Abstract: An optical recording/reproducing apparatus and an OPC-performing method are provided for restudying drive characteristics of an optical source after performing OPC test recording and OPC measurement to ensure accurate optimum power control (OPC) for recording data on an optical disc, particularly, when the drive characteristics vary according to temperature changes of the optical source. The OPC-performing method comprises performing OPC recording as test recording for OPC and OPC measurement as measurement of an OPC recording state; performing a power analysis of drive characteristics of an optical source, and obtaining optical source drive characteristics after the OPC recording and the OPC measurement; and performing OPC calculation for determination of an optimum optical source drive level as an optical source drive level for enabling optimum beams of optimum recording power to be emitted from the optical source, based on the OPC recording state and the optical source drive characteristics obtained.

Abstract: A tilt controller controlling a tilt of an actuator of an optical pickup based on distortion-free control signals and an optical reproducing apparatus including the tilt controller. A control signal generator generates firs and second control signals to control the actuator. A reference control signal generator generates a reference control signal using the first and second control signals. A driving signal generator generates driving signals for the actuator using the first and second control signals, and the reference control signal. Protection circuits prevent the reference control signal generator from affecting first and second control signals. Accordingly, distortion of the actuator driving signals is eliminated.

Abstract: A method and apparatus to record data on an optical recording medium include generating a recording waveform having an erase pattern comprising a multi-pulse having a high level which is higher than an erase power level and a low level which is lower than the erase power level. A power level of a leading one of the multi-pulse of the erase pattern and a power level between an end of the erase pattern and a start point of a leading pulse of a recording pattern are controlled to be the low level and the high level, respectively, the high level and the high level, respectively, the high level and the low level, respectively, or the low level and the low level, respectively.

Abstract: An information storage medium and a method of recording data on and/or reproducing data from the information storage medium, includes an information storage medium having at least one information storage layer. Data is recorded in the form of protruding or indented pits in the entire or partial area of the information storage medium, and information regarding the protruding or indented pits is recorded. Smooth tracking can be achieved using the information regarding the protruding or indented pits, that is, push-pull polarity information.

Abstract: An information storage medium and a method of recording data on and/or reproducing data from the information storage medium, includes an information storage medium having at least one information storage layer. Data is recorded in the form of protruding or indented pits in the entire or partial area of the information storage medium, and information regarding the protruding or indented pits is recorded. Smooth tracking can be achieved using the information regarding the protruding or indented pits, that is, push-pull polarity information.

Abstract: A physical identification data (PID) addressing method using a wobble signal, a wobble address encoding circuit, a method and circuit for detecting the wobble address and a recording medium therefor. Groove tracks are classified into odd groove tracks and even groove tracks. Address information indicating physical identification information is phase modulated using wobble signals having a predetermined phase difference between two adjacent groove tracks, and recorded in each groove track so that address information modulated using the wobble signals having the phase difference of 90° between adjacent two groove tracks can be a quadrature phase shift keying (QPSK) signal. Accordingly, a larger amount of data can be recorded on the recording medium, and since an interval in which a wobble signal disappears is not caused, recovery of a wobble clock signal can be advantageously performed.

Abstract: An apparatus for detecting wobble information of an optical disc and a method thereof are disclosed. The apparatus comprises an eliminator for outputting a second harmonic signal by eliminating subharmonic from an input wobble signal. A detector is provided for generating a cosine signal and a sine signal having a phase identical to the second harmonic signal, and detecting a phase difference of the second harmonic signal the generated signals. A compensator is provided for counting the phase difference and compensating the phase difference by shifting a phase of the cosine signal and the sine signal according to the counted value. Also, a signal output unit is provided for outputting a detection signal by multiplying the compensated cosine signal and the second harmonic signal, integrating the multiplied signal, and discriminating a signal. Accordingly, the phase error and the errors are minimized. Also, the detection accuracy increases, and the performance of detecting the saw-tooth wobble is improved.

Abstract: Disclosed are an apparatus for detecting wobble information from an optical disc and a method thereof. The apparatus for detecting wobble information has a phase lock loop (PLL) for generating an oscillation signal with a frequency equal to that of a wobble signal having a minimum keying (MSK) mark; a control signal generator for generating at least one control signal in accordance with the oscillation signal; a memory for generating at least one heterodyne signal with a frequency equal to that of the MSK mark according to the at least one control signal; a multiplier for multiplying the wobble signal by the at least one heterodyne signal; an integrator for integrating the multiplied signal outputted from the multiplier, respectively; and a comparator for comparing each of the integrated values outputted from the integrators with a predetermined threshold to output a detection signal.

Abstract: An optical pickup apparatus includes a detection unit detecting a light beam reflected/diffracted by the recording medium and passing through the objective lens by dividing the light beam into a plurality of light areas, and a signal processor detecting a difference between widths T1 and T2 indicating that first and second focusing signals are greater than a predetermined threshold value and a thickness signal of the recording medium by using the detected difference when an S-curve of a focus error signal detected by using detection signals of the light areas output from the detection unit is obtained by subtracting a second detecting signal from a first detecting signal or by subtracting the first focusing signal from the second signal. Thus, a spherical aberration due to a change in thickness of the recording medium can be corrected by driving a spherical aberration correcting device according to a thickness signal corresponding to the change in thickness of the recording medium.

