Bit Image Density
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Bit Image Density
Bit Image Graphics mode may be printed in different dot densities selected by
the following control codes:
•ESC K selectsthe Single Density mode.
•ESC L selectsthe Double Density mode.
•ESC Y selects the Double Speed, Double Density mode.
•ESC Zselects the Quad Density mode.
Bit Image Graphics mode was originally intended to be used on printers
having 60 dpi (or 120 dpi) horizontal resolution and 72 dpi vertical resolution.
Other print modes can be used, but the horizontal and/or vertical dimension
might change and/or overlaps or gaps might appear. For details concerning
available modes, see Chapter 4, “Serial Matrix Printer Protocol,” Chapter 5,
“IBM Proprinter III XL Printer Protocol,” or Chapter 6, “Epson FX-1050 Printer
Protocol.”
In Single Density Bit Image graphics from the Letter Gothic (DP) print mode,
printed dot density is 60 dots per inch (dpi) horizontally and 72 dpi vertically.
From the Courier (NLQ) print mode, horizontal dot density is 120 dpi and
vertical density is 144 dpi.
The Double Density mode prints up to twice the number of dots per inch
horizontally (up to 120 dpi from the Letter Gothic [DP]mode). The vertical dot
density remains the same as in the Single Density mode. Double horizonta l
density requires twice the number of input data bytes to print the same length
line as Single Density.
When the Double Density, Double Speed control code is received, the data
can be printed at up to double the current horizontal dot density; but all
adjacent dots are removed, which affects the final density of the printed
image.
Quad Density characters are processed the same as Double Density
characters. Each character is stored in successive dot columns, and
successive pairs of data characters are logically OR'ed together. Quad
horizontal density requires twice the number of input data bytes to print the
same length line as Double Density.