Abstract: Proposed is an optical disk device capable of optimally adjusting a current value of a direct current and a high frequency superimposed current for driving a laser diode. This optical disk device includes a laser driver for superimposing a high frequency current on a direct current to obtain a drive current and supplying the drive current to the laser beam source and driving the laser beam source, and a control unit for adjusting a current value of the direct current and/or the high frequency superimposed current supplied by the laser driver to the laser beam source based on the servo signal or the reproduction signal.

Abstract: An optical information record/playback device of the present invention includes: a light source; a current driver for supplying current to the light source; an optical system for condensing light from the light source onto a recording medium; a monitoring section for monitoring light emission power of the light source; a current driver control section for controlling output current of the current driver; and an arithmetic/control section for controlling an operation of the current driver control section. Before recording information, the arithmetic/control section sequentially conducts a first test light-emission to cause the light source to emit light by using a closed loop circuit and a second test light-emission to cause the light source to emit light by using an open loop circuit, and compares first and second sampling values, which are respectively obtained by sampling the outputs of the monitoring section during the first and second test light-emissions.

Abstract: A method for tuning a plurality of write strategy parameters of an optical storage device includes detecting a plurality of patterns. Each pattern corresponds to a pit or a land on a phase-changed type optical storage medium accessed by the optical storage device. The method further includes performing calculations corresponding to a plurality of data types and generating a plurality of data-to-clock edge deviations respectively corresponding to the data types. Each pattern belongs to a data type. The data-to-clock edge deviations are utilized for tuning the write strategy parameters corresponding to the data types respectively.

Abstract: An optical disc apparatus includes a light source for emitting laser light, a light source drive unit for driving said light source, an optical element for splitting the laser light into a plurality of light fluxes, an optical element drive unit for controlling the optical element, an element for focusing the laser light onto the optical disc, and a detection unit for detecting the laser light reflected by the optical disc. Reproduction of the optical disc is performed by switching effectiveness and ineffectiveness of a function of splitting the light flux of the optical element, and adjustment of an outgoing laser power is performed.

Abstract: A hologram recording and reproducing device controls an optical beam output from an external cavity semiconductor laser to improve a diffraction efficiency. The hologram recording and reproducing device includes an external cavity laser, a photodiode, a laser drive circuit and a laser diode controller. The external cavity laser has a laser diode adapted to emit an optical beam that is used to generate data light and reference light with which a hologram recording medium is irradiated. The photodiode detects the amount of the optical beam output from the external cavity laser. The laser drive circuit supplies a current to the external cavity laser. The laser diode controller controls the laser drive circuit to ensure that a value obtained by integrating the detected intensity of the optical beam with respect to time over a predetermined period is equal to predetermined recording energy.

Abstract: By referring to a table of reproducing conditions and medium specific parameters, stored in an optical disc or optical disc apparatus and/or generated by the optical disc apparatus, the medium specific parameters to be used for performing reproducing power adjustment are changed in accordance with the reproducing condition to execute reproducing power adjustment.

Abstract: An evaluation method and print wire method which includes (a) fitting a modulation characteristic formula M,m=Msat (1?(Pws?Pasy)/(Pw,m?Pasy)) having a saturated modulation Msat, write start power Pws, and asymptotic power Pasy as parameters to a relation between a plurality of kinds of write power Pw,m and a modulation M,m which is obtained from a signal amplitude of a trial-written signal, and finding an index value of an error which occurs in the fitting step; and (b) evaluating whether or not the relation between the write power and the modulation is valid for write power adjustment by using the index value of the error and a predetermined value the print write method further including (c) setting the write power based upon the result of evaluating and executing a write power process with the set write power.

Abstract: Prevention of deletion of data in an unintended recording layer of an optical disc is ensured even when servo deviation occurs while controlling data reproduction. A light source outputs a light beam with light intensity according to a driving current on which a high frequency signal is superimposed. The light beam is collected on a recording layer of an optical disc. As triggered by detection of servo deviation during data reproduction, a light intensity controller adjusts a superimposed amount of the high frequency signal in the driving current to suit to a specific recording layer with the lowest reproduction tolerance in the optical disc and thereby controls the light intensity of the light beam output from the light source.

