Usually, we don’t even think about how much time is needed for a new discovery to become applicable in our ordinary, day-to-day life. How much additional energy, finances and calculations is needed to drive those theoretical developments to their practical application.
Today, we are speaking about printing methods, and there are definitely more than a few. But we will have a closer look at the three most popular ones.
Matrix printers are one of the first automatic printing devices. The printer is equipped with a printhead (carriage), which moves along the text lines and applies symbols to the paper when needles are hitting it through the ink impregnated strip. Matrix printers are called matrix since all of the available printing symbols are a part of the matrix that is formed by the arrangement of needles (the number of needles is 9 or 24).
The needle is driven by a small electromagnet. Judging from all mentioned above, it is clear that a typical matrix printer is able to print only one line at a time. But still there are ones that print a few “packed” lines in order to increase point density.
One of the very first matrix printers was a LA30, manufactured by Digital Equipment Corporation. The device was able to print only uppercase alphabetics 5 by 7 points in size and 30 symbols per second using the paper of a certain size (80 symbols per line). The print head was driven by a stepper motor, and the paper was fed by a not quite reliable and noisy motor with a clickwork. LA30 had both serial and parallel interfaces, but in the former case the carriage return was followed by fill characters being printed in the line.
Following LA30 there was LA36, and it had a lot more commercial success and became the actual archetype of a matrix printing computer terminal. The new model used the LA30 printhead, however the line length have been expanded up to 132 symbols of various register and the usual perforated paper could be used. The carriage was driven by a more powerful electric servomotor, optical position sensor and tachometer. And the paper was fed by the familiar clickwork motor.
LA36 had only a serial interface; however, no fill characters were used. While the printer had never received more than 30 symbols per second from a computer, it was able to print two times faster. And so, during the carriage return, next symbols were getting into the buffer and the next line was printed at a speed of 60 symbols per second. Due to this, printer could be recognized because of the interchanging sounds of the fast and regular printing.
When Digital Equipment Corporation was expanding their printer product line, basing on LA36, Centronics Company was taking care of Brother Industries printer mechanisms implementation having a goal of budgetary solutions. In process, the company has developed an eponymous interface, well known by each matrix printer user. The interface became a de facto standard and it was until in 1990th the USB interface came.
In general, matrix printers were considered as inexpencive devices, and until 1990th were the most popular on the market. Probably the most popular model was Epson MX-80. Since then, the prices were holding on the same one level, what provided favorable environment for laser and jet printers to become cheaper. Moreover, users at home and at the offices were confronted with sharp clickwork engine noise (late models become quieter). And the printing quality was not always acceptable, what caused many users for purchasing software like Bradford or Windows 3.1, speaking of which printer’s performance was slowed down. All of this eventually caused matrix printers to give the wall to the laser and jet printers, retaining only the narrow specialization of printing pay checks and similar documents. They are also used in accounts departments and ticket offices for printing text into the blank documents.
Adapted from http://www.ixbt.com/