Epson Stylus Pro 7400, Service Manual

Page: 157 / 428

EPSON Stylus Pro 7400/7800/9400/9800 Revision B
Operating Principles Print Mechanism Components 157
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Paper size detection sequence (front edge)
Conditions:
For execution of this processing, the paper level threshold value must be
known. (Execute this processing after detection of the right and left edges.)
Error display:
Set the paper correctly
When the paper width detection function is turned off, use the paper size front
position as the user paper setting position. (On the assumption that detection
is not made by the edge sensors)
Figure 2-7. Paper Size Detection Sequence (Front Edge)
Paper absence detected
Front edge detection start
No
The CR moves onto Fl_Box. (320CPS)
While monitoring the edge sensor output, the PF moves in
the negative direction (picks up paper) (40CPS)
The PF stops if paper absence is detected *
2
Paper absence is detected by edge sensor?
No
Note "*1":Paper left upper detection
position = Paper left edge
po 27.5 mm
"*2":PF maximum travel =
- 260mm (Self-diagnostics
mode: - 340mm)
No change in sensor output
even when this travel has
been exceeded is handled as
an error.
"*3":PF moving target position =
The 1st nozzle position
(0.00 mm)
No change in sensor output
even when this position has
been passed is handled as
an error.
"*4":Paper right upper detection
position = Paper right edge
position - 27.5mm
"*5":In the figure below, the left
upper leading edge is
handled as the paper size
front position. (On the
assumption that the paper
front edge is not correctly
perpendicular to the paper
feed direction)
The CR moves to the paper left upper detection position *
1
While monitoring the edge sensor output, the PF moves in the
positive direction (feeds the paper forward) (5CPS)
The position where paper presence is detected is judged to be
the left front edge position of the paper * 2
The CR moves to the paper right upper detection position (320CPS) * 4
While monitoring the edge sensor output, the PF moves in
the positive direction (feeds the paper forward) (5CPS).
PF stops if paper presence is detected.
(Prevention of skew at leading edge) *
4
Paper absence detected
No
Paper absence detected
No
Yes
Edge sensor LED turns OFF.
Return Error
Yes
Yes
Yes
The upper right leading edge of paper is determined as the
front position of the paper size *
5
While monitoring the edge sensor output, the PF moves
in the negative direction (picks up paper) (40CPS)
The PF stops if paper absence is detected * 2
Solid Line: Paper
Broken Line: Printable Area
Right Upper
Leading Edge
detection
position
Left Upper
Leading Edge
detection
position
Edge sensor LED turns OFF.
While monitoring the edge sensor output, the PF moves in the
positive direction (feeds the paper forward) (5CPS).
The position where paper absence is detected is
judged to be the right front edge position of the paper *
3