Abstract: An optical disc drive (ODD) includes one or more sensors which detect a user placing a disc in the loading path. In response, a process is triggered for sensing the thickness of a protective layer of the disc even while the disc is moving toward a turntable. An initial determination of the type of the disc (e.g. CD, DVD or Blu-ray®) can be determined based on the thickness and reported to a host computing device. The host, in turn, determines an application to load based on the disc type. The loading of the application can begin sooner than if the ODD waited until the disc was seated on the turntable to detect the disc type. A final determination of the disc type can be made while the disc is seated as well. The host is informed if there is a disagreement between the initial determination and the final determination.

Abstract: An optical information storage medium system is provided. The optical information storage medium system includes an optical pickup, which comprises a photo-detector configured to control light power detected by receiving a portion of light emitted from a light source and obtains an output signal proportional to output light power of the light source from a signal detected by the photo-detector, and a signal processor configured to signal-process the output signal input from the optical pickup. The signal processor includes a sensitivity acquisition unit configured to acquire a sensitivity value of the photo-detector, a gain calculator configured to calculate a target gain value to be used in comparing the sensitivity value of the photo-detector, which is acquired by the sensitivity acquisition unit, with a target sensitivity value to be used by the optical information storage medium system, and a gain adjustment unit.

Abstract: A data phase locked loop circuit includes a phase locked loop circuit, a judging circuit, a detecting circuit and a control circuit. The phase locked loop circuit outputs a reference signal according to a data signal, which is generated by an optical drive reading an optical disk. When the judging circuit judges that a jitter signal is smaller than a threshold value, the control circuit stores a frequency of the reference signal. When the detecting circuit detects a defect zone of the optical disk read by the optical drive, the phase locked loop circuit fixes the frequency of the reference signal to a latest stored one.

Abstract: An optical drive apparatus that reproduces an optical disk having a land and a groove, the optical drive apparatus including a first tracking-error-signal generating unit that generates a first tracking error signal by using a DPD method, a second tracking-error-signal generating unit that generates a second tracking error signal by using a DPP method, a tracking servo unit that controls the optical system, and a determining unit that determines that an irradiation point of an optical beam is in a non-recorded area. The tracking servo unit switches over to a control based on the second tracking error signal in response to a result of determination by the determining unit during performing a control based on the first tracking error signal.

Abstract: Provided are a light detecting element, and an optical pick-up device and an optical disc drive including the light detecting element. The light detecting element includes a terminal resistance unit that is provided between an amplification unit and an output port to limit an electric current of the output signal.

Abstract: In a system of detecting an interference light with a light not irradiated onto an optical disc to increase the S/N ratio, it is difficult to stably acquire a reproduced signal with a simple configuration. Since the recording density is not improved, an improvement in transfer rate is difficult. In an optical information recording/reproducing apparatus where two optical beams face each other and are focused at the same place of a recording medium to record a standing wave developed by interference of the two optical beams, a phase difference of the two optical beams is modulated in a multiple stage and recorded. During reproduction, an interference light of a reproduced light from the recording medium and another reproduction reference light is detected as a reproduced signal, and a phase servo control stabilizing the phase of interference during reproduction by using a low frequency component of the reproduced signal is conducted.

Abstract: In a small-sized optical pickup device for enabling to obtain a stable servo-signal, as well as, a focus error signal and a tracking error signal, without receiving ill influences of stray lights from other layers, when recording/reproducing a multi-layer optical disc, a reflection light from the multi-layer optical disc is divided into plural numbers of regions by a diffraction grating. And, it is divided into at least four (4) regions, by a division line in the tangential direction of the optical disc and a division line in the radial direction thereof. Light receiving parts, for detecting either one of grating diffraction lights, i.e.

Abstract: An optical disc device comprising: a controller for reading data from an optical disc having a plurality of recording layers, wherein: the controller, in shifting a focus of the laser light from a first layer to a second layer, performs a first change that changes a setting on the high frequency signal to a predetermined value at which the high frequency signal is superimposed to suppress peak power of the drive signal if a light density of the second layer is higher than a light density of the first layer; the controller shifts the focus from the first layer to the second layer; and the controller, after the focus has been shifted, performs a second change that changes the setting on the high frequency signal to a predetermined value at which the high frequency signal is superimposed to increase the peak power of the drive signal.

