4–9
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ït
çi
RECORDING SECTION
As a result, as the printer prints one dot of the image data using 1.772 dots,
this can be converted to the following integer ratio:
→
1:1.772 = about 9:16
So, the printer knows that nine dots of image data are to be printed using
16 dots.
• Vertical scanning direction
→
7.7 (dots/mm)
×
25.4 (mm/inch) = 195.58 (dots/inch)
→
360 (dots/inch)
÷
195.58 (dots/inch) = about 1.847
→
1:1.847 = about 13:24
Accordingly, the printer prints 13 dots of image data using 24 dots. Fig. 4-
7 shows an example of the dot array in mm/inch conversion.
Fig. 4-7 mm/inch Conversion
When printing is actually performed, density conversion of pixels (hori-
zontal scanning direction) is also performed simultaneously with mm/inch
conversion. This example describes a case where printing is performed on
a BJ printer. The purpose of density conversion is to prevent smudging
when ink adheres to the recording paper and to prevent the printed image
from collapsing. Black pixels are skipped according to the density conver-
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Horizontal scanning
V
e
rtical
scanning
7.7 dots/mm (13 dots)
360dpi (24 dots)
8 dots/mm (9 dots)
360dpi (16 dots)
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