Gestetner G060, Service Manual

Page: 253 / 1106

LASER EXPOSURE
SM 6-23 G060
Det
a
iled
De
s
c
ri
ptions
The machine automatically executes the adjustment when it detects one of the
following:
1. Depends on setting of SP5-993-1. The default is as follows:
•
If a process control self check is done (except after toner end recovery and
developer initialization)
•
New PCU installed
•
If the temperature measured by the sensor on the laser optics housing unit
differs by 5
°
C from the temperature at the previous adjustment when a color
printing job starts, or during a printing job, or at any time during standby
mode.
2. When the user or technician starts the adjustment with a user tool or SP5-993-
2
NOTE: The skew adjustment is done only if a PCU is replaced with a new one
or a forced image position adjustment is executed with SP5-993-2 or a
UP mode.
After measuring the patterns, the machine cleans the transfer belt by applying a
positive dc charge to the cleaning roller and turns the belt three full rotations.
If an error is detected three times consecutively, SC285 is generated.
Sub Scan Line Position for YCM
The machine measures the gaps between lines of each color on the pattern on the
transfer belt. If the gaps are not correct, the machine moves the image for the
required color up or down the sub scan axis. To do this, it changes the laser write
timing for that color.
Main Scan Line Position for KYCM
If the machine detects that the image is out of position in the main scan direction, it
changes the laser write start timing for each scan line.
Magnification Adjustment
If the machine detects that magnification adjustment is necessary, it changes the
LD clock frequency for the required color.