e-STUDIO167/207/237 © 2007 - 2008 TOSHIBA TEC CORPORATION All rights reserved
DEVELOPMENT SYSTEM
12 - 10
2) Function of auto-toner sensor
- The auto-toner sensor consists of the following circuits:
Drive winding:
A magnetic head (primary side) with a high-frequency magnetic field, which forms a magnetic cir-
cuit in the developer material.
Detection winding:
Receives the change in the magnetic resistance of the developer material through the magnetic
circuit (secondary side).
DC conversion circuit:
Converts a high-frequency output from the detection winding into a DC signal (auto-toner output
V
ATS
).
Fig. 12-5
- When the toner density is low
The ratio of the toner against the carrier in the developer material decreases.
→ The magnetic resistance decreases.
→ The detection output increases.
→ The auto-toner output V
ATS
increases.
- When the toner density is high
The ratio of the toner against the carrier in the developer material increases.
→ The magnetic resistance increases.
→ The detection output decreases.
→ The auto-toner output V
ATS
decreases.