Abstract: A method of controlling a tracking error balance in an optical disc apparatus, and the optical disc apparatus are discussed. In an embodiment of the present invention, when a tracking error balance for writing is controlled, a beam power that is appropriate for the writing characteristics of an optical disc is applied. The beam power can be determined based on the Manufacturer Identifier (MID) of the optical disc and writing power information for different MIDs. The beam power can be determined to be a value of 20 to 50% of the prestored writing power for the MID of the optical disc.

Abstract: The present invention is related to a method and a reading device (1) for retrieving information from an optical record carrier (10) in which the read power level of a radiation beam (3) for scanning the optical record carrier is set in dependence on the read-out speed. The invention is also related to a record carrier for use with such a method and a reading device.

Abstract: In an optimal recording power calibration method for improving seeking stability on a recording power calibration area, a specific area serves as a data recording area during an optimal recording power calibration, wherein a length of the specific area is such that a plurality of times of optimal recording power calibrations can be performed. The method includes: an optimal recording power calibration step of recording, with different recording power, a first length of calibration data in the specific area, and calibrating optimal recording power, wherein a data sector recorded in this step is defined as a calibration recording sector; and a data recording step of recording, with data recording power, a second length of information having a logical address beside the calibration recording sector of the specific area, wherein a data sector recorded in the step is defined as an information recording sector.

Abstract: The present invention provides an optical recording/reproducing apparatus which can record information on the whole plane of the optical disk with a stable quality, even when the temperature has largely changed during a recording standby period in an intermittent recording process. The present optical recording/reproducing apparatus reproduces the information from a recorded portion on which the information has been already recorded, to evaluate the signal quality of the reproduced information, and simultaneously detects a temperature in the apparatus to correct a recording power of a laser beam when restarting the recording, on the basis of the evaluation result and the detected temperature in the apparatus, during the recording standby period in the intermittent recording process.

Abstract: An optical disc recording device according to the present invention is capable of quickly performing the OPC operation for a rewritable optical disc, and is also capable of setting the proper writing power for both an unwritten area and a written area. A microcomputer reads out, from a memory, preliminary writing conditions for the optical disc in question, and then performs preliminary writing so that data is written to a test writing area of the optical disc under the preliminary writing conditions. After that, test writing to the test writing area, which has been subjected to the preliminary writing, is performed with the writing power being changed, and thereby the optimum writing power is determined. Information about the writing power and the erasing power is stored in the memory on an optical disc type basis. The information is used for the preliminary writing.

Abstract: A method for reducing overall power calibration time and increasing the number of power calibrations that can be done on an optical record carrier includes performing a first set of power calibration procedures on an optical record carrier at a first recording speed in a first set of calibration areas, and performing a further set of power calibration procedures on the optical record carrier at a recording speed different from the first recording speed. The further set of power calibration procedures partly uses information from the first set of calibration areas.

Abstract: In order to provide an optical recording condition setting method which reduces effects from uneven properties of a rewritable or recordable optical disk and an optical recording/reproducing device, and to provide an optical recording/reproducing device which executes the method, (i) a test writing is carried out with respect to an optical disk under various settings of recording-power parameters for use in forming a shortest record-mark (S1 to S3), (iii) a test pattern used in the test writing is reproduced (S4), and then (iv) recording-power parameters that result in a good quality of reproduced signals are selected (S5).

Abstract: In an optimal recording power calibration method for improving seeking stability on a recording power calibration area, a specific area serves as a data recording area during an optimal recording power calibration, wherein a length of the specific area is such that a plurality of times of optimal recording power calibrations can be performed. The method includes: an optimal recording power calibration step of recording, with different recording power, a first length of calibration data in the specific area, and calibrating optimal recording power, wherein a data sector recorded in this step is defined as a calibration recording sector; and a data recording step of recording, with data recording power, a second length of information having a logical address beside the calibration recording sector of the specific area, wherein a data sector recorded in the step is defined as an information recording sector.

Abstract: This invention provides accurate control of laser light power in a recording operation to achieve more stable recording operation. An optical disc drive in an embodiment of this invention monitors the power of laser light with a monitor diode and controls the laser light power based on the result of monitoring. The optical disc drive changes data transfer rate (recording frequency) depending on the disc radial position. The optical disc drive controls the gain of the monitor diode across the recording surface depending on the recording frequency. This control improves the accuracy in laser light power control to achieve stable recording operations by precise servo control.

