signal to be inputted to the control loop, which amplifies the first sinusoidal signal to obtain a second sinusoidal signal. The parameter regulator filters the second sinusoidal signal and calculates a relationship between the first sinusoidal signal and the second sinusoidal signal to obtain a control parameter. The parameter regulator adjusts the compensator to output the compensated signal according to the control parameter.

Abstract: The device includes a servo control unit, a data path control unit, a defect detection unit, and a logic combination unit. The data path control unit further includes a preamplifier receiving data from a lens and generating RF signals for data process. The defect detection unit receives the various signals for detecting different kinds of defects to set corresponding defect flag signals. The defect detection unit includes means for ADefect1 detection, means for EFMDefect detection, means for RPDefect detection, means for Interruption detection, means for ADefect detection, and means for DSPDefect detection.

Abstract: A method and a device for adjusting control parameters of a servo system of an optical disk drive. A first sinusoidal signal is introduced into a control loop of the servo system, while a band-pass filter is used to extract a second sinusoidal signal. Gain and/or phase variations of the control loop are derived by comparing signal parameters of both the first and second sinusoidal signals. A compensator is then employed to adjust the derived gain and/or phase variations of the control loop so as to overcome the disadvantage of system instability after a long-term working.

Abstract: Method and device for generating a stable power control signal in a CD recorder. The power control signal for controlling a laser diode may be a read level, an erase level and a write level. A pickup device outputs a feedback control signal to a read control circuit, and a read power control voltage is thus obtained. Then, the read power control voltage is inputted to a write control circuit, which generates first and second write power control voltages. The read level equals a reference voltage added by the read power control voltage, the erase level equals the read level added by the first write power control voltage, and the write level equals the erase level added by the second write power control voltage, so the read power control voltage and thus the read, erase and write levels are automatically and dynamically adjusted as the feedback control signal varies.

Abstract: The method for estimating recording power Pow_tilting of a tilting part of a tilting disk is shown based on a power compensation formula: Pow_comp=A*(A*K). After a focus error (FE) signal of the tilting part of the tilting disk is manipulated as a focus servo output (FOO) signal, the parameter A is derived by low-pass filtering the FOO signal. Thereafter, another parameter K is then derived from a reference lookup table by using curve fitting approach based on parameter A such that the power compensation Pow_comp could be estimated by substituting parameters A and K into the above formula. A recording power Pow_tilting of the tilting part of the tilting disk could be estimated by adding a given recording power Piwrtpwr to the power compensation Pow_comp.

Abstract: A control module includes a plurality of switching elements, a control chip, and an identification unit. The switching elements are connected to a power terminal through a corresponding resistor each, wherein the resistances of corresponding resistors or equivalent resistance of combination thereof are different. The switching elements generate an input current according to operating conditions thereof. The input current is sent to the control chip through an input/output terminal and is transformed to a digital value. The identification unit identifies the operating conditions of the switching elements according to a lookup table and the digital value, such that the control chip executes a corresponding logic operation.

Abstract: A method and related apparatus for feedback control of laser power provided by a pick-up head of an optical disk drive. The pick-up head can adjust a cross-voltage of a laser generator according to a signal level of a control signal such that the laser power is changed correspondingly. The method includes updating the signal level of the control signal according to feedback of the cross-voltage or the control signal, such that the laser power is adjusted accordingly.

Abstract: A control module includes a plurality of switching elements, a control chip, and an identification unit. The switching elements are connected to a power terminal through a corresponding resistor each, wherein the resistances of corresponding resistors or equivalent resistance of combination thereof are different. The switching elements generate an input current according to operating conditions thereof. The input current is sent to the control chip through an input/output terminal and is transformed to a digital value. The identification unit identifies the operating conditions of the switching elements according to a lookup table and the digital value, such that the control chip executes a corresponding logic operation.

Abstract: A circuit for generating tracking error signal using differential phase detection, comprising a quadrant photodetector for receiving optical signal and inducting splitting signal A, splitting signal B, splitting signal C and splitting signal D, two adders for generating group signal (A+C) and group signal (B+D). A plurality of equalizers for receiving, equalizing and amplifying splitting signal A, splitting signal B, splitting signal C, splitting signal D, group signal (A+C) and group signal (B+D). A plurality of phase detectors for receiving the output of equalizers and comparing phase difference of splitting signal A and group signal (A+C), group signal (A+C) and splitting signal B, splitting signal C and group signal (B+D), and group signal (B+D) and splitting signal D, and outputting a plurality of adjustment signals respectively. A circuit for eliminating the phase difference by adding and subtracting some adjustment signals with same phase difference.

Abstract: A device for protecting a preamplifier in reading signals on a defect disc from disturbance and instability is provided. The device includes a defect detection unit, a logic combination unit and a preamplifier. The defect detection unit receives a plurality of defect detection signals to detect various defects for setting a plurality of defect flag signals. The logic combination unit performs logic operation on the defect flag signals in order to detect a specified defect. The preamplifier receives data from a pickup head and generates an RF signal for data process, servo control signals for a servo control unit and various signals for defect detection. The preamplifier includes an equalizer and an auto gain control (AGC) unit. Wherein the equalizer uses corresponding boost gain or cut-off frequency to equalize and recover an IRF signal affected by the specified defect. The AGC unit controls a gain for the equalized RF signal affected by the specified defect.

Abstract: A device for protecting a PLL in reading signals on a defect disc from disturbance and instability is provided. The device includes a defect detection unit, a logic combination unit and a PLL. The defect detection unit receives a plurality of defect detection signals to detect various defects for setting a plurality of defect flag signals, wherein the plurality of defect detection signals include at least an envelope of RF signal and bit modulation signals. The logic combination unit performs logic operation on the defect flag signals in order to detect a specified defect. Wherein, when the specified defect is detected, the PLL uses different bandwidths to compensate a digitalized RF signal affected by the specified defect. A method for protecting a PLL in reading signals on a defect disc is also provided.

