Epson Stylus Pro 9000 - Print Engine, Service Manual, Page: 31 / 198

EPSON Stylus Pro 9000
Technical Overview 31
PAPER WIDTH DETERMINATION (LEFT AND RIGHT EDGE
DETECTION)
Before printing, the printer sets the platen gap and then flushes the printheads
to make sure no ink smears the paper. The printer then detects the left and
right edges of the paper. Note how “left” and “right” are defined below:
To detect the left and right edges, the printer performs the following steps:
Table 2-5. Left and Right Edge Detection
Purpose Step Action
To make sure
paper is
loaded
correctly
1
The carriage moves just to the inside of where the left edge
should be, if the paper is loaded correctly.
2
The Paper Width Sensor checks for paper. If paper is
detected, go to step 3; otherwise report “Reload Paper” error.
To establish
sensor signal
level
3
The printer registers the sensor’s “paper present” (ON) signal
level.
To make sure
paper is
loaded
correctly
4
The carriage moves just to the outside of where the left edge
should be, if the paper is loaded correctly.
5
The Paper Width Sensor checks for paper. If paper is not
detected, go to step 6; otherwise report “Reload Paper” error.
To establish
sensor signal
level
6
The printer registers the sensor’s “no paper” (OFF) signal
level.
Right Paper Edge
Printable Area
Left Paper Edge
To determine
position of left
edge
7
The carriage moves to the left paper edge and registers its
position.
To determine
position of
right edge
8 The carriage moves to the right edge of the paper.
9
The Paper Width Sensor checks for paper. If paper is not
detected, go to step 10; otherwise, report “Reload Paper”
error.
10
The printer registers the position of the right edge of the
paper.
To verify left
edge position
and determine
paper width
11 The carriage returns to the left paper edge.
12
The Paper Width Sensor checks for paper. If paper is not
detected, go to step 13; otherwise, report “Reload Paper”
error.
13
The printer verifies the edge position and registers the
distance from one edge of the paper to the other.
Table 2-5. Left and Right Edge Detection (continued)
Purpose Step Action