Abstract: An approach is described that allows an optical disc drive to accurately verify the power level of irradiation beam power levels associated a write strategy used in high speed, high density optical disc media formats using a front monitor diode with a relatively slow rise time and/or relative slow fall time compared to the clock cycle speed of the write strategy signal. A portion of encoded data to be written to an optical disc media may be overwritten to include a predetermined data pattern. During write strategy processing of the data, the predetermined data pattern is replaced with a constant write strategy power level. The constant write strategy output placed within the write strategy signal may control the optical disc drive laser to emit a constant irradiation beam for a duration sufficiently long to allow the front monitor diode to obtain an accurate measure of the irradiation beam power level.

Abstract: Circuitry for controlling mode selection of a CD/DVD reader is described. In one embodiment, the CD/DVD reader has a first device having at least one analog output, a second device having at least one digital input and at least one analog input, and an interface circuit coupling the analog output of the first device to the digital input and the analog input in the second device. The interface circuit includes a circuitry to use a single control signal from the analog output of the first device to control the digital input and the analog input in the second device. Other embodiments are also described.

Abstract: An optical pickup and an information storage medium system using the same. The optical pickup includes a light source that emits light having a plurality of different wavelengths. The optical pickup includes a diffraction device having a plurality of diffraction patterns corresponding to the plurality of different wavelengths to divide the light incident from the light source unit into main light and sub light. The optical pickup further includes a photo-detector having a first main light reception unit that receives the main light and a first sub light reception unit that receives the sub light so as to detect an information signal and/or an error signal by receiving reflected light. The first sub light reception unit of the photo-detector is shaped so as to reduce reception of noise sub light due to diffraction based on an undesired diffraction pattern of sub light generated the diffraction device.

Abstract: For obtaining stable servo-signals without receiving ill influences of stray lights from other layers, on both a focus error signal and a tracking error signal, when recording/reproducing a multi-layer optical disc having small gap between layers thereof, a light beam is divided with using a first and a second diffraction gratings. The first diffraction grating is a polarization diffraction grating, and is mounted on an actuator. The second diffraction grating is disposed on a fixed portion. The first diffraction grating has a first region having a center of a light beam and other(s), and among signal lights reflecting from the disc, the light beam entering into the first region is diffracted, and the light beam entering into the second region transmits therethrough. The second diffraction grating transmits the light beam diffracting on the first region of the polarization diffraction grating therethrough, while diffracting the light beam diffracting on the second region.

Abstract: An optical information reproducing apparatus includes: an irradiation section irradiating a light beam onto an optical information recording medium, in which holes are formed along a virtual track on a recording medium, along the virtual track; a light receiving section receiving a reflected light beam when the light beam is reflected by the optical information recording medium and sequentially generating a light receiving signal corresponding to the light intensity; a detection section detecting a variation pattern appearing when a signal level of the light receiving signal changes according to the hole; and a code string generating section, when generating a code string corresponding to the signal level, generating a code corresponding to the one hole from the variation pattern if the variation pattern falls within a range and generating a code string, which includes a plurality of codes, from the variation pattern if the variation pattern exceeds the range.

Abstract: This invention relates generally to a photon/light based data storage, distribution and simultaneous data access system for a multiprocessor computer system.

Abstract: Reflected and scattered electrons generated by emitting an electron beam onto a substrate are detected by a detecting unit. The product of the area (SN) and the irradiation time (tN) of the Nth shot in a predetermined measurement unit obtained from writing data is computed by a computing unit. The value obtained by accumulating an instructed equivalent value in the predetermined measurement unit and the value obtained by integrating the signal (DN) from the detecting unit in the predetermined measurement unit are compared and determined by a comparing unit to determine whether or not abnormality occurs in the irradiation amount of the electron beam.

