Abstract:
본 발명에 따른 광섬유 모재 제작 장치는 회전 및 상하 이동 가능한 척에 장착된 지지봉과, 상기 지지봉에 성장되는 광섬유 모재와, 상기 광섬유 모재를 성장시키며 상기 광섬유 모재를 관찰하기 위한 복수의 시창들이 일측에 형성된 가열로와, 상기 가열로의 시창을 따라서 상하로 움직이며 상기 광섬유 모재의 외경 변화를 감시하기 위한 광을 생성하는 레이저 광원과, 상기 광섬유 모재를 중심으로 상기 레이저 광원 대향되게 위치되며, 상기 광섬유 모재를 투과한 상기 광으로부터 상기 광섬유 모재의 직경 변화를 감시하기 위한 수광 스캐너를 포함한다. 광섬유 모재, 레이저, 외경
Abstract:
본 발명은 반도체 집적 회로 내의 지연된 클록 신호를 발생하는 장치에 관한 것이다. 본 발명에 따른 지연된 클록 신호 발생장치는, 입력 클록 신호(CLK1)에 응답하여 복수의 위상 지연 클록 신호를 발생하는 지연 신호 발생 회로; 상기 복수의 위상 지연 클록 신호 중에서 상기 입력 클록 신호(CLK1)와 제 1 위상 차를 갖는 위상 지연 클록 신호를 검출하고, 출력 클록 신호(CLK2)를 출력하기 위한 선택 신호를 발생하는 위상 검출 회로; 상기 입력 클록 신호(CLK1) 및 상기 복수의 위상 지연 클록 신호 중에서 서로 인접하여 입력되는 두 신호를 미리 설정된 내분비로 내분하고, 상기 두 신호의 위상 차보다 작은 위상 차를 갖는 복수의 위상 보간 클록 신호를 발생하는 위상 보간 회로; 및 상기 선택 신호에 응답하여 상기 복수의 위상 보간 클록 신호 중에서 상기 입력 클록 신호(CLK1)와 제 2 위상 차를 갖는 출력 클록 신호(CLK2)를 출력하는 선택 회로를 포함한다. 본 발명에 의하면, 입력 클록 신호의 반주기를 감지하여 외부 제어신호나 피드백 루프의 필요 없이 입력 클록 신호보다 π/2 또는 3π/2 등 원하는 위상 차만큼 지연된 클록 신호를 얻을 수 있다.
Abstract:
본 발명은 광자결정 광섬유용 모재를 제조하는 방법에 관한 것이다. 본 발명은 단량체와 이량체가 혼합된 실리카 슬러리(slurry)를 이용하여 실린더 형태로 성형 후 건조시켜서 실린더형 건조 젤을 만들고 공기구멍 천공 작업을 통해 상기 건조 젤에 원하는 크기와 배열의 공기구멍을 형성한 데 특징이 있다. 본 발명에 의하면 공기구멍의 크기 및 배열 등의 조절이 용이하여 다양한 모양의 광자결정 광섬유용 모제를 제조할 수 있다.
Abstract:
PURPOSE: A delayed clock signal generator is provided to acquire a clock signal delayed as much as a desired delay period regardless of an external control signal or a feedback loop by sensing a half period of a clock signal. CONSTITUTION: A clock signal generator(100) is used for generating a clock signal. A delayed signal generation circuit(200) is used for receiving the clock signal and generating a phase-delayed clock signal. A phase detection circuit(300) is used for detecting the phase of the phase-delayed clock signal and generating a selection signal. A phase interpolation circuit(600) is used for receiving the phase-delayed clock signal and generating a phase-interpolated clock signal by interpolating two adjacent signals. A selection circuit(700) is used for outputting a delayed signal delayed as much as a phase difference of the phase-interpolated signals.
Abstract:
PURPOSE: A data recording method for stable data reproducing on a recordable disk is provided to remarkably expand margins where a data linking process is carried out up to a tail length except the third identifier, thereby properly reproducing data even though the data is frequently recorded on a recordable disk. CONSTITUTION: The second identifier is discovered(801). If the first identifier is discovered within a predicted section from the second identifier(802), a system decides that a body is started from the detected first identifier(803). If the first identifier is not discovered within the predicted section though the second identifier is discovered(802), the system inserts the first identifier into a predicted position from the second identifier, and decides that the body is started from the inserted first identifier(804). If the second identifier is not discovered and the first identifier is discovered within a certain section from a position decided as the third identifier(805), the system decides that the body is started from the detected first identifier(803). If neither the second identifier nor the first identifier is not discovered, the system re-searches the second identifier.
