baber/WOPTO huggingface dataset:
Patent KR-20000013754-A (KR)
Title: Slide type ring binder
Inventor: KIM DONG CHAN
IPC: B42D15/00
Filed: 1998-08-10
Abstract: PURPOSE: An improved binder is provided to make sure that a noise is not made when opening and closing it and a finger is not injured by a sharp tooth of the ring, preventing papers inserted in a bottom part of the binder from bending round. CONSTITUTION: The binder has: a fixing unit(10) consisted of a fixing hole(20), a mating track(28, 30, 32, 34) and fixed on a base member(16), including a left side ring(18); a moving unit(12) including a fourth lower end mating track(42), a right side base member(24) and a ring(26) attached and fixed on the right base member; a locking device(14) consisted of a first, a second, a third and a fourth element(44, 46, 48, 50); herein, the left and the right base members are made in the thickness of 0.5 to 3mm.
Patent KR-20000015053-A (KR)
Title: Apparatus for informing a wearing of a safety belt
Inventor: LEE DONG HYUN
IPC: G09F19/00
Filed: 1998-08-27
Abstract: PURPOSE: An apparatus for informing a wearing of a safety belt is provided, which is installed at a road circumference and informs a wearing of a safety belt. CONSTITUTION: The apparatus for informing a wearing of a safety belt comprises: a car model plate (1); a background plate (2) which a man model (3) with a driving state is fixed; an arm model (4) to be combined to the man model (3) and be rotated by a driving device (10); and a safety belt (5) to be fixed to a front terminal of the arm model (4), wherein the driving device (10) includes a motor frame (11) to be fixed on an upper portion of a support plate (6), an AC motor (12) to be fixed to the motor frame (11), a rotation blind (13) to be fixed to the AC motor (12), a road bar (14) for inserting a road bearing between the rotation blind (13) and a connecting axis (15); a road bar (16) to be inserted into one side of the connecting axis (15), an axis fixing bush (17) for combining and fixing the road bar (17) with a main axis (18), and a bearing housing (19) for combining the main axis (18) to the background plate (2). Thereby, it is possible to maximize the informing effect.
Patent KR-20000019299-A (KR)
Title: Asynchronous transferring mode based access device
Inventor: KIM JIN HEE
IPC: H04L12/28
Filed: 1998-09-10
Abstract: PURPOSE: An ATM based access device is provided to supervise efficiently an operation channel between a broadband station system and a subscriber connection system by using an operation communication protocol processor. CONSTITUTION: The ATM based access device comprises: an operation communicational protocol process unit further comprising: an IPC process unit(111) for generating IPC data; an operation and maintenance process unit(112) for supervising an IPC channel; an optical transmitting and receiving unit(113) for reading the routing tag information cells from the IPC process unit and transmitting the accorded IPC cell to a subscriber connection unit; and the operation communication protocol process unit being included in both of a broadband station system and a subscriber connection system.
Patent KR-20000026015-A (KR)
Title: Apparatus of controlling power consumption of television and method thereof
Inventor: KANG DEOK CHEOL
IPC: H04N5/63
Filed: 1998-10-16
Abstract: PURPOSE: A method of controlling power consumption of a television is provided to reduce power consumed in power-off state by cutting off the main power. CONSTITUTION: A method of controlling power consumption of a television comprises: a first step of outputting video and audio signals by turning a main relay and a sub relay when a direct current of 5 voltages is supplied from the power source and a reset signal is generated in a microprocessor; and a second step of cutting off the video and audio signals according to whether an input of the power key exists and whether a reserved power-off exists, and cutting off a main power by turning the main relay off according to whether a reserved power-on exists.
Patent KR-20000026953-A (KR)
Title: Apparatus for electric explosion using aluminum foil
Inventor: LIM GEUN HUI
IPC: F42D1/045
Filed: 1998-10-24
Abstract: PURPOSE: An economical and safe electric exploding apparatus using an aluminum foil could be obtained more easily than aluminum wire or aluminum powder and an aluminum foil attached structure are provided. CONSTITUTION: An aluminum foil(4) attached on an electric exploding apparatus flows a pulse charged current via the aluminum foil and the resistance of the aluminum foil generates heat so that the resistance of the aluminum foil becomes stronger. The resistance increases non-linearly and the most part of the energy stored in a capacitor is consumed in the aluminum foil. The aluminum is evaporated, gasified and then becomes plasma according to the concentrated consumption of energy. An explosive power is generated by the expansion of the aluminum and secondary chemical energy is erupted by the reaction of the aluminum plasma with the oxygen in water. Thereby, explosive power is generated.