Abstract: An optical pickup device includes an astigmatism element which imparts astigmatism to laser light reflected on a disc, a spectral element which changes propagating directions of four light fluxes obtained by dividing a light flux of the laser light reflected on the disc to disperse the four light fluxes from each other, and a photodetector having a sensor group which receives the four light fluxes. The optical pickup device is further provided with a memory which holds a correction value for suppressing a DC component in a tracking error signal resulting from a positional displacement of the spectral element. The tracking error signal is corrected by the correction value to thereby suppress the DC component.

Abstract: An optical-pickup apparatus includes: a first laser light source including a first laser diode to emit a laser beam having a first wavelength, and a back-monitor photodetector to receive the laser beam emitted in a backward direction, not being an optical-disc direction, and output a first monitor signal; a second laser-light source including a second laser diode to emit a laser beam having a second wavelength; a light-receiving circuit including a front-monitor photodetector to receive the laser beam emitted in a forward direction, being the optical-disc direction, and output a second monitor signal, and a switch circuit to be inputted with the first and second monitor signals, and output the first or second monitor signal according to a switch signal; and first and second drive circuits to drive the first and second laser diodes according to the first and second monitor signals outputted from the light-receiving circuit, respectively.

Abstract: An optical pickup includes a light source, an objective lens, a diffraction grating that divides an optical beam reflected from a predetermined information layer, into a plurality of optical beams, and a detector having a plurality of photo-receivers to receive a plurality of optical beams. The diffraction grating has a predetermined region for dividing from a signal light beam a region including a central portion of a spot which the signal light beam will form on the diffraction grating. A distance from a central section of the detector to that of a spot center photo-receiver on the detector, the spot center photo-receiver being provided to receive the optical beams formed by division in a predetermined region of the diffraction grating, is equal to or greater than a spot radius of the unwanted light beams entering the predetermined region of the diffraction grating, on the detector.

Abstract: The present invention provides a method for writing data on a multilayer optical disc with N information storage layers (where N is an integer and N?2). The kth deepest one (where k is an integer and 1?k?N) of the storage layers of the multilayer optical disc is called a kth information storage layer.

Abstract: A recording device includes a light irradiation portion which irradiates an optical recording medium with laser light emitted from a light source via a field lens, a light emission drive portion which drives and causes the light source to emit light, a front monitor which receives the laser light emitted from the light source, a light receiving portion which receives reflected light which is obtained from the optical recording medium in response to the laser light irradiation, a focus servo control portion which controls a focus servo of the field lens on the basis of a light receiving signal by the light receiving portion, a surface jump controller which controls the focus servo control portion so as to perform a focus jump operation to a surface of the optical recording medium, and a surface APC corrector which performs a process as an auto power control (APC) correction process.

Abstract: Systems, methods and compute program products for compensating for asymmetry variations are described. The asymmetry variations may be monitored both circumferentially and radially across an optical storage medium such that effects of the asymmetry variations may be compensated or minimized. In some implementations, effects of asymmetry variations may be compensated or minimized by first determining light reflected from a circumferential location of an optical storage medium. Then, at least one quality measure based on the detected light is determined. The correlation may be established based on the at least one quality measure and a corresponding circumferential location. A power level of a light source that emits the light is then adjusted based on the correlation.

Abstract: An optical storage apparatus and a method for eliminating a write power transient thereof are provided. The method includes following steps. First, a target voltage level of a write voltage when next time the optical storage apparatus writes data is obtained. Then, a command value is updated by using the target voltage level according to a relationship between the command value and the write voltage. Next, the write voltage of the optical storage apparatus is pre-charged to the target voltage level according to the updated command value. Thereby, the write power transient of the optical storage apparatus can be eliminated.

Abstract: An optical disc apparatus includes an optical pickup including: a light source; an objective lens for converging a light flux emitted from the light source and forming an optical spot on an information recording plane of an optical disc; and an optical modulation unit divided into a plurality of areas for modulating an area containing a main beam of the light flux to change a shape of the optical spot, wherein data is reproduced by converting a reproduction signal read from the optical disc with the optical pickup into an NRZI signal of a predetermined modulation rule by a PRML method. An optical spot shape, laser power setting and PRML setting are changed with each optical disc and each drive operation state.

