What types of printers exist. The main types of printers and their characteristics. Advantages and disadvantages

We constantly print all kinds of documents at work or at home - from photos to texts. We simply send the document for printing, and then we take it from the printer. Have you ever wondered how all kinds of printers put images and texts on paper? Inkjet, laser, matrix devices - they all work differently, each has its pros and cons. Let's find out in different technologies print.

How a Printer Works: An Overview of Printing Technologies

Core Technology Exotic for Originals

The pile is small

Is it so difficult to understand how to print? Are there many? In fact, there are only two main ones, that is, those that are used everywhere and continuously: office and home. Scared of gradation? Then let's denote it more formally: office - in 99 percent of cases it turns out to be laser printing, home - inkjet. Of course, there are exceptions, we will talk about them in more detail when describing each printing method.

Why do we need to know all this? The fact is that we are used to choosing printers according to our habits - “I have had an N inkjet machine all my life, so I will buy the same one, only fresher.” Agree, this approach to the choice of equipment is not always logical - the printer is not a refrigerator, it is much more complicated, and the capabilities of different models are different.

Core Printing Technologies

In order not to get lost in the forest of terms and concepts related to printing technologies, let's look at each of them in order. Let's start, of course, with the most popular - laser.

A ray of light

The oldest of all technologies, it is she who is the basis of all copiers - laser printing. Thanks to its existence, all office workers can print in a few seconds Text Document(sometimes even color) excellent quality.

Laser printers print very quickly and clearly, which is why they are loved in offices.

Look at the printer that you have in your office - most likely, it is a good example of this section of our collection. A fairly large gray box that spits out finished printouts at a fairly high speed, almost without thinking. What does he have inside? Why does it print so quickly and with high quality?

Inside such an apparatus is a drum, which is directed electric charge corresponding to the printed output. This charge attracts toner - a special powder (black, or color, depending on the type of printer). Then this powder is transferred to a sheet of paper (or to some intermediate carrier, and only then to paper). So that the picture does not crumble, the sheet passes through the oven - a special heater that bakes the toner on paper. Because of it, an unpleasant smell appears during long printing. However, not only the stove "spoils the atmosphere" - laser printers emit harmful ozone gas during their work.

How a laser printer works

Well, we remembered the main negative features (bad smell and ozone emission) of laser printers. Let's add to them the high cost of the devices themselves - that's all the disadvantages of such a solution. The undoubted advantages of laser printing include very high quality and speed of printing.

LED printers are the ideal choice for home text printing

LED printers are analogous to laser printers. They actually work in the same way, only instead of a laser, a row of LEDs is used to form an image on the drum. The method has only one drawback - the print quality is slightly inferior to laser. The print speed here depends on the number of colors: black-and-white printers work a little slower than laser counterparts, but color LED printing is faster. In all other respects, LED printers have gone far ahead - they cost little, they Consumables also cheaper (though laser toners also cost little), and most importantly, they are considered less harmful to health than laser ones.

in the jet

The exact opposite of laser printing is inkjet printing. As a rule, this is a slow application of a high-quality color image to paper, and not at all a lightning-fast printout of black text. Let's look at such a printer from the inside.

The inside of the inkjet printer is very loose.

Obviously, the device of such an apparatus is much simpler than that of a laser one. There is no drum, no lasers, no stove. Only a lone cartridge (or several) dangles inside an almost empty case. So, just two main elements in an inkjet printer are the cartridge and the print head. By the way, some manufacturers have cartridges equipped with a built-in print head. Why is this necessary?

Mankind has invented several inkjet technologies. Depending on your needs, one or another printing technology will be more suitable. There is a thermal jet and piezoelectric technology.

Diagram of the operation of a piezoelectric inkjet printer

Thermal inkjet technology involves the use of cheap printheads. This is done in order to be able to change them as soon as necessary. Printer manufacturers are divided on how often the print head should be changed - someone thinks only in the event of a global blockage, and someone - every time you change the cartridge.

The technology itself is based on the fact that in order to apply a picture or text on paper, the ink is heated sharply, and they, expanding, fly out, imprinting treasured dots on the paper. A cheap print head is needed here precisely in order to ensure the user's peace of mind - what if the ink dries tightly in the nozzles of the head before it comes out?

The scheme of operation of a thermal inkjet printer

The founders of piezoelectric technology claim that their printheads literally last forever and do not need to be replaced. If this is true, you will know when the printer refuses to print just one or two dots. However, the nozzles can be cleaned - either with the help of a driver and a large amount of fresh branded ink, or with the help of a service center.