Abstract: A device for protecting a slicer in reading signals on a defect disc from disturbance and instability is provided. The device includes a defect detection unit, a slicer and a logic combination unit. The defect detection unit receives a plurality of defect detection signals to detect various defects for setting a plurality of defect flag signals, wherein the plurality of defect detection signals at least include an envelope signal of a RF signal and bit modulation signals. The slicer receives and digitalizes the RF signal. The logic combination unit performs logic operation on the defect flag signals in order to detect a specified defect and to trigger defect protection for the slicer. A method for protecting a slicer in reading signals on a defect disc is also provided.

Abstract: A device for protecting a servo in reading signals on a defect disc from disturbance and instability is provided. The device includes a defect detection unit and a logic combination unit. The defect detection unit receives a plurality of defect detection signals to detect various defects for setting a plurality of defect flag signals, wherein the plurality of defect detection signals at least include an envelope signal of a RF signal and bit modulation signals. The logic combination unit performs logic operation on the defect flag signals in order to detect a specified defect. The logic combination unit indicates a servo control unit generating low-pass output signals according to said plurality of defect flag signals for controlling related electromechanical devices to prevent from disturbance and instability when the specified defect is detected. A method for protecting a servo in reading signals on a defect disc is also provided.

Abstract: An apparatus and related operating method for generating slice levels adapted to an optical system is disclosed. The apparatus basically encompasses a multiplexer, a low-pass filter, a digital signal processor (DSP), a digital-to-analog converter, and a comparator. In the beginning of the track-crossing operation, the optical system will enter the first DAC mode that a pre-stored slice level derived from a calibration process is accessed and converted by the digital-to-analog converter before being referred as the slice level in the first DAC mode. When the low-pass filter can follow the RFRP signal variations, the low-pass filter is used to receive the RFRP signal and derive the slice level in the low-pass-filter mode. When a track-on command is given, the optical system will enter the second DAC mode and find an average value of the last peak-hold and bottom-hold values derived at the end of the low-pass-filter mode.

Abstract: A method for controlling read power and an open-loop read control device using the same. The open-loop read control device is used in an optical disk writer and includes a memory, a DAC and an amplifier. The optical disk writer includes a pickup head device having a laser diode. When writing is disabled, the read power of the optical disk writer for reading the disk corresponds to a specific voltage. The memory stores a relationship curve and outputs a corresponding reference value corresponding to the specific voltage. The DAC converts the corresponding reference value into an analog corresponding reference value. The amplifier receives the analog corresponding reference value and outputs a read power control voltage, which controls the laser diode to generate a substantially constant read power in the write process.

Abstract: The recording speed controlling method for a recording and reproducing apparatus of the present invention including: compensating the focus error (FE) signal as a focus servo output (FOO) signal; low-pass filtering the FOO signal with second order into a FOO_LPF signal; detecting if a peak-to-peak voltae (Vpp) of the FOO_LPF signal reaches a limited voltage; and if yes, reducing the recording speed, else, keeping the recording speed. The tracking error (TE) signal could be an alternative of the FE signal, or both the two signals are taken as the judgment of controlling recording speed.

Abstract: The present invention discloses a method for sampling optic disc data. The method includes the following steps. First, a first sync tag signal and a data signal are provided, and the previous first sync tag signal is saved as a second sync tag signal. Then, it is checked and determined whether the value of the first sync tag signal and the second sync tag signal is true or false so as to divide the data signal. Since the neighboring sync tag signals are detected simultaneously, and the timing for sampling the data in the frame is determined according to whether the two contiguous sync tag signals are true or false, the present invention can improve the disadvantages of the prior art.

Abstract: The present invention provides an anti-burn method for a recording and reproducing apparatus when mechanism problem happen. The method includes: low-pass filtering a center error (CE) signal which shows the position of an optical pickup unit; detecting if the filtering CE signal is lower than a threshold value, then stopping recording and marking a stop point when the filtering CE signal is lower than the threshold value. The method further includes: continuing recording process from the stop point when the filtering CE signal is higher than the threshold value. The continuing recording process includes: preparing recording data; seeking the stop point of a disk; and continuing recording the disk from the stop point.

Abstract: A method for protecting a phase lock loop (PLL) in an optical system is disclosed. The disclosed method will determine whether the currently reading data is erroneous and then maintain the frequency currently locked by the PLL circuit when the waveform lengths of the EFM signal in a detecting window contain at least one waveform length longer than 11T and at least one waveform length shorter than 3T. Otherwise, the PLL circuit will adjust the locked frequency according to the waveform length of the detected EFM signal so that the system clock frequency can be adjusted based on the locked one. In addition, when the optical system seeks tracks for reading required data under a constant angular velocity (CAV) modulation mode, the PLL circuit will increase the locked frequency gradually as the pick-up head moves towards the outer tracks of the optical disc, and decrease the locked frequency gradually as the pick-up head moves towards the inner tracks of the optical disc.

Abstract: The present invention provides a device for detecting the signal on a defect disc. The device includes a servo control unit, a data path control unit, a defect detection unit, and a logic combination unit. The servo control unit handles the related electromechanical devices. The data path control unit further includes a preamplifier receiving data from a lens and generating RF signals for data process, servo control signals for the servo control unit and various signals for defect detection; a slicer receiving and digitalizing the RF signals; a phase lock loop (PLL) synchronizing the digitalized RF signals to a system clock and counting the length of the digitalized RF signals; and a decoder decoding the length of the digitalized RF signals to a host. The defect detection unit receives the various signals for detecting different kinds of defects to set corresponding defect flag signals.