Class / Patent application number | Description | Number of patent applications / Date published |
369440250 | Servo signal compared to a reference signal | 21 |
20080239891 | Apparatus For Reproducing Signal From Multi-Layered Optical Disk - An optical pickup apparatus for shining light on an optical disk having two recording layers and for detecting reflected light from the optical disk includes a light source, an optical system situated on a path of a light beam returning from the optical disk inclusive of light reflected by a first recording layer of the optical disk and light reflected by a second recording layer of the optical disk, the optical system including a light condensing optical unit to turn the returning light beam into a condensing light beam, and a light beam regulating unit to extract from the condensing light beam a partial light beam corresponding to part of a cross section of the condensing light beam, and one or more photo detectors, situated between a position where the light reflected by the first recording layer contained in the partial light beam is condensed and a position where the light reflected by the second recording layer contained in the partial light beam is condensed, the one or more photo detectors having a first photo detecting section to detect the light reflected by the first recording layer and a second photo detecting section to detect the light reflected by the second recording layer. | 10-02-2008 |
20090010114 | Optical Data Access Apparatus And Method Thereof - A method for controlling an OPU and an optical data access apparatus are provided. A signal generator is configured to generate a servo signal in response to data access. A comparator is configured to compare a threshold level and the servo signal, and generate a control level if a level of the servo signal against the threshold level when the OPU is controlled. An adjustment unit is configured to adjust a control signal according to the control level. The OPU is controlled according to the adjusted control signal. | 01-08-2009 |
20090022018 | FOCUSING CONTROL METHOD FOR LABEL SIDE OF LIGHTSCRIBE DISCS - A focusing control method on a light-scribed disc firstly focuses a base voltage on a label side. Light summed signals are detected and recorded. The biggest light summed signal is determined, and subtracts the light summed signal of each spoke to form an error signal. The error signal is multiplied by a gain to form a gain signal. The base voltage adds the gain signal to form an upper referring voltage, and subtracts the gain signal to form a lower referring voltage. The label side is focused with the upper referring voltage and the lower referring voltage respectively. The light summed signals are detected and recorded, to determine the biggest light summed signal of each spoke. According to the corresponding voltage of the biggest light summed signals, a focusing control curve is approached to determine optimum parameters. | 01-22-2009 |
20090034375 | METHOD AND APPARATUS OF SEEK END POLARITY DETECDTION FOR OPTICAL DISK DRIVE - The present invention discloses a method and apparatus of seek end polarity detection for an optical disk drive. The method comprises the steps of providing a horizontal level between the peak and the trough of the tracking error signal when the tracking error signal is used to determine the polarity of the tracking error; and determining the tracking error polarity by examining whether or not the adjacent waveform level is smaller or larger than the horizontal level after the tracking error signal passes through the horizontal level. | 02-05-2009 |
20090161503 | METHOD AND OPTICAL DRIVE FOR DETECTING A HEADER REGION ON AN OPTICAL CARRIER - The present invention relates to a method of detecting a header region for a writeable optical carrier. The method initially obtains a data signal (RF) from the optical carrier, and performs a low pass filtering the data signal (RF) for a pre-determined time constant. Subsequently, there is performed a comparison between the low pass filtered data signal (LPF_RF) and a dynamically determined threshold level (RF_th), whereby a positive indication of a header region (I, II, III) is obtained, if the low pass filtered data signal (LPF_RF) is above the dynamically determined threshold level (RF_th). In an advantageous embodiment, there is further performed a comparison of a polarity signal (DPII) to a previous polarity signal (DPI) so as to provide an indication of a land-groove transition. The present invention provides a simple and robust method of detection and header region and possibly a land-groove transition compared to the hitherto known solutions. | 06-25-2009 |
20090238049 | AVERAGE SERVO CONTROL METHOD AND SYSTEM, AND TARGET LEVEL DETERMINATION METHOD APPLIED IN THEREOF - An average servo control method is provided. A target level of at least a servo signal is first detected, which is corresponding to a present condition of the optical disc drive. The target level is then compared with a current level of the servo signal, and a average servo loop gain is adjusted based on the comparison result. A target level calibration may be performed before the gain adjustment. The target level calibration analyzes the servo signal to determine a plurality of preset target levels each corresponding to a different condition. The preset target levels and corresponding conditions are stored as a lookup table. In this way, the target level is acquired based on the lookup table and the present condition. | 09-24-2009 |