Why such sacrifices? Firstly, a cartridge, which is just an ink bottle in the truest sense of the word, costs quite a bit. And this certainly pleases all users. Secondly, the technology really allows you to put clear microscopic dots on paper: at the inception stage, this printing method was really the best (in fairness, it is worth saying that now both technologies are doing their job perfectly).

So, we figured out the print heads. And what is ink? Certainly not the colored water that fountain pens fill. By modern standards, the ink of any printer must meet at least two conditions - to be moisture and light resistant, in addition, it is desirable that microscopic drops can be formed from them.

Currently, the size of a drop in some printers does not exceed one picoliter (in terms of thickness, this value can be equated to one tenth of the thickness of a human hair, that is, about 1/100 mm). It is worth noting that not all companies make the main bet on the size of the drop. For example, some manufacturers (for example, HP) are trying to improve quality through better color mixing, rather than reducing the size of inaccurate droplets. Generally speaking, minimum dimensions ink drops range from 1-1.5 (for Canon and Epson) to 4-5 (for Lexmark and HP) picoliters.

In general, ink is divided into two groups - pigment and water-soluble. It is believed that water-soluble ink conveys the colors of pictures and photographs better, although at present both options deserve very warm words. Pigment inks are waterproof, although water-soluble inks (if not soaked in water) are sometimes very strong.

Someone is not enough?

Undoubtedly, the two printing technologies described are just the beginning. There are many printing methods used either out of old memory or professional necessity. So…

Matrix

The cheapest way to print an image or text on paper is to use a dot matrix printer. Remember typewriters from the middle of the last century? So heavy, with hard buttons that you have to hammer with your fingers at full strength. The device of a dot matrix printer is practically no different from those machines. That is why, by the way, they work so noisily.

Dot matrix printers are more convenient to refill roll paper

An ink ribbon is stretched inside the printer, or several multi-colored ribbons in the case of a color pattern. To display the picture on paper, a print head equipped with rigid needles passes along the tape. Each of the needles hits the tape at the right time and a dot is printed on the paper. By the way, dot-matrix printers were called because the needles on the head form a kind of matrix, while foreigners prefer to call such devices "dot".

Dot matrix printer operation scheme

The main advantage of such printers is the very low cost of prints: ink ribbons cost a penny, but they last for a long time.

dried ink

There are printers appearance very strongly reminiscent of laser. Style of work, speed - everything in them implies the presence of a laser. However, their print quality is too good, comparable to real printing, and the price of the devices themselves will frighten even sophisticated printers. This is solid ink printing technology.

Solid ink printers are refilled with ink chips

Here we have combined several technologies into one, taking only the best from each. So, we put multi-colored blocks of ink into the compartments, similar to dried gouache, turn on the printer, press the “Print” button on the desired document and watch how a printout of perfect printing quality flies out of the machine in a matter of seconds. Dream? No, reality, only very expensive.

Scheme of operation of a solid ink printer

The basis of solid ink printing is that the ink is melted immediately before being applied to paper. The main component of the ink is ordinary wax, which melts very quickly, and immediately hardens when it gets on the paper. In general, the technology repeats the inkjet: microscopic multi-colored dots are applied to paper and form a pattern on it.

The main and main advantage, we repeat once again, is the impeccable print quality. Moreover, the printouts look not just good, but professional - the wax shines in the light, adding gloss.

Sublimation

Undoubtedly, in the office, with an unlimited number of banknotes in the budget, a solid ink printer will become indispensable assistant. There is also a home version of such a printer: a sublimation photo printer. Enthusiastic amateur photographers will like this technology already because the quality of their prints is sometimes better than in photo labs.

Sublimation printers are compact and simple - you can even take them with you on a trip.

In fact, the technologies of sublimation and solid ink printers can be combined into a single one - thermal printing. We did not do this for the reason that the purpose of the devices is completely different. And the optimal quality of prints is achieved not due to the clarity and correctness of applying dots to paper, but, on the contrary, due to mixing, superimposing adjacent dots on top of each other. It is thanks to this manifestation of technology that it is so appreciated by amateur photographers.

Scheme of operation of a sublimation printer

Basically, sublimation printers use four-layer film cartridges. In a special roller there is a film on which three primary colors and a protective layer are applied. The printer heats up sequentially each color layer of the film and the ink, evaporating, falls on the photo paper. To prevent the layers from being erased during the use of the printout, a protective layer is applied over the ink - it will endure the dirty hands of the beholder, and even scuba diving.