Abstract:
PURPOSE: A data modulation device capable of suppressing a DC(Direct Current) by using parity information of a synchronous codeword is provided to set a bit for controlling a parity within a synchronous codeword, so that the parity of the synchronous codeword can multiplex input data according to an even number or an odd number, thereby effectively suppressing DC components of a codeword stream without deteriorating a code rate. CONSTITUTION: A multiplexer(20) attaches 1-bit multiplexing information to each data string divided by a divider(10), multiplexes into 2 data strings, and converts it into 2 kinds of pseudo random data according to the information. The first and second synchronous/multiplexing ID inserters(31,32) of a synchronous codeword inserter(30) insert synchronous codewords into the pseudo random data. An encoder(40) generates codewords during an insufficient DC suppression RLL(Run Length Limited) modulation, groups the codewords, and performs the RLL modulation. A comparator/selector(50) compares modulation streams of 2 channels, and selects a modulation stream having small DC components.
Abstract:
PURPOSE: A method and a device for modulating an RLL(Run-Length-limited) code limiting RMTR(Repeated Minimum Transition Run) and having a parity preserving characteristic are provided to secure a stable playback performance and system stability, and improve a line density more than a usual code having no limit to the RMTR. CONSTITUTION: The device comprises an RLL(d,k) PP(Parity Preserve) code encoder(100) and an RMTR RLL(d,k) PP code table(200). The encoder reads a code word corresponding to the input source data from the RMTR RLL(d,k) PP code table and outputs a modulated code word.
Abstract:
PURPOSE: An information recording medium, and a device and a method for recording/playing/detecting/evaluating data are provided to form a pit of the 'nT' length for information data and not form the pit of the (n+/-1)T length for the information data. CONSTITUTION: A modulator/synchronization inserter(41) performs modulation for the information data recorded to the disc and inserts a synchronization pattern by using a modulated clock signal(BipCLK). A clock rate converter(42) generates/provides the clock signal of the (N X BipCLK) to a bit expander(43) and a recording waveform generator(44). The clock rate converter multiplies the clock signal used for expanding or recording of a bit stream from the clock signal used for the modulation, or demultiplies the clock signal used for the modulation from the clock signal used for expanding or recording of the bit stream.
Abstract:
Disclosed is a system for drawing an optical fiber for controlling polarization mode dispersion. A furnace is provided for uniformly heating an optical fiber preform in the drawing system mounted to an optical fiber draw tower. The furnace comprises: (a) a main body; (b) a sub-body placed coaxially with the main body and having a diameter smaller than that of the main body; and (c) an upper gas feeding section over the main body, wherein the upper gas feeding section includes a first hollow rotary body having at least one slit in the inner surface thereof along the longitudinal direction of an optical fiber and at least one opening extended in the direction of the center, whereby a gas artificially/periodically creates non-contact polarization to the optical fiber by the first hollow rotary body. Effective non-contact control can be carried out about polarization mode dispersion of the optical fiber.
Abstract:
PURPOSE: Apparatus and method for manufacturing optical fiber preforms by modified optical vapor deposition(MCVD) are provided, which is characterized by using the second burner to prevent secondary deposition unlike conventional MCVD method. Accordingly, the resultant preforms have homogeneous physical property and stable geometric structure. CONSTITUTION: The manufacturing method of optical fiber preforms comprises the steps of: (i) forming the first high temperature range inside a cylinder-shaped tube(210) for deposition by using a first burner(262); (ii) forming reactants(310) by flowing source gases such as SiCl4 and GeCl4 into the first high temperature range, which is expressed by the formula, SiCl4 + O2 --> SiO2, GeCl4 + O2 --> GeO2 + 2Cl2; (iii) depositing the reactants on the inner wall of tube by thermophoretic mechanism; (iv) forming the second high temperature range inside the tube by using the second burner(266), which results in that the reactants descending to the inner wall of tube raise up to the center of tube for preventing the reactants from being deposited on the inner wall and discharge to the outside of tube. The first and second burners are placed at a distance, desirable more than 300m.