Canon Color Bubble Jet BJC-2000 Series, Service Manual

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2.2 Printing Modes
2.2.1 Printing mode
Depending on the cartridge installed, the media, the printing mode, the resolution, the
print data, etc., the printer varies the carriage movement, bubble jet head driving
frequency, etc., to attain high-quality printing without any bleeding or shifting in the
printout.
When the 720 dpi printing feature is used, the carriage feed pitch is set to 1/720
inch. Although, the bubble jet head drive frequency (ink ejection frequency) is
increased, the carriage speed is slowed, so that the overall printing throughput
decreases.
During color printing at a single pass, different colors printed at the same time
overlap, often causing the colors to run. By printing with three passes, color bleeding
is less prone to occur since the color printed immediately before is stable by the time
the next color is printed over it.
When print data is processed internally by the printer, the data is recognized and the
number of ink nozzles to be used by the black ink is changed automatically.
For color printing with Color-HQ2, at 720 dpi, processing is executed in such a way to
prevent the color and black inks from running at their mutual borders and to prevent
white mist.
This processing is executed as follows:
During internal processing by the printer, the borders where the color and black inks
meet are identified. Cyan and black ink are mixed in the printed black portion to suit
the state of the distance and density of the black and color dots.
The printing method for the respective printing modes are listed below.
2.2.2 Photo print mode
Photoprint mode can be used to obtain high level gradation print quality when using
the Photo BJ cartridge. These cartridges contain a light density ink which achieves a
high level of gradation by printing several times over the same dot.
The printer driver divides the pixel data into a maximum of 4-values (not printed,
print 1 dot, print 2 dots and print 3 dots) enabling each pixel to be printed in up to 4
gradations. The printer therefore makes three passes using a maximum of 150%
more ink than usual.
It is therefore necessary to use the exclusive print driver when printing with the Photo
BJ cartridge.
The exclusive printer driver outputs multiple print data to the printer when
photoprinting. If for some reason, a standard color BJ cartridge is installed and used
for photoprinting, everything printed will be doubled in size in the carriage direction.
On the other hand, if color printing is performed with a Photo BJ cartridge, not only
will printed images appear light, the user will be notified of a mis-match as images
will be printed in half their normal size.
2.2.3 Multi-Drop print mode
When a color cartridge or a photo color cartridge using drop modulation technology is
installed, the Canon original driver must be used. By selecting a drop modulation
mode such as fine or photo mode, large and small ink droplets can be printed. When
large and small dots are used efficiently, the granularity of the light areas can be
improved.
To avoid slowdown, large and small droplet printing is not used for HQ and HS modes
since these modes do not give a gradation.
Part 4: Technical Reference
4-6
BJC-2000