| 摘要 |
PURPOSE:To prevent a recoring paper from overtension without making it a loop, by controlling a driving speed of a fixing roller so as to keep pace with a carrying speed of the recording paper, using a detecting signal for the carrying speed of the recording paper. CONSTITUTION:A carrying roller 5 of recording paper 1 is driven by a paper driving motor 8 of a pulse motor, a fixing roller 14 is driven by a fixing roller driving motor 17 of a DC motor, and is connected to a controlling circuit 18. In this constitution, in accordance with a step pulse signal of the motor 8, sparse and dense information of its driving frequency is detected by a carrying speed detecting means 35 extending from an oscillator 19 to an inverter 34, in accordance with which driving voltage of the fixing roller driving motor 17 is switched to 3 stages such as high, middle and low speed by a motor speed control means 54 extending from resistances 36-38 to a transistor 50. In this way, overtension of recording paper is prevented without making the recording paper a loop by chaning a speed of the fixing roller. |
