Bj Cartridge Drive; Print Drive Control - Canon QY8-1360-000 Service Manual

Part 4: Technical Reference

1.4 BJ Cartridge Drive

The BJ cartridges are driven according to the print data and control signals output by
the logic board. The control signals determine the timing with which ink is ejected from
the nozzles in the BJ heads and the amount of ink. These are optimized by the printer
controller according to the conditions shown bellow. The control signals also stabilize
the amount of ink by keeping the BJ heads at the optimum temperature.
The drive frequency is changed to 14.4kHz, 10.56kHz or 9.6kHz by print modes.
• BJ head temperature (heater board) and printer temperature
• Fluctuations in the heater characteristics of the BJ heads (head rank)
• Print mode and media being printed on

1.4.1 Print drive control

In the BJC-7100, printing is achieved by block dispersal drive, in which the three
vertical rows of nozzles fire sequentially and driven alternately odd/even to minimize
the concurrent firing of neighbouring nozzles.
The heat enable signal consists of a pre-pulse and main pulse. To keep the ink jetting
in the optimum state, the pulse width is varied according to the internal state of the
printer, such as the head rank, printer temperature, and head temperature.
The BJC-7100 uses a range of inks and, when printing on plain paper or
envelopes in other than draft mode, an ink optimizer for plain paper. The
ink optimizer is an almost colorless, transparent fluid.
For simplicity in this manual, we refer to the ink optimizer for plain paper
simply as ink optimizer or just optimizer. We also refer to the various
colored inks and the ink optimizer for plain paper simply as "inks".
4-4
BJC-7100