To each according to his needs

Of course, there are other printing technologies, and therefore other applications for printers at work or at home. But even from this review of the main printing methods, one can draw a disappointing conclusion that the habit of using the same technology for many years is simply not practical. Do you only need photo printing at home? Replace your inkjet printer with a sublimation printer. And if there is a need to delight customers with beautiful branded brochures, think about buying a solid ink machine.

In any case, a brief introduction to the basics of printing technology should make it easier not only to choose a new device, but also to better understand the old one.

Many users have already dealt with printers, but not everyone will be able to answer the question of what a printer is. So the printer is an external device personal computer, whose main function is to output graphics / text stored on a PC to a hard drive. As the latter, paper or polymer film is most often used. It is also worth noting that this device is usually used where printing is needed in small runs from units to several hundred without creating a so-called. printed form.

This is what these devices differ from the equipment used in modern printing, which allows you to print cheaper and faster circulation of paper products of several thousand copies.

The printing process is usually referred to as "printing", and the resulting document is called a "hard copy" or "printing". It should also be added that a special variety called a plotter has gained some distribution.

About the main characteristics

When buying such printing equipment, you must definitely take into account the main characteristics of the printer. This will allow you not to make a mistake with the choice made, otherwise the purchase made may become a waste of time and money.

• One of the most important characteristics of any such device is its resolution, measured in dpi - dots per inch. The higher it is, the better and more detailed image you can print on it.
• Speed ​​is also an equally important characteristic, especially for large offices. Usually given parameter for printers whose device is designed for inkjet printing, it is from 3 to 8 pages of text per minute. But in the case of printing illustrations, the speed drops significantly and it can take from 1 to 5 minutes to print one page. As for laser devices, they have this parameter in the range of 7-20 standard pages.
• Laser printers have another important characteristic, namely: the volume of the built-in random access memory. The larger it is, the faster the necessary documentation will be printed accordingly. The typical value is usually 4-8 MB. But far from always it is enough, therefore, in individual models laser devices, it is possible to increase this memory.
• Separately, the inkjet apparatus has such an opportunity as photo printing in color. For this purpose, this device should provide for the installation of a special photo cartridge. There are inkjet printer models that were originally designed for making photographs and quite often - directly from a digital-type camera, without the participation of a PC. Often, a separate type of paper carrier called photographic paper is also used for this purpose.
• There is also such a characteristic as the type of connection interface, i.e. connection of office equipment with a data source. Most modern printers are equipped with a USB port. information is transmitted over the Universal Serial Bus an order of magnitude faster - this, in turn, makes it possible to increase the speed of printing. But there are models that are equipped with an LPT or COM port. In addition, some printers have the ability to connect via wireless communication via Bluetooth, Wi-Fi and infrared.
• Paper feed method. In modern models of printing devices, paper can be loaded either from the lower or from the top tray. The first method is called horizontal, and the second - vertical feed.
• In addition, printing devices of this type have such a characteristic as compatibility. Professional models tend to have PostScript support, while personal devices have full support PostScript is a rarity. To a greater extent, they are able to only partially emulate this language, which is generally quite enough. There is also PCL, a language that acts as a standard for many laser printers.

Classification

According to the principle of printing, printers are mainly distinguished by inkjet, laser and matrix types. Of course, there are several other printing technologies, for example, sublimation, but they are used much less often. There is also the so-called. LED printing, which is similar to laser printing, but instead of a laser beam and a system of mirrors, it uses a ruler with LEDs.

• The inkjet variety has been losing ground to its laser counterparts in recent years, but due to its low cost, it still enjoys some demand. If you are interested in the answer to the question of how this type of printer prints, then it should be said that text or graphics on paper when using such a device is formed from dots. For this purpose, the so-called. the printhead that carries out the printing process with ink. Such a printer is a device consisting of a carrier system unit, paper feed system, print head, cartridge or CISS, as well as a control system. It should be added that according to the type of printed material, such a printer can be roll, flatbed, souvenir and hybrid (roll + flatbed). .
• For laser devices, the image is formed by creating and superimposing dots on paper. It happens that users have a question about what this type of printer does for printing graphics and text information. Initially, the document is formed in the memory of the device and only then it is transferred to a special printing mechanism. Each image is formed using dots located appropriately on the cells of the matrix/grid. The device for laser printing consists of a laser scanning unit, a unit responsible for transferring the image and a unit that fixes the image. The node for transferring graphic and text information means a cartridge and an element such as a transfer roller. The laser in such an apparatus generates a thin light beam due to the microcontroller, which, in fact, controls it. From this article you can learn more about.
• As for the matrix device, the functions of this type of printer are to form an image using a print head, consisting of a large number of the finest needles. The quality of printing text or graphics in this case is determined by the number of needles located on the matrix. They are powered by electromagnets. It should be noted that some types of matrix devices equipped with 24 needles have the ability to print color pictures through the use of a multi-color ribbon. Despite the low print quality, such printers have several advantages, which are a long operating life, low cost of consumables and low cost per sheet of paper. .