Abstract: An information processing apparatus includes: a signal reproduction section configured to obtain a reproduced signal from a recording medium by radiating a laser beam emitted by a laser-beam source to the recording medium; and a high-frequency signal superposition section configured to superpose either a first high-frequency signal or a second high-frequency signal having a frequency higher than the frequency of the first high-frequency signal on a driving signal used for driving the laser-beam source, wherein, in a first signal reproduction operation, the high-frequency signal superposition section superposes the first high-frequency signal on the driving signal whereas, in a second signal reproduction operation to measure information on the amplitude of the reproduced signal, the high-frequency signal superposition section superposes the second high-frequency signal on the driving signal.

Abstract: An optical disk drive controls recording power with high accuracy in accordance with a measured ? value and a target ? value. A system controller of the optical disk drive determines a ? value at which jitter or an error rate becomes minimum, in both an inner radius and an outer radius of an optical disk, and determines a difference between the determined ? value and the target ? value for each of the inner and outer radii. A corrected value for an arbitrary position, arbitrary speed, and an arbitrary temperature is calculated from a difference achieved at the inner radius and a difference achieved at the outer radius, by means of linear interpolation. The measured ? value for the arbitrary position, the arbitrary speed, and the arbitrary temperature is compared with the target ? value after having been corrected, thereby controlling recording power.

Abstract: An optical disk device and recording method of recording data on an optical disk by driving a laser light source with a driving current superimposed with a high-frequency current. The device and method includes a controller for disabling tracking servo and establishing conditions for reproducing a signal from a predetermined region of the optical disk, for generating a tracking error signal by superimposing the high-frequency current varied in amplitude on the driving current for the laser light source, for determining an amplitude of the high-frequency current that provides an optimum quality of the generated tracking error signal, and for recording data on the optical disk by applying the driving current for the laser light source superimposed with the high-frequency current of the determined amplitude.

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: An optical disc discriminating method and an optical disc discriminating apparatus which can discriminate a type of optical disc with a simple configuration, causes a drive means to vary an incident angle of a laser light beam with respect to an optical disc while irradiating the optical disc with the laser light beam from a light beam generating section, causes a photodetector to detect a diffraction light of the laser light beam from a recording track of the optical disc, detects a value corresponding to the incident angle when the diffraction light is detected, and discriminates the type of the optical disc on the basis of the detected value.

Abstract: In an optical disk recording apparatus, a monitor monitors a recording power of a laser light. A laser control circuit enables a laser diode to perform test recording while using the monitor to monitor the recording power of the laser light and while controlling a laser drive voltage, so that the monitored recording power reaches a given reference value during the test recording. A voltage measurement section measures the laser drive voltage when the recording power of the laser light reaches the reference value. A calculation section calculates an initial laser drive voltage from the reference value of the recording power and the measured laser drive voltage corresponding to the reference value. A main controller allows the laser control circuit to set the calculated initial laser drive voltage and to start the recording while supplying the laser control circuit with the target value so that an actual recording power of the laser light promptly reaches the target value during the course of the recording.

Abstract: An information recording apparatus (1) is provided with: a recording device (102) for recording information onto an information recording medium (100) by irradiating the information recording medium with a recording laser beam (L); a controlling device (103) for recording calibration data onto the information recording medium by using the recording laser beam in which the power is adjusted gradually; and a detecting device (107) for detecting with a push-pull signal after the recording of the calibration data, the recording of the calibration data being ended if the push-pull signal exceeds a predetermined range, an optimum power of the recording laser beam being determined from a jitter amount included in a reproduction signal.

