Epson MX-80 User Manual page 45

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How Dot Matrix Printing Works

Chapter 5

How Dot Matrix Printing Works

To really understand DOT MATRIX PRINTING,

should understand how the

print head works. It contains 9 "needles" or "wires" positioned one above the

other, as seen in Figure 5-1.

Head movement direction

Figure 5-1

Each needle is driven by a "gun", or electromagnet which "fires" when told to

do so by the electronics inside the Printer. The Printer electronics responds to

ASCII code instructions received from your computer.

As an Example, to print the letter "I", wires 1 and 7 are first fired. They hit the

ribbon. That makes marks on the paper where the left top and bottom of the

letter " I " should be.

Then the head shifts over a bit and wires 1,2,3,4,5,6, & 7 all fire at once, printing

the center of the letter "I". One more shift and one more shot of needles 1 & 7

and the letter " I " is completed. (See Figure 5-2)

— N

J * I

Needle # 1

G O ®

#2—

# 3 -«•

# 4 -—

# 5 —

# 6 —

# 7 ^

e o o

Figure 5-2