User Guide

■ Computation of Toner Level Detection

Figure 3-510a

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

Toner present

Toner absent

(TEP*occurs)

Result cleared Result cleared

T1 T2 T1 T2 T1 T2

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3. OPERATIONS AND TIMING