Mita PointSource Ai 3010, Service Manual

Page: 42 / 478

2AR
1-3-22
TFM+
TFM
TFM–
TNS SIG
TNS CONT
DB REM
DB CONT
24 V DC
HVTPCB EPCB
CN1-4
DB
CN1-5
CN1-10
CN8-17
CN8-18
CN8-22
CN8-24
CN9-11
CN9-10
CN9-5
Figure 1-3-19 Developing section block diagram
Toner density is detected by the toner sensor (TNS).
The sensor section of the toner sensor detects the ratio of toner to carrier in the
developer near it and converts it into a voltage. As more toner is used, the ratio of toner
to carrier decreases, increasing the toner sensor output voltage.
When the ratio drops below the specified value, the increase in toner sensor output
voltage triggers toner replenishing. When toner is added and the ratio of toner to carrier
returns to normal, the toner sensor output voltage drops to the point where toner
replenishing stops.