| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 369440350 | Servo loop gain/switching control | 11 |
| 20080225657 | Optical Disc Actuator Control at Optimal Bandwidth - A method and apparatus for a feedback loop ( | 09-18-2008 |
| 20090196133 | SIGNAL PROCESSING APPARATUS FOR OPTICAL DISC AND METHOD THEREOF - A signal processing apparatus for an optical disc with a first type region and a second type region includes a processing module and a determining unit. The processing module is used for transforming an input signal to generate a first output signal according to a first amplifying gain, or to amplify the input signal to generate a second output signal according to a second amplifying gain, wherein the input signal is derived from an optical pickup head. The determining unit is coupled to the processing module and arranged to control the processing module to output the first output signal when the input signal is derived from the first type region. Also, the determining unit outputs the second output signal when the input signal is derived from the second type region. | 08-06-2009 |
| 20090285060 | METHOD OF ADJUSTING GAIN BALANCE OF OPTICAL TRANSDUCER - A method of adjusting gain balance of an optical transducer includes the following steps. First, two external gains are predetermined. Next, the projection position of a reflection spot is adjusted toward one side of the optical transducer, and the current output values of the optical transducer each corresponding to one of the external gains are measured, respectively, Next, the projection position of the reflection spot is adjusted toward the other side of the optical transducer, and the current output values of the optical transducer each corresponding to one of the external gains are measured, respectively. Then, a gain balance value of the optical transducer is adjusted, and is set as the external gain. Next, the projection position of the reflection spot is adjusted. Finally, the projection position of the reflection spot, where the current output value of the transducer is equal to 0, is locked to complete the adjustment rapidly. | 11-19-2009 |
| 20100182881 | RECORDING DEVICE, AND OPTICAL DISK SIGNAL PROCESSING METHOD - An optical disk signal processing unit ( | 07-22-2010 |
| 20110134733 | TILT ADJUSTMENT CONTROL METHOD OF NEAR-FIELD OPTICAL SYSTEM - A tilt adjustment control method for a near-field optical system is provided. The method includes the following steps. A gap between a lens and a disc is detected. A gain corresponding to the gap is provided. A tilt signal is detected. A tilt compensation value according to the tilt signal and the gain is obtained. A tilt adjustment control is performed on the lens according to the tilt compensation value. | 06-09-2011 |
| 20110249541 | OPTICAL DISC UNIT AND SERVO CONTROL METHOD FOR ACTUATOR THEREOF - In servo control of actuators of an optical disc unit, a gain margin is secured by measuring a mean current or mean voltage applied to each of a focus actuator and a tracking actuator, estimating a displacement quantity of each of the actuators from the measurement values, changing the frequency characteristic or overall servo loop characteristic of a focus servo filter and a tracking servo filter respectively by switching ON/OFF a notch filter according to a displacement condition of the corresponding actuator, and switching control operation between stages of servo control characteristic of each of the focus servo filter and tracking servo filter. | 10-13-2011 |
| 20110261663 | INTEGRATED CIRCUIT AND OPTICAL DISC APPARATUS - An integrated circuit includes a focus control section configured to perform focus control to generate a drive signal for the focus direction displacement section based on a focus error signal, a focus control error determination section configured to determine whether there is a focus control error or not, and a memory section configured to store error-time control signals which are used when there is a focus control error and correspond to a plurality of rotation angles. The focus control section stops the focus control and generates the drive signal for the focus direction displacement section, according to a rotation angle, based on the error-time control signals stored in the memory section at a radial position where it is determined by the focus control error determination section that there is a focus control error. | 10-27-2011 |
| 20130308432 | METHOD AND APPARATUS FOR GENERATING TRACKING ERROR SIGNAL AND OPTICAL INFORMATION STORAGE SYSTEM INCLUDING THE APPARATUS - Provided are an apparatus and method of generating a tracking error signal, and an optical information storage system including the apparatus. The apparatus includes a bias signal generator for generating a bias signal for canceling a direct current (DC) offset of a push-pull signal using a tracking control signal generated by the tracking controller. Accordingly, an offset generated in a tracking error signal may be canceled or otherwise reduced using the bias single instead of using an additional side beam. | 11-21-2013 |
| 20140029400 | Servo Processor Receiving Photodetector Signals - A focus servo system for an optical disk drive includes an optical pick-up unit comprising at least one photodetector. At least one analog to digital converter is configured to digitize signals received from the at least one photodetector. At least one processor is configured to execute a digital servo algorithm to process the versions of the digitized signals to calculate a focus error signal (FES) from the versions of the digitized signals and to indicate a focus open condition based on the FES and the versions of the digitized signals. | 01-30-2014 |
| 369440360 | Variable gain | 2 |
| 20090147633 | OPTICAL DISK APPARATUS, SIGNAL PROCESSING SEMICONDUCTOR INTEGRATED CIRCUIT CONSTITUTING THE SAME, AND OPERATION METHOD - In order to cancel an offset caused by a variation of a signal inputted from an optical pickup, variations of elements in an integrated circuit, etc., a calibration circuit which generates and feeds back an offset adjustment amount that makes the offset zero by a comparison with a reference value, and an offset adjustment circuit that makes the offset zero using the fed-back control signal are provided in an analog front-end LSI. The offset adjustment by the calibration circuit is automatically done in response to commands supplied from a digital signal processing LSI, a host control device, etc. On the other hand, as for a signal on which arithmetic processing such as gain control, addition and subtraction, is performed, the offset adjustment is performed by sending the offset adjustment amount obtained by an arithmetic operation performed by software processing of the digital signal processing LSI to the analog front-end. | 06-11-2009 |
| 20100046332 | SIGNAL PROCESSING DEVICE FOR OPTICAL DISKS AND OPTICAL DISK APPARATUS - A signal processing device for optical disks includes a reflected light process section configured to convert reflected light received by an optical pickup into an electric signal based on a first gain, wherein the optical pickup emits laser light to an optical disk and receives reflected light from the optical disk; a servo signal generation section configured to generate a servo signal by using the electric signal generated by the reflected light process section; a servo signal control section configured to control the servo signal so that a change in the amplitude of the servo signal, in response to an increase or decrease of the amount of the reflected light from the optical disk, is suppressed using an attenuator that attenuates the servo signal generated by the servo signal generation section by a factor of a second gain; and a gain setting section configured to set the first gain to the reflected light process section and the second gain to the servo signal control section substantially simultaneously. | 02-25-2010 |
