Test Pattern Image Mode - Ricoh PRIPORT VT 2000 Series Service Manual

4. TEST PATTERN IMAGE MODE

The purpose of this mode is to distinguish whether the cause of the image
problem is located before or after the image processing.
Output image:
Master processing length:
Main scan (Horizontal) direction:
Sub scan (Vertical) direction:
Test Pattern Image
Fluorescent Lamp
CCD
Original Feed
Motor
This test pattern is generated by the image processing PCB.
[Example] Problem:
Possible Cause 1
Possible Cause 2
The normal output of this test pattern image mode is one
of the Dither matrix pattern as illustrated below.
A
A/D Conversion
PCB
Full width of the thermal head
Same as the vertical size of
the original set on the original
table.
Magnified Test Pattern Image
Test Pattern in
Line Mode
Image Thermal Head
Processing PCB Drive PCB
Master Feed
Motor
Vertical white lines appear on the print.
If the same problem appears on the output
Image from the thermal head in Test Pattern
image mode, the cause should exist in area
B as shown above.
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 should exist in area A as shown
above.
4-17
28 February '91
Test Pattern in
Photo Mode
(VT2300/VT2500
only)
B
Thermal Head