Toshiba e-STUDIO163 Service Manual page 177

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 Developer material
Drive
Magnetic resistance Magnetic resistance
winding
Magnetic circuit
- 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
- 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
December 2005 © TOSHIBA TEC
Detection
winding
Fig. 12-5
increases.
ATS
decreases.
ATS
12 - 9
Auto-toner sensor
DC
output
conversion
circuit
ATS-1A
e-STUDIO163/203 DEVELOPMENT SYSTEM
To the A/D converter
( MAIN board )
12