Ricoh FT5034 Service Manual page 66

1. Normal Toner Density
(Vsg: 4 V)
Vsp is about 1/8 Vsg (=0.5 V) in the normal toner
density condition.
2. Low Toner Density
(Vsg: 4 V)
If the toner density is low, the ID sensor pattern
image on the drum is dimmed.
Consequently, Vsp is higher and the toner is
supplied until the next ID sensor check cycle
(11 sheets → 20 sheets).
Toner Supply Condition
If Vsp > 1/8 Vsg, the toner supply signal is generated.
3. High Toner Density (Vsg: 4 V)
When the toner is supplied, the toner density
becomes higher and the ID sensor pattern image
becomes darker.
Consequently, Vsp is lower than the reference value
and the toner is not supplied.
4. Abnormal Vsg
If Vsg becomes less than 2.5 volts four times continuously, the CPU determines
that the detected value is abnormal. It then changes from the detect mode to the
fixed supply mode.
Even under the abnormal Vsg condition, the CPU continues the ID sensor check
every 10th copy. If Vsg returns to the normal range, the copier returns to normal.
(Vsg abnormal)
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(Normal)
(Low)
(High)