Canon W8400 Series, Service Manual, Page: 71 / 224

Chapter 2
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2.3.3.1.2 Roll media feeding
0009-9374
Roll media feeding is performed mainly when the power is turned on or when the media is replaced. When replacing the roll media, pre-feeding is
performed (to assist the user when pulling the roll media on the platen) to load the roll media when setting the media. Also, when replacing the media,
since the roll media may have a barcode pattern containing media information at the leading edge of the media, the barcode pattern is read and then cut
after loading the media if the settigs to cut is ON.
<1.Roll media feeding when the power is on>
The load command is executed when the printer power is turned on while the roll media is set.
After calibrating the registration sensor, media width detection, skewing detection, and media leading edge detection are performed and then the roll media
is stopped at the print standby position.
The roll media is then fed by a length equivalent to the margin of the leading edge, and printing is started. Feeding of the roll media during printing is
performed by controlling the rotation of the feed rollers according to the printing mode.
F-2-23
1.Roll media feeding starts
2.Registration sensor calibration
1) Feed 133mm forward from the media set position.
2) Drive the carriage and move the registration sensor over the media.
3) Determine sensor output and check the registration sensor input value over the media.
4) Drive the carriage and move the registration sensor over the platen
5) Check the sensor input value over the platen.
6) Determine the sheet edge threshold.
7) Retract the head from the media (to prevent head wear).
8) Feed the media 133mm backward.
3.Media width detection
1) Feed 133mm forward from the media set position.
2) Drive the carriage and move the registration sensor over the media.
3) Drive the carriage and detect the media left edge (momentarily stop carriage return movement when detected).
4) Drive the carriage and move the registration sensor to position over the media.
5) Drive the carriage and tentatively detect the media right edge (momentarily stop carriage forward movement when detected).
6) Drive the carriage and move the registration sensor to media right edge detection start position (30mm inside the media right edge tentative detection
position: on media).
7) Drive the carriage and detect the media right edge (momentarily stop carriage forward movement when detected).
4.Media skewing detection
1) Feed 300mm forward from the media set position.
2) Drive the carriage and move the registration sensor to media right edge detection start position.
3) Drive the carriage and detect the media right edge (stop carriage return movement when detected), compare with media right edge determined during
media width detection, and determine the skew amount (skew amount depends on the detection precision).
5.Media leading edge detection
1) Feed 300mm forward from the media set position.
2) Drive the carriage and move the registration sensor 30mm in the forward direction from the media left edge (10mm in the forward direction when in
cutting dust reduction mode).
3) Feed the media backward and detect temporary the leading edge of the media (stop feeding when detected).
4) Drive the carriage and move the registration sensor 30mm in the forward direction from the media left edge (10mm in the forward direction when in
cutting dust reduction mode).
5) Feed the media 50mm forward.
6) Feed the media backward and detect the leading edge of the media (stop feeding when detected).
6.Roll media feeding ends
1) Print standby position
7.Print
<2.Roll media feeding during media replacement>
When replacing the media, the user adjusts the skew of the roll media on the platen and then presses a key on the control panel to feed the media.
When replacing the media, barcode data is always scanned before feeding because a barcode pattern (media information) may be printed on the leading
edge of the media.
If media information is detected after barcode data scanning, the leading edge of the media is cut.
After calibrating the registration sensor, media end temporary detection, barcode pattern detection, media width detection, skewing detection, media
cutting, and media leading edge detection are performed and then the roll media is stopped at the print standby position.
1.Roll media feeding starts
3.Media width detection
4.Media skewing detection
5.Media leading edge detection
6.Roll media feeding ends
7.Print
2.Registration sensor
calibration