COPYRIGHT © 1998 CANON INC. CANON NP7161/NP7160 REV.0 AUG. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON) 4–17CHAPTER 4 IMAGE FORMATION SYSTEMFigure 4-205DC controller PCBCleaning bladeWaste toner feedingscrewPhotosensitve drumFlag PS8Waste toner feeding screw locked detection signal (TRQMLDT)Main motor drive commandGear A M1Spring clutchC. Monitoring the Waste Toner Feeding ScrewIf the waste toner inside the drum cartridge cakes and, as a result, hinders the rotation of thewaste toner feeding screw, waste toner can start to leak from the pipe. To prevent such aproblem, the copier is equipped with a waste toner feeding screw detection mechanismconstructed as shown in Figure 4-206.The waste toner feeding screw is linked with a spring clutch and a flag, and is rotated by theengagement of the spring clutch with the gear A.The rotation of the flag is monitored by the waste toner feeding screw sensor (PS8) at alltimes while the main motor (M1) is rotating.When the waste toner feeding screw locks, the spring clutch is subjected to force in the axialdirection and moves in the direction of the arrow, causing the flag to stop rotating. If the wastetoner feeding screw lock signal (TRQMLDT) remains unchanged for 0.5 sec or more, the DCcontroller PCB will assume that the waste toner feeding screw became locked, and willimmediately indicate ‘E013’ on the control panel and stop responding to a press on the Start key.
