Toshiba e-STUDIO167 Service Manual page 202

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
Developer material
Magnetic resistance
Magnetic circuit
- When the toner density is low
The ratio of the toner against the carrier in the developer material decreases.
o The magnetic resistance decreases.
o The detection output increases.
o The auto-toner output V
- When the toner density is high
The ratio of the toner against the carrier in the developer material increases.
o The magnetic resistance increases.
o The detection output decreases.
o The auto-toner output V
e-STUDIO167/207/237
DEVELOPMENT SYSTEM
Drive Detection
winding winding
increases.
ATS
decreases.
ATS
Auto-toner sensor
DC
conversion
circuit
Fig. 12-5
© February 2007 TOSHIBA TEC CORPORATION All rights reserved
12 - 10
output
To the A/D converter
( MAIN board )
ATS-1A