EPSON Stylus Pro 4400/4450/4800/4880/4880C
Revision C
Operating Principles
Printer Mechanism Components
148
DOT MISSING DETECTION
A pattern for dot missing detection is printed and dot missing is detected by
scanning the pattern. The pattern is printed by all the nozzles, with 1 nozzle
printing 1 block, and a block for a abnormal nozzle will not print. If dot missing
is detected, the printer will execute cleaning automatically.
Figure 2-54. Dot Missing Detection Pattern
AUTOMATIC UNI-D ADJUSTMENT
A pattern for adjustment is printed, the pattern is scanned and acceptable
values are calculated from the collected values, and then adjustment is
automatically executed.
The pattern first prints the matte black vertical line row (standard lines) and
then prints an overlapping vertical line row in a different color (adjustment lines)
that has been shifted by 1/1440 block unit in the main scan direction. If the
standard lines and adjustment lines overlap, the collected A/D value (light
quantity) becomes higher because the width detecting the paper is wide. The
location detected with the most raised A/D values is determined to be the
acceptable level of Uni-D alignment.
Figure 2-55. Automatic Uni-D Adjustment
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28 dot / (28/360 inch)
18 dot / (18/360 inch)
O.K. Pattern
N.G. Pattern
A/D
Value
Scan Position
Most A/D values are high
= Uni-D acceptable
Adjustment lines
Standard lines
(Matte Black)
Summary of Contents for Stylus Pro 4800 Portrait Edition
Page 9: ...C H A P T E R 1 PRODUCTDESCRIPTION ...
Page 113: ...C H A P T E R 2 OPERATINGPRINCIPLES ...
Page 156: ...C H A P T E R 3 TROUBLESHOOTING ...
Page 200: ...C H A P T E R 4 DISASSEMBLY ASSEMBLY ...
Page 366: ...C H A P T E R 5 ADJUSTMENT ...
Page 448: ...C H A P T E R 6 MAINTENANCE ...
Page 457: ...C H A P T E R 7 APPENDIX ...