Samsung Electronics Co., Ltd.

Sung-ro Go

Won Sik Kim

Byung-in Ma

Jin-gyo Seo

Chang-jin Yang

Sung-un Yang

Moon-noh Lee

In-sik Park

Pyong-yong Seong

Yong-jae Lee

Joong-eon Seo

Soo-yul Jung

Young-jin Choi

Jong-hoon Lee

Dong-Jin Lee

Byeong-Ho Park

Jong-koog Lee

Hyun-seok Yang

Gwang-ho Lee

Il-Hong Suh

Ki-bong Yun

Kyoung-bok Jin

Joo-yeup Kim

Hong-gul Jun

Min Hwangbo

Gi-bong Song

Hong-rok Kim

Wan-kyun Chung

Kyoung-bog Jin

Jin Gyo Seo

An automatic power calibration apparatus for optical recording devices and a method therefore. The power calibration apparatus includes an optical emission unit, an optical emission unit driving unit which outputs a signal for driving the optical emission unit in response to two or more first channel signal values and/or two or more second channel signal values, an optical detection unit which detects two or more first output signal values and two or more second output signal values corresponding respectively to the first and second channel signals, a memory, a central processing unit which receives the first and second output signal values from the optical detection unit; and an automatic power control unit which adjusts the first channel signal value to maintain the first output signal value to be equivalent to a first reference signal, according to the first reference signal, which is a reference signal of the first channel signal input from the central processing unit, and the first output signal input from the optical detection unit, and outputting the adjusted first channel signal value to the optical emission unit driving unit. Use of the power calibration apparatus enables cost reduction, improvement in productivity, and upgrading of recording quality.

Automatic power calibration apparatus for optical recording device and automatic power calibration method therefor

An apparatus and method for slicing an RF signal and compensating for the slice level of an RF signal reproduced from a disk, which minimizes a block error rate by optimizing the slice level of the RF signal according to variations in symmetry of the RF signal when slicing the RF signal. A comparator converts the RF signal reproduced from the disk into a digital signal by comparing the RF signal with a slice level, a low-pass filter low-pass filters the digital signal and provides the result to the comparator as the slice level, and a slice level compensator compensates for the slice level provided to the comparator by the low-pass filter according to variations in symmetry of the RF signal.

Apparatus and method for slicing RF signal and compensating for the slice level of RF signal in disk drive

An optical recording apparatus and method thereof form a mark and a space by radiating a laser signal corresponding to a recording pulse having a peak level and a bias level onto an optical recording medium. The optical recording apparatus includes a recording pulse generator to generate the recording pulse by overlapping a fine adjustment pulse with an amplitude less than the peak level and the bias level, and a laser diode to generate the laser signal according to the recording pulse.

Method and apparatus for recording data on an optical recording medium

A method of and an apparatus for controlling a power of a light emitter in an optical disc drive to stabilize a servo control operation by efficiently compensating a slow tail effect occurring in a photodiode monitoring outputs of the light emitter are provided. The method includes: detecting an intensity of a laser signal reflected from a recording medium; normalizing the reference value using the detected value; and adjusting the reference value using the normalization result.

Method and apparatus for controlling power of laser diode in optical disc drive

An optical pickup apparatus includes a first light source to emit a first light beam having a predetermined wavelength, a first optical path changer to change a proceeding path of the first light beam, an objective lens to focus the first light beam on a recording medium, a diffraction member to divide the first light beam reflected by the recording medium into five light regions, the diffraction member having a first diffraction region having a wide width in a direction corresponding to a tangential direction of the recording medium and second through fifth diffraction regions sequentially arranged around the outside of the first diffraction region in a direction corresponding to a radial direction of the recording medium, and a first photodetector having first through fifth light receiving portions to receive the first light beam reflected by the recording medium.

