Fresa G024, Руководство по обслуживанию

Страница: 31 / 178

PROCESS CONTROL 31 March, 1999
2-4
Step 1: ID sensor calibration
To calibrate the ID sensor, the light reflected from the bare transfer belt is
measured. The LED current is adjusted until the sensor output is 2.5 V. The
detector for black is used for the calibration. The LED current will be adjusted for
color toner detection, based on the adjustment that was made during the
calibration for the black toner detector.
Calibrating the ID sensor in this way compensates for any changes in the sensor's
response caused by changes in transfer belt surface conditions or impurities in the
ID sensor light source/receiver.
Step 2: K development bias initialization
The machine makes a patch of black toner on the
transfer belt. The specifications for this pattern are as
follows.
Size: Main scan 20 mm x sub-scan 40 mm
Laser power: 210 (out of a maximum of 255)
The ID sensor detects the density of this pattern.
Based on the result, the development bias for black is
adjusted to obtain a M/A of 0.58 mg/cm
2
on the
transfer belt for areas of maximum image density. This
development bias is called V
B
.
This step is needed when a new machine is installed,
or when a black DTM is changed. This is because the
amount of toner that adheres to the development roller
varies for each unit. This means that the amount of
toner transferred to the image for a certain
development bias will not be the same.
Step 3: Color development bias initialization
The initialization for the Color DTM is the same as for black.
V
B
is obtained for each of the color toners in the order of Y, C, then M.
The target M/A for each color is as follows:
Cyan, Yellow = 0.56 mg/cm
2
Magenta = 0.62 mg/cm
2
Generate the toner pattern
on the transfer belt
Detect the density of the
toner pattern by the ID
sensor
Specify a development bias
(V
B
) that ensures a solid
area toner amount of 0.58
m g / c m
2
G024D530.WMF