Epson DFX 8000, User Manual

Page: 149 / 346

Graphics
The print head
To urtderstand dot graphics you need to know a little ‘about ‘how
your printer's print head works.
.
As the print head moves across the page, electrical impulses cause
the pins to fire. Each ‘time a pm fires, it strikes the inked ribbon
and presses it against the paper to produce a small dot. As the head
moves across the page, the pins fire time after time in different
patterns to produce letters,
or symbols.
Dot patterns
The DFX’s print head is able to print graphics as well as text
because graphic images are formed on the printer about the same
way that pictures in newspapers and magazines are printed. If you
look closely at a newspaper photograph, you can see that it is made
up of many small
Your also its
images
with
patterns of dots,
as
many as 240 dot positions per inch horizontally
and 72 dots vertically. The images printed by the printer can,
therefore, be as finely detailed
as the one on
page 4-10.
In one dots
for each code it receives, and it uses only the top eight of the nine
pins.
Therefore,. your program send codes for dot
patterns, one for in a line. each
columns, the print of dots have
specified.
To print figures taller than eight dots, the print head makes more
than one pass, The printer prints one line, then advances the paper
and prints another,
as it does with text.
To keep the print head from leaving the graphics lines
as it does between the text lines, spacing must be changed
to eliminate the a in line spacing,
your printer can print finely detailed graphic images that give no
indication that they are made of separate lines,
no more than
8/72nds of an inch tall.
Software and Graphics 4-11