| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect whether a cooling fan is normally operated. <P>SOLUTION: An image forming apparatus comprises: a cooling fan 101 which changes its rotation speed according to a driving voltage; a transistor Tr1 which supplies the driving voltage corresponding to a PWM signal to the cooling fan; partial pressure resistances R1, R2 which detect a driving current value of the cooling fan driven by the driving voltage supplied from the transistor; and a CPU 103 which controls an output value of the PWM signal for outputting to the transistor on the basis of the driving current value detected at the partial pressure resistances so as to allow the transistor to supply a predetermined driving voltage to the cooling fan. The CPU detects an error of the cooling fan on the basis of the rotation speed of the cooling fan calculated from a period of time between when the PWM signal whose output value is over a threshold is output, and when the PWM signal whose output value is smaller than the threshold is once output and the PWM signal whose output value is over the threshold is output again. <P>COPYRIGHT: (C)2013,JPO&INPIT |
