Canon QY8-1360-000 manual Carriage structure, 4-34, Part 4 Technical Reference, BJC-7100

Part 4: Technical Reference BJC-7100

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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