Ricoh Aficio 2035e Service Manual page 408

DEVELOPMENT
Image Pixel Count Mode
This mode should only be used only as a temporary measure while waiting for
replacement parts, such as a TD sensor. This mode controls the toner supply
amount using the same method for determining the toner bottle motor on time.
However, the values that were in effect when the toner density control mode was
changed over to image pixel count mode with SP2-208-1 (Toner Supply Mode)
remain in effect and cannot be changed.
6.9.6 TONER NEAR END/END DETECTION
The toner near-end condition is detected based on the Vt(10) output from the TD
sensor. If the difference between Vref (toner supply reference voltage) and Vt (10)
is less than or equal to –0.45, then toner concentration is judged be very low and K
(the toner supply coefficient) is set to 0.25, the machine enters the toner near end
condition and the machine switches on the toner supply motor.
If a difference greater than –0.45 is detected, then toner concentration is judged as
low but the machine does another test by comparing Vref and Vt (10). If the
machine determines that Vt (10) is greater than Vref 40 times, the toner supply
motor switches on and remains on for twice the time that Vt (10) was greater than
Vref. If the toner concentration is still low, then the machine enters the toner near
end condition.
The final toner end is detected using the ID sensor. If the ID sensor detects that the
ID sensor pattern is very light (Vsp drops below 2.0V), then the sensor triggers the
toner end condition.
If Vsp is less than 2.0V, the density of the ID sensor pattern is very light, so the
machine detects the toner end condition. However, if Vsp remains higher than 2.0V
but 90 copies have been made after toner near end was determined, the machine
enters the toner end condition.
NOTE: The number of copies between toner near-end and toner end can be
changed with SP2-213. The default is 90 copies.
B135/B138 6-64 SM