Patent ID: 9547270
Date: 2017-01-17
CPC Classifications: G01N,G03G

Claim:
1. An image forming apparatus, comprising: a humidity sensor element having a first terminal and a second terminal, and configured to vary, in accordance with humidity change, an electric resistance value between the first terminal and the second terminal; a resistor having a third terminal and a fourth terminal, with the third terminal serially connected to the second terminal, and having a prescribed electric resistance between the third terminal and the fourth terminal; a clock supply section configured to supply a first clock signal to the first terminal and a second clock signal having an opposite phase to the first clock signal to the fourth terminal; a detection section configured to detect a humidity on the basis of a divided voltage value obtained by the humidity sensor element and the resistor; and a determination section configured to acquire the divided voltage value at a first timing within a period from a rising edge to a falling edge of the first clock signal and at a second timing within a period from a falling edge to a rising edge of the first clock signal, and to determine that the humidity sensor element has a malfunction when the divided voltage value acquired at the first timing is a low-level potential value of the first and second clock signals and the divided voltage value acquired at the second timing is a high-level potential value of the first and second clock signals.