PRINTER is a computer device is a device that prints computer information on a paper. Many printers are used as output device of the computer. Printers can be of various kinds, differing by its printing quality, speed, used resources, ease of use and so on.

Printers according to the principle of operating can be divided into 2 main categories: Contact and contactless, Attributed to contact printers: hammer and dot matrix printer, contactless – inkjet and laser.

Inkjet printers are working quietly, as they print point by spraying special ink and do not contact the paper surface, also it can print in colours. Moreover it prints better than dot matrix printers. For each colour to spray there are several columns of mini, almost invisible sprayers that are controlled by the electric signals. The ink used for printers can be liquid or plastic. Liquid ink is sprayed evenly or pulsing. The colour printing is approximately 5 times slower than the black and white printing.

Laser printer operating principle is based on laser device (laser beam and multifaceted mirror) ability to form document’s electrostatic image on a circular shaped drum.  Laser printer prints the entire page at once, as copy machine. First, a special razor cleans the drum surface. Then, the surface is ionized with electric discharge. Laser beam modulated by the recorded information is spread in lines on the drum surface by multifaceted mirror. It inverts surface charges and converts them into negative. Thus, we get electrostatic printing image. The image is cleared out with help of ink powder of positive charge, which glue on the negative charge area of the drum surface. Then paints are transferred on the paper of negative charge.  Laser printers must have big operative memory.


Printer technology was improved by many specialists and inventors, but the breakthrough occurred only after 20 years from it was invented. Laser printer was also invented by “Xerox” employee. Inventor of the laser printer is considered to be Gary Starkweahter. His invention changed the operation principle of copy machines. According to him, the image is created by the computer, rather than the light reflected from the copy. This concept changed the passive printing to the active control of printing. The first innovation – use of laser to discharge the photoconductor. The second – inventive way to scan an ultra-thin laser beam along the rotating mirror of the drum.  It is difficult to believe that “Xerox” company head department failed to see anything worthy of attention. “Xerox” ordered to stop the project regarding the laser printer. Inventor moved to “Xerox Palo Alto Research centre (PARC), where his work was evaluated and Gary Starkweather continued his project. 1971 prototype of the first laser printer was created and printed one page/sec 500 pixels resolution. “Xerox” invented a new device, but did not know what to do with it. Personal computers were not popular in eighties, as without it the laser printer was not really useful. “Xerox” proposed this unwanted technology to anyone, who might find it attractive. Company “Canon” got interested. Company created first laser printing engines,  that used disposable toner cartridges and  strived to create the market for themselves. Company presented their invention in exhibition publicly in 1975, which was visited by William Hewlett, the director of “Hewlett-Packard” . Since then, HP started to participate in laser printing business.

Health effects

Around the world, operating laser-printers pollute the air in the office with unfiltered mixture of small dust, nano-particles ant such pollutants like heavy metals, (TBT) and volatile organic compounds (VOC) (styrax and benzene). If to breath in the nano particles, which are so small that can even reach blood and internal organs. Because of them poisons reactions happen in lungs also becomes the cause of heart and cancers diseases. The last 15 years the international scientific publications are based on the global problem. International Researches from Germany, England, Spain, Poland and Australia suggest: laser printers very often cause poisonous pollution and also is the cause for disorders of respiratory system, eye and skin irritation and inflammation and headache as well. Recent studies, performed in Germany showed that affecting DNA, toner cartridge powder kills human lung cells and other human genes.