3. OPERATION AND TIMINGCOPYRIGHT © 2001 CANON INC. CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)3-118As shown in Figure 3-549, the hopper consists of a main hopper and a sub hopper. Bk toner requireshigher precision than color toner for supply operation because its amount of supply is based on a valuecomputed from video signals. To ensure precision, the main hopper, in which toner tends to cake less, isused to supply toner to the developing assembly.Figure 3-549If the results of measuring the toner density indicate that the density of toner inside the developingassembly is below a specific value, the DC controller sends the toner supply signal to turn on the tonersupply clutch. As a result, the drive of the Pick-up motor will be transmitted to the toner supply screw tosupply the developing assembly with toner.The toner density signal is used to determine how long toner should be supplied, i.e., how long the tonersupply clutch should remain on.CL4CL5M10Toner supplyclutch (upper)Toner supplyclutch (lower)Toner levelsensor (lower)(TS5)Pick-up motordrive signal (M10MD)Toner supply (upper) signal (CL4D*)Pick-up motor toner supply(lower) signal (CL5D*)Toner level detection (lower) signal (BKTEPL*)Toner level detection (upper) signal (BKTEPU*)DCcontrollerPCBToner level sensor(upper)(TS4)
