A laser printer is a type of computer printer that uses a laser beam 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, text or photographic, the quality of which corresponds to the offset printing used to print books and magazines.
Basic laser printer settings
Today, a huge number of models of laser printers are produced. In order not to get lost in this diversity, it is necessary to have clear guidelines. The main parameters of laser printers include print speed, resolution (image sharpness), printer control language, internal memory size and paper size used. Since non-contact printing technology is used in laser printers , they are very quiet, and many users consider the absence of noise 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 - print on both sides. They can print color images, but most of them are monochrome. Thus, the basic parameters of laser printers also include 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 indicators such as speed in single-sided images per minute and in pages per minute. These speeds are the same for single-sided printers, and two-sided printers print two images on one sheet. Since duplex is typically a single-sided printer capable of turning paper on the other side, double-sided printing in pages per minute is approximately half the speed of a simplex printer.
The parameter indicated by manufacturers of printing devices is the highest speed that the printing mechanism is capable of providing. When printing simple pages with a minimum of text or complex graphics, most devices will achieve the performance stated by the manufacturer, however, complex pages, with a lot of text or complex graphics, can load the controller so much (the processor that forms the data into an image) that a long processing time will not allow device to operate at full speed. The consequence of this is that when printing complex pages, the actual print speed may not exceed 10% of the nominal.
For the first color laser printers, printing each color required a separate passage through the printing mechanism. Most color devices use four colors, magenta, cyan, black, and yellow, and can print in color as well as black and white. In color printing, they operate at a speed 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 generally classified by speed. Personal printing devices operate at speeds of up to about 20 pages per minute, office or desktop printers fall in the range of 20-40 pages per minute, workgroup printers - 40-60-, and large printing machines - up to 60 pages per minute and more. The speed of the fastest printers exceeds 200 ppm.
Resolution
If you evaluate the basic parameters of laser printers, resolution is an important indicator of their quality of work. Resolution corresponds to the number of individual dots that it can print within a given area. Laser printers create an image using an array of dots called a “raster image”. Modern laser printers achieve 1200 dpi resolution. 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 both on the horizontal and vertical axis. Some of the latest models of laser printers have a resolution of 38,400 x 600 dpi or 23,040,000 dots per square inch. Obviously, the higher this indicator, the thinner and more detailed the image the printer can produce.
ImageREt Technology
Manufacturers use other image enhancement technologies. For example, the Hewlett-Packard ImageREt system changes the size and position of the points that make up the text or image, for example, allowing you to place very small dots at the edge of the pixel, making the image sharper, with sharp, smoothly outlined contour lines. In addition, she:
- uses multi-level printing, due to which, to achieve the desired pixel shade, the printer before mixing, using complex algorithms, varies the amount of toner of each color;
- Applies adaptive halftoning using multi-level printing technology to smooth outlines and evenly 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 intentionally overlapping one color with another to improve image quality in transition areas;
- reduces halo - automatically removes one color from the edge of another, reducing overlapping zones and making them less visible;
- Automatically conducts closed color calibration by pre-printing the image on an electrostatic tape and selecting the amount of toner that is necessary for reliable and stable color reproduction.
Technologies that enhance the core features of laser printers are HP's exclusive, innovative technologies. Currently, several ImageREt levels have been developed:
- 2400 - used in the HP Color LaserJet 2550, 2600, 3000, 2800aio series;
- 3600 - used in the series 3600, 3800, 4700, 4730mfp;
- 4800 - used in the 9500, 9500mfp series.
Printer Management Language
The language used in the printing device is a set of commands that it executes to format data transmitted from a computer. These commands are embedded and interpreted by the printer. There are many control languages: some are specifically designed for laser printers, while others that were previously used in simple devices are interpreted by some devices to be compatible with older software.
The control language belongs to the main parameters of laser printers, since most computer applications support only a certain part of the entire variety of languages. IBM mainframes and minicomputers support management languages created by IBM. On Macintosh, most applications use Adobe PostScript, the industry standard language for describing complex pages.
Printer management languages fall into two categories. A distinction is made between page description languages (PDL) and ESC sequence languages. The former, as a rule, are more versatile and complex and allow you to print more complex pages and graphics that are suitable for creating such high-quality products as presentation materials, technical instructions, catalogs, handouts, etc. The latter are used by software packages that produce complex, extremely formatted output, including in graphic design programs, word processors, spreadsheets with wide graphing capabilities.
The main disadvantage of 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 stand out:
- PostScript is the language of Adobe Systems, originally used on Apple computers. Its advantage is greater detail of the image and the independence of printing results from the used printing device, and the disadvantage is slowness, increased memory requirements and lack of support on many platforms.
- PCL is a language created by Hewlett-Packard, 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, the result may not look the same on different printing devices, and the language is not supported on Macintosh.
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 dots 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 are directly dependent on the amount of internal memory. The larger it is, the more data it can use at the same time.
In addition, additional memory allows you to speed up printing, since the controller can prepare a bitmap image of the page while the previous one is printed. This will not increase the maximum print speed, the printer will simply become more likely to achieve it.
