There are several printer technologies used in today's home, office and banking printers.
Dot matrix printers, known also as
impact printers, represent the oldest printing technology, are still the widespread today, grace of it's best 'price per page' ratio. Dot matrix printers are divided on two main groups:
serial dot matrix printers and
line printers (or
line dot matrix printers).
Line printers as well as serial dot matrix printers use pins to strike against the inked
ribbon, making
dots on the paper and forming the desired characters. The differences are that line printers use
hammer bank (or
print-shuttle) instead of print head, this print-shuttle has
hammers instead of print wires, and these hammers are arranged in a horizontal row instead in vertical column. The hammer bank uses the same technology as the permanent magnet print head with the small difference that instead of print wires the print-shuttle has hammers.
The
printing mechanism works as follow. The permanent magnetic field holds the hammer spring in stressed, ready to strike position. The driver sends electrical current to hammer coil, which then creates electromagnetic field opposite to the permanent magnetic field. When both fields equalize, the energy stored in the spring is released to strike the hammer against the ribbon and prints a dot on the paper. The hammer printhing mechanism is shown in action at the picture bellow.
The line printer mechanism in action:
How the line dot matrix printers work?
During printing process the print-shuttle vibrates in horizontal direction with high speed while the print hammers are fired selectively. So each hammer may print a series of dots in horizontal direction for one pass of the shuttle, then paper advances at one step and the shuttle prints the following row of dots
The line printing process
Line matrix printers are the right solutions for high-volume impact printing and are superior in speed, reliability and quality. As price-performance leaders, line printers cost less to service and less to use. The fastest line matrix printers available on the market are
Tally T6218 and
Printronix P5220, with a claimed print speed between 1800 and 2000
lines per minute (
lpm).