20100054094 | Optical Disc Drive - To obtain optimum conditions for writing data on the disc. Provided is an optical disc drive for writing/reading data on/from a loaded optical disc medium comprising: a pickup for writing/reading data on/from the optical disc medium using laser light; and a controller for controlling an operation of the optical disc drive. The controller judges whether the loaded optical disc medium is unrecorded; records a first piece of data on a test area of the optical disc medium in a case where the loaded optical disc medium is judged to be unrecorded; determines optimum output power for recording the data by reproducing the first piece of data; records a second piece of data on the test write area using the determined optimum output power; and adjusts focus balance by reproducing the second piece of data. | 03-04-2010 |
20100118668 | OPTICAL DISK DRIVE - Rotation synchronization detection means is provided which detects a specified rotational phase having a period of one revolution of an optical disk. An output of the rotation synchronization detection means is synchronized with an output of rotation phase detection means for detecting a rotation phase on the basis of a FG signal and thereafter, information of surface vibration component and eccentricity component is memorized in memories before a sleep process in accordance with the output of the rotation phase detection means or a timing until jump is determined in accordance with the output of the rotation phase detection means and during recovery from the sleep status of stopping the disk once, the output of the rotation synchronization detection means is again synchronized with the output of the rotation phase detection means adapted to detect the rotation phase on the basis of the FG signal. | 05-13-2010 |
20100142335 | METHOD FOR GRADUALLY CLOSING DOWN A FOCUS CONTROL LOOP OF AN OPTICAL DRIVE SYSTEM - The present invention relates to a method for operating an optical drive system ( | 06-10-2010 |
20100322046 | OPTICAL DISK DEVICE - The optical disk device includes a generation means and a LC servo means. The generation means generates a lens error signal based on an electrical signal output from a pickup head. After amplifying the lens error signal with a predetermined gain, the generation means outputs the lens error signal. The LC servo means performs lens center servo control based on the lens error signal. The optical disk device further includes a measurement means which measures, before the lens center servo control, a first and a second amplitude values of the lens error signal. The measurement means calculates a current gain based on the first and second amplitude values, the latest gain which is currently set, and a predetermined target amplitude value. Then the measurement means sets the current gain to the generation means. | 12-23-2010 |
20110164481 | RECORDING METHOD FOR OPTICAL DISC AND OPTICAL DISC DEVICE - A recording method for an optical disc and an optical disc device are provided. In one embodiment of the present invention, delay at upward transition of laser diode output driven by a recording pulse can be compared with a predetermined reference value; when the delay is larger than the predetermined reference value, the delay at the upward transition can be compensated by adjusting the recording pulse through a pulse of a reserved output channel; and data can be recorded in an optical disc by driving the laser diode by using the adjusted recording pulse. The amount of delay at the upward transition can be detected through a front photo detector of the laser diode; and the comparison and the compensation can be carried out when fast recording more than specified performance on the optical disc is requested. | 07-07-2011 |
20110228655 | COMPENSATION METHOD IN RADIAL DIRECTION ON LABEL SIDE OF OPTICAL DISC - The disclosure discloses a compensation method in a radial direction on a label side of an optical disc. An optical disc is inserted into an optical disk drive. The data side of the optical disc is divided into at least one compensation area. An optical pick-up head (OPU) is moved from inner to outer rings by simulating a writing process. The OPU is moved to some pre-determined points and radial-directional compensation is performed to obtain radial-directional voltage gains at the pre-determined points. The voltage gains are recorded. The label side of an optical disc is inserted into the optical disk drive. The simulated track number is calculated on the basis of the required moving distance for the OPU to write pattern on the label side. The OPU is moved to write the label side by a radial-directional lens driving voltage compensated with a gain obtained from a compensation formula. | 09-22-2011 |
20110292777 | METHOD FOR CALIBRATING TRACKING ERROR SIGNAL IN OPTICAL DISK DRIVE - A method is provided to start calibrating TE signals in an optical disk drive by checking the change of focus balance, outputting a first TE signal by adjust to a predetermined gain, measuring the peak and trough of the first TE signal, changing the laser power to output a second TE signal on condition of the same focus balance and predetermined, measuring the peak and trough of the second TE signal, calculating and adjusting to a calibrated gain to quickly calibrate the TE signal. | 12-01-2011 |
20110299372 | OPTICAL DRIVE - An optical drive according to the present invention can write information on an optical disc, which includes a substrate on which a number of pre-pits ( | 12-08-2011 |