Patent KR-20000027301-A (KR)
Title: Pulse generating circuit
Inventor: GWON GYU WAN
IPC: H03K5/00
Filed: 1998-10-27
Abstract: PURPOSE: A pulse generating circuit is provided to shorten time needed to pump a high voltage pulse. CONSTITUTION: A pulse generating circuit comprises: a precharge circuit for pre charging an output node of the precharge circuit to a level of a power supply voltage by a low voltage pulse signal; a capacitor for bootstrapping the output node of the precharge circuit to a voltage level higher than the power supply voltage level by the low voltage pulse signal; and a level shift circuit for outputting the bootstrapped high voltage according to the low voltage pulse signal and the inverted low voltage pulse signal.
Patent KR-20000031283-A (KR)
Title: Image coding device
Inventor: JEONG YOUNG AHN
IPC: H03M1/10
Filed: 1998-11-02
Abstract: PURPOSE: An image coding device is provided to improve an efficiency of a zero tree coding by rearranging DCT(Discrete Cosine Transform) coefficients and performing zero tree coding for them. CONSTITUTION: An image coding device comprises a conversion portion, a rearrangement portion(201), and a zero tree coding portion(202). The conversion portion converts space areas of each block to frequency areas after dividing an input frame into a plurality of block. The rearrangement portion classifies conversion coefficients form the conversion portion according to an important degree of the image information. The zero tree coding portion codes information related to locations and sizes of the rearranged coefficients according to an order of the important degree.
Patent KR-20000031450-A (KR)
Title: Method for securing transmitted data in fax machine
Inventor: SIN BONG YEON
IPC: H04N1/32
Filed: 1998-11-06
Abstract: PURPOSE: A security method of transmitted data in a fax machine is provided to prevent a fax machine from being printed in user's absence though the fax machine receives data by storing the received fax data in his absence, and setting a security code to print the received data stored in a memory. CONSTITUTION: A security method of transmitted data in a fax machine comprises steps of checking if an absence time setting key is selected, requesting the user to input the absence time via an LCD, checking if the user inputs the absence time, storing the absence time in a memory, requesting the user to input a security code after finishing the input of the absence time, checking if the security code is input, storing the security code in a memory, checking if an external data is transmitted(S301), searching for the current time(S302), checking if the current time is in a range of the set absence time(S303), storing the received data in a memory if the current time is within the set absence time(S304), checking if storing the data is finished(S305), checking if a print key is selected(S306), requesting the user to input the security code(S307), approving the input security code(S308).
Patent KR-19990063062-A (KR)
Title: 표시관용 양극기판과 그 제조방법
IPC: H01J31/12
Filed: 1998-12-15
Abstract: 컬러 필터가 표시관용 양극 기판 내면을 평활층에 따라 평활한다. 
     1) 붕규산 유리 기판(1)위에 무기 안료계 재료로 적녹청 각색의 컬러 필터(R,G,B)을 형성한다. 3) ZnO-B 2 O 3 -SIO 2 계 저융점 유리의 평활층(2)을 형성한다. 4)∼6) 내산성 보호막(3)과 투명도전막(4)위에 포토레지스트(5)를 도포하고, 마스크(6)를 통해 노광한다. 7) 현상후, 8) 기판(1)을 에칭하고, 9) 세정한다. 10) 형광층(r,g,b)을 형성한다. 평활층(2)을 구성하는 ZnO계 저융점 유리는 연화점과 왜곡점의 온도차가 적다. ZnO계 저융점 유리는 왜곡점이 대략 500℃이고, 표시관 제작의 후공정에 있어서의 소성 온도와 동일 정도로 되어 있어서 투명 도전막(4)이 단선될 위험이 없다. 평활층(2)을 구성하는 ZnO계의 저융점 유리의 연화점은 유리 기판의 왜곡점보다 충분히 낮고, 안전하다.
Patent KR-20000041376-A (KR)
Title: Latch circuit
Inventor: LEE DO YOUNG
IPC: H03K3/02
Filed: 1998-12-22
Abstract: PURPOSE: A latch circuit is provided to reduce an occupied area by minimizing the number of required transistors. CONSTITUTION: A latch circuit comprises three inverters(INV1,INV2,INV3), a PMOS transistor(PM1) and an NMOS transistor(NM1). The inverter(INV1) receives output data(Data_out) to invert the output data, and the inverter(INV2) inverts the input data(Data_in). The PMOS and NMOS transistors(PM1,NM1) are connected between an output terminal of the inverter(INV1) and an output terminal of the inverter(INV2), and the gates of the PMOS and NMOS transistors(PM1,NM1) are connected to receive a control signal(C). The inverter(INV3) inverts a signal outputted from a common drain of the PMOS and NMOS transistors(PM1,NM1).
