Operation Of Auto-Toner Sensor; Functions Of Auto-Toner Sensor - Toshiba 1550 Service Manual

Operation of auto-toner sensor

(1) Functions of auto-toner sensor

A Initialization adjustment function:
– When new settings are entered or when developer is replaced. –
Automatic or semi-automatic adjustment is made so that the output of the auto-toner sensor
will be 2.3 – 2.5 V (input of IC8) against the toner density of the new developer material.
B Toner density stabilization function:
– During copying operation –
• Toner consumption
detected
~ The toner density is maintained at a constant level.
C Toner-empty detection and release function:
• Detects toner-empty state inside toner cartridge
~ Drives toner motor
change
• Release of toner-empty state
~ Toner cartridge replacement
toner density returns to normal value
(2) Operation of auto-toner sensor
The auto-toner sensor is composed of the following circuits:
• Drive winding:
• Detection winding:
• DC conversion circuit:
Magnetic
resistance
Drive
winding
(Developer
material)
Magnetic circuit
1550/1560 DEVELOPER
toner density decreases
toner motor is driven
auto-toner sensor output is not changed
judges that there is no toner (toner empty)
drives toner motor
Magnetic head which receives a high-frequency magnetic field (primary
side). When placed in developer material, it forms magnetic circuit.
Receives the changes in magnetic resistance of the developer material
via a magnetic circuit (secondary side).
Converts the high-frequency output emitted from the detection winding
to a DC signal.
Auto-toner output VATS
Detection
auto-toner sensor output changes are
toner is supplied to developer unit from toner cartridge.
auto-toner sensor output changes
toner-empty state is released.
DC
conversion
circuit
10 - 12
toner density does not
Auto-toner
output
To microprocessor
V
ATS
Mar. 1998 © TOSHIBA