Line Matrix Printing
Line Matrix Printing
Your printer creates characters and graphics by a printing technique called line matrix printing. Line matrix printing consists of printing patterns of ink dots on paper, an entire line at a time.
Each text character is stored in memory as a pattern of dots on a logical grid called the dot matrix. (See Figure 2.) The actual ink dots are made by a row of hammer springs mounted on a shuttle that sweeps rapidly back and forth.
Printer logic divides every printable line into horizontal dot rows. The hammer springs put dots at the required positions for the entire line by striking a moving ink ribbon and the paper.
Dot Column
Matrix visible only to the printer
Dot Row
Ink dots formed by hammer tips
Character Row
Character Column
Figure 2. Dot Matrix Character Formation
Unlike serial dot matrix printers, which form complete text characters one at a time with a moving printhead, a line matrix printer divides each printable line into horizontal dot rows, then prints a dot row of the entire line with every lateral sweep of the shuttle. (See Figure 3.)
During each sweep of the shuttle, the hammers print dots at the required positions in the dot row. At the end of a sweep, the shuttle reverses direction, the paper advances one dot row, and the hammers print the next row of dots as the shuttle sweeps in the opposite direction.
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