Abstract: An optical pickup includes a semiconductor laser, a beam splitter, a collimating lens, an objective lens, an aperture and a front monitor. The beam splitter splits a light beam emitted by the semiconductor laser into transmitted light and reflected light. The front monitor detects luminous energy of the transmitted light. The front monitor is disposed near an optical axis of the transmitted light so that the following is satisfied: 1?(S×L)/(s×f)?6.8. S is an area of an entrance pupil of the objective lens, f is an optical distance from an emission portion of the semiconductor laser to the collimating lens, s is an effective receiving area of the front monitor, and L is an optical distance from the emission portion of the semiconductor laser to the front monitor.

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: A method for determining an optimum laser power for a recording medium. The method includes checking if a portion of an unused area in a test area on the recording medium is defective, and performing an optimum laser power operation in a used area in the test area, in which the used area is a non-defective area that was used to test the optimum laser power for the recording medium.

Abstract: Playback durability of a writable optical disk is ensured. A method of controlling a playback condition includes continuously irradiating an optical disk with a laser beam having a power level lower than a mark formation level and detecting a change of a state of a signal caused by a return light from the optical disk, and setting a playback condition for the optical disk according to the change of the state of the signal. The playback durability of the optical disk can be ensured by adaptively controlling the playback condition as stated above.

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 fabrication method of a multilayer optical recording medium having a plurality of recording layers, comprises a step of preparing an optical recording medium having at least one record area; a write-position mark generating step of recording write-position marks in the record area beforehand; a step of preparing an optical system including a common objective lens to focus a data recording beam and a position mark recording beam on different positions in a thickness direction of the record area; a first data writing step of writing data between the write-position marks with following the write-position marks by the data recording beam; a position mark recording step of, in parallel with the first data writing step, recording new write-position marks in the record area by the position mark recording beam; and a second data writing step of writing data between the new write-position marks with following the new write-position marks by the data recording beam.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a light emitter which emits light; a drive section which drives the light emitter according to a control signal; a light amount detection section which detects an amount of light which is emitted from the light emitter; an analog to digital converter which converts the amount of light into a digital value; a feedback controller which controls the control signal based on the digital value and a reference value, and outputs the control signal to the drive section; and a setting change section which sets a change unit used by the feedback controller to control the control signal.

Abstract: An optical disk apparatus according to the present invention generates a divided clock signal by dividing a recording clock signal, and based on the divided clock signal, determines a test emission pattern for test recording which is used for controlling the power of a light beam that is output from an emission section. When the linear velocity at recording changes, the division ratio is adjusted in a direction of reducing a change in frequency of the divided clock signal. In an optical disk apparatus which performs laser power control by conducting a test emission with multipulses in a test area, a good detection accuracy of a multi-pulse average value can be maintained even at high x-speeds.

Abstract: A recording/reproducing apparatus and a tracking control method which can perform data processing for reliably recording or reproducing data on or from a recording medium are disclosed. Tracking error signal (TE) is generated using difference signal (A?B) produced from reflected light from a recording medium and an offset included in the difference signal is compensated for using another reflected light received separately from the reflected light. Offset-compensated tracking error signal ((A?B)?k(C?D)) is obtained by subtracting another difference signal (C?D) produced from the separately received reflected light according to gain (k) from difference signal (A?B). Different gains may be used for areas on the recording medium having different reflectances. Thus, the tracking error signal can be compensated for an optical offset caused by lens movement and an offset caused by different reflectances and light radiated to the recording medium can accurately follow its track to perform reliable data processing.

Abstract: An information recording apparatus such as an optical disc that can avoid an unrecordable condition between a power-on operation and an available state for recording thereby to solve a problem that an image taking chance is missed in a recording step, wherein its constitution is such that: receiving a command to turn on the apparatus after switching, a system controller drives a power-supply circuit to activate a drive controller and a memory controller; if the optical disc is not replaced while in power-off operation by a sub-battery, the system controller issues a request for high-speed activation, based on information stored in an EEPROM, to the drive controller, and drives plural drive control units one after another thereby to establish an activation period confirmedly, allowing the memory controller to accept a request for a recording start from the system controller without waiting for a report of activation completion to be issued by the drive controller.

