Id Sensor Output - Ricoh FT5233 Service Manual

PROCESS CONTROL

1.2.2 ID Sensor Output

VSG = 4.0 ± 0.2
1/10 VSG = 0.4
When in the toner density check cycle, the CPU receives two voltage values
directly from the ID sensor: Vsg and Vsp. Vsg is the voltage value for the
area of the drum made bare by the erase lamp unit before the ID sensor
pattern is exposed. Vsp is the voltage value for the developed ID sensor
pattern. The CPU compares these two values to monitor the image density
on the drum and with this controls the toner supply.
[Standard setting]
Black toner
Red/Blue toner
Green toner
Vsg is the reference voltage of the ID sensor output and is automatically
adjusted to 4V whenever SP mode #54 is called.
The development bias for the ID sensor pattern is fixed for each toner color.
This is to avoid any influence from the manual ID level setting on toner
density control. (See chart.)
LED
ON
VSG
(V)
1/10 VSG
0
(T)
Sensor
Bare
pattern
drum
0 to 500 copies
– 220 V
– 200 V
– 240 V
2-4
LED
ON
VSP
VSG
VSP
Low image density
High image density
0
Over 500 copies
– 200 V
– 180 V
– 220 V
12 February 1992