Mediatek Corporation

Kuo-Jung Lan

Chih-Ching Chen

Ming-Jiou Yu

Shu-Hung Chou

Chia-Wei Liao

Bing-Yu Hsieh

Yu-Hsuan Lin

Yuh Cheng

Chun-Yu Lin

Jong-Woei Chen

Kuan-Hua Chao

Kun-Hung Hsieh

Wei-Yu Lin

Gwo-Huei Wu

Hao-Hui Yin

You-Wen Chang

Tzu-Ming Chou

Yao-Lung Chuang

Chun-Jen Chen

Shiue-Shin Liu

Chia-Hua Chou

Tysh-Bin Liu

Chih-chung Wu

Shu-Ching Chen

Tzu-Ching Yang

Yung-chi Shen

Chih-Chung Wu

Chuan-Li Wang

Ming-Tsung Huang

Shih-Hao Ko

Shih-jung Chiu

Wei-hsin Hsu

Yuh Chen

Shu-Cing Chen

A temperature measurement device is provided to measure an environment temperature and includes a thermistor, a resistor, a determination circuit, and a measurement circuit. The thermistor is coupled to a first node. The thermistor has a specific impedance value at a specific environment temperature point. The resistor has a first terminal coupled to the first node. The determination circuit determines a real impedance value of the resistor. The measurement circuit is coupled to the first node for receiving a measurement value signal generated at the first node and obtains a value of the specific environment temperature point according to the measurement value signal and the real impedance value of the resistor.

Temperature measurement devices

A power saving method and a power saving system are applied in an optical disk drive. The power saving system comprises a power controlling unit for differentiating the specific sets of circuits not being used at a specific operation rate and powering them down. The sets of circuits not being used will be powered up while the associated operation rate at which they are required to operate is nearly started.

Power saving method and system applied in optical disk drive

An apparatus and a method for compensating periodic signal in an optical disc drive are described. The control apparatus includes an amplitude processing unit, a phase processing unit, a wave generator, a first switch module and a second switch module. The amplitude processing unit processes the amplitude of the input signal based on a reference signal for generating an amplitude signal. The phase processing unit processes the phase of the input signal based on the reference signal for generating a phase signal. The first switch module switches the amplitude signal to select one of the amplitude value and a predetermined amplitude value. The second switch module switches the phase signal to select one of the phase value and a predetermined phase value. The wave generator generates a compensated wave signal based on the selected amplitude value and the selected phase value, and outputs the compensated wave signal.

Method and apparatus for compensating periodic signal

A recording apparatus for an optical disk drive is provided. The recording apparatus includes a driver, a servo signal generator, a filter, and a counter. The driver controls a recording speed of the optical disk drive. The servo signal generator generates at least a servo signal. The filter with a specific bandwidth filters the servo signal to generate a filtered servo signal. The counter generate a count value according to the filtered servo signal and instructs the driver to decrease the recording speed of the optical disk drive when the count value exceeds a trigger value, so as to record with the decreased recording speed.

Recording method and apparatus for optical disk drive

The present invention sets forth a power saving method and a power saving system applied in an optical disk drive. The power saving system comprises a central processing unit, a spindle motor, an optical pick-up unit, an analog portion of control circuits and a digital portion of control circuits. Each of the analog or digital portions of control circuits can be divided into several sets of circuits. Each set of circuits is coupled to an associated operation mode of the optical disk drive. The power saving system further comprises a power controlling unit for differentiating the specific sets of circuits not being used in the specific operation mode and powering them down. The sets of circuits not being used will be powered up while the associated operation mode in which they are required to operate is nearly started. The present invention also provides a power saving method of powering down the sets of circuits not being used relative to a specific operation mode of the optical disk drive.

An automatic power control system, an automatic power control method, 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. The controller, coupled to the counter, disables the counter when the digital data is invalid. The comparator, coupled to the down sampling circuit, compares the representation data with predetermined target data to generate error data. The digital-to-analog converter, coupled to the comparator, converts the error data to analog to generate the control signal.

Automatic power control system for optical disc drive and method thereof

A method and system for calibrating an initial driving signal for driving an optical pick-up head of an optical disk drive is provided. On one embodiment, said optical disk drive is utilized for reading or writing data on an optical disk, the optical disk includes a plurality of auto power control areas (APC areas) and a plurality of data areas, and the APC areas and the data areas are interleaved in between. In at least one of the APC areas that before the data areas for a normal data writing, an initial driving signal is used for the normal data writing to drive the optical pick-up head to emit laserbeam. A detected level of the laserbeam is then obtained. An update initial driving signal is then calibrated according to the detected level and a target level.

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 when the optical disk drive encounters an operating state transition. In a first 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 a second 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.

Apparatus for controlling servo signal gains of an optical disc drive and method of the same

A method for calibrating an initial driving signal for driving an optical pick-up head of an optical disk drive is provided. On one embodiment, said optical disk drive is utilized for reading or writing data on an optical disk, the optical disk comprises a plurality of auto power control areas (APC areas) and a plurality of data areas, and the APC areas and the data areas are interleaved in between. First, in the APC areas, an initial driving signal is used to drive the optical pick-up head to emit laserbeam. A detected level of the laserbeam is then obtained. An update initial driving signal is then calibrated according to the detected level and a target level.

A track-jump control system and method are provided. The track-jump control system applied in an optical disc drive comprises a signal generator, a protection device, a velocity estimator, and a controller. The signal generator receives the signal from the PUH and generates a tracking signal and a position signal. The protection device receives the position signal and when the position signal represents the PUH pass a predetermined position of the optical disc, the protection device generates a protection signal. The velocity estimator estimates the velocity of the PUH according to the tracking signal, and then generates a velocity signal. The controller receives the velocity signal and the protection signal, protects the velocity signal according to the protection signal, and generates a control signal to control the track-jump according to the protected velocity signal.

Track-jump control system and method for maintaining track-jump stability

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.

Apparatus for controling servo signal gains of an optical disc drive and method of same

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. The controller, coupled to the counter, disables the counter when the digital data is invalid. The comparator, coupled to the down sampling circuit, compares the representation data with predetermined target data to generate error data. The digital-to-analog converter, coupled to the comparator, converts the error data to analog to generate the control signal.

A method for controlling a position of a laser spot of a laser beam on an optical storage medium of a land and groove recording/reproduction type is provided. The method includes: detecting a pulse occurring in a reference signal while the laser spot is passing through a boundary between a groove track and a land track, wherein the reference signal is generated according to a reflected laser beam from the optical storage medium; determining a compensation value of the reference signal according to the pulse; utilizing the compensation value to adjust the reference signal for generating an adjusted reference signal; and utilizing the adjusted reference signal to control the position of the laser spot.

Method and system for controlling optical pick-up head locked to track center of optical storage medium

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.

Apparatus and methods for light spot servo signal detection

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.

Growing community of inventors

Jhonghe, Taiwan

Kuo-Jung Lan