Canon BJC-55 Series, Service Bulletin

Page: 143 / 249

3.5.2 Carriage section structure
a) BJ cartridge mounting section
The BJ cartridge is fixed to the carriage by the carriage contact spring.
When the BJ cartridge is mounted on the carriage, the contacts of the carriage
ribbon cable connect with the signal contacts of the BJ cartridge to transfer printing
signals sent from the control board.
There are wiping hooks that set and release the wiper on the back of the carriage.
There also is a home position edge that shields the home position sensor on the
chassis on the back of the carriage.
b) Carriage drive section
The power from the stepping type carriage motor moves the carriage horizontally
with the carriage belt. After the home position sensor attached to the rear of the
carriage detects the home position edge, the carriage is controlled with the stepping
pulses transmitted to the carriage motor. The pulses driving the carriage motor are
controlled by the MPU section to have the optimum pulse width. (PWM control) This
reduces the operating noise. Also, if the print position is shifted mechanically, it is
corrected automatically, the home position sensor detects the home position edge on
the carriage, and the print start position is shifted with software. This adjustment is
conducted when the initial operation is performed after the printer is powered on by
the
POWER button, or when the printing operation is performed after the print mode
is changed.
4-33
BJC-50
Part 4: Technical Reference
Contact Point
Home Position Edge
Cartridge Lock Hook
Wiping Hooks
Carriage Ribbon Cable
Carriage Belt
Figure 4-25 Carriage Section Structure