Toner Control - Epson AcuLaser C4000 Service Manual

EPSON AcuLaser C4000/C4100/C3000

2.8.7 Toner Control

Installation of the toner bottle is detected by the SWITCH TCRU ASSY
(PL12.2.10), and the presence/absence of toner in the bottle is detected by the
SENSOR TONER LOW (PL12.2.9). There is a set of these sensors for each
color, and each functions separately.
2.8.7.1 About SENSOR TONER LOW (PL12.2.9)
A SENSOR TONER LOW is installed for each color, but the printer cannot
monitor each color at the same time, so checking is done one at a time.
Checking of each color takes 3.5 seconds, so the total time for all four colors is
14 seconds. A single check for toner presence/absence of all four colors takes
14 seconds.
The SENSOR TONER LOW is installed in the HOLDER ASSY (PL12.2.5~8),
and it detects presence/absence of dispensed toner inside the HOLDER ASSY
as it is transported from the toner bottle by the Toner Motor.
Because material sticking to the SENSOR TONER LOW surface can cause it
to malfunction, it is cleaned by an installed film inside the HOLDER ASSY near
the Auger when toner is being dispensed. This film rotates with the Auger when
toner is dispensed, cleaning toner from the surface of SENSOR TONER LOW.
When the Toner Motor is stopped, however, the film may be positioned in such
a way that toner presence may be judged even though there is no toner and
toner absence may be judged when there is actually toner available. This
misjudgment is avoided by the control functions inside the printer.
2.8.7.2 Toner Presence/Absence Control
An overview of Toner Presence/Absence Control is shown below.
1) Activation Timing
• Whenever the power is turned on or the front cover is closed
• Every 14 seconds
2) Output of "No Toner Warning"
The "No Toner Warning" is output when SENSOR TONER LOW detects
the absence of toner twice in a row, provided that the Toner Dispense
was active between those two detections.
Operating Principles
This condition is established to prevent erroneous detection that can
occur due to position of the film as explained at "2.8.7.1 About SENSOR
TONER LOW".
3) Output of "No Toner Error"
After a "No Toner Warning" is output, the toner dispense time is
calculated. If a predetermined value has been exceeded, "No Toner
Error" is output.
4) Cancellation of "No Toner Warning" and "No Toner Error"
After output of "No Toner Error" , toner dispense is activated for 1.5
seconds when the toner bottle installation is confirmed. After this, if
SENSOR TONER LOW detects toner in accordance with toner
presence/absence timing control, the "No Toner Warning" or "No Toner
Error" will be cancelled.
However, in this case, the printer continues to recognize this as a "No
Toner" condition. When the SENSOR TONER LOW detects the
presence of toner three times in a row while toner is dispensing, the
printer will revert to the "Toner Present" condition.
Control
Revision F
2-89