20120044791 | RECORDING APPARATUS - A recording apparatus, which records information in an optical recording medium, includes: a mode-lock laser unit including a saturable absorber section that applies a bias voltage, a gain section that feeds a gain current, a semiconductor laser that emits laser light used to record the information on the optical recording medium, and an external resonator; an optical modulation unit performing amplification modulation on the laser light emitted from the mode-lock laser unit; a reference signal generation unit generating a master clock signal and supplying a signal synchronized with the master clock signal to the gain section of the semiconductor laser; a recording signal generation unit generating a recoding signal based on the master clock signal; and a driving circuit generating a driving pulse used to drive the optical modulation unit based on the recording signal. | 02-23-2012 |
20120120782 | CIRCUIT FOR GENERATING TRACKING ERROR SIGNAL - A circuit for generating a tracking error signal is provided. The circuit includes a digitizing circuit, a short signal removing circuit and phase comparator. The digitizing circuit receives first and second pick-up signals outputted from a pick-up head, and respectively compares the first and the second pick-up signals with a reference signal to obtain a first digital signal and a second digital signal. The short signal removing circuit is used for removing pulses in the first and the second digital signals, wherein the pulse width of the removed pulses are shorter than a preset time, and the first and second digital without the removed pulses are respectively served as a first determining signal and a second determining signal. The phase comparator receives the first determining signal and the second determining signal for outputting the tracking error signal according to a phase difference between the first and the second determining signals. | 05-17-2012 |
20120120783 | GUIDE-LAYER SEPARATED OPTICAL DISK, OPTICAL DISK DRIVE APPARATUS, AND TRACKING CONTROL METHOD - A guide-layer separated optical disk which includes a guide layer having a guide structure whose tracking guide tracks are divided into areas by discontinuous portions, the areas each having concentric guide tracks of arc shape at a regular track pitch, the guide tracks in adjoining two of the areas across one of the discontinuous portions deviating from each other in a radial direction of the disk by ΒΌ the track pitch. An optical disk drive apparatus and a tracking control method in which a servo optical system switches the tracking center of the irradiation spot of a first laser beam between on the guide tracks and in between the guide tracks alternately each time the irradiation spot passes two of the discontinuous portions. | 05-17-2012 |
20120140606 | INFORMATION STORAGE DEVICE, INFORMATION RECORDING MEDIUM, AND INFORMATION STORAGE METHOD - An information storage device includes an information recording medium, at least a single light source that emits laser light, an illuminating unit that illuminates substantially the same position of the information recording medium with two light rays generated from the laser light, in different directions, a light detecting unit that detects reflection light of the two light rays reflected from the information recording medium and outputs a detection signal, an operation unit that calculates position error information of the information recording medium based on the detection signal; and, a driving device that changes the position of the information recording medium based on the position error information. | 06-07-2012 |
20120163141 | OPTICAL DISK DEVICE, OPTICAL PICKUP, AND OPTICAL RECORDING MEDIUM - The present invention can properly correct spherical aberration. | 06-28-2012 |
20130272105 | Servo Processor Receiving Photodetector Signals - A servo processor for an optical disk drive is provided that includes: an analog-to-digital converter for converting versions of photodetector output signals into digital signals; and a digital signal processor configured to receive the digital signals, the digital signal processor being further configured to determine a focus error signal (FES) and a tracking error signal (TES) from the digital signals, the digital signal processor being further configured to process TES and FES through servo algorithms to produce tracking and focus control signals. | 10-17-2013 |
20140119165 | POSITION CONTROL APPARATUS AND POSITION CONTROL METHOD - There is provided a position control apparatus including a light radiating/receiving unit that performs radiation of laser light for recording and laser light for adjacent track servo onto an optical disc recording medium through a common objective lens, and receives return light of the laser light for the adjacent track servo and the laser light for the reference surface, a tracking mechanism unit that displaces the objective lens, a reference surface tracking error signal generating unit that generates a reference surface tracking error signal, a reference surface tracking servo control unit that controls the tracking mechanism unit, a recording layer tracking error signal generating unit that generates a recording layer tracking error signal, an integrating unit that integrates the recording layer tracking error signal, an offset providing unit that provides an integration output by the integrating unit, and a feedforword control unit that generates a control signal. | 05-01-2014 |