Abstract:
PURPOSE: A controlling device for pull-in of a focus servo is provided to control the pull-in of the focus servo by using a simple circuit controlling a driving signal of the focus servo through recognizing subtract and adding signals of an optical detector. CONSTITUTION: The first switch(200) outputs a focus error signal. A phase compensator(210) compensates phase of the focus error signal. An independent power(220) applies power for establishing an initial state. A second switch(230) outputs the phase compensator or the independent power. A current controller(240) outputs the control signal as a driving signal. An actuator(250) vertically drives a lens by the driving signal. A lens(251) reflects and concentrates a beam on a disk. A light source(252) concentrates beam reflected from the disk. A collimating lens(253) forms the beam from the light source into parallel beam. A half mirror(254) concentrates beam reflected from the disk. An optical detector(260) detects the reflected beam as an electric signal. A differential amplifier(270) differentiates an output signal of the optical detector. An add amplifier(280) adds output signals from the optical detector. A pull-in decide unit(290) decides pull-in point of a focus servo by a focus error signal.
Abstract:
본 발명은 광디스크 드라이브의 트래킹 제어 방법에 관한 것으로, 특히 광디스크 드라이브의 트랙 인입 서보 제어 방법에 관한 것이다. 목표 본 발명의 목적을 달성하기 위해 목표 트랙과 현재 트랙의 차를 비교하여 탐색 동작이 완료되었는가를 판단해서 탐색 동작중이던 속도 제어 연산을 수행하여 그 결과를 출력하고, 탐색 동작이 완료되면 트랙인입을 시도하여 트랙 추종 제어를 수행하는 제1단계; 트랙 인입을 시도하는 제1단계 후, 오프 트랙이 발생했는 가를 판단해서 오프 트랙의 발생시 트랙 추종 제어 신호를 0로 하여 트랙 추종 제어 값을 출력하는 제2단계, 트랙 인입 재 시도 완료 후 트랙 추종 제어 신호를 출력하는 제3단계를 포함하는 것을 특징으로 한다. 본 발명에 의하며 광 디스크 드라이브의 트랙 탐색 동작후 트랙 인입시 오프 트랙이 발생한 경우에도 인접 트랙에의 안정된 트랙 인입이 가능하도록 할 수 있는 잇점이 있다.
Abstract:
본 발명은 트랙 횡단 신호로부터 노이즈를 제거하는 방법, 이에 기초한 광 디스크 드라이브 제어 방법, 노이즈 제거 장치, 광 디스크 드라이브, 및 재생 장치에 관한 것이다. 트랙 횡단 신호로부터 노이즈를 제거하는 방법은 (a) 상기 트랙 횡단 신호를 트랙킹 액츄에이터를 위한 지령 속도를 기초로 설정된 히스테리시스 설정값을 참조하여 이치화함으로써 노이즈를 제거하는 단계; 및 (b) 이치화된 트랙 횡단 신호로부터 미리 설정된 시간값을 기초로 글리치 노이즈를 제거하는 단계를 포함하는 것을 특징으로 한다. 이에 의해, 고속 탐색 및 저속 탐색의 모든 경우에 노이즈를 보다 효과적으로 제거할 수 있다.
Abstract:
PURPOSE: A method for removing a noise from a track cross signal, a method for controlling an optical disk drive based on the same, an apparatus for removing a noise, an optical disk drive, and a playback unit are provided to effectively remove a noise from a track seek signal, thereby accurately and effectively controlling a pickup. CONSTITUTION: A controller(3) generates an order speed for a tracking actuator(5) to provide the order speed to an adaptive comparator(1). The adaptive comparator binarizes a track cross signal by referring to two references, that is an upper level and a lower level according to a hysteresis value adaptively set to the order speed of a pickup. A noise remover(2) removes a glitch signal from the binarized track cross signal, that is a track zero cross signal by using a noise removing width. A drive(4) drives the tracking actuator based on the order speed from the controller. The tracking actuator moves the pickup for placing an optical spot on a wanted track.
