Canon PC940 Service Manual - Page 110
Measuring the Density of Originals, Outline
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CHAPTER 4 IMAGE FORMATION SYSTEM F. Measuring the Density of Originals 1. Outline The machine is equipped with an auto density adjustment (AE) mechanism designed to control the DC component of the developing bias. The AE mechanism enables production of copies free of fogging as long as the original is more or less uniform in density by varying the DC component of the developing bias according to the density of the original. Scanning lamp +24V + +24V + AE sensor J601 J107 -3 -2 AEREF +5V -2 -3 AE +24V + VR103 +5V +24V + VR102 (Q101) Developing cylinder Photosensitive drum Microprocessor Microprocessor (Q900) Developing DCON signal Serial communication DC controller PCB Figure 4-113 Composite power supply PCB 4-16 COPYRIGHT © 1999 CANON INC. CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
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