Abstract: A method and circuit for providing a playback signal which is compensated for time delay. The circuit includes a time delay compensator for detecting a time difference between outputs of a photodetector and temporally matching part of the outputs of the photodetector and another part of the outputs of the photodetector, between which the time difference occurs, to compensate for time delay between different outputs of the photodetector, and an operational unit for summing the part of the outputs of the photodetector, which is compensated for the time delay, and the other part of the outputs of the photodetector to provide a playback signal. Accordingly, the circuit compensates for the time delay between the outputs of the photodetector, thereby increasing the degree of modulation of the data playback signal.

Abstract: An optical recording medium with a wobbled header area and a data recording method and an apparatus therefore. The optical recording medium includes a wobbled track to which a wobble signal is recorded, and a wobbled header track to which a wobble header signal comprising header information and predetermined header marks are recorded. Accordingly, the physical geometry of a header area is uniform so that a decrease in the quantity of light reflected is prevented when data is recorded to the optical recording medium.

Abstract: An information storage medium and a method and apparatus recording data to the information storage medium, the information storage medium having a write pattern for recording data, the write pattern including at least one pulse and a number of the at least one pulse being determined depending on a length of a recording mark. This makes it possible to record data using a write pattern having an optimal number of pulses, thereby preventing degradation in jitter characteristics due to residual heat or heat build-up caused by the use of unnecessary pulses even during high speed recording.

Abstract: A method of detecting a reproducing signal, and a circuit therefor. This circuit includes a detector, a control unit and a compensator. The detector detects the outputs of an optical detection device corresponding to a combination of signals corresponding to sections of the optical detection device arranged in the tangential direction, the outputs corresponding to a combination of signals corresponding to sections of the optical detection device arranged in the radial direction, and/or the outputs corresponding to a combination of signals corresponding to sections of the optical detection device arranged diagonally. The control unit provides a selection control signal and a compensation signal on the basis of the results of detection of the data conditions recorded on the optical recording medium, the interference between optical signals reflected/diffracted from pits in close proximity to each other and from adjacent tracks on a recording medium, and/or various system states.

Abstract: A physical identification data (PID) addressing method using a wobble signal, a wobble address encoding circuit, a method and circuit for detecting the wobble address and a recording medium therefor. Groove address information indicating physical identification information is phase modulated using a wobble clock signal and recorded in one of the two walls of a groove track, and land address information is phase modulated using a wobble clock signal obtained by shifting the phase of the former wobble clock signal and recorded in the other wall. That is, address information is phase modulated and recorded in each track using the wobbles having a phase difference of 90° between adjacent tracks so that a sum of wobble signals from the adjacent tracks can be a quadrature phase shift keying (QPSK) signal. Therefore, more data can be recorded in the recording medium, and since an interval in which a wobble signal disappears is not caused, recovery of a wobble clock signal can be advantageously performed.

Abstract: An information storage medium and a method of recording data on and/or reproducing data from the information storage medium, includes an information storage medium having at least one information storage layer. Data is recorded in the form of protruding or indented pits in the entire or partial area of the information storage medium, and information regarding the protruding or indented pits is recorded. Smooth tracking can be achieved using the information regarding the protruding or indented pits, that is, push-pull polarity information.

Abstract: An information storage medium includes BCA marks, having unique information, formed near the outer edge of the information storage medium. The BCA marks may be formed at the outermost edge of the information storage medium. This new layout enables miniaturization of the information storage medium so that the information storage medium is applicable to portable information recording and reproduction apparatuses.

Abstract: A method of and apparatus for recording data on an optical recording medium form a mark or a space by using a recording waveform having an erase pattern containing a multi-pulse. The method and the apparatus prevent distortion of the mark or the space and improve a mark shape such that a recording/reproducing characteristic of the optical recording medium is improved.

Abstract: A recording medium with a wobble-modulated track, and a method of and an apparatus for detecting a header region of the same. The recording medium includes a wobbled track on which a wobble signal is recorded, a header region on which header information is recorded, and a wobble-modulated track on which a wobble modulation signal obtained by modulating the wobble signal is recorded. Accordingly, the header region is reliably detected, and the reliability of header information read is increased.

Abstract: A method of and a circuit for providing a playback signal, which is compensated for time delay, from a photodetector having a plurality of outputs. A time difference between a first signal corresponding to a part of the outputs of the photodetector and a second signal corresponding to another part of the outputs of the photodetector is detected and one of the first and second signals is temporally shifted to compensate for a time delay between different outputs of the photodetector. The temporally shifted signal is summed with the other signal to provide a playback signal. Accordingly, the time delay between the outputs of the photodetector is compensated, thereby increasing the degree of modulation of the data playback signal. In addition, distortion or degradation of the signal is suppressed and occurrence of errors in the playback signal is minimized, thereby improving the reliability of the playback signal.

Abstract: A method and apparatus to record data on an optical recording medium include generating a recording waveform having an erase pattern comprising a predetermined pulse having a high level which is higher than an erase power level and having a low level which is lower than the erase power level.