Patent KR-20000041425-A (KR)
Title: Method for fabricating capacitor which can suppress chemical reaction between pt bottom electrode and sbt ferroelectric film
Inventor: YOO YONG SIK
IPC: H01L27/10
Filed: 1998-12-22
Abstract: PURPOSE: A method for fabricating a capacitor is provided which can suppress the chemical reaction between a Pt bottom electrode and a SBT ferroelectric film generated by the volatilization or the diffusion of Bi in a rapid thermal process to crystallize the SBT film. CONSTITUTION: To suppress the chemical reaction between a Pt bottom electrode(17) and a SBT ferroelectric film, a first SBT film(18A) is formed on the Pt bottom electrode, and the first SBT film is rapid thermal processed at a first temperature. Then, a second SBT film(18B) is formed on the first SBT film and then is rapid thermal processed at a second temperature higher than the first temperature. A third SBT film(18C) is formed on the second SBT film and is thermally processed at a first temperature. After thermally processing the first, second and third SBT films, a capacitor is fabricated by forming a Pt top electrode(19) on the third SBT film.
Patent KR-20000041559-A (KR)
Title: Suction hole of vacuum cleaner
Inventor: KIM KYEONG CHUL
IPC: A47L9/02
Filed: 1998-12-23
Abstract: PURPOSE: A suction hole of a vacuum cleaner is provided to improve suction performance and to buffer noise according to the desire of a user by making a suction passage composed on the lower plate of a suction hole varied. CONSTITUTION: A variable lever(210) is pushed in the direction of an arrow according to the need of high suction performance. A protrusion(211) formed on the lower of the variable lever contacts to the upper face of a support protrusion(131) formed on a suction passage(130). The support protrusion pushes down the suction passage and the suction passage is kept in the pushed state by the elasticity of an elastic member(311) installed between fixing protrusions(111,132) formed between the upper plate(110) of a suction device and the suction passage to face each other. The suction passage is rotated a desired angular degrees by centering on hinges(P,P') fixed to a hinge support part(121) formed on both ends of the lower plate of the suction device. A gap possible to generate in the shape matching part of the upper plate and the lower plate of the suction device according to the variable rotated distance of the suction passage is prevented by a combustible member(150). Thereby, cleaning is performed while maintaining high suction state.
Patent KR-20000042206-A (KR)
Title: Device for measuring level of molten material in blast furnace
Inventor: JEONG JIN SU
IPC: C21B5/00
Filed: 1998-12-24
Abstract: PURPOSE: A device for measuring the level of molten material in a blast furnace is provided to endure external noise by obtaining large voltage signal and to stably measure the level of the molten material for a long period. CONSTITUTION: A carbon bar(9) is inserted into a carbon brick(7) having a tap for being rotationally attached. And, a copper bar(10) is connected with a signal cable(11) for collecting voltage signals in a computer(15) after passing through an amplifier(14). Herein, the space between the carbon bar and the carbon brick is filled with carbon. Moreover, a splash preventing plate(3) is installed for preventing the infiltration of cooling water sprayed to an iron surface. Then, a K-typed thermocouple is installed at the same location with the splash preventing plate for checking the temperature of the carbon brick.
Patent KR-20000043253-A (KR)
Title: Method for preparing styrene derivative having functional group, syndiotactic polystyrene and styrene/olefin copolymer using thereof and method for preparing thereof
Inventor: KIM JEONG AN
IPC: C07C211/44
Filed: 1998-12-28
Abstract: PURPOSE: A method for preparing a styrene derivative having a various functional group, a syndiotactic polystyrene and styrene/olefin copolymer using thereof which are able to enlarge the application fields as new high molecular materials and a method for preparing thereof are provided. CONSTITUTION: A styrene derivative having the protected functional group of the following formula 4, where X is either -O-SiR2R3R4R5 or -NR6R7, where all R2, R3 and R4 are CH3; or R2 and R3 are CH3 and R4 is tertiary butyl group; and each R6 and R7 is one selected from the group consisting of CH3, -Si(CH3)3 and -Si(CH3)2(tertiary-butyl), is prepared by: (i) protecting hydroxyl group or amine group of benzene aldehyde of the following formula 3, where X is either OH or NH2, with silane; and (ii) methylenating the aldehyde group by using 'Tebbe' material. The syndiotactic polystyrene and styrene/olefin copolymer are prepared by polymerizing more than one styrene derivative having the protected functional group of the formula 4, where X, R2, R3, R4, R6 and R7 are same as defined above, or copolymerizing the styrene derivative either with more than one styrene monomer of the following formula 5, where R1 is either H or CH3 and R2 is one selected from the group consisting of H, CH3, tertiary butyl, Cl and CH2Cl, or with more than one olefin monomer of the following formula 6, where all R1 and R2 are H; or R1 is H and R2 is CH3.