Optical pickup apparatus and optimal light spot focusing method

An apparatus to remove periodic disturbances in a recording medium having large eccentricity and deflection mass includes an actuator to change a position of a pickup in response to a combination of first and second compensation signals, an error detector to detect an error between positions actuator and the recording medium, a first compensator to receive the detected error and to output the first compensation signal that the actuator uses to actuate the pickup along the recording medium in upper and lower directions, and right and left directions; and a second compensator to output the second compensation signal from which the disturbance has been removed, to combine the compensated error and previous first and second compensation signals, and to filter the combined result at a predetermined bandwidth.

Apparatus and method of removing disturbances during optical recording and/or reproducing

A differential phase detection device receives first through fourth detection signals from a photodetector and detects a differential phase signal therefrom, the differential phase detection device includes a slicer slicing and digitizing each of the detection signals with respect to a reference level. A synthesizer synthesizes the digitized detection signals and generates therefrom synthesis signals. A phase difference detector compares phases of the synthesis signals and outputs a first phase difference signal and a second phase difference signal. A matrix circuit processes the first and second phase difference signals to output the differential phase signal.

Differential phase detection device and tracking error signal detection apparatus using the same

A vibration quantity measuring apparatus and method, and a loop design method in which a vibration quantity generated in a focus and tracking loop is accurately measured to optimally design a focus and tracking loop of an optical disc drive. The vibration quantity measuring apparatus includes an error gain adjusting unit which adjusts an amplitude of a focus and tracking error which occurs where a disc rotates, so as to maintain the amplitude of the focus and tracking error constant, a loop gain adjusting unit which compares a closed loop phase of a focus and tracking loop and a predetermined reference closed loop phase, and maintains a constant gain of the focus and tracking loop to compensate for a gain difference of an actuator, and a measuring unit which calculates and outputs a vibration quantity using an error adjusted by the error gain adjusting unit and the loop gain adjusting unit, and an output of a controller which controls a focus and tracking of the disc. According to the methods and apparatus, a focus and tracking vibration quantity that occur differently depending on the type of a disc, on which data is recorded on or read from, or depending on a speed factor of a disc drive, can be measured.

Apparatus and method of measuring vibration quantity and method of designing loop

An automatic power control (APC) apparatus reducing time necessary for stabilizing an APC circuit at the initial stage of automatic power control of a disc drive is provided. The APC circuit is designed such that a voltage of a predetermined percent of an expected output voltage is previously added to an APC output voltage of the APC circuit of a laser diode, thereby greatly reducing a stabilizing time necessary for stabilizing an APC output voltage at an initial stage in a write or read mode. Therefore, the loss of data in a high speed write or read mode can be reduced. Particularly, the loss of data in a high speed write mode can be greatly reduced.

Automatic power control apparatus of disc drive

An optical recording/reproducing apparatus which controls the power of a laser diode (LD) and a method therefor. A current power level of an optical signal output by the LD is compared with a reference level and the output of the LD is controlled according to the comparison result. A photo detector (PD) monitors the current power level of the optical signal output by the LD. The current power level is compared with a reference level and power to the LD is controlled based on the comparison. Two different control loops are provided. In a first loop, comparison data is continually provided and in a second loop, sampled comparison data is provided based on a non return to zero inverted (NRZI) signal. Rapid change in an optical output is controlled using the different loops according to a kind and state of a medium such as a disc.

Apparatus for and method of controlling auto laser diode power

A servo controlling apparatus of an optical disk drive and a control method thereof are provided for achieving precise control by automatically controlling the gain of error signals caused by the difference in the amount of light irradiated during recording and reproducing, and then using the automatically gain-controlled signal. In a first control step, a focus error signal and a tracking error signal generated from a photodetecting portion via an operator are multiplied by a predetermined value in different multipliers, and then each obtained value is divided by an RF sum signal to control the value of error to within a predetermined target value. In a second control step, each multiplied focus error signal and tracking error signal are divided by a DC signal corresponding to the average level of the RF sum signal when the error value reaches the target value.

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Gyeonggi-do, South Korea

Sung-ro Go