In addition, depending on the number of colors, monochrome and color printers are distinguished. On the latter, the following colors are most often used as the basis: cyan, magenta, yellow and black. In addition to these basic colors, such printing devices can be provided with "lights", the use of which allows to increase the apparent resolution. Some models are additionally equipped with white color, which is necessary when printing on color media.

In addition, printers are divided depending on the design features and the method of text / graphics formation into impact and non-impact types. There is also a classification according to the possibility of printing information of a graphic type - in this case, such office equipment is graphic and alphanumeric.

Thus, printers differ from each other not only in price or quality and print speed, but also in the principle of operation, color capabilities and resolution. All modern manufacturers of such office equipment strive to increase the printing speed of their devices, improve the quality of the finished printout and reduce the costs associated with printing. In general, from year to year, such printing equipment as printers is becoming more and more perfect, reliable and fast.

A printer is a computer peripheral device designed to transfer text or graphics to a physical medium, from one usually stored electronically.

Multifunctional devices (MFPs) have become widespread, in which the functions of a printer, scanner, copier and telefax are combined in one device. Such a combination is technically rational and convenient in operation.

Large format printers are sometimes erroneously referred to as plotters.

Classification

According to the principle of transferring images to media, printers are divided into:

• lettered;
• matrix;
• laser (also LED printers);
• jet;
• sublimation;
• thermal,

Some printers (mostly inkjet photo printers) have offline (i.e. without a computer) printing capability, with a flash card reader or digital camera interface port, allowing you to print photos directly from a memory card or cameras.

Network printer - a printer that allows you to receive print jobs (see Print Queue) from several computers connected to local network. Software network printers supports one or more special data transfer protocols such as IPP. This solution is the most versatile, as it allows printing from various operating systems, which cannot be said about Bluetooth and USB printers.

Matrix printer

The image is formed by the print head, which consists of a set of needles (needle matrix) driven by electromagnets. The head moves line by line along the sheet, while the needles hit the paper through the ink ribbon, forming a dot image.

Main disadvantages dot matrix printers are monochrome (although there were also color matrix printers, at a very high price), low speed operation and high noise level, which reaches 25 dB.

High-speed line matrix printers are also produced, in which a large number of needles are evenly spaced on a shuttle mechanism (frette) across the entire width of the sheet.

Matrix printers, despite their complete displacement from the household and office spheres, are still widely used in some areas (banking - carbon copy printing, etc.)

Jet printer

The principle of operation is similar to dot matrix printers in that the image on the media is formed from dots. But instead of heads with needles, inkjet printers use a nozzle matrix (the so-called head) that prints with liquid dyes. The print head can be built into dye cartridges (this approach is mainly used on office printers by Hewlett-Packard companies). In other models of office printers, replaceable cartridges are used, the print head is not dismantled when replacing the cartridge. On most industrial printers, ink is supplied to the heads mounted in the carriage through a system automatic feeding ink.

There are two ways to technically implement the dye spraying method:

Piezoelectric(Piezoelectric Ink Jet) - a piezoelectric crystal is located above the nozzle. When an electric current is applied to the piezoelectric element, it (depending on the type of print head) bends, elongates or pulls the diaphragm, as a result of which a local area of ​​​​high pressure is created near the nozzle - a drop is formed, which is subsequently pushed onto the material. In some heads, the technology allows you to change the droplet size.

Thermal(Thermal Ink Jet) (also called BubbleJet, the developer is Canon, the principle was developed in the late 1970s) - a microscopic heating element is located in the nozzle, which, when passing through electric current instantly heated to a temperature of several hundred degrees, when heated, gas bubbles form in the ink (English bubbles - hence the name of the technology), which push liquid drops from the nozzle onto the media.

