Epson Stylus Pro 7500, Service Manual

Page: 63 / 274

EPSON Stylus Pro 7500 Revision A
Operating Principles Print Mechanism Components 63
position, the sensor is configured to go “Off”, and during a sensing operation, and
the point where the head changes from moving up to moving down and the sensor
output switches from “OFF” to “ON” is recognized as the mechanical home
position.
o
P_EDGE (Paper Width Detection) Sensor
This sensor is mounted on the left rear of the carriage. It detects the left and right
edges of the paper and carries out paper width recognition and skew judgment. A
reflective type photosensor is used and the paper edge (presence or absence of
paper) is judged with the sensor output in the form of an 8-bit A/D converted
value.
NOTE: It is possible to turn this sensor off in 1.6.1, “Printer Setting Menus.”
Figure 2-4. Carriage Unit Paper Width Detection Sensor
The Paper width detection sequence is shown in the figure at right.
Figure 2-5. Paper Width Detection Sequence
P_EDGE Sensor
Carriage
Left edge Right edge
Paper
HP Side
Set the maximum moving distance and
while detecting the paper level, move
the CR to the position where the "No
paper" level is detected at the paper's
left edge.
Paper Left/Right
Edge Detection
CR in home position?
Move the CR to an
empty suction position.
Move the CR to a
position where there is
paper.
Solid Line: Paper
Broken Line: Printable Area
Right Edge Left Edge
Carry out periodic
flushing (in the cap).
Is there paper?
Move the CR to the
no paper position.
No paper?
Measure the no
paper level.
Move the CR to the
position where there
is paper.
Set the maximum moving distance and
while detecting the paper level, move
the CR to the position where the "No
paper" level is detected at the paper's
right edge.
No paper?
Paper right edge
detection.
No paper?
Paper left edge detection.
Return
Error
Error Content:
(Set the paper correctly.)