Optimum Printing Direction Control - Canon BJC-1000 Service Manual

BJC-1000 Part 4: Technical Reference

2.3 Optimum Printing Direction Control

To prevent vertical misalignment of the printed characters, etc., when print data is
printed continuously in the direction of the paper feeding direction, printing is executed
with the carriage moving in only one direction.
However, when printing in the paper feeding direction is not continuous, since vertical
misalignment is not so noticeable, the printing direction is alternated so that printing is
also executed from the opposite carriage direction. This improves the throughput.
If four or more successive null rasters are detected in the lower (in the direction of
paper ejection) 24 nozzles for the printing data in the printer buffer during single-pass
printing, printing is executed up to the null raster. From the null raster onward,
printing is executed from the opposite carriage direction. From the next raster onward,
printing is executed from the same carriage direction until the direction changes again.
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