Continuous Ink Jet - the ink supply during printing occurs continuously, the fact that the ink hits the printed surface is determined by the ink flow modulator (it is alleged that the patent for this printing method was issued to William Thomson in 1867 [source not specified 264 days]). In the technical implementation of such a print head, a dye is supplied to the nozzle under pressure, which, at the outlet of the nozzle, breaks into a sequence of microdrops (with a volume of several tens of picoliters), which are additionally charged with an electric charge. The dye flow is divided into drops by a piezocrystal located on the nozzle, on which an acoustic wave is formed (with a frequency of tens of kilohertz). The droplet flow is deflected by an electrostatic deflection system (deflector). Those drops of dye that should not fall on the printed surface are collected in the dye collector and, as a rule, are returned back to the main dye tank. The first inkjet printer made using this method dye supply, released by Siemens in 1951.

On Demand Delivery - Ink is dispensed from the printhead nozzle only when ink actually needs to be applied to the appropriate nozzle area of ​​the printed surface. It is this method of supplying the dye that is most widely used in modern inkjet printers.

Classification

By type of printed material:

• Roll - equipped with systems for winding and winding roll material, designed for printing on self-adhesive, paper, canvas, banner fabric
• Sheet solid - for printing on PVC, polystyrene, foam board. The sheet of material is fixed on the bed using a vacuum clamp or clamps. The carriage (equipped with the X-axis movement drive) is fixed on the portal, which, together with the carriage, moves over the material (along the Y-axis).
• Souvenir - the movement of the workpiece relative to the head, along the Y axis, is provided by a servo drive of the movable table, in addition, the table is equipped with a mechanism for adjusting the distance between the workpiece and the carriage (for printing on workpieces of different heights). Are applied to the press on disks, phones, to marking of details.
• Sheet flexible - for printing on paper and film in standard sizes (A3, A4, etc.). Equipped with a mechanism for gripping and winding sheet material.

In addition, there are inkjet printers for 3D printing of three-dimensional forms.

Type of ink used:

Solvent ink is the most common type of ink. Solvent inks are used in large format and interior printing. They are characterized by very high resistance to water and atmospheric precipitation. They are characterized by viscosity, granularity and solvent fraction used.

• Alcohol - not widely used, since the heads that print with alcohol ink dry out very quickly.
• Oil - used in industrial marking systems and for testing printheads.
• Pigment - used to obtain high-quality images, in interior and photo printing.
• UV curable inks are used as an environmentally friendly replacement for solvent inks and for printing on rigid materials.
• Thermal transfer ink - a distinctive feature of thermal transfer ink is the ability, using a thermal press, to transfer the printed image from the substrate to the fabric. Used to print logos on clothing.

By appointment:

• Large-format — the main purpose of large-format printing is outdoor advertising. Large format printers are characterized by a large print width (most often 3200 mm), high speed printing (from 20 sq.m per hour), not high optical resolution. In recent years, most of the widescreen inkjet printers produced in China. Large format printer manufacturers: WitColor, Jeti, DGI, Flora, Infiniti.
• Interior - the scope of interior printing - printing of interior design elements, printing of posters, information stands, drawings. The main format is 1600 mm. The main manufacturers of interior printers: Roland, Mimaki.
• Photo printers - designed to print photos, print on small format materials (usually on rolls 1000 mm wide). The color model is not worse than CMYK + Lc + Lm (six-color printing), sometimes the color model is supplemented with orange, white paint, silver (to obtain metal effects), etc.
• Souvenir - used for printing on small parts, for printing on disks, and blanks of complex shape. Manufactured by many companies: TechnoJet, Epson, Canon, HP, etc.
• Office printers differ from photo printers in the absence of lights and sheet feed. The main manufacturers of office printers: Epson, HP, Canon, Lexmark.
• Marking - are included in the production lines. The print head, fixed above the conveyor belt, marks the moving products.

According to the ink supply system:

Continuous, with the location of the subtanks and heads at the same level (the pressure at the inlet of the heads is regulated by the height of the subtanks).

Structure: ink cans --> pump --> filter --> flexible path --> carriage --> non-return valve --> sub-tanks equipped with ink level sensors --> heads.

Continuous, with sub-tanks located above the heads. The pressure of the high column of ink on the heads is balanced by a vacuum system consisting of a vacuum pump and vacuum adjustment devices.

Structure: ink canisters --> pump --> filter --> flexible path --> carriage --> non-return valve --> sub-tanks equipped with ink level sensors and connected to a vacuum system --> heads.