Abstract: This invention provides an optical disc drive with more accurate and stable power control for a laser light source. An optical disc drive in an embodiment of this invention includes a monitor photodetector for receiving laser light emitted by a laser light source to monitor the laser light power. The monitor diode is a photodetector for generating an electric signal corresponding to the laser light power. A laser light controller controls drive current to the laser light source based on a result of measurement by the monitor diode. The optical disc drive measures output variations of the monitor diode and controls the gain of the monitor diode based on the result of the measurement. This gain control improves accuracy and stability in laser light control so that stability in recording/reading can be attained.

Abstract: According to a method for setting the laser beam power applied to reproduce information recorded on an optical disc, information recorded in a region on the optical disc is reproduced using three or more test reproduction powers (S22B), the number of reproductions until the degradation of the quality of the reproduced signal reaches a prescribed value is determined as the degradation number of reproductions (S22F), the relation between the test reproduction power and the degradation number of reproductions is approximated by a curve, and a reproduction power restricting the degradation of the reproduced signal quality to a predetermined amount or less over a certain guaranteed number of reproductions is determined (S25F). In optical reproduction from an optical disc on which information is recorded, the optimum power of irradiation for reproduction can be set, and degradation of the information due to the reproducing light can be prevented.

Abstract: Data is recorded in a phase-change optical storage medium having data layers. A first recording pulse sequence is generated for recording to a first data layer located most remote from a beam-incident surface. The first sequence has a recording pulse carrying an erasing power and a recording power rising from the erasing power, and a cooling pulse carrying a bottom power lower than the erasing power. A second recording pulse sequence is generated for recording to a second data layer. The second sequence has recording pulse carrying an erasing power and a recording power rising from the erasing power, a cooling puse carrying a bottom power lower than the erasing power, and an erasing top pulse carrying an erasing top power higher than the erasing power.

Abstract: An optical recording/reproducing system 1 reads a recorded signal written to a recording track of a recording medium 3 by light. The light is modulated by a drive signal on which a frequency signal is superimposed. The light is scanned along the recording track at a predetermined scan velocity. The optical recording/reproducing system 1 includes a computer 13 and an LD driver 17 that control, based on the scan velocity, a superimposed magnitude of the frequency signal on the drive signal.

Abstract: A recording method is provided, which comprises the steps of (a) generating a plurality of pulse sequences corresponding to a plurality of linear velocities, (b) while rotating a recording medium with a linear velocity selected from the plurality of linear velocities, forming at least one of a recording mark and a space by irradiating the recording medium with a pulse sequence selected from the plurality of pulse sequences, the pulse corresponding to the linear velocity. The step (a) comprises the steps of (a-1) measuring at least one first recording parameter corresponding to at least one linear velocity selected from the plurality of linear velocities, (a-2) determining a second recording parameter corresponding to the plurality of linear velocities based on the at least one first recording parameter measured, and (a-3) generating the plurality of pulse sequences corresponding to the plurality of linear velocities based on the second recording parameter measured.

Abstract: When an optical disc apparatus of the present invention writes to an optical disc, it detects the level of the drive voltage for its laser drive circuit and, based on the detected level, adjusts the drive voltage for its laser diode so as to adjust the drive voltage for the laser drive circuit to a level within an appropriate range. Further, the write speed is also adjusted in accordance with the above adjustment of the drive voltages for the laser drive circuit and the laser diode.

Abstract: The invention relates to the field of the optical recording of information on a medium, such as an optical disc. To read an optical disc in super-resolution mode, a procedure for optimizing the power of the read laser beam is implemented. This optimization is based on the observation that a correlation exists between the power allowing the disc to be read without risk in super-resolution mode and the amplitude of the read signal which results from the reading of marks having the smallest possible dimension (marks 2 T). The amplitude of the optical disc is measured for several powers of decreasing values of the read laser, the reduction in amplitude is observed. A read power is selected as a function of the power for which a decrease (for example 5%) is noted in the amplitude measured at the start.

Abstract: A calculation of a reliability value |Pa?Pb|?Pstd, representing represents a maximum likelihood decoding result on a portion which corresponds to a start or termination edge of a recording mark and has a high probability of error occurrence by a maximum likelihood decoding method, is performed on each combination of a predetermined mark length and a space length immediately before the mark and each combination of the mark length and a space length immediately after the mark. Based on the calculation result, a recording parameter is optimized, and recording reflecting the optimized recording parameter is performed.

