• 제목/요약/키워드: Pixel capacitance

검색결과 48건 처리시간 0.024초

A Charge-Pump Passive-Matrix Pixel Driver for Organic Light Emitting Diodes

  • Seo, Jong-Wook;Kim, Han-Byul;Kim, Bong-Ok;Kim, Young-Kwan
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.108-112
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    • 2002
  • A new pixel driving method for organic light-emitting diode (OLED) flat-panel display (FPD) is proposed. The new charge-pump passive-matrix pixel driver consists only of a storage capacitance and a rectifying diode, and no thin-film transistor (TFT) is needed. The new driver not only supplies a constant current to the OLED throughout the whole period of panel scanning like an active-matrix driver, but also provides a highly linear gray-scale control through a pure digital manner.

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New Voltage Programming LTPS-TFT Pixel Scaling Down VTH Variation for AMOLED Display

  • Nam, Woo-Jin;Lee, Jae-Hoon;Shin, Hee-Sun;Jeon, Jae-Hong;Han, Min-Koo
    • Journal of Information Display
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    • 제7권3호
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    • pp.9-12
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    • 2006
  • A new voltage-scaled compensation pixel which employs 3 p-type poly-Si TFTs and 2 capacitors without additional control line has been proposed and verified. The proposed pixel does not employ the $V_{TH}$ memorizing and cancellation, but scales down the inevitable $V_{TH}$ variation of poly-Si TFT. Also the troublesome narrow input range of $V_{DATA}$ is increased and the $V_{DD}$ supply voltage drop is suppressed. In our experimental results, the OLED current error is successfully compensated by easily controlling the proposed voltage scaling effects.

펜타센 TFT를 이용한 AMOLED 픽셀회로 설계 (Design of Pixel Circuit for AMOLED Using Pentacene TFTs)

  • 류기성;최기범;이명원;송정근
    • 대한전자공학회논문지SD
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    • 제43권6호
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    • pp.1-8
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    • 2006
  • 본 논문에서는 OTFT를 기반으로 하는 AMOLED 디스플레이 구현을 위해 두 개의 OTFT와 하나의 캐패시터 그리고 하나의 OLED로 구성된 화소 회로를 설계하였고 그 동작을 시뮬레이션을 통하여 분석하였다. 먼저, 화소 회로를 이론적으로 설계하였고, $32\times32$ AMOLED 패널을 제작하기 위한 화소의 Layout을 설계하고 TFT W/L과 저장 캐패시터의 용량을 설계하였다. 그리고 설계된 화소 회로의 전기적 특성을 분석하기 위해 HSPICE 시뮬레이션 하였다 시뮬레이션 결과 OTFT 기반의 AMOLED 구현 가능성을 확인하였다.

Extension of the Dynamic Range using the Switching Operation of In-Pixel Inverter in Complementary Metal Oxide Semiconductor Image Sensors

  • Seong, Donghyun;Choi, Byoung-Soo;Kim, Sang-Hwan;Lee, Jimin;Lee, Jewon;Lee, Junwoo;Shin, Jang-Kyoo
    • 센서학회지
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    • 제28권2호
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    • pp.71-75
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    • 2019
  • This paper proposes the extension of the dynamic range in complementary metal oxide semiconductor (CMOS) image sensors (CIS) using switching operation of in-pixel inverter. A CMOS inverter is integrated in each unit pixel of the proposed CIS for switching operations. The n+/p-substrate photodiode junction capacitances are added to each unit pixel. When the output voltage of the photodiode is less than half of the power supply voltage of the CMOS inverter, the output voltage of the CMOS inverter changes from 0 V to the power supply voltage. Hence, the output voltage of the CMOS inverter is adjusted by changing the supply voltage of the CMOS inverter. Thus, the switching point is adjusted according to light intensity when the supply voltage of the CMOS inverter changes. Switching operations are then performed because the CMOS inverter is integrated with in each unit pixel. The proposed CIS is composed of a pixel array, multiplexers, shift registers, and biasing circuits. The size of the proposed pixel is $10{\mu}m{\times}10{\mu}m$. The number of pixels is $150(H){\times}220(V)$. The proposed CIS was fabricated using a $0.18{\mu}m$ 1-poly 6-metal CMOS standard process and its characteristics were experimentally analyzed.

지문인식센서용 회로설계 (A Circuit Design of Fingerprint Authentication Sensor)

  • 남진문;정승민;이문기
    • 한국통신학회논문지
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    • 제29권4A호
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    • pp.466-471
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    • 2004
  • 반도체 방식의 용량형 지문인식센서의 신호처리를 위한 개선된 회로를 설계하였다. 최 상위 센서플레이트가 지문의 굴곡을 감지한 용량의 변화를 전압의 신호로 전환하기 위해서 전하분할 방식의 회로를 적용하였다. 지문센서 감도저하의 가장 큰 원인인 센서플레이트에 존재하는 기생용량을 최소화하고 융선(ridge)과 계곡(valley) 사이의 전압차를 향상시키기 위하여 기존과는 다른 아날로그버퍼회로를 설계하였다. 센서전압과 기준전압 신호를 비교하기 위해서 비교기를 설계하였다. 제안된 신호처리회로는 0.3$\mu\textrm{m}$ 표준 CMOS 공정으로 레이아웃을 실시하였다.

