The main parameters of laser printers are ... Types of printers

A laser printer is a kind of computer printer in which a laser beam is used to create an image. The image is created as an array of very small dots. The use of a laser in this case allows you to create very clear detailed images, textual or photographic, the quality of which corresponds to the offset printing used for printing books and magazines.

Basic parameters of the laser printer

Today, a huge number of models of laser printers are produced. In order not to be lost in this diversity, it is necessary to have clear guidelines. The main parameters of laser printers include the speed of printing, the resolution (clarity of the image), the language of the printer's control, the amount of internal memory and the format of the paper used. Since the laser printers use non-contact printing technology, they are very quiet, and many users consider noise-free to be an important criterion when buying a device for office use. Laser printers are simplex, that is, they print only on one side of the paper, and duplex printers print on both sides. They can print color images, but most of them are monochrome. Thus, the main parameters of laser printers are also such parameters as noise level, the possibility of two-sided printing and the ability to print color images.

Print speed

Laser printers are available in a wide range of speeds. The main parameters of laser printers include such indicators as speed in one-sided images per minute and in pages per minute. These speeds are equal for one-sided printers, and in two-sided prints two images are printed on one sheet. Since a duplex is usually a one-sided printer capable of turning the paper over to the other side, the speed of duplex printing in pages per minute is about half the speed of a simplex printer.

The parameter that manufacturers of printing devices indicate is the fastest speed that a printing mechanism can provide. When printing simple pages with a minimum of text or complex graphics, most devices will achieve the values declared by the manufacturer, however complex pages, with a lot of text or complex graphics, can so load the controller (the processor that forms the data into the image) that a long processing time will not allow The device to run at full speed. The consequence of this is that when printing complex pages, the real print speed may not exceed 10% of the nominal.

In the first color laser printers, printing each color required a separate pass through the printing mechanism. Most color devices use four colors, magenta, cyan, black and yellow, and can print in both color and black and white images. With color printing, they operate at a rate of a quarter of the speed of their printing in monochrome. There are also color devices that create a full-color image in 1 pass.

Laser printers are usually classified by speed. Personal printers work at speeds of up to 20 pages per minute, office or desktop printers fall within the range of 20-40 ppm, workgroup printers are 40-60, and large typographic machines - up to 60 ppm And more. The speed of the fastest printers exceeds 200 ppm.

Resolution

If we evaluate the main parameters of laser printers, the resolution is the most important indicator of their quality of work. The resolution corresponds to the number of individual points that it can print within the specified area. Laser printers create an image with an array of points called a "raster image." Modern laser printers achieve a resolution of 1200 points per square meter. inch. Since most devices have the same horizontal and vertical resolution, this measurement is usually reduced to "dots per inch" (dpi), which corresponds to the resolution of both the horizontal and vertical axis. Some of the latest models of laser printers have a resolution of 38400x600 dpi or 23,040,000 dots per square inch. Obviously, the higher this figure, the thinner and more detailed the image the printer can produce.

Technology ImageREt

Manufacturers use other image enhancement technologies. For example, Hewlett-Packard's ImageREt system changes the size and position of points composing text or image, which allows, for example, to place very small dots at the edge of the pixel, making the image more clear, with sharp smoothly outlined lines of the contour. In addition, she:

- uses multi-level printing, due to which to achieve the required shade of a pixel printer before mixing, using complex algorithms, the amount of toner of each color varies;

- applies adaptive halftoning using multilevel printing technology to smooth contours and uniformly print large areas, increasing or decreasing the frequency of digital halftones by reducing or increasing the distance between them;

- uses color capture - a patented technology of deliberately overlapping one color with another to improve image quality in transition areas;

- reduces halo - automatically removes one color from the edge of the other, reducing overlapping areas and making them less visible;

- automatically conducts closed color calibration by pre-printing the image to the electrostatic tape and selecting the amount of toner that is necessary for reliable and stable color transfer.

