Ricoh Aficio MP 2550B, Service Manual

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Development
SM 6-47 D017/D018/D019/D020
Det
ailed
Des
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6.9.8 TONER NEAR-END/END DETECTION AND RECOVERY
The toner near end and end conditions are detected using the Vt and Vref values, in a
similar way to toner density control.
This is done in all toner supply modes except for fixed mode 2, when toner end is not
detected.
Toner Near-end Detection
If Vt is at level 6 (see the table on the previous page) five times consecutively, the machine
enters the toner near end condition and the toner end indicator starts blinking. Then the
machine supplies toner for a certain time, which depends on the setting of SP 2-923 (see
above).
Toner Near-end Recovery
If the machine detects “S/2 <
Δ
Vt < or = 4S/5” twice consecutively when in one of the
following situations, the machine leaves the toner near end condition.
ƒ
While in the toner recovery cycle (supplying toner on and off for 30 s – see the
previous page) after the machine has detected a toner near end condition.
ƒ
During copying in the toner near end condition.
ƒ
If the front cover is opened and closed for more than 10 seconds while a toner near
end condition exists.
Toner End Detection
There are two situations for entering the toner end condition.
ƒ When Vt is level 7 three times consecutively, the machine enters the toner end
condition.
ƒ
When “4S/5 <
Δ
Vt < or = S” is detected in the toner near end condition, then 50 copies
can be made after this condition (the number of copies between this condition and
toner end can be changed using SP2-213).
Toner End Recovery
If the front cover is opened and closed for 10 seconds while a toner end condition exists
and the toner bottle is replaced, the machine attempts to recover using the same
procedure as for toner near end/end detection.