| 摘要 |
PURPOSE:To drive a cooling fan by a single power supply by continuously running the cooling fan at the time of forming an image, and at the time of forming non-image, turning on and off power supply to the cooling fan to execute intermittent running of the cooling fan. CONSTITUTION:When a main motor 55 is on during the image formation, an 'L0' level signal is inputted to a binary counter 52. Since the binary counter 52 is set up under said state, the 'L0' level signal is inputted to a fan motor driving circuit 53 and a fan motor is continuously driven. Since the main motor is off during waiting (non-image formation), the 'L0' level signal is not inputted to the reset terminal of the binary counter 52 and respective signals 'Q1', 'Q2', OR', 'AND' based upon the reference frequency signal from an oscillator 51 are inputted to the circuit 53, so that the fan motor 55 is intermittently driven by repeating ON and OFF. Since the cooling fan is rotated at a single rotational frequency by a single power supply, plural power supplies are not required and the size and cost of the device can be reduced. |