Abstract: An image formation width calculation circuit and an image formation shift amount determination circuit are provided so that, before a visible image is formed, an effective image formation diameter of an image formation laser spot is measured, and based on the result, a shift amount of the laser spot is adjusted. An optical pickup which forms a plurality of laser spots on an optical disk is also provided. An image formation focus control laser power control circuit and an image formation laser power control circuit are also provided. A focus control laser spot is located ahead of the image formation laser spot.

Abstract: A recording apparatus includes: a first calculating device for calculating an optimum power for recording the data pattern into a recording-scheduled area (RSA) in an inner area; a first controlling device recording the data pattern with the optimum power outside an end on an outer side of the RSA; a second calculating device calculating an adjustment power used in adjusting a recording condition outside the end on the outer side of the RSA, considering a difference between recording sensitivity inside and outside the RSA; a second controlling device recording the data pattern for adjusting the recording condition with the adjustment power outside the RSA; a reading device obtaining a read signal; a measuring device measuring read signal jitter; an adjusting device adjusting the recording condition for satisfactory jitter; and a third controlling device to record the data pattern into the RSA using the optimum power and the adjusted recording condition.

Abstract: An optical disc apparatus and a method of performing an optical power study and detecting writing power in the optical disc apparatus. An optical pickup includes a light source to emit a laser beam according to an input optical power signal, an optical power detector to detect optical power of the laser beam using part of the laser beam, and an actuator to drive a lens to form a beam spot. To reduce the time required for the power study, a controller positions the optical pickup in a specific area of a disc and applies a predetermined range of optical power signals to the light source to perform the power study to determine its optical power characteristics using the optical power signal and the detected optical power while maintaining the actuator in a driving state in which writing and reading is possible.

Abstract: A power adjustment method in which a modulation index is calculated from reproduced signals of patterns recorded by irradiating light onto an optical information recording medium with a recording power varied and an optimum power of irradiation light is set up using the modulation index. The power adjustment method includes calculating an optimum value PcO of a predetermined correction term Pc using a relation of a value obtained by subtracting the predetermined correction term Pc from the recording power and the modulation index, finding a value Pth of the recording power at which the modulation index becomes substantially zero in the relation of the value obtained by subtracting the optimum value PcO from the recording power and the modulation index, and setting up a value obtained by multiplying the value of Pth by a predetermined constant as a recording power of each of the recording patterns.

Abstract: A write analysis system is described for an optical drive, where the optical drive includes an optical storage medium. The write analysis system includes a filter that receives a reflected signal that is based on a reflection of a diffracted laser beam. The reflection of the diffracted laser beam includes a reflection of a first write signal. The filter generates a filtered signal by filtering the first write signal from the diffracted laser beam. The system also includes a read-back module that receives the filtered signal and that compares the filtered signal to a second write signal that was written to the optical storage medium prior to the first write signal.

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: 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: In an optical disk drive, running OPC (ROPC) is performed without fail, to thus enhance recording quality. ROPC is performed by use of a remaining portion of an area for APC operation within an APC area of a recording unit (RUB) in a next-generation optical disk such as a blu-ray disk. ROPC is performed by means of tentatively writing test data having a length of 50 T longer than a specified length of data to be recorded; and detecting level B of the amount of light reflected at that time. The APC area is formed from five wobble periods. APC is performed in periods of first two wobbles, and ROPC is performed in remaining three wobble periods.

Abstract: An apparatus and method to write/reproduce data to/from an optical disc, which are capable of preventing an error from occurring at the time of examination of a writing strategy and searching for an optimum writing condition for a short period of time, by examining the writing strategy after adjusting a focus in a test region, in order to set a writing condition at the time of writing data. The apparatus to write/reproduce data to/from an optical disc includes a matrix jitter measuring unit which measures length errors and jitters of edges of a mark and a space of a written data pattern from an RF signal generated at the time of reproduction of the optical disc; and a CPU which extracts at least one of the RF signal, a jitter and an error rate, controls a focus bias, and performs an optimum power calibration (OPC) for searching for optimum power of laser.

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.