Many personal and office printers come standard - only with enough memory to print ordinary text documents. Since graphics occupies a significant 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, the parameters of photos and text files (their size, number of fonts used, degree of load) that need to be printed have a significant effect on laser printers.
The memory is usually supplied on a printed circuit board that plugs into the printer controller. In some devices, it has the design features of the printer manufacturer, in others, you can use standard modules designed for PCs.
Since the printer controller is a specialized computer, it needs access to data. Small devices store information in ROM, but users using a lot of fonts, such as graphic designers, may need extra storage space. And some printers provide the ability to connect a hard drive or SSD. Drives can be built-in or supplied with their own power and can be connected to the printer with a cable.
Paper size
Another question asked when choosing a laser printer: "What options depend on the paper you are using?" Laser printers typically use stationery sheets. The page size is limited by the size of the input tray - a container inserted into the paper feed mechanism. Most laser printers come with trays in one standard size, which is called Letter (8.5 x 11 inches) in the United States and A4 (210 mm x 297 mm) in the rest of the world. Other paper sizes can be used with appropriate size trays, usually sold separately, or in the very inconvenient manual feed mode. Therefore, the format of the paper used in them can be attributed to the main parameters of laser printers.
Some models allow you to customize the tray for various paper sizes. Due to their size, desktop laser printers are not designed for paper sizes larger than A4 or Letter. Large printers are able to print on paper A3 or 17 "x11" at a speed half that nominal.
In addition to paper, most laser printers can print on other materials, including thin cardboard, stickers and overhead films. It is also possible to print on envelopes using manual feed or with an optional envelope feeder.
The number and capacity of trays depends on the size and type of printer. Most personal printing devices have one input feeder per 100 sheets of standard paper and a manual feeder. Office printers usually have two trays of 250 sheets 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 with a capacity of up to 3,500 sheets each.
Simplex and Duplex
The possibility of duplex printing also refers 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 optional duplex module that flips a sheet of paper before printing the other side. Floor printers are almost all equipped with an integrated duplex unit. Duplex is necessary when printing working documentation, technical manuals, but is not necessary for the needs of office printing.
Bilateral print one side of the paper, turn it over, and then print on the other side, that is, two print operations are spent on one sheet. Because of this, the print speed of duplex printers is half that of a single-sided one.
For office users, a duplex printer is usually not needed, but in rare cases duplex printing is necessary. Therefore, printers allow you to work in the "manual duplex" mode, when one side of the document is printed, and then the user turns the sheet of paper over and continues printing. Manual two-sided printing of multi-page documents is difficult because it requires the software to print even and odd pages separately.
Duplexes are usually less reliable than simplexes, since the paper rotation mechanism is mechanically complex and the paper may jam in it. In addition, the printing mechanism does not always feed the paper perpendicularly, so the edge of the printed sheet is not always parallel to the edge of the paper. This skew is especially noticeable with duplex printing.
What else to consider?
In addition to the above, the main parameters of laser printers include:
- start page printing time;
- print area;
- advanced software features of the device;
- average monthly load;
- number of fonts and headsets;
- processor speed;
- network connections and supported network protocols;
- compatible operating systems;
- mobile printing;
- attached software;
- security features;
- power consumption and energy saving;
- control panel options;
- dimensions and weight;
- equipment;
- guarantee.
Parameters of the best MFPs in 2016
The best multifunction devices of 2016, according to the British computer magazine PC Advisor, are as follows: Samsung Xpress M2022W, Xpress M2070W (laser printers) and Samsung MFPs. Their parameters are such that they allow almost any user to choose a device to their liking. Next, we consider them in more detail.
Samsung Xpress M2875FW - Samsung Laser Printer. Options :
- single-color printer, scanner, fax, copier;
- control language: emulator PCL6, PCL5e, SPL;
- printing speed of A4 sheets, ppm - up to 28;
- resolution, dpi - 4800 x 600;
- built-in duplex printing;
- 128 MB of memory;
- 250-sheet tray
- sheet sizes: A4, A5, B5, Legal, Letter, Executive, Folio, Oficio, etc.
HP Color LaserJet Pro MFP M277dw - HP Laser Printer. What parameters to consider:
- color, scanner, fax, copyist;
- control language: PCL5e, PCL6, UFRII-LT, PostScript L3 emulator;
- speed, ppm - 18 (monochrome), up to 11 (two-sided color);
- resolution 600 dpi, HP ImageREt 3600;
- automatic duplexer;
- 50-sheet automatic feeder
- 256 MB of internal memory;
- 150-sheet trays
- sheet sizes: B5, B6, A4, A5, A6, cards, envelopes.
Canon i-SENSYS MF6180dw - Canon Laser Printer. Main settings:
- monochrome, scanner, fax, copyist;
- control languages: UFRII-LT, PCL5e, PCL6, PostScript L3 emulator;
- speed, ppm - 33;
- resolution, t / d - 600;
- automatic two-sided printing;
- 256 MB of memory;
- 50 and 250 sheet trays, optional 500 sheet feeder;
- sheet sizes: A4, A5, B5, Executive, Legal, Letter, etc.