Abstract: A method for controlling a specific output power level emitted from a laser diode (LD) in an optical pick-up head unit (OPU) is disclosed. The LD is configured to provide a plurality of output power levels for accessing/recording an optical disc. The method includes: determining a specific power control value according to a first output power level, a second output power level, a first power control value of the first output power level, and the specific output power level, wherein the first output power level is less than the specific output power level and greater than the second output power level; and driving the LD to emit the specific output power level according to the specific power control value, the first power control value, and a second power control value of the second output power level.

Abstract: The invention provides a wobble detection circuit. An exemplary embodiment of the wobble detection circuit comprises an automatic gain control module, an analog to digital converter, a digital band pass filter, and a digital band pass filter. The automatic gain control module amplifies a first input signal and a second input signal detected by a pickup head to the same magnitude to obtain a first amplified signal and a second amplified signal. The adder then subtracts the second amplified signal from the first amplified signal to obtain an analog wobble signal. The analog to digital converter then converts the analog wobble signal to a first digital wobble signal. Finally, the digital band pass filter accepts frequency components of the first digital wobble signal within a pass band and rejects frequency components of the first digital wobble signal outside the pass band to obtain a second digital wobble signal.

Abstract: An automatic power control system, a down sampling circuit and a down sampling method. The automatic power control system is incorporated in an optical disc drive comprising a laser diode for receiving a control signal to generate a laser beam; and a photodetector for detecting the laser beam to generate an analog input signal. The automatic power control system comprises an analog-to-digital converter, a down sampling circuit, a comparator, and a digital-to-analog converter. The analog-to-digital converter converts the analog input signal to digital data. The down sampling circuit, coupled to the analog-to-digital converter, comprises a down sampler, a counter, and a controller. The down sampler receives a predetermined amount of digital data to generate representation data. The counter, coupled to the down sampler, calculates the amount of digital data, and resets the down sampler when the amount equals or exceeds the predetermined count.

Abstract: An automatic power control system, a down sampling circuit and a down sampling method. The automatic power control system is incorporated in an optical disc drive comprising a laser diode for receiving a control signal to generate a laser beam; and a photodetector for detecting the laser beam to generate an analog input signal. The automatic power control system comprises an analog-to-digital converter, a down sampling circuit, a comparator, and a digital-to-analog converter. The analog-to-digital converter converts the analog input signal to digital data. The down sampling circuit, coupled to the analog-to-digital converter, comprises a down sampler, a counter, and a controller. The down sampler receives a predetermined amount of digital data to generate representation data. The counter, coupled to the down sampler, calculates the amount of digital data, and resets the down sampler when the amount equals or exceeds the predetermined count.

Abstract: A method for controlling a specific output power level emitted from a laser diode (LD) in an optical pick-up head unit (OPU) is disclosed. The LD is configured to provide a plurality of output power levels for accessing/recording an optical disc. The method includes: determining a specific power control value according to a first output power level, a second output power level, a first power control value of the first output power level, and the specific output power level, wherein the first output power level is less than the specific output power level and greater than the second output power level; and driving the LD to emit the specific output power level according to the specific power control value, the first power control value, and a second power control value of the second output power level.

Abstract: A high pass filtering device for an optical disc drive comprises a first low pass filter (LPF) of a first sampling rate, filtering a digital input signal; a down-sampler receiving a first filtered signal form the first LPF to down-sample the first filtered signal by an integer factor N; a second LPF of a second sampling rate, filtering a first down-sampled signal from the down-sampler, wherein the second LPF has a corner frequency corresponding to a desired frequency of the high pass filtering device, and the second sampling rate is equal to 1/N times the first sampling rate; an up-sampler receiving a second filtered signal from the second LPF to up-sample the second filtered signal by the factor N; and a subtractor subtracting an up-sampled signal output by the up-sampler from the digital input signal when the filter frequency is below a threshold frequency.