Technologies that improve the basic parameters of laser printers are HP's exclusive innovative technologies. At the moment, several levels of ImageREt have been developed:

• 2400 - used in the HP Color LaserJet series 2550, 2600, 3000, 2800aio;
• 3600 - used in the series 3600, 3800, 4700, 4730mfp;
• 4800 - used in the 9500 series , 9500mfp.

Printer Management Language

The language used in the printing device is a set of commands that it performs to format the data sent from the computer. These commands are built in and interpreted by the printer. There are many control languages: some are specially designed for laser printers, and others that were used earlier in simple devices are interpreted by some devices for compatibility with old software.

The control language is one of the main parameters of laser printers, since most computer applications support only some of the variety of languages. IBM mainframes and minicomputers support management languages created by IBM. In the Macintosh environment, most applications use Adobe PostScript, a standard industry language for describing complex pages.

Printer management languages fall into two categories. Distinguish between page description languages (PDL) and ESC-language languages. The first ones are usually more versatile and complex and allow printing more complex pages and graphics that are suitable for creating such high-quality products as presentation materials, technical instructions, catalogs, advertising brochures, etc. The latter are used by software packages that produce complex, Highly formatted output, including in graphic design programs, word processors, spreadsheets with extensive graphing capabilities.

The main drawback of the page description languages is that they require significant computational resources, as a result of which PDL printers format data more slowly. This is overcome by installing a more powerful printer controller, which affects the cost of the device.

Among the PDL-languages are:

- PostScript is the language of Adobe Systems, originally used on Apple computers. Its advantage is a greater detail of the image and the independence of the results of printing from the printing device used, and the disadvantage is sluggishness, increased requirements for memory and lack of support on many platforms.

- PCL is a language created in Hewlett-Packard company, the main difference of which is the use of printer resources for image formation, which reduces the size of the transmitted file, speeds up processing and reduces printing time. However, on different printers, the result may not look the same, and in Macintosh, the language is not supported.

Memory

The main parameters of laser printers include the availability, types and amount of memory used in them. The latter is the main component in the printer controller. It contains an array of points that forms the image, raw data and commands sent by the computer, as well as fonts, shapes and graphics. The parameters of the laser printer depend directly on the amount of internal memory. The more it is, the more data it can use at the same time.

In addition, additional memory allows faster printing, since the controller can prepare a bitmap image of the page while the previous one is being printed. This will not increase the maximum print speed, the printer will simply become more likely to reach it.

Many personal and office printers come standard - only with enough memory to print plain text documents. Since graphics occupy a large part of it, the device is not able to print large images. In addition, additional fonts can be stored in memory, which reduces the space available for images. Additional memory is often needed for complex applications, such as graphics, presentations and desktop publishing. Thus, for laser printers, photo parameters, text files (their size, the number of used fonts, the degree of loading) that are required to print, have a significant impact.

Memory is usually supplied on a printed circuit board that plugs into the printer controller. In some devices it has design features of the printer manufacturer, in others it is possible to use standard modules intended for a PC.

Since the printer controller is a specialized computer, it needs access to the data. Small devices store information in ROM, but users who use many fonts, such as graphic designers, may need additional storage space. And some printers provide the ability to connect a hard drive or an SSD drive. Discs can be built-in or supplied with their own power and can be connected to the printer with a cable.

Paper Size

Another question that is asked when choosing a laser printer: "What parameters depend on the paper used?" Laser printers usually use sheet paper. The page size is limited by the size of the input tray - the container that is inserted into the paper feed mechanism. Most laser printers come with one standard size tray, which in the United States is called Letter (8.5x11 inches), and in the rest of the world - A4 (210 mm by 297 mm). Paper of a different size can be used with trays of appropriate size, usually sold separately, or in a very inconvenient manual feed mode. Therefore, the main parameters of laser printers can be attributed and the format of paper used in them.

Some models allow you to customize the tray for different paper sizes. Desktop laser printers, because of their size, are not designed for a paper size larger than A4 or Letter. Large printers are able to print on paper A3 or 17 "x11" at a speed of half the nominal.

