Ricoh C211, Руководство по обслуживанию

Страница: 370 / 769

4.4 THERMAL HEAD TEST
The function of this mode is to distinguish if the cause of the image problem
is located before or after image processing.
Output image: The normal output of this test pattern image mode is one
of the dither matrix patterns as illustrated below.
Master processing length:
Main scan (Horizontal) direction: Full width of the thermal head
Sub-scan (Vertical) direction: Same as the vertical size of
the original set on the original
table.
The test pattern is generated by the image processing PCB.
[Example] Problem: Vertical white lines appear on the print.
Possible Cause 1 If the same problem appears on the output
image from the thermal head in test pattern
image mode, the cause is in area
B, as shown above.
Possible Cause 2 If the output image from the thermal head is
correct in test pattern mode but the output
image in the normal mode is incorrect, the
cause is in area A, as shown
above.
4.4.1 OPERATION: (To Enter Test Pattern Image Mode)
1) Turn the power switch off
2) Remove the front cover.
Te s t P a tte rn in
L in e M o d e
Te st P a tte rn in
P h o to M o d e
Magnified Test Pattern Image
Test Pattern Image
M a in C o n tro l
P C B
A /D C o n v e rs io n
P C B
C C D
O rig in a l F e e d
M o to r
M a s te r F e e d
M o to r
T h e rm a l H e a d
% $
F lu o re s c e n t L a m p
C224 4-12 SM