Atdc Sensor Control - Develop QC 2235 Plus Service Manual

Developing section
8.3.6

ATDC Sensor control

• The ATDC Sensor is mounted on the underside of each of the Developing Sections. The
sensor for C, M, and Y is an optical type, while that for Bk is a magnetic type. Each of
these sensors detects toner-to-carrier 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 ATDC Sensors. The sensors cannot be adjusted manually.
• The target T/C is 8 % both for color and Bk. This T/C can, however, be changed using
"ATDC Level" of "Image Adjust" available from the Tech. Rep. mode.
A. Optical ATDC sensor
• A bias is applied to the ATDC Sensor window to prevent toner from sticking to it. There is
a magnetic brush provided for the Conveying Screw portion to clean the surface of the
window.
• The sensor portion is separated from the Developing Section (Imaging Unit). When the
ATDC Sensor is replaced, it is necessary to replace the Imaging Unit with a new one.
• This represents the fact that the ATDC Sensor is adjusted only when a new Imaging Unit
is installed. In addition, if the LPH Unit is to be replaced, it is necessary to remove the
ATDC Sensor from the old LPH Unit and mounted it in the new LPH Unit.
B. Magnetic ATDC Sensor
• 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
ATDC Sensor.
• The ATDC Sensor is integrated with the Imaging Unit. When the ATDC Sensor is to be
replaced with a new one, the entire Imaging Unit must be replaced.
ATDC Sensor/Y, M, C
Optical ATDC Sensor
Magnetic
Brush
ATDC
Sensor
Window
QC 2235plus Theory of Operation Ver.1.0 Feb. 2004
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ATDC Sensor/C, M, Y
(PWB-N1, N2, N3)
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2-24
ATDC Sensor/Bk
Magnetic ATDC Sensor
Mylar
ATDC Sensor/Bk
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