CLEANING DEVICE FOR SPEED DETECTING ROLL FOR ENDLESS BELT OF IMAGE FORMING DEVICE

摘要

PURPOSE:To prevent the variation of the outside diameter of a speed detecting roll by removing the foreign material adhering on the speed detecting roll. CONSTITUTION:When the foreign material 31 such as toner adheres on an encoding roll 28, during the use of an image forming device, the foreign material 31 is shifted to a cleaning brush 33, accompanied with the revolution of the encoding roll 28. The foreign material 31 is scraped off from the encoding roll 28 by the cleaning brush 33, and collected in a foreign material collecting part 34a. Since the foreign material 31 adhering on the encoding roll 28 is surely scraped by the cleaning brush 33, the outside diameter of the encoding roll 28 is prevented from being varied. Accordingly, the encoding roll 28 can correctly detect the revolution speed of a copying belt 7.