Operating Principles - Epson Stylus Pro 7400 Service Manual

EPSON Stylus Pro 7400/7800/9400/9800
Paper size detection sequence (left and right edges)
Error display:
Set the paper correctly
Transition to this sequence is allowed only at paper initial.
C H E C K
At inter-page skew checking, transition to
P O I N T
sequence for left and right edges (skew check) (p.158)
Solid Line:
Broken Line: Printable Area
Right edge
detection position

Operating Principles

Simplified detection
takes place.
Paper
Left edge
detection position
Print Mechanism Components
Left and right edge detection start
Edge sensor LED lights up
Edge sensor sensitivity control
While monitoring the edge sensor, the CR
moves away from its home position toward
1
the max. printable position (320CPS)* .
Paper absence detected
Yes
The CR moves toward its home by 2 mm (240CPS) from the position where the sensor
output has changed.
While monitoring the edge sensor output, the CR moves outward at 5 cps. The position
where paper absence is detected is judged to be the right edge position of the paper.
The CR moves toward its home by 2 mm (320CPS) from the position where was
detected as the paper edge.
While monitoring the edge sensor, the CR moves toward its home position (toward the
min. printable position)
Paper absence detected
Yes
The CR moves toward the opposite direction of its home by 2 mm
(240CPS) from the position where the sensor output has changed.
While monitoring the edge sensor output, the CR moves toward the
home at 5 cps. The position where paper absence is detected is judged
to be the left edge position of the paper.
Paper width is 179 mm
(182 - 3)? * 3
Yes
Return
Figure 2-6. Paper Size Detection Sequence (left and right edges)
Revision B
Note "*1":Printing area MAX position
· Stylus Pro 9400/9800
1,257.91mm + 7.0mm (Reserved width)
· Stylus Pro 7400/7800
759.91mm + 7.0mm (Reserved width)
"*2":Printing area MIN position
137.31mm - 7.0mm (Reserved width)
"*3":A countermeasure for mis-detection of the
edge sensor. The sensor may detect a tab
on the platen as paper in spite of paper
absence. To ensure the paper detection,
the printer judges that no paper is set if the
paper width is narrower than 182 mm (B5
size) - 3 mm.
No
(320CPS)* 2 .
No
No
Edge sensor LED turns OFF.
Error
156