| 摘要 |
PURPOSE:To reduce the occurring frequency of uncomfortable sound upon rise-up of an image forming device so as to improve the use environment by synchronizing the rise-up of rotation of a motor for driving a polygon mirror with previous rotation for preparation of image forming. CONSTITUTION:A fixing unit has upper and lower rollers, and a heater lamp 81 for heating the outer surface of the upper roller up to a fixing temperature is located in the upper roller. Just after energization of a power switch, the heating of the upper roller by the heater 81 is at once started. When a thermistor 102 detects such a condition that the temperature of the outer surface of the upper roller reaches a predetermined value, a printer part control CPU 79 delivers an instruction to a mechanical drive circuit 117 so as to start the previous rotation for preparation of image forming. In synchronization with this, the control CPU 79 delivers an instruction for applying a voltage to a polygon motor control circuit 112. Since the period of the previous rotation includes the rise time of the polygon motor 120, noise from the polygon motor become not audible by being masked by the noise from the previous rotation. |
