To measure wear amount of a pair of gears with one sensor.
An image forming apparatus has a gear train rotationally driven by a motor, and a sensor downstream of the gear train that detects the rotation of the gears. The image forming apparatus further includes: sensor signal recording means that temporarily reverses the rotation of the motor in an initial state where the gears are not worn, and adjusts timing of a sensor signal obtained during the reverse rotation to the timing reference to a motor drive signal and records the sensor signal in a recording area; and wear amount measuring means that temporarily reverses the rotation of the motor during measuring the wear amount, and compares a sensor signal obtained during the reverse rotation with the sensor signal in the initial state recorded in the recording area so as to measure the wear amount of the gears.
SHIMIZU KEISUKE
MAEBATAKE YASUHIRO
YASUDA JUN
MURAKAMI HIROAKI