Abstract: A reading devices suppresses deterioration of the recording marks caused by increasing the output laser power to compensate for a drop in the S/N ratio when reading at a high speed information recorded to a high density recording medium. To read information recorded to an optical data recording medium that is written and read using a laser beam output from a semiconductor laser, the reading method modulates a high frequency current on the drive current of the semiconductor laser to output the laser beam, and changes the light modulation rate according to the selected linear velocity used for reading. The light modulation rate is the ratio Pp/Pave between the peak power Pp and the average read power Pave of the light intensity of the high frequency modulated laser beam.

Abstract: A recording device for performing recording supporting an optical disk-shaped recording medium having a laminated structure includes a first recording layer and a second recording layer. The recording device includes: a recording section configured to record data in the first recording layer and the second recording layer by irradiating the optical disk-shaped recording medium with laser light; a recording control section configured to control the recording section so as to perform recording in the first recording layer first and next perform recording in the second recording layer when the recording is performed sequentially on the optical disk-shaped recording medium; a pseudo defect area setting section configured to set a pseudo defect area in the second recording layer; and a defect registering section configured to register the real defect area and the pseudo defect area as a defect area.

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: An exemplary method for optimizing a recording signal of an optical recording apparatus to record data onto a disc, the recording signal having a first pulse-width parameter, the method includes selecting an initial value of the first pulse-width parameter; generating adjusted values based on the initial value to record test data onto the disc respectively; measuring mark lengths of lands; determining average lengths of the mark lengths of lands; determining differences between the average lengths and a predetermined standard length; linear curve fitting the adjusted values and the differences employing the following linear curve fitting equation: Y=AX+B to obtain the constants A and B, wherein X represents the adjusted values, Y represents the differences; determining and storing an optimum value of the first pulse-width parameter to be used for recording the data onto the disc, this optimum value equals to ?B/A. An optical recording apparatus is also provided.

Abstract: An optical recording/reproducing system 1 reads, based on a predetermined reproduction clock, information associated with a recording track of a recording medium by irradiating frequency light. The frequency light is scanned at a predetermined scan velocity. The optical recording/reproducing system includes a computer 13, a DSP 49, and a LD driver that modulate light by a drive signal on which a frequency signal is superimposed to thereby output the frequency light, and synchronizes a frequency of the frequency signal with a frequency of the reproduction clock according to the scan velocity.

Abstract: A data recording/reproducing system (1) reads a recording signal written on a recording track of a recording medium (3), by using light, which is modulated by a drive signal wherein a frequency signal is superposed for scanning the signal along the recording track at a prescribed scanning speed. Then, the system reproduces the read signal as data. The data recording/reproducing system is provided with a computer (13) for controlling the superposition frequency of the frequency signal for the drive signal corresponding to the scanning speed, and an LD driver (17).

Abstract: The present techniques provide methods and systems for alignment of a read head with data tracks on an optical data disk. In embodiments, a multi-pixel detector that is segmented into multiple areas, or detector segments, may be used to detect a pattern in the light reflected from an optical data disk. The detector system may then combine the quantized values from each of the detector segments mathematically to determine the alignment of the read head with a target data track. If the read head drifts to one side or the other, detectors to the side of a center detector may start to pick up energy from the adjacent tracks. If this energy is continuously summed for the detectors on each side, the read head may be centered by balancing the sums from the detectors on each side.

Abstract: A recording apparatus (1) is provided with: a recording device (11) for recording a data pattern onto a recording medium (100); a first controlling device (22) for stopping the recording; a reading device (11) for reading the data pattern which is recorded immediately before the recording is stopped, thereby obtaining a read signal; a measuring device (19) for measuring jitter of the read signal; an adjusting device (21) for adjusting a recording condition such that the jitter satisfies a desired condition, and a second controlling device (22) for restarting the recording of the data pattern by using the adjusted recording condition.

