A Circuit for thwarting error of LCD Monitor

• Main Authors: KIM, UNG GYU, LEE, JAE MIN
• Format: Patent
• Language: English; Korean
• Published: 01.11.2001
• Edition: 7
• Subjects: ADVERTISING; ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICESUSING STATIC MEANS TO PRESENT VARIABLE INFORMATION; CRYPTOGRAPHY; DISPLAY; EDUCATION; PHYSICS; SEALS

PURPOSE: A circuit for preventing a malfunction of an LCD monitor is provided to detect a composite synchronous signal stably without regard to a signal pattern and a signal level in a SOG(Synchronous signal on Green) signal. CONSTITUTION: An amplification unit(10) comprises a transistor(Q1) whose turning on/off is determined by receiving the SOG signal through a base, and the first capacitor(C1) connected to the base of the transistor, and the first resistor(R1) whose one end is connected to a collector of the transistor and another end is connected to a supply power, and the second resistor(R2) whose one end is connected to an emitter of the transistor and another end is grounded. A clamp unit(20) comprises the second capacitor(C2) connected to the amplification unit, and the first diode(D11) whose cathode is connected to the second capacitor in parallel and the third capacitor(C3) whose one end is connected to an anode of the first diode and another end is grounded. A clip unit(30) comprises the second diode(D12) whose anode is connected to the clamp unit in parallel and the fourth capacitor(C4) whose one end is connected to a cathode of the second diode and another end is grounded. And an integration unit(40) comprises the third resistor(R3) connected to the clip unit and the fifth capacitor(C5) whose one end is connected to the third resistor in parallel and another end is grounded. 에스오지(SOG) 신호에서 신호패턴 및 신호레벨에 관계없이 안정적으로 복합 동기신호를 검출할 수 있도록 한 모니터의 오 동작 방지회로에 관한 것으로, A/D 컨버터를 구비한 모니터에서, PC로부터 전송되는 에스오지(SOG) 신호를 증폭시키는 증폭부와, 상기 증폭부의 출력신호에서 싱크의 중간레벨이 검출되도록 클램프(Clamp) 시키는 클램프부와, 상기 클램프부의 출력신호에서 소정레벨 이상의 신호를 클리핑(Clipping)하는 클리프부와, 상기 클리프부에서 클리핑된 신호에서 피킹(Peaking) 성분을 제거하기 위한 적분기와, 상기 적분기의 출력에서 복합 동기신호를 검출하여 상기 A/D 컨버터에 입력하는 복합 동기신호 검출부에 관한 것으로 에스오지(SOG) 신호에서 동기신호 레벨에 관계없이 안정적으로 복합 동기신호를 추출할 수 있으므로 입력패턴에 따른 오 동작을 미연에 방지할 수 있는 효과가 있다.