| 摘要 |
PURPOSE:To detect the output difference of a current-voltage converting circuit connected to each switch and to obtain a reading-out output having improved SN ratio, by separating MOS-FET switches into two groups and driving one switch in each group simultaneously. CONSTITUTION:Plural MOS-FET switches 31-3n are divided into a group corresponding to odd numbers of photodiodes 11-1n-1 and a group corresponding to even numbers of photodiodes 12-1n. The current-voltage converting circuits 5a, 5b are connected to the output sides of respective divided groups, the outputs of the converting circuits 5a, 5b are applied to a differential amplifier 7 and the difference signal is outputted to an output terminal 6. The switches 31- 3n-1 and 32-3n are driven one by one simultaneously by a shift register 4 and the difference of outputs of the converting circuits 5a, 5b is detected by an amplifier 7. Thus, the integrated circuit giving output values with an improved SN ratio is constituted. |
