The dot matrix printing method allows a printer to easily form any desired
character. It has a print head that contains 9 needles vertically and can create
distinctive characters like with typewriter. In that sense it is one of the key
features that the printer has. EPSON’s MX-80 Type II can control each needle
programmably, expanding the ability of the printer.
See next how the print head works and forms a character.
(1) Dot Matrix Printer
The print head contains 9
“needles” or “wires” vertically. Each dot wire is
driven by an electromagnet which fires when told to do so by the electronics
inside the printer.
Signals from the computer cause the appropriate dot wires to be fired from
the holder and to impact carbon, causing the character to be printed as a series
of dots.
As an example (see Fig. 61). to print the letter “E", dot wires 1 through 7 are
fired first. They hit the ribbon. That makes marks on the paper. Then the head
shifts over a bit and dot wires 1, 4 and 7 are fired. In this manner, the character
“E” is formed.
This is called “Dot Matrix Printing”.
Dots are printed according to a pre-designed “Matrix” or “Grid” system,
where each letter, number and punctuation mark is formed by arrangement
of dots. In the above figure, the print head moves from left to right. Since the
MX-80 Type II is a bidirectional printing type, the head can also move from
right to left to print characters.
NOTE: In the Text mode, a maximum of 7 dot wires are used for character formation.
See Appendix 4, Character Fonts.
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