process for the production of copies in which multiple tonerbilder on one and the same kopierblatt transfer

摘要

PURPOSE:To prevent wrinkling and to enable maintenance of satisfactory copying accuracy in the stage of multiple-copying by changing over of the press contact force of a fixing roller higher in the pressure of the final time than the pressure of the 1st time. CONSTITUTION:A cam shaft 82 is driven by a DC brushless motor 78 via gears 75, 76. An eccentric cam 85 is fitted to the shaft 82. The cam 86 is in contact with an arm 79 coaxial with a lower heat roller 222 of a fixing device 22. The roller is therefore provided adjustably in the press contact force according to the position of the cam. The cam is positioned between the point (a) and the point (d) and fixing is accomplished under the prescribed intermediate pressure in the 1st time of fixing in the above-mentioned constitution. The top dead point (a) where the max. pressure is exerted is pressed to the roller in the final time or multiple copying. Wrinkling is thus obviated owing to the low pressure in the 1st time and the defective fixing is prevented by the substantial pressure in the final time. Copying with good accuracy is thus made possible.