In addition to paper, most laser printers can print on other materials, including thin cardboard, stickers and diaprojection films. It is also possible to print on envelopes using manual feed or with an additional envelope feeder.

The number and capacity of the trays depends on the size and type of the printer. Most personal printers have one input feeder per 100 sheets of standard paper and a manual feeder. Office printers usually have two 250-sheet trays each. Printers of working groups are equipped with special feeders with an electric drive with a capacity of 1000 sheets. Large production printers can have several feeders with a motor drive capacity of up to 3,500 sheets each.

Simplex and duplex

The possibility of two-sided printing also belongs to the main parameters of laser printers. Most desktop devices are simplex, that is, they print on one side of the paper. Some are equipped with an additional duplex module that turns the sheet of paper before printing the other side. Outdoor printers almost all have a built-in duplex unit. Duplex is required when printing working documentation, technical manuals, but it is not necessary for office printing needs.

Two-sided print one side of the paper, turn it over, and then print on the other side, i.e., two printing operations are consumed on one sheet. Because of this, the duplex printing speed is half that of a one-sided printer.

For office users, usually a duplex printer is not needed, but in rare cases, two-sided printing is necessary. Therefore, printers allow you to work in "manual duplex" mode, when one side of the document is printed, and then the user independently turns the sheet of paper and continues printing. Manual two-sided printing of multi-page documents is complicated, because it requires that the software can print even and odd pages separately.

Duplexes are usually less reliable than simplexes, since the paper rotation mechanism is mechanically complex, and the paper in it can jam. In addition, the printing mechanism does not always feed the paper perpendicular, so the edge of the printed sheet is not always parallel to the edge of the paper. This skew is especially noticeable when double-sided printing.

What else to consider?

In addition to the above, the main parameters of laser printers include:

• Time of the initial page printing;
• Print area;
• Advanced software functions of the device;
• Average monthly load;
• Number of fonts and headsets;
• Processor speed;
• Network connections and supported network protocols;
• Compatible operating systems;
• Mobile printing;
• The supplied software;
• Means of ensuring security;
• Energy consumption and energy saving;
• Parameters of the control panel;
• Dimensions and weight;
• equipment;
• guarantee.

Parameters of the best MFU 2016

The best multifunctional devices of 2016, according to the British computer magazine PC Advisor, are the following: Samsung Xpress M2022W, Xpress M2070W (laser printers) and Samsung multifunction devices. Their parameters are such that they allow almost any user to choose a device to their liking. Let us consider them in more detail.

Samsung Xpress M2875FW - laser printer "Samsung". Options :

• Single-color printer, scanner, fax, copier;
• Control language: emulator PCL6, PCL5e, SPL;
• The speed of printing A4 sheets , ppm - up to 28;
• Resolving power, t / d - 4800 x 600;
• Built-in double-sided printing;
• 128 MB of memory;
• A 250-sheet tray;
• Sheet sizes: A4, A5, B5, Legal, Letter, Executive, Folio, Oficio and others.

HP Color LaserJet Pro MFP M277dw is an HP laser printer. What are the parameters to take into account:

• Color, scanner, fax, copier;
• Control language: PCL5e, PCL6, UFRII-LT, PostScript L3 emulator;
• Speed, ppm - 18 (monochrome), up to 11 (color double-sided);
• Resolution 600 dpi, HP ImageREt 3600;
• Automatic two-sided printing module;
• Automatic feeder for 50 sheets;
• 256 MB of internal memory;
• Trays for 150 sheets;
• Sheet sizes: B5, B6, A4, A5, A6, postcards, envelopes.

Canon i-SENSYS MF6180dw is a Canon laser printer. Main settings:

• Single-color, scanner, fax, copier;
• Control languages: UFRII-LT, PCL5e, PCL6, PostScript L3 emulator;
• Speed, ppm - 33;
• Resolution, t / d - 600;
• Automatic two-sided printing;
• 256 MB of memory;
• Trays for 50 and 250 sheets, an optional 500-sheet feeder;
• Sheet sizes: A4, A5, B5, Executive, Legal, Letter, etc.