Toner Near End/End Detection And Recovery - Ricoh K-C3 Service Manual

B245/B276/B277/B268/B269 Service Manual
TD Sensor
The TD sensor output is checked every copy. If the readings from the TD sensor become
abnormal, the machine changes the toner density control mode to fixed supply mode 2, and
the toner supply amount per page is always 200 ms, regardless of the value of SP 2925. If the
machine detects the TD sensor error condition 10 times consecutively, an SC code is
generated (SC390) and the machine must be repaired.

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 2923 (see the
previous page).
Toner Near End Recovery
If the machine detects "Vt < (Vref or Vts) + 4S/5" twice consecutively in any of the following
situations, the machine clears the toner near end condition.
While in the toner recovery cycle (supplying toner on and off for 30 seconds) after the
machine has detected a toner near end condition.
During copying in the toner near end condition.
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.
When Vt is level 7 three times consecutively, the machine enters the toner end condition.
When 50 copies have been made since entering the toner near end condition. The
number of copies between toner near-end and toner end can be changed using SP
2213.
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