PHOTOELECTRIC CONVERSION DEVICE AND IMAGING SYSTEM

• Main Author: KUMAGAI TOMOYA
• Format: Patent
• Language: English; Japanese
• Published: 22.04.2021
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

To provide a photoelectric conversion device that comprises comparators having high comparison accuracy, and a method for driving the same.SOLUTION: A photoelectric conversion device has: a plurality of pixels that form a plurality of columns; a plurality of comparators that are provided in correspondence with the plurality of columns; and a control circuit that controls the comparators. The plurality of comparators include first comparators that are connected to first pixels in a first color, second comparators that are arranged in a column adjacent to the first comparators and connected to second pixels in a second color, and third comparators that are arranged in a column adjacent to the second comparators and connected to third pixels in the first color. Each of the comparators is configured to compare a pixel signal output from a pixel in a corresponding column with a reference signal whose level is changed with the lapse of time, and output a comparison signal indicating a level that is made different between a case where the difference is smaller than a threshold and a case where the difference is larger than the threshold. The control circuit controls the threshold for the comparators so that the threshold is gradually changed in order of the first, third, and second comparators.SELECTED DRAWING: Figure 1 【課題】比較精度の高い比較回路を備えた光電変換装置及びその駆動方法を提供する。【解決手段】複数の列をなす複数の画素と、複数の列に対応して設けられた複数の比較回路と、比較回路を制御する制御回路と、を有し、複数の比較回路は、第１の色の第１の画素に接続された第１の比較回路と、第１の比較回路の隣の列に配され、第２の色の第２の画素に接続された第２の比較回路と、第２の比較回路の隣の列に配され、第１の色の第３の画素に接続された第３の比較回路と、を含み、比較回路の各々は、対応する列の画素から出力される画素信号と、時間の経過に応じてレベルが変化する参照信号とを比較し、これらの差が閾値よりも小さい場合と大きい場合とで異なるレベルを示す比較信号を出力するように構成され、制御回路は、第１、第３、第２の比較回路の順序で閾値が段階的に変化するように比較回路の閾値を制御する。【選択図】図１