COPYRIGHT © 2001 CANON INC. CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON) 3-1173. OPERATION AND TIMINGg. Supplying Bk TonerAs shown in Figure 3-547, the sequence of supply operations is based on the detection of the density ofthe image and the measurement of the density taken by the SALT sensor.When the original has been exposed, the video signals are counted, and the toner supply period isdetermined based on the cumulative count.When copying operation ends, the SALT sensor measures the density of toner on the photosensitivedrum is measured. If the resulting measurement is higher than the ideal density (too much toner), asubtraction will be made from the count of video signals so that the supply period (amount) will be less; if themeasurement is lower than the ideal density (too little toner), on the other hand, opposite correction is madeto supply a larger amount of toner.Figure 3-547The toner density is measured by the SALT sensor as follows. When making single copies,measurements are taken each time copying ends; in continuous copying, measurements are taken when allcopies have been made. However, if the copy count is set to ‘100’ or higher, measurements are taken whenthe 100th copy has been made. (See Figure 3-548.)Figure 3-548COPYStart keyONLSTR STBY COPYStart keyONOriginal exposedVideo signal countedToner supply period determinedToner density measuredby SALT sensorOriginal exposedToner supplied Toner suppliedVideo signal countedToner supply period determined4 copies210 copies1st1st2nd 3rd100th 200th 201st101st 199th4th210thToner densitymeasurement