Patent KR-20000045338-A (KR)
Title: Decoupling capacitor of semiconductor device
Inventor: LEE BYUNG RYEOL
IPC: H01L27/108
Filed: 1998-12-30
Abstract: PURPOSE: A decoupling capacitor of semiconductor device is provided to realize decoupling capacitor in accumulation mode using triple well, thereby enabling high integration of semiconductor device. CONSTITUTION: A decoupling capacitor of semiconductor device comprises plural wells(3,2,4), a device division film(6), a gate oxide(7), a gate electrode(10), a transistor and plural well pickups(13,14,15). The wells(3,2,4) are formed on a P type substrate(1) through ion injection process. The device division film(6) is formed on a non-active area of the substrate(1), and the gate oxide(7) and the gate electrode(10) are formed on an active area. A N type source/drain junction area(11) and the N well pickup(13) in the well(3) are formed by injecting N type impurity on the substrate. The pickups(14,15) are respectively formed in the wells(2,4) by injecting p type impurity.
Patent KR-20000047087-A (KR)
Title: Assembly of multi-core optical connector
Inventor: LEE HO GYEONG
IPC: G02B6/38
Filed: 1998-12-31
Abstract: PURPOSE: An assembly is provided to prevent the physical impact applied to the outer case and the humidity or impurity permeating to the junction part, and make connection easy. CONSTITUTION: A pair of multi-core connectors(40) placed opposite to each other are inserted through an inserting groove(11) to be coupled them on relatively similar position. A front paddle(41) is inserted into an aligning hole(21) of an alignment part(20) and a pair of guide pins(22) is inserted into a guide hole(42) so the connectors are coupled on correct position. A leg(37) of a supporting part(30) is coupled tightly to a rear part of the coupled connector through a coupling hole(17) so an elastic part(39) of the supporting part supports the connectors with certain elastic force. Because rear part of the connector is coupled tightly to the leg, the connector can not be disconnected each other even the outer physical force or impact is applied to it.
Patent KR-19990028800-A (KR)
Title: 수신기, 복조기, 및 복조 방법
IPC: H04L27/14
Filed: 1997-04-30
Abstract: 주어진 위상 분해를 갖는 양자화된 위상 신호가 위상 레벨 전달에서 발생된 펄스로부터 데이터를 재구성하는 위상-감지 복조기에 공급되는, 다중-브랜치 및 보간 직각 수신기가 기술된다.  수용할 수 없는 데이터 지터를 방지하기 위하여 위상 해상도가 고려되야 한다.  그에 의해, 공지된 수신기는 복잡하게 되고, 전력 소비에 대하여 불만족스럽게 된다.  매우 정확하고 전력 소비가 감소된 직각 수신기가 제안된다.  이러한 목적을 위하여, 직각 수신기에 있어서 데이터 신호 재구성 순간들은 반대 극성의 연속하는 복조 펄스 사이의 사전설정된 순간에서 결정되고, 데이터는 이들 순간에 출력된다.  사전설정된 순간들은 사용된 변조 방법 및/또는 전송 파라미터에 따라 선택된다.
Patent KR-19990035815-A (KR)
Title: 전자 문서 표시 장치, 그 방법 및 기록 매체
IPC: G06F17/30
Filed: 1997-05-22
Abstract: 검색 횟수·빈도에 관한 정보에 기초하여 표시를 수식함으로써, 사용자가 사용하기에 편리한 전자 사서를 제공하는 것, 및 복수의 사람이 사용가능한 전자 사서를 제공하는 것을 목적으로 한다.  키보드(1a) 및 마우스(1b)와, 문서를 미리 전자적으로 기억하는 사서 메모리(6)와, 사서 메모리(6)로부터 1회 이상 검색된 문서에 관한 속성 정보를 각각 기억하는 마크 파일(7-1, ···, 7-n)과, 검색된 문서를 표시하는 표시부(5)와, 입력 수단(1a, 1b)의 출력 신호를 수신하여 사서 메모리(6)를 검색함과 함께 이 검색된 문서를 마크 파일의 속성 정보에 기초하여 색을 바꾸면서 표시부(5)에 표시하는 CPU(3)를 구비한다.  마크 파일(7)은 복수의 사용자 한 사람 한 사람에 대응하여 설치된다.
