Toshiba e-studio550 Service Manual page 183

12. 5. 2. Operation of auto-toner sensor
(1) Functions of the auto-toner sensor
a. Initializing function: When the copier is set up or when the developer material is replaced
The automatic adjustment is made so that the output of the auto-toner sensor (input value of the
main CPU) will be 2.45 to 2.55V for the toner density of new developer material.
b. Toner density stabilizing function: During the printing operation
Through the following phases, the toner density is kept constant.
Toner consumed
Toner density decreased
Output change of the auto-toner sensor depending on the humidity detected
Recycle toner hopper and new toner supply motor driven
Toner supplied to the developer unit from the recycle toner hopper and toner cartridge
c. Toner-empty detection, release function
Toner-empty detection in the toner cartridge.
New toner supply motor driven
Output of the auto-toner sensor not changed
Toner density not changed
Toner-empty detected
Toner-empty release
New toner supply motor driven
Toner supplied from the toner cartridge
Output of the auto-toner sensor changed
Toner density recovering to its normal value
Toner-empty released
(2) Operation of the auto-toner sensor
The auto-toner sensor is composed of the following circuits.
Drive winding
Detection winding
DC conversion circuit : Converting the figh-frequency output from the detection winding to a
Magnetic resistance
Drive
winding
(Developer material)
Magnetic circuit
e-STUDIO550/650/810 DEVELOPER UNIT
: Magnetic head (primary side) with a high-frequency magnetic field,
which forms a magnetic circuit in the developer material
: Receiving the changes in the magnetic resistance of the developer
material via a magnetic circuit (secondary side)
DC signal
Detection
winding
12 - 10
Auto-toner output
DC
conversion
circuit
V
ATS
JUNE 2002 © TOSHIBA TEC
Main CPU
(LGC)