Abstract:
PURPOSE: A latency time reducing method for a disc eject of an optical disc drive is provided to reduce a latency time and prevent a reverse rotation by minimizing a section of an eject time at the control open time. CONSTITUTION: The third Hall sensor(105) senses a speed and an A/D converter(401) converts and applies the speed into a digital signal to a digital signal processor(117). A D/A converter(123) generates and converts and applies a speed reduction signal into an analog signal to an amplitude controller(109). A speed of a spindle motor(100) is reduced. When an open control time comes by sensing of the third Hall sensor(105), an angle location of the spindle motor(100) is controlled. When an output of the third Hall sensor(105) is converged to '0' by a control of the angle location of the spindle motor(100), a control loop is opened to perform a disc eject operation.
Abstract:
개시된 내용은 광디스크의 트래킹서보시스템에서 대물렌즈의 광축 벗어남에 의해 트래킹에러신호에 나타나는 직류오프셋(offset)을 경감하기 위한 방법 및 장치에 관한 것이다. 본 발명은 이송모터계에 대한 트래킹액추에이터의 상대위치를 감지하기 위한 렌즈위치센서를 사용하지 않는 대신에 트래킹액추에이터의 전달함수와 동일한 특성의 관측기(observer)를 구현하여 관측기에서 검출되는 트래킹에러신호와 트래킹에러가 0이 되도록 하기 위한 트래킹서보제어신호를 입력받아 렌즈위치를 추정하고, 추정된 렌즈위치에 의해 발생하는 직류오프셋만큼이 검출된 트래킹에러신호에서 경감하도록 구성한다. 따라서, 본 발명은 비용을 절감할 뿐 아니라 하드웨어적 변형이 없어 제조공정이 간단하여 시스템성능을 향상시킬 수 있는 효과를 제공한다.
Abstract:
PURPOSE: A servo control system by using a hardwired filter on an ODD(Optical Disc Drive) is provided to offer the optimized servo control system by making a control filter of relatively lower needs for flexibility while using many parts of an operation volume of a DSP(Digital Signal Processor). CONSTITUTION: A DSP processes a signal by receiving an electric signal matched with the light reflected from an optical disc. A memory stores data and filter coefficients. The hardwired filter performs a periodic calculation and outputs a result by receiving the electric signal matched with the light reflected from the optical disc, and referring to the data and the filter coefficients stored in the memory.
Abstract:
PURPOSE: A device and a method for generating an adaptive track zero crossing signal in a disc drive are provided to correct the offset and balance by duty correction for generating a precise track zero crossing signal, thereby precisely carrying out the seek servo control by precise velocity and position information obtained from the track zero crossing signal. CONSTITUTION: A device for generating an adaptive track zero crossing signal in a disc drive includes an analog signal processing circuit(1000) formed of an adder(201), a comparator(202), and a D/A converter(203), and a digital signal processing part(2000) as an offset correcting operation part formed of a counting part(204), an operating part(205), a correcting signal generating part(206), and a noise removing filter(207). The comparator has a first input terminal applied with a reference voltage(Vref), and a second input terminal applied with a tracking error signal(TZCA) added with a correcting signal(U) for correcting offset and balance output from the D/A converter. The comparator compares the signals applied to the first and second input terminals, and generates a high output if the signal applied to the second input terminal is larger than the reference voltage or a low output in the other case, wherein the output signal from the comparator is to be a track zero crossing signal(TZC) of square wave.
Abstract:
PURPOSE: A device and method for controlling a track jump are provided to reduce an overshoot at a track pull-in and to jump at high speed when a large eccentric disk is driven. CONSTITUTION: An optical spot position command generating unit(302) generates optical spot position command data to designate the position of an optical spot per a specific sampling cycle by responding to track jump command. A switching unit(304b) generates switching control polar data for a switching control. An adding unit(304a) subtracts track error data from the optical spot position command data. The adding unit(304a) transmits the optical spot position command data originally or by inverting its polarity. In jumping one track, a track jump controller operates as a track follow mode for the entire section of the jump. Therefore, a stable jump is performed in a jump starting point. In driving a disk having a large eccentricity, an overshoot at a track pull-in is reduced.
Abstract:
본 발명은 스핀들모터의 급제동방법에 있어, 상기 스핀들모터에 연결된 홀센서의 출력신호로부터 스핀들모터의 회전속도를 감지하여 제동하되 스핀들모터의 회전속도가 일정 속도이하로 감속되었을시 위치 제어루프를 가동시켜 상기 스핀들모터를 급제동하고 속도가 충분히 감속되었을시 제어루프를 개방시키고 디스크 이젝트를 행함을 특징으로 한다.