Tcr Sensor Control - Konica Minolta bizhub C250 Service Manual

12. Developing section
12.3.5

TCR sensor control

• The TCR sensor is mounted on the underside of each of the developing sections. The
sensor for C, M, Y and K is a magnetic type. Each of these sensors detects toner-to-car-
rier ratio (T/C) of the developer. The reading is used for determining the amount of toner
supplied.
• Only when a new imaging unit is installed in the machine, an automatic adjustment is
made of each of these TCR sensors. The sensors cannot be adjusted manually.
• The target T/C is 8% for color and 7% for K.
• The magnetic permeability (powder density) of the carrier in the developer is measured
to determine the T/C.
• A mylar is provided for the conveying screw portion to scrape toner off the surface of the
TCR sensor.
• The TCR sensor is integrated with the imaging unit. When the TCR sensor is to be
replaced with a new one, the entire imaging unit must be replaced.
TCR sensor
Mylar
TCR sensor
44
4038to503c0
Theory of operation ver. 3.0 Aug. 2006
Magnetic TCR sensor
4038T2C031AA