Abstract: An information recording apparatus (2) is for forming a record mark corresponding to a recording signal by applying a laser beam to a recording medium, and is provided with: a light source (21) for emitting the laser beam; and a signal generating device (22) for generating a recording pulse signal for driving the light source on the basis of the recording signal, the recording pulse signal includes a mark period and a space period, a level of the recording pulse signal corresponds to a recording power by which waveform distortion is greater than or equal to an upper limit (L) or is less than or equal to a lower limit (?L) of an amplitude limit value on a limit equalizer (15), in the mark period corresponding to a long mark.

Abstract: The optical disk recording apparatus has the function of correcting the timing shift of the write strategy signal caused by the change in the operating environment of the digital signal processing circuit including the write strategy generating circuit, the laser drive circuit for driving the laser at the time of recording and the flexible printed board for electrical connection between the digital signal processing circuit and the laser drive circuit. Upon determination that the timing shift correction is required, the timing shift is reduced by operating the timing shift correcting function.

Abstract: A method and apparatus for recording data on an optical disk calculates an optical power at a first recording speed, compares the calculated optical power to a predetermined value, and then determines whether to apply the first recording speed based on a result of the comparison. The optical power at the first recording speed is calculated based on a reference optical power and a measured optical power, and the predetermined value may correspond to the maximum allowable power of a laser pickup. The method and apparatus may be used to control the speeding, timing, and/power of a data recording operation, as well as to compensate for temperature variations and/or power margins of one or more circuits in an optical disk device.

Abstract: An apparatus for effecting at least one of recording and reproducing information. A first light source has a light intensity and emits a light beam having an emission wavelength. A second light source has another light intensity and emits a light beam having an emission wavelength different from that of the first light source. An optical system guides a light beam emitted from the first light source to a recording medium and guides a light beam reflected from the recording medium to a first photodetector, which generates an output. Another optical system guides a light beam emitted from the second light source to the recording medium and guides another light beam reflected from the recording medium to the second photodetector. A separating optical element guides the light beam emitted from the first light source to the second photodetector, which generates an output.

Abstract: In a super-resolution optical disk for the purpose of achieving an increase in the density of recording data by reproducing a recording mark smaller than optical resolution, the optimum reproduction power needs to be determined since the quality of a super-resolution reproduced signal strongly depends on the reproduction laser power. However, since the track error signal required for tracking servo also depends on the reproduction power, there is a need for a method for determining the reproduction power taking into account both the stabilization of tracking servo and a quality improvement of the reproduction signal. The reproduction power is changed under conditions with focusing servo applied but without application of tracking servo. Thereby, a cross track signal is detected to identify a reproduction power region that leads to quality improvement of both a reproduction signal and a track error signal.

Abstract: In order to provide an optical recording condition setting method which reduces effects from uneven properties of a rewritable or recordable optical disk and an optical recording/reproducing device, and to provide an optical recording/reproducing device which executes the method, (i) a test writing is carried out with respect to an optical disk under various settings of recording-power parameters for use in forming a shortest record-mark (S1 to S3), (iii) a test pattern used in the test writing is reproduced (S4), and then (iv) recording-power parameters that result in a good quality of reproduced signals are selected (S5).

Abstract: An apparatus for recording/reproducing data using holography technology and a method of reproducing data using the same are disclosed. The recording/reproducing apparatus includes an optical path adjuster which adjusts the path of light emitted from a light source and irradiates the light to a predetermined position of a recording medium, a light reflecting unit which reflects the light transmitting through the recording medium to the predetermined position of the recording medium, an image sensor which receives the reflected light and reproduces data included in the reflected light, and a light receiving unit receiving light, which is not transmitted through the recording medium and is diffracted from the recording medium, and generating a monitoring signal. Accordingly, it is possible to provide a simple optical system suitable for the recording/reproducing apparatus using the holography technology and an efficient method of reproducing data using the same.

Abstract: A data readout method is disclosed that is able to read data from an optical disk capable of super resolution readout with high accuracy. The data readout method allows reading data recorded in an optical disk by irradiating a laser beam onto the optical disk. The method includes the steps of varying a light emission power level of the laser beam while the laser beam is irradiated onto the optical disk, and acquiring a reflectivity of the optical disk corresponding to each light emission power level; calculating a second derivative of a curve representing correlation between the reflectivity and the light emission power with respect to the light emission power; calculating an extreme value of the second derivative; and calculating an optimum readout power level for super resolution readout based on the extreme value.

