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2010/05/24 13:43:22

Laser printers

The laser printer - one of main types of printers. Main advantages of devices of this class, first of all, in high performance, and as a result, lower cost value of each printed leaf. Besides, the laser printer represents ampler opportunities of work with paper. The directory of the Office equipment is available on TAdviser.

Content

The laser technology of printing is quite old if to measure it on time of development of high technologies. The first laser printer was developed in 1971. Fall forward of printing, improvement of quality of a print and multimillion profits of the companies became result of this work. The first laser printers cost more than $17 thousand and much more than 40 kg weighed, and, above all - displaid only monochrome prints. Today anyone can purchase an easy color printer.

Technology

The principle of electrostatic transfer is the cornerstone of technology of a laser printing. If not to press in technology of process, then in brief everything occurs so: the photolayer which under the influence of light changes a charge is applied on previously charged reel. Because of a difference of potentials in those places where there did not pass the laser beam, the toner is attracted. Transfer of dye from a drum on paper goes the next stage, and there is it also because of the difference of a charge of a drum and a toner. After that the sheet of paper with the "stuck" dry ink gets to the furnace where the toner melts and implemented into paper fibers. As a result the print which cannot be washed away, unlike the prints made on inkjet printers turns out.

The color laser printing does not differ essentially from described above. When sending the text or picture for printing the special renderingovy engine separates the picture into the being colors, creating several images for every color. In the majority of laser printers four separate passes when every color it is put consistently are used, and after that the sheet of paper moves in "oven". Thanks to use of the laser when lighting the reel it is possible to achieve high resolution. Besides, use of technology improves quality of a print, reduces the cost of each sheet and increases operating time from one gas station of a cartridge.

Prices of laser printers

As it was already mentioned, the price of laser printers began to fall promptly in recent years. In 2004 for one of the cheapest laser printers the buyer was forced to give on average $250-300 while today the majority of budget models of this class are estimated no more, than to $160 - $170. However, the price range of laser printers significantly differs for "house" and "office models". Printers of initial level are focused, first of all, on individual users, besides, such devices are optimal for small offices where there is a need of regular printing of black-and-white documents for small amounts. The resource of the printer is the main indicator of belonging of the printer to this or that class. Unlike huge and powerful office "monsters", "lazernik" of initial level are expected printing up to 7,000 - 15,000 sheets a month, and the loading recommended by the producer, as a rule, makes up to 1,000 sheets. It is simple to count that the recommended loading does not exceed 35 sheets a day, and maximum fluctuates in the range from 230 to 500 sheets. Such opportunities are quite enough for small offices and, especially, for home users who extremely seldom go beyond indicators even of the recommended loading. At increase in loading the toner is quicker spent, and the photodrum wears out quicker.

Main Characteristics

Permission of printing It is measured in dpi, i.e. in number of dots per inch, and usually makes 600x600, 1200x1200. Such permission provides high quality of printing of text documents and also contrast graphics. In many models the corporate systems of program interpolation of the output image to 1200 and even 2400 dots per inch (dpi) are implemented. In most cases these modes really increase printing quality: for example, the letters gathered by a small size become more accurate due to lack of "fringe". Nevertheless, naturally, such printers fall short of hardware values. Sometimes inexpensive "lazernik" from real 1200 dpi, but it more likely an exception, than the rule meet.

Time of a release of the first page This indicator is more important for "house" models as office printers, generally constantly work in the included mode. The best samples issue the first page less than in 7 seconds from the moment of inclusion, and an average value for this class of machines - about 10-15 seconds. The delay reason at printing of the first page purely technology: to fix a toner on paper, the heating element ("oven") is used, and the warming up of "oven" up to the working temperature requires time.

Maximum speed of printing This indicator also varies depending on a printer class: for house models - 15-20 pages per minute, for office and production - from 20 - 25.

For printing of difficult texts with graphics elements, it is necessary to pay attention to existence of the internal memory and also to a possibility of its expansion. The vast majority of budget models are equipped with 8-16 megabytes of memory without a possibility of expansion so if it is going to print a lot of graphics, models from 32 and 64 MB of RAM are necessary.

Interface Once printers were equipped with the standard parallel port LPT, now the overwhelming quantity of models is connected via the universal USB connector. Speed and stability of operation of the printer, of course, does not depend on the interface, but here the compatibility with other devices cannot be neglected.

Operating systems It is clear, that all printers are guided by work in Windows, but in the modern world, often to users of it insufficiently. It is necessary for much that the printer could work in other operating systems, for example in Mac OS, Linux or in DOS. For this purpose it is necessary to watch the description attentively: usually there capability of the printer in less widespread operating systems is specified to work.

As for dimensions of laser printers then there is nothing mysterious: office models have the big capacity of trays for paper and their bigger quantity. What gives to model the additional weight and the sizes.

Additional options Are saturated with the different additional options adding the price to the printer, generally office models. Here existence of both the LCD display, and network interfaces, and additional trays, and the paper automatic feeder enters.

When choosing the optimal laser printer, it is necessary to represent as in what amounts it is necessary to print. The difference in the price of house and office models is expected, first of all, cost value of each printed leaf at recalculation on the stated loadings. The big printer for the house - money to burn, and an error in the opposite direction threatens with extremely fast breakdown of the printer because of overloads. Well and, certainly, to print the text and graphics is not same, the printers capable to work with a large number of formats and information, also add monetary units to the price label of goods.

Links

What it is necessary to know about the laser printer