Canon GP215 Service Manual page 125

Computation of Toner Level Detection
Toner present
Toner absent
(TEP*occurs)
Since toner is stirred by the stirring rod inside the developing assembly, the toner absent and present
states repeat at intervals as shown in Figure 3-510a.
• The absence of toner is assumed by monitoring TEP* only while the developing clutch remains ON;
i.e., such periods as when the developing clutch remains ON are added.
• The sum of periods from when the toner absent signal (TEP*) occurs until the end of the toner
absent signal occurring as a result of stirring the toner is referred to as T1.
• The sum of period from the start of the next toner absent signal until the end of the toner absent sig-
nal is referred to as T2.
• Thereafter, the sums are cleared and replace by alternately adding subsequent T1 and T2.
Based on the results of the foregoing additions, the absence of toner is assumed for the following:
• (T1 + T2) > 20 sec .............toner absent level 1
• (T1) or (T2) > 160 sec........toner absent level 2
COPYRIGHT © 1996 CANON INC.
Result cleared
T1 T2 T1
Figure 3-510a
CANON GP215/200 REV.0 JULY 1996 PRINTED IN JAPAN (IMPRIME AU JAPON)
3. OPERATIONS AND TIMING
Result cleared
T2 T1 T2
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