Patent KR-19990067063-A (KR)
Title: 라인 에스-보정을 수행하는 다이오드 변조기
IPC: H04N3/23
Filed: 1997-06-25
Abstract: 본 발명은 실질적으로 상이한 라인 스캔폭에서 화상 튜브(CRT)의 라인 스캐닝의 S-선형성 에러에 대해 허용가능한 S-보정을 제공하도록 채택되는 다이오드 변조기 회로를 제공한다.   공지된 다이오드 변조기는 두 개의 루프를 포함한다.   제 1 루프는 라인 편향 코일(LD) 및 S-캐패시터(CS)의 직렬 구조체를 포함하며, 이 직렬 구조체는 제 1 플라이백 캐패시터(CF1) 및 제 1 다이오드(D1)와 병렬로 배열된다.   제 2 루프는 제 2 플라이백 캐패시터(CF2) 및 제 2 다이오드(D2)와 병렬로 배열되는 변조기 코일(LB)을 포함한다.   이 두 개의 루프는 직렬로 배열된다.   라인 편향 전류(Id)와, 변조기 코일(LB)을 통해 흐르는 변조기 전류(Ib)가 서로 반대 방향으로 흐르는 공통 경로내에 내부-핀쿠션 캐패시터(CSM)가 배열된다.   S-보정의 양은 S-보정 캐패시터(SC) 및 내부-핀쿠션 캐패시터(CSM)에 따라 달라진다.   S-캐패시터(CS)는 본 발명에 따른 다이오드 변조기에서 생략하였다.   이런 식으로 하여, 다이오드 변조기가 평형 상태에 있을 경우, 공통 경로에 흐르는 공통 전류(Im)가 제로이기 때문에, 최소 스캔폭에서 수행되는 S-보정의 양은 제로로 될 것이다.   따라서, 본 발명에 따른 다이오드 변조기는, 작은 스캔폭에서 수행되는 S-보정의 양을 감소시키기 위해, 부가적인 캐패시터(CS2)와, 부가적인 캐패시터(CS2)를 활성화시키기 위한 사이리스터 스위칭 회로(T)를 필요로 하지 않으면서, 작은 스캔폭에서 매우 작은 양의 S-보정이 수행될 것을 요구하는 화상 튜브(CRT)에 잘 대처할 수 있다.   본 발명은, 16/9 종횡비를 갖는 디스플레이 튜브상의 16/9 및 4/3 스캔폭 사이의 연속적인 줌이 간단한 방식으로 수행되어야 할 경우 특히 유용하다.
Patent KR-19990067133-A (KR)
Title: 플로우 펌프
IPC: F04D29/66
Filed: 1997-04-15
Abstract: 펌프 케이싱내에 형성된 펌프실이 설치되어 있고 그 펌프실이 서로 간격을 유지하고 배치된 반경 방향으로 연장되는 2 개의 측벽(12)과 이들 측벽(12)을 그 외주부를 따라서 서로 결합하는 원주방향벽에 의해서 제한되어 있으며, 또, 측벽(12, 13)중의 한쪽에 배치된 펌프실(11)로 향해서 개방하는 홈형상의 하나 이상의 측방향 통로(20, 21)가 설치되어 있으며, 그 측방향 통로(20, 21)가 측방향 통로 종단부(02, 212)와 측방향 통로 시단부(201, 211)와 사이에서 흐름 방향에 관련해서 측방향 통로(20, 21)에 잔존하는 중단 웹을(35, 23)을 구비하고 있으며, 펌프 축선(22)에 대해서 동심적으로 연장되어 있으며, 또한, 펌프실내에서 회전하는 날개를 구비한 임펠러가 설치되어 있는, 특히, 자동차의 연료탱크에서 연료를 공급하기 위한 플로우 펌프에서 날개 주파수의 주파수 진동의 국소적으로 매우 높은 압력 진폭을 감소시키기 위해서 펌프실로 향해서 개방하는 만곡된 완충홈(36)이 중단 웹(35)으로 측방향 통로 종단부(202) 부근에 설치되어 있으며, 이 완충홈(36)은 대략 측방향 통로의 폭에 걸쳐서 연장되어 있다
Patent KR-19990087767-A (KR)
IPC: G07F7/10
Filed: 1997-03-04
Abstract: PCT No. PCT/DE97/00407 Sec. 371 Date Sep. 14, 1998 Sec. 102(e) Date Sep. 14, 1998 PCT Filed Mar. 4, 1997 PCT Pub. No. WO97/34254 PCT Pub. Date Sep. 18, 1997The invention relates to a chip card having a card body (2) and a semiconductor chip (3) which is accommodated within the card body (2) and on which a control circuit (7) and a semiconductor memory device, which is electrically coupled to the control circuit (7), are constructed in an integrated manner, which control circuit (7) is supplied with a supply voltage generated by a voltage supply circuit (12) and with a clock generated by a clock supply circuit (13), which is arranged separately from the control circuit (6). The control circuit (7) of the semiconductor chip (3), which is accommodated within the card body (2), is assigned a sensor circuit (14) which detects a deviation of the allowed operating state of the control circuit (7) and, if a disallowed operating state of the control circuit is present, generates a triggering signal which is fed to a triggering circuit (18), which is connected downstream of the sensor circuit (14), is assigned to the semiconductor memory device and, as a reaction to the triggering signal, controls an at least partial erasure of the data content of memory cells of the semiconductor memory device.
Patent KR-20000005055-A (KR)
Title: Circuit device having many electronic circuit components
Inventor: SEDLAK HOLGER
IPC: G06F12/14
Filed: 1997-03-26
