COPYRIGHT © 2003 CANON ELECTRONICS INC. CANON DR-6080/9080C REV.0 SEPT. 2003 2 - 17CHAPTER 2 FUNCTIONS & OPERATION4. Staple DetectionIn this unit, a staple detection mechanism isemployed which detects the jumping up ofstapled documents. This mechanism is designednot to detect the staple itself, but to detect thejumping up of the stapled documents, and to stopthe feeding. As such, it prevents stapleddocuments from being torn apart.Fig. 2-307 shows a stapled documentjumping up due to the pick-up roller.Pick-up rollerStapleDocumentsFig. 2-307Fig. 2-308 shows the configuration of thestaple detection.The staple detection consists of staple LEDsand a staple photo-sensor, arranged on bothsides of the document pick-up opening. If there isno staple in the documents, the light emitted fromthe LEDs is received by the photo-sensor. If thestapled documents jump up, the light getsblocked and the documents are found to bestapled, resulting in stopping the feeding.The five staple LEDs are mounted on thestaple LED PCB. The staple photo-sensor hasfive sensors that correspond to the five LEDs onthe staple LED PCB, and is directly mounted onthe document tray control PCB (10_SUB).DocumentsStaplephoto-sensorStaple LEDFig. 2-308Note: Because the documents do not jump upunder the following conditions, the stapledetection sensor will not work:• When there are two or more stapledplaces.• When the staple is not positoned at acorner.• When the documents are smaller thanA5.Document curl must be 3 mm or less inheight and the documents cannot becreased.It is possible to change the level ofdetection accuracy with the user mode.
