| 摘要 |
PURPOSE:To ensure the linearity and to extend dynamic range especially at a low luminous intensity by shutting at least one of photoelectric elements, taking a photoelectric output extracted from the photoelectric element as a dark current component and eliminating it from the output of photoelectric elements. CONSTITUTION:A self-scanning type photoelectric converting element section 1 consists of a scanning circuit 2, a photoelectric converting element array 3, and a photodetector array 4. At least one of photoelectric elements P1, P2-Pm-1, Pm constituting the photoelectric conversion element array 3, e.g., the Pm-1 is shut and used for the dark current compensation. That is, a photoelectric output Vi extracted from a signal line 25 is inputted to a sampling hold circuit 27 and a subtraction circuit 28 via an amplifier circuit 26. A photoelectric output of the photoelectric element Pm-1 shut is sampled and held in the sample-and-hold circuit 27, this is subtracted at the subtraction circuit 28 and the photoelectric output eliminated the dark current component is obtained. |
