First, it should be noted that not everyone knows what a dot matrix printer is. nowadays, inkjet and laser mfp have become widespread. It appeared a long time ago, because this mechanism was first demonstrated back in 1964 by the specialists of Seiko Epson. It was a printer of this kind that became in those years the first device that could provide the production of the printed products necessary in those years.
The purpose of this type of printers is to display text and graphic information on a paper surface. Moreover, the structure of such devices includes one or several rows of needles, and very thin ones. It should be added that, despite the fact that such a needle printer came out more than half a century ago, it still has some distribution.
For example, a needle printer is used to print PIN envelopes for SIM cards, multipart forms, airline tickets, etc. Thus, office equipment of this type is in demand in all those cases where relatively inexpensive mass printing using multilayer forms is needed, when high requirements are not imposed on the quality of the final result, for example, it can be printing tags and labels.
Design
The most expensive part of a dot matrix printing device is undoubtedly its print head, which, as mentioned above, is located on a special movable carriage. Various characteristics of such a printer depend on its design, for example, print speed. Its housing contains electromagnetic drives, which are capable of drawing in or throwing out the core on which the needles are fixed. In one pass, this kind of detail is capable of displaying only one line of text.
A part such as a ribbon cartridge is a plastic box that holds the ink ribbon inside. When printing, this ribbon is fed to the head only in fresh areas, which, in turn, ensures normal and stable printing. T.N. the tape drive mechanism consists of two rollers, between which this product is pulled.
To pull paper through the device and hold it during the printing process, a paper feed drum is provided in office equipment of the matrix variety. So that it can provide a really reliable adhesion to the surface of the paper, it is coated with one of the following materials: plastic, rubber. In addition, rollers are installed along with it, which must support and press the sheets of paper against this drum. The movement of the latter is provided by a stepper motor.
Also in the case of the dot matrix printer is a device responsible for feeding a sheet of paper, which helps to hold it until it is pulled by the drum. Another function of this part is the correct positioning of the paper. In the event that printing is performed using paper rolls, then the device must be equipped with a special holder.
Another important component of the matrix device is the controller board, which includes a control device, buffer memory, etc. interface circuits designed for communication with a PC. Thus, its purpose is to help office equipment perform all of its functions. It is itself a microprocessor that decrypts commands from a computer. Separately, it should be said that the function of the board’s buffer memory is to temporarily place information at the time when it is printed.
More about device operation
If we talk about how a dot matrix printer works, then it should be said that the text with the help of this device is formed with the participation of such an element as the print head. It is a set of needles, the movement of which is possible through the use of electric magnets. The head, which is located on the carriage when the device is running, begins to move along special guides across the paper. When printing dot matrix printers, the needles in a certain sequence begin to hit the surface of the paper. But before they pierce the sheet, they pass through the ink ribbon, which is usually found in a part such as a matrix cartridge. Thanks to this simple principle of operation, a set of letters and text appears on checks or labels, having a certain font.
The movement of the matrix carriage is carried out in most cases by a belt drive. The drive is the so-called. stepper electric motor. This type of device is called Sequential Impact Matrix (SIDM). But there is also a line matrix printer that stands out for its increased print speed. It uses a kind of hammer that is evenly spaced on a special shuttle mechanism. With its help it is possible to print the text of a certain font much faster than in SIDM, because it uses technology to print a line in just one pass. In general, the principle of operation of a dot matrix printer is quite simple.
In order to obtain a particular font, matrix office equipment uses simultaneous strikes on the ribbon of a certain combination of needles. That is, in this way, you can get almost any desired font. Sometimes the embedded software for dot matrix printers has support for downloading additional fonts. In addition, many models of devices of this type have a mode of individual control of needles directly from a PC. Thanks to this, you can print some kind of graphics. But, of course, this mode has a negative impact on the print speed.
It should be added that at different times for dot matrix printers, 9, 12, 14, 18, as well as 24, 36 and 48 needles were used. Both print speed and its resolution directly depend on their number. Despite such a wide variety, models with 9 and 24 needles have become the most popular. The former are suitable in the case when high print speed is required without special requirements for its quality. It should also be said that roll / perforated fanfold paper is most often used for such devices. This, in turn, significantly reduces the cost of printing all kinds of checks.