Patent ID: 7868882
Filing Date: 2011-01-11
Classification: G01J

Abstract:
1. An electronic circuit having transistors disposed on a substrate, each transistor including an active layer made of thin-film polysilicon, the electronic circuit comprising: a sensor that converts a measured quantity into a current value; a current-voltage conversion circuit that converts the current value into a voltage; and a voltage detection circuit that detects the voltage converted by the current-voltage conversion circuit and outputs a predetermined signal, wherein the current-voltage conversion circuit includes a storage circuit and a range-switching circuit that switches a current-voltage conversion range of the current-voltage conversion circuit by switching the capacitance of the storage circuit between a first capacitance value and a second capacitance value, wherein the storage circuit includes a first capacitive element and a second capacitive element connected to the sensor, and the range-switching circuit electrically connects either one or both of the first capacitive element and the second capacitive element to the sensor in response to a range-switching signal, wherein the storage circuit includes a capacitive transistor having an active layer made of thin-film polysilicon, the range-switching signal is connected to a source electrode and a drain electrode of the capacitive transistor, and an end of the sensor is connected to a gate electrode of the capacitive transistor.