Patent ID: 9291971
Filing Date: 2016-03-22
CPC Classification: G03G

Claim Text:
1. An image forming apparatus comprising: a fixing roller configured to be able to rotate in contact with a printing medium while being heated by a heating device and contact and heat a toner image formed on the printing medium so as to weld the toner image to the printing medium; a motor configured to supply a rotational force to the fixing roller; a motor driver configured to receive a drive voltage supplied from a power supply and control drive of the motor by the drive voltage; a cover member configured to be able to change a position thereof between an open position to open an opening formed in a housing of the image forming apparatus and a closed position to close the opening, and be opened or closed when the printing medium that has stopped in contact with the drive roller is removed; a cover switch including a contact whose one end is connected to the power supply and another end is connected to the motor driver, and configured to output an open signal corresponding to the open position and a close signal corresponding to the closed position, and power off the motor by opening the contact when the cover member is at the open position; a rotation signal detection portion connected to a voltage supply path which extends from the cover switch to the motor driver, and configured to output, as a rotation signal indicating that the fixing roller is rotated, a counter electromotive force generated from the motor as a result of the fixing roller being rotated while the motor is being powered off by the cover switch; and a control portion connected to the cover switch in such a way that the open signal and the close signal can be input, connected to the rotation signal detection portion in such a way that the rotation signal can be input, and configured to, when the rotation signal is input from the rotation signal detection portion while the open signal has been input from the cover switch, and then the close signal is input from the cover switch, determine that the printing medium that has stopped in contact with the fixing roller is removed, wherein when the rotation signal is not input from the rotation signal detection portion while the open signal has been input, and then the close signal is input from the cover switch, the control portion interrupts a power supply circuit that supplies power to drive loads including the motor.