Epson Stylus Pro 7000 Series, Руководство по обслуживанию, Страница: 73 / 231

EPSON Stylus Pro 7000 Revision B
Operating Principles Printer Mechanism Operation Outline 73
†
Paper size detection - right and left edges
Before printing the printer needs to determine the distance from the right
and left paper edges to the right frame and left frame (home position).
As shown in the following flowchart, the printer flushes the heads to
make sure no ink smears the paper as the printheads move across the
paper. Then the carriage moves to where paper should definitely be (if
loaded properly), near the vertical guide line. There the Paper Width
sensor determines the brightness level (high) of the light reflected off the
paper. (If no light is reflected, paper is not loaded or is not loaded
properly and a “Reload Paper” error occurs.) The carriage moves back
toward the home position, where paper definitely should not be if loaded
properly, and determines the brightness level (low) when light is not
reflected off the paper. This procedure is necessary to set the high/low
levels when adjusting for different media types, such as glossy or plain
paper.
Next the carriage moves from the home position toward the opposite
frame and measures the distance from the home position to the opposite
(right) edge of the paper according to the brightness high and low levels.
If the paper edge has not been determined by a certain point (outside of
the printheads’ print range), the paper is loaded too far to the right and a
“Reload Paper” error occurs
Once the opposite-side paper edge has been found, the carriage moves
from the opposite frame to the home position and measures the distance
from the opposite frame to the HP-side (left) edge of the paper.
Figure 2-19. Paper Size Detection - R/L edges
R
ig
h
t/Lef
t E
d
g
e
Detec
tion
In
H
P
?
Ye
s
No
Yes
Yes
Yes
Yes No
No
No
No
E
rro
r
Retu
rn
P
a
per exis
ts
?
Paper
load
ed
Op
pos
it
e edge is
d
e
term
in
ed
C
R
mov
e
s
t
o
ps
ue
d
o
su
cti
o
n po
s
iti
o
n
CR
moves
to near
vert
ic
a
l guid
e
line
Per
for
m r
e
gu
lar
fl
ush
ing
CR moves
t
o
exp
ec
ted
n
o
-p
a
p
er loc
a
tion
Deter
m
ine “N
o-
pap
e
r”
s
ign
al lev
e
l
C
R
det
e
ct
s
paper
edg
e
(
H
P)
side
Paper
exis
ts
?
Pap
e
r exis
ts
?
CR
d
e
te
rmines
d
is
tanc
e
from HP to
o
ppo
sit
e
ed
ge
(sig
nal
C
R
d
e
termin
es
di
s
ta
n
ce
f
ro
m
o
ppo
sit
e
s
ide t
o
HP-
The ed
ge on
HP s
ide
is
fo
und
Left-
to
p
ed
ge
R
ight
-t
op
ed
ge
Blac
k
lin
e = pap
e
r
edg
e
D
o
tt
ed
line =
printable area
E
rro
r t
y
p
e
:
Reload P
a
per