Canon MultiPASS C50, Service Manual

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2.6 720 dpi Printing/Smoothing Feature
2.6.1 Canon extension mode
In the Canon extension mode, the printer driver creates 720 dpi data for the horizontal axis and sends it to
the printer, resulting in high-quality printing.
With a black BJ cartridge installed, the printer driver smoothies the printed character’s edges at 720 dpi
along the horizontal axis. The 720 dpi data for the horizontal axis is sent to the printer and the edges are
smoothed at a high resolution.
When a color BJ cartridge is installed, the multi-value data of the picture elements processed by the
printer driver for color correction, etc., is assigned three values (no printing, single-dot printing, two-dot
printing) for the picture elements. In the case of two-dot printing, the second dot is printed in the 720 dpi
position. As a result, the degree of gradation is high in the printing.
2.6.2 Emulation mode
When a black BJ cartridge is installed for printing, the printed character’s edges can be smoothed at a
high resolution of 720 dpi along the horizontal axis. Dots along the character’s edges are added or
deleted for smoothing the edge. Along the horizontal axis, dots are also overlapped by a half-dot space.
This eliminates jaggies and increases the equivalent horizontal resolution at twice.
This smoothing feature greatly improves low-resolution, 180 dpi characters. However, it does not give
noticeable improvement to True Type fonts and illustrations.
Note that with a color BJ cartridge installed, the emulation mode’s smoothing feature cannot be used.
Chapter 2: Technical Reference
2-7
BJ
1/720 inch
1/360 inch
Add Dots
Delete Dot
1/360 inch
Figure 2-5 720 dpi Printing/Smoothing Feature