Abstract: A signal processing apparatus includes sample and hold units for holding a plurality of analog photo diode signals. A signal holding controller generates control signals to the sample and hold units for holding the analog photo diode signals. Analog adjusting modules adjust the held analog photo diode signals. A multiplexer selectively couples one input end of the multiplexer to the output end of the multiplexer for outputting the adjusted analog photo diode signals. An analog to digital converter converts the adjusted analog photo diode signals into digital photo diode signals.

Abstract: An apparatus and method of generating a zero crossing signal for an optical disc drive to reduce width deviation due to sampling effect, thereby improving servo control and detection. An embodiment of the apparatus comprises a reshaping device receiving a first digital servo signal of the optical disc drive to upsample the first digital servo signal data, thereby generating a second digital servo signal with higher resolution than the first digital servo signal; and a servo control-and-detection device receiving and slicing the second digital servo signal to generate a servo zero crossing signal.

Abstract: The invention provides a wobble detection circuit. An exemplary embodiment of the wobble detection circuit comprises an automatic gain control module, an analog to digital converter, a digital band pass filter, and a digital band pass filter. The automatic gain control module amplifies a first input signal and a second input signal detected by a pickup head to the same magnitude to obtain a first amplified signal and a second amplified signal. The adder then subtracts the second amplified signal from the first amplified signal to obtain an analog wobble signal. The analog to digital converter then converts the analog wobble signal to a first digital wobble signal. Finally, the digital band pass filter accepts frequency components of the first digital wobble signal within a pass band and rejects frequency components of the first digital wobble signal outside the pass band to obtain a second digital wobble signal.

Abstract: The invention provides an automatic gain controller processing an input signal for wobble detection circuit. An exemplary embodiment of the automatic gain controller comprises an envelope detection module, an analog to digital converter, a digital control module, a digital to analog converter, and a variable gain amplifier. The envelope detection module detects an envelope magnitude of an amplified signal. The analog to digital converter converts the envelope magnitude from analog to digital to obtain a digital envelope signal. The digital control module determines a digital gain signal for amplification of the input signal according to the digital envelope signal. The digital to analog converter converts the digital gain signal to an analog gain signal. The variable gain amplifier then amplifies the input signal according to the analog gain signal to obtain the amplified wobble signal.

Abstract: A laser power control system and related method for reducing a settling time in a target laser power transition are disclosed. The laser power control system includes a state decision circuit, for generating a state decision signal according to a selected operational state of a target circuit; a plurality of buffers, for storing a plurality of control data corresponding to a plurality of candidate operational states of the target circuit respectively; and a multiplexer, coupled between the state decision circuit and the buffers, for coupling a selected buffer of the buffers and the target circuit according to the state decision signal for outputting a control datum stored in the selected buffer to the target circuit.

Abstract: An asymmetry measurement apparatus is disclosed. The asymmetry measurement apparatus is designed for detecting the recorded data reproduction waveform of an optical storage device in digital domain. The asymmetry measurement apparatus includes an Analog to Digital Converter (ADC) for converting an analog signal to a digital signal; a detection unit for detecting plurality values of the digital signal; and an asymmetry calculation unit for generating an asymmetry value of the digital signal according to the plurality values.

Abstract: An apparatus for light spot servo signal detection for reading an optical recording medium having a plurality of non-writable areas between writable data areas containing address information. An optical pickup provides a light spot to the non-writable areas of the optical recording medium with a predetermined state according to a control signal, and detects optical reflecting signals from the optical recording medium to generate a detection signal. A signal adjusting module offsets signal levels of the detection signal to an operating range to generate an offset shifted detection signal. An analog to digital converter digitizes the offset shifted detection signal to generate a digital signal. A detection circuit detects the servo detection signal according to the digital signal.

