| 摘要 |
PURPOSE:To accurately perform a photoelectric-conversion even if a short- circuiting current generated in a photodiode is small by setting the voltage of a back gate of an MS transistor to the potential within + or -1V of the potential of an anode electrode (or a cathode electrode) connected of the photodiode. CONSTITUTION:The operation for converting short-circuiting currents generated in photodiodes 3, 4 to voltages is the same as that of a conventional circuit, and the voltages of the back gates of N-ch MOS transistors 1, 2 are set to the potentials within + or -1V of the potentials of the anode electrodes of the photodiodes 3, 4. Thus, the potential difference between the source, drain, channel of the MOS transistors for forming a switch and the back gate becomes zero. A leakage current between the source, drain, channel of the MOS transistor and the back gate can be set to almost zero. Accordingly, short-circuiting currents generated from the photodiodes 3, 4 can be fed 5to a photodiode 8 for voltage-converting almost all the currents to voltages to accurately perform a photoelectric-conversion. |