Abstract: A driver circuit for use with a variety of OPU circuits has both a single-ended input and a differential input. The single-ended input is coupled to a single-ended signal path having a variable gain stage and a variable level shifter. The differential input is coupled to a differential signal path having a variable gain stage and a variable level shifter. The single-ended signal path and the differential signal path may be selectively coupled to an output. The respective variable gain stages and variable level shifters can be adjusted so that an output signal at the output has a desired dynamic range.

Abstract: A method of optimizing a write strategy (WS) based on an adaptive WS study used in an optical recording apparatus includes recording buffered user data to a rewritable optical disk, performing a WS study when the recording of the buffered user data is completed, and recording additional user data that is buffered afterward according to an WS obtained based on the WS study. Accordingly, since an optimal WS is obtained in real time by performing the WS study during an interval occurring during the UD recording operation, the UD is optimally recorded.

Abstract: A method for determining optimum write power for an optical disc in an optical disc recording apparatus includes, test writing the optical disc as a recording medium at a first position where a write sensitivity is higher than an average write sensitivity of the optical disc and at a second position where the write sensitivity is lower than the average write sensitivity by the same amount of difference as the difference between the write sensitivity at the first position and the average write sensitivity, using the same write power to the both of the first position and the second position, and obtaining an optimum write power for the optical disc from an average of a write characteristics of the test written positions.

Abstract: An optical disc apparatus includes: an obtaining unit obtaining a sensitivity coefficient indicating a relation between a light power of a semiconductor laser and a monitor value; a first deriving unit deriving a first monitor value in setting the light power at a peak power; a second deriving unit deriving a second monitor value in setting the light power at an erase power; a converting unit converting the first and the second monitor values into first and second light power values based on the sensitivity coefficient; a first calculating unit calculating a ratio between the first and the second light power values; a second calculating unit calculating a correction coefficient based on a setting value of a ratio between the peak power and the erase power and a calculation value of the ratio between the first and the second light power values; and a correcting unit correcting the light power of the semiconductor laser based on the correction coefficient.

Abstract: The invention relates to a method for setting an optimum value of a write parameter for use in an optical recording apparatus for writing information on an optical recording medium by means of a radiation beam. The optimum value of a write parameter is found by curve-fitting a function and obtaining a characteristic write power level (PChar) from the curve-fitting function. It is then assessed if the characteristic write power level (PChar) qualify as an optimum value of a write parameter. If the characteristic write power level (Pchar) does not qualify as an optimum value of a write parameter then an iteration procedure is started, where the subsequent initial values of write power level (Pini, n), are given by Pini, n+1=A Pini, n+(1?A)Pchar, n, where A is a constant, and n is an integer. The invention also relates to an optical recording apparatus and an optical recording medium according to the invention.

Abstract: In order to provide an optical recording condition setting method which reduces effects from uneven properties of a rewritable or recordable optical disk and an optical recording/reproducing device, and to provide an optical recording/reproducing device which executes the method, (i) a test writing is carried out with respect to an optical disk under various settings of recording-power parameters for use in forming a shortest record-mark (S1 to S3), (iii) a test pattern used in the test writing is reproduced (S4), and then (iv) recording-power parameters that result in a good quality of reproduced signals are selected (S5).

Abstract: A laser power which is lower than an optimum reproduction laser power is set as an initial value. The reproduction laser power is increased from the initial value while trial reproduction is performed until a quality level of a reproduction signal is not lower than a reference level. At the time the quality level of the reproduction signal is not lower than the reference level, the reproduction laser power is set as the reproduction laser power with respect to an optical disk which is of a reproduction target.

Abstract: An optical storage system includes a pickup head for picking up data from a storage medium. Firstly, the maxima of a tracking error signal and runout are obtained in a calibration procedure in a close loop formed by an optical pickup head, a pre-amplifier, a compensator, a band-pass filter and a maximum detector. A calibration factor is then defined and derived by using the obtained maxima and nominal factors of a power amplifier and the optical pickup head of the optical storage system. The path formed by the series-connected band-pass filter and maximum detector is then disabled, while the calculated calibration factor is then stored in the compensator. The optical storage system may operate in a close loop formed by the optical pick head, pre-amplifier, compensator, a power amplifier under a normal operation procedure so that the optical storage system may record or read data onto/from an optical disc under the compensation provided by the calibration factor.

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.