Journal of the Institute of Electronics Engineers of Korea SC (전자공학회논문지SC)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Design of a CMOS Image Sensor for High Dynamic Range

광대역의 동작 범위(Dynamic Range)를 갖는 CMOS 이미지 센서 설계

  • Yang, Sung-Hyun (Dept. of Computer and Communication Engineering, Chungbuk National University) ;
  • Cho, Kyoung-Rok (Dept. of Computer and Communication Engineering, Chungbuk National University)
  • 양성현 (충북대학교 정보통신공학과) ;
  • 조경록 (충북대학교 정보통신공학과)
  • Published : 2001.06.30
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Abstract

In this paper, we proposed a new pixel circuit of the CMOS image sensor for high dynamic range operation, which is based on a multiple sampling scheme and a conditional reset circuit. To expand the pixel dynamic range, the output is multiple-sampled in the integration time. In each sampling, the pixel output is compared with a reference voltage, and the result of comparison may activate the conditional reset circuit. The times of conditional reset, N, during the integration will contribute to the increase of the dynamic range by the times of N. The test chip was fabricated with 0.65-${\mu}m$ CMOS technology (2-P, 2-M).

본 논문에서는 CMOS 이미지 센서의 동작 범위(Dynamic Range; DR)를 높이기 위해서， multiple sampling 방법과 조건적 reset 기능을 갖는 새로운 픽셀 회로를 제안한다. 제안된 구조는 한 번의 integration 시간 내에서 픽셀의 출력이 일정한 간격으로 여러 번 sampling되고 sampling된 각 신호는 기준 전압과 비교되며 이 결과에 따라 해당 픽셀을 rest 할지의 여부가 결정된다. 제안된 방법을 사용하면 이미지 센서의 최대 DR은 축적 기간 동안의 총 sampling 회수인 N 배로 증가될 수 있다. 테스트 칩은 0.65-${\mu}m$ CMOS 공정(2-P, 2-M)으로 제작되었으며 이에 대한 측정결과로 본 논문의 알고리듬이 DR의 증가에 효과적임을 확인하였다.

Keywords

References

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