Abstract: PURPOSE: A circuit device is provided to achieve independent operation of external clock supply without considerably increasing circuit expenditure or region necessary condition of the device by automatically resetting a selected circuit component to a logical zero value. CONSTITUTION: The device comprises many electronic circuit components. An operation state of the component is converted into an erasure state by a predetermined control or data signal which can be applied to each of the components. Data content of the components has a logic zero value in the erasure state. Each of the components is allocated to each open stage of a selection circuit. An open signal outputted by a final open stage of the selection circuit is applied to an input a just previous open stage in a feedback loop.
Patent KR-20000005125-A (KR)
Title: Preparation of substituted aromatic amines
Inventor: WHEELER EDWARD L
IPC: C01C3/12
Filed: 1997-03-13
Abstract: PURPOSE: Amines such as N-phenyl-P-phenylenediamines disclosed wherein an amine substituted aromatic such as aniline are oxidized with oxygen or hydrogen peroxide in the presence of a preferred trisodium pentacyano ferrate(II) complex containing various water soluble ligands, such as ammonia, mono alkyl amine, dialkyl amines, and trialkyl amines. The complex is subsequently catalytically reduced by hydrogenation using certain heterogeneous metal catalysts to yield the desired aromatic amine CONSTITUTION: After aromatic amine is oxidized with oxygen or hydrogen peroxide in the presence of pentacyano ferrate(II) composed of potassium or sodium between pH10 and pH12, the compound is oxidized in the presence of heterogeneous metallic catalysts such as white metal platinum, palladium, nickel, rhodium or ruthenium under the 1-100 atmospheric pressure of oxide or hydrogen at 40-60°C, and the compound is subsequently deoxidized at 5-60°C to be transformed into final compound.
Patent KR-20000005156-A (KR)
Title: Closed loop servo operation for focus control
Inventor: CESHKOVSKY LUDWIG
IPC: G11B7/13
Filed: 1997-03-24
Abstract: PURPOSE: A closed loop servo operation technique is disclosed for focus control of a beam of radiant energy. CONSTITUTION: A detector (712) of the beam has first (368) and second (376) outputs responsive to a position of the focal point of the beam. A circuit is coupled to the outputs of the detector for producing an error signal representing a displacement of the focus from a predetermined position, wherein the error signal has a periodic characteristic relative to the displacement. A servo (700) responsive to the error signal restores the displaced beam to the predetermined position. A local feedback loop (344) is coupled to the outputs of the detector, and includes first (360) and second (364) periodic function generators, each responsive to the error signal. The second periodic function generator has an output that differs from an output of the first periodic function generator by a phase angle, preferably 90 degrees. A first multiplier (332) multiplies the first output of the detector by the output of the first periodic function generator. A second multiplier (336) multiplies the second output of the detector by the output of the second periodic function generator, wherein the outputs (460, 472) of the first and second multipliers are provided as inputs (476, 480) of the circuit to modify the error signal.