Dual Sampling-Based CMOS Active Pixel Sensor with a Novel Correlated Double Sampling Circuit

  • Jo, Sung-Hyun;Bae, Myung-Han;Jung, Joon-Taek;Choi, Pyung;Shin, Jang-Kyoo
    • 센서학회지
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    • 제21권1호
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    • pp.7-12
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    • 2012
  • In this paper, we propose a 4-transistor active pixel sensor(APS) with a novel correlated double sampling(CDS) circuit for the purpose of extending dynamic range. Dual sampling techniques can overcome low-sensitivity and temporal disparity problems at low illumination. To accomplish this, two images are obtained at the same time using different sensitivities. The novel CDS circuit proposed in this paper contains MOS switches that make it possible for the capacitance of a conventional CDS circuit to function as a charge pump, so that the proposed APS exhibits an extended dynamic range as well as reduced noise. The designed circuit was fabricated by using $0.35{\mu}m$ 2-poly 4-metal standard CMOS technology and its characteristics have been evaluated.

Novel Structure of 21.6 inch a-Si:H TFT Array for the Direct X-ray Detector

  • Kim, Jong-Sung;Joo, In-Su;Choo, Kyo-Seop;Park, June-Ho;Chung, In-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.13-14
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    • 2000
  • 21.6" a-Si:H TFT array for direct conversion X-ray detector with 2480 by 3072 pixel is successfully developed. To obtain good X-ray image quality, novel structure, storage on BCB structure, is proposed. The structure reduces the parasitic capacitance of data line, one of the main sources of signal noise. Also, the structure shows higher failure resistance against defects than that of the old design.

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Fabrication of OTFT-backplane with solution process for Electrophoretic Display panel

  • Lee, Myung-Won;Lee, Mi-Young;Park, Jong-Seung;Song, Chung-Kun
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.428-430
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    • 2009
  • We fabricated flexible OTFT-backplanes with combining printing technique and conventional photolithography process for the electrophoretic display(EPD). The active area size of backplane was 6" in diagonal direction and consisted of $192{\times}150$ pixels, containing 1 OTFT employed bottom contact structure and 1 capacitance in each pixel.

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픽셀내 다수의 박막트랜지스터로 구성된 듀오픽스TM 엑스선 영상센서 제작 (duoPIXTM X-ray Imaging Sensor Composing of Multiple Thin Film Transistors in a Pixel for Digital X-ray Detector)

  • 전승익;이봉구
    • 한국방사선학회논문지
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    • 제16권7호
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    • pp.969-974
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    • 2022
  • 디지털 엑스레이 디텍터 영상 취득에 있어 동적 범위를 최대화하고 영상지연을 최소화하기 위해서는 엑스레이 영상센서의 픽셀내 포토다이오드에 존재하는 잔류 정전기생용량을 빠르고 완전하기 제거하는 것이 매우 중요하다. 이러한 요구사항은 특히 고속 프레임과 낮은 영상지연이 필요한 산업용 2D/3D 자동화 엑스레이 검사와 의료용 CT 엑스레이 디텍터에 특별히 요구된다. 본 연구는 리셋 박막트랜지스터, 리드아웃 박막트랜지스터 그리고 포토다이오드로 픽셀이 구성된 듀오픽스TM 엑스레이 영상센서를 처음으로 제안한다. 듀오픽스TM 엑스레이 영상센서의 구동을 검증하기 위해 105 ㎛의 픽셀 사이즈, 347 mm × 430 mm의 영상영역 그리고 3300 × 4096의 픽셀 (13.5M pixels)을 갖는 듀오픽스TM 엑스레이 영상센서를 설계, 제작하여 모듈테스터와 영상취득 프로그램을 통해 영상을 취득하였다.

이중 샘플링 기반의 넓은 동작 범위 CMOS 이미지 센서의 동작 및 시뮬레이션을 통한 특성 분석 (Operation of a wide dynamic range CMOS image sensor based on dual sampling mechanism and its SPICE simulation)

  • 공재성;조성현;이수연;최경화;서상호;신장규
    • 센서학회지
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    • 제19권4호
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    • pp.285-290
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    • 2010
  • In this paper, a dynamic range(DR) extension technique based on a 3-transistor active pixel sensor(APS) and dual image sampling is proposed. The feature of the proposed APS is that the APS uses two or more photodiodes with different sensitivities, such as a high-sensitivity photodiode and a low-sensitivity photodiode. Compared with previously proposed wide DR(WDR) APS, the proposed approach has several advantages, such as no-external equipments or signal processing, no-additional time-requirement for additional charge accumulation, simple operation and adjustable DR extension by controlling parasitic capacitance and sensitivity of two photodiodes. Approximately 16 dB of DR extension was evaluated from the simulation for the situation of 10 times of sensitivity difference and the same size of parasitic capacitance between those two photodiodes.