Carriage Structure - Canon QY8-1360-000 Service Manual

Part 4: Technical Reference

3.4.2 Carriage structure

1) Print head mount
The cartridge hook secures the BJ cartridge to the carriage with a plate spring.
When the BJ cartridge is locked on the carriage, the signal contacts of the ribbon
cable are pressed against those of the bubblejet head so that the print signals are
transferred from the logic board to the BJ cartridge.
2) Carriage drive mechanism
The stepping-type carriage motor moves the carriage horizontally across the print
media, the drive being transmitted by the carriage belt. The home position sensor
(photo-interrupter) on the carriage board detects the home position edge of the
chassis as the initial position, then the stepping pulse is applied to the carriage
motor to control the carriage. The carriage motor is current-controlled by the motor
drive control from the carriage motor driver. The excitation signals that drive the
carriage motor are controlled to the optimum drive pulse width by the printer
controller. Mechanical print aberrations during bidirectional printing are
automatically corrected by software adjustment of the timing based on home
position edge detection.
3) Paper feed motor drive switching mechanism
The paper feed motor drive switching mechanism switches the paper feed motor
drive to the purge unit, paper feed, or sheet feeder according to the position of the
carriage.
Except when the carriage is at the right edge of the printer, the slide lock lever of the
purge unit locks the operation of the transmission arm.
When the carriage is moved further to the right of the capping position (the right
edge of the printer), the slide lock lever is released. While the lock is released, the
direction of paper feed motor rotation is switched to select either purge operation or
sheet feeder operation. If the feed roller is rotated in the direction of feed while the
slide lock lever is released, the transmission arm gear moves to the sheet feeder
drive gear to drive the sheet feeder.
If the feed roller rotates against the direction of feed while the slide lock lever is
released, the transmission arm gear moves to the purge drive gear to drive the purge
unit.
4) Ink optimizer head wiper drive mechanism
The ink optimizer head wiper wipes the rows of ink-optimizer nozzles horizontally
when a page is printed using the ink optimizer (when printing on plain paper in
other than draft mode). The movement of the carriage operates the latch lever and
wiper lever.
By combining the ink optimizer head wiper with the purge unit wiper, it is possible
to improve the removal of the hard-to-eliminate ink optimizer and ink aggregates in
one wiping operation.
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