| 摘要 |
PURPOSE:To prevent overtension of recording paper without forming it into a loop, by controlling a driving speed of a fixing roller by a detecting signal of a carrying speed of the recording paper, also detecting its slackness, and controlling an operation of the fixing roller. CONSTITUTION:A carrying roller 5 is driven by a paper driving motor 8 of a pulse motor, a fixing roller 14 is driven by a fixing roller driving motor 19 of a DC motor, a controlling circuit 20 is connected, and a slackning detecting switch 21 is provided. In this constitution, in accordance with a step pulse signal of the motor 8, sparse and dense information of a driving frequency is detected by a carrying speed detecting means 38 consisting of an oscillator 19, etc., in accordance with which driving voltage of the motor 19 is switched to 3 stages such as high, middle and low speed by a motor speed control means 57 consisting of resistances 39 41, etc. In the event of overtesnion of recording paper 1, the switch 21 is turned on and the motor 19 is stopped temporarily. In this way, the overtension of the recording paper 1 is prevented. |