Abstract: The invention provides an apparatus for controlling servo signal gains of an optical disc drive. The apparatus adjusts the gains of a plurality of servo signals controlling a servo system of the optical disc drive according to a closed-loop mode or a state-reloading mode whenever the optical disk drive encounters an operating state transition. In closed-loop mode, at least one AGC loop of the apparatus compensates the gains of the servo signals with a selectable bandwidth during a specific period after the operating state transition to accelerate the convergence of the servo signals. In state-reloading mode, at least one AGC loop of the apparatus reloads the previously saved convergence values or pre-determined values as the initial values according to the current operating state immediately after the operating state transition to accelerate the convergence of the servo signals.

Abstract: An apparatus of processing an input signal generated according to accessing of an optical storage medium is disclosed. The apparatus has a detecting circuit and a decision logic. The detecting circuit is coupled to the input signal for detecting a target peak value and a target bottom value of the input signal within a time period, wherein the time period is not less than a period of a reference signal generated according to accessing of the optical storage medium. The decision logic is coupled to the detecting circuit for determining a reference level according to the target peak value and the target bottom value.

Abstract: An automatic power control system, a down sampling circuit and a down sampling method. The automatic power control system is incorporated in an optical disc drive comprising a laser diode for receiving a control signal to generate a laser beam; and a photodetector for detecting the laser beam to generate an analog input signal. The automatic power control system comprises an analog-to-digital converter, a down sampling circuit, a comparator, and a digital-to-analog converter. The analog-to-digital converter converts the analog input signal to digital data. The down sampling circuit, coupled to the analog-to-digital converter, comprises a down sampler, a counter, and a controller. The down sampler receives a predetermined amount of digital data to generate representation data. The counter, coupled to the down sampler, calculates the amount of digital data, and resets the down sampler when the amount equals or exceeds the predetermined count.

Abstract: A system for determining groove/land (G/L) switching points of an optical disc is disclosed. The system includes a motor rotating signal generating apparatus, an detection apparatus, and a G/L switching point generating apparatus. The motor rotating signal generating apparatus is for sensing the rotation of a motor to generate a motor rotating signal with a period corresponding to the rotation of the optical disc. Also, the detection apparatus is used for receiving the motor rotating signal and an original G/L switching point signal and utilizing the motor rotating signal and the original G/L switching point signal to determine a location of an reproduced G/L switching point of the optical disc. The G/L switching point generating apparatus is for generating an reproduced G/L switching point signal according to the location of the reproduced G/L switching point determined by the detection apparatus.

Abstract: The present invention discloses read and write power control methods and system for an optical recording device that records information on an optical disk having read-only areas. The read and write power control methods respectively introduce the steps of determining a specific level of a former power control signal output based on a former power control, and then according to the specific level, setting a predetermined level of a power control signal to induce a present power control for rapidly outputting a proper power of the pick-up head. Accordingly, the level transition of the read/write power control signal can be shortened and even eliminated. An unstable read/write power output for the pick-up head can be avoided.

Abstract: A method for controlling the recording speed of a multi-layered optical disc divides a multi-layered optical disc into a plurality of zones with each zone having a corresponding recording speed. It is then determined which zones need the recording speed to be reduced according to the quality of the optical disc. When the optical drive records data onto an inferior quality zone, it reduces the recording speed to guarantee the reliability of recorded data and enhance recording quality. When the optical drive records data on the next recording layer and has passed the zone that corresponds to the inferior quality zone of the previous recording layer, it increases the recording speed. Thereby the method ensures both quality and efficiency. Furthermore, the recording speed of each subsequent zone of the next recording layer corresponds to the recording speed of each previous zone of the recording layer.

Abstract: A method of controlling write power for recording data into sectors of an optical storage medium. The optical storage medium comprises a plurality of sectors, each having a header, a data recording area, and a redundant area. The method comprises sampling a write power output from an optical emitter when the redundant area of the sectors is pointed thereby; generating a write power control force according to a deviation of the sampled write power from an ideal write power corresponding to a write power command; and adjusting the write power according to the write power error control force. Additionally, the redundant area is not a gap section or a mirror region. A circuit and method for determining whether to carry out automatic power control or not during recording data on an optical storage medium are also disclosed.