By gravity. Heads and ink canisters are connected by tubes passing through a flexible path. The only intermediate element is a damper that filters the ink and dampens pressure fluctuations that occur when the flexible path moves.

Ink supply from cartridges that move with the carriage. The main advantage of this system is its low cost. Disadvantages: a small supply of ink in the cartridges, the weight of the carriage with cartridges, the pressure at the inlet of the heads slowly drops, caused by a decrease in the level of ink in the cartridges.

The main characteristic of the printer, on which the optical resolution most strongly depends, is the type, number and location of the print heads on the carriage. Photo printers and office printers rarely come with more than one head per color. This is due to the low requirements for printing speed, in addition, the fewer heads, the simpler and more efficient the system for their calibration and convergence. Large-format and interior printers are equipped with two to four heads for each color.

Inkjet printers are equipped with bed heating systems for efficient drying and preventing material sticking.

In office printers, in order to reduce the cost of printing and improve some other printing characteristics, a continuous ink supply system (CISS) is also used, which is a kind of “gravity-flow” ink supply system. The role of the damper is played by the cartridge.

Currently, A4 and A3 inkjet printers are being actively replaced by color laser printers. This trend is due to significantly lower consumption and lower cost of consumables used for laser printing, ease of Maintenance color laser printers, which comes down to just replacing the toner and rollers. The most significant advantage of inkjet printing over laser printing is the length of a continuous print, limited only by the length of the roll material. On laser printers, the length of the print is limited by the long circumference of the intermediate medium - the roller or ribbon. On the largest laser printers, print lengths can be up to a meter. On office inkjet printers, due to the extreme customization and automation of printers, the poor performance of the Print Manager (Windows), the high cost of programs that replace the Print Manager (Windows) such as FlexiSign, Caldera, etc., and the complete lack of mechanisms necessary for printing on roll media, in most cases, it is impossible to realize continuous printing of unlimited length.

sublimation printers

Thermal sublimation (sublimation) is the rapid heating of the dye when the liquid phase is bypassed. Steam is immediately formed from the solid dye. The smaller the portion, the greater the photographic latitude (dynamic range) of color reproduction. The pigment of each of the primary colors, and there can be three or four of them, is located on a separate (or on a common multilayer) thin lavsan tape (Mitsubishi Electric thermal sublimation printers). The final color is printed in several passes: each ribbon is sequentially pulled under a tightly pressed thermal head, consisting of many thermal elements. These latter, when heated, sublimate the dye. The dots, due to the small distance between the head and the carrier, are positioned stably and are obtained in a very small size.

The sensitivity of the ink used to ultraviolet light can be attributed to the serious problems of sublimation printing. If the image is not covered with a special layer that blocks ultraviolet, then the paint will soon fade. When using solid dyes and an additional laminating layer with an ultraviolet filter to protect the image, the resulting prints do not warp and tolerate humidity, sunlight and even aggressive environments well, but the price of photographs increases. For the full color of sublimation technology, you have to pay with a long print time for each photo (printing one 10-15 cm image with a Sony DPP-SV77 printer takes about 90 seconds). Manufacturers write about the photographic color latitude of 24 bits, which is more desirable than actual. Realistically, the photographic color latitude is no more than 18 bits.

The most famous manufacturers of thermal sublimation printers are Canon and Sony.

Laser printer

Technology - the progenitor of modern laser printing appeared in 1938 - Chester Carlson invented a printing method called electrography, then renamed xerography.

The principle of technology was as follows. A static charge is evenly distributed over the surface of the photodrum by a charge corona (scorotron) (charge shaft), after which the LED laser (in LED printers - with an LED ruler) removes this charge in the right places - thus a latent image is placed on the surface of the photodrum. Next, toner is applied to the drum unit. The toner is attracted to the discharged areas of the drum surface that retained the latent image. After that, the photoconductor is rolled over the paper, and the toner is transferred to the paper by the transfer corotron (transfer roller). After that, the paper passes through the fusing unit (fuser) to fix the toner, and the photoconductor is cleaned of toner residue and discharged in the cleaning unit.

The first laser printer was EARS (Ethernet, Alto, Research character generator, Scanned Laser Output Terminal), invented and created in 1971 at the Xerox Corporation, and their mass production was launched in the second half of the 1970s. Xerox printer The 9700 was available at the time for $350,000, but it printed at 120 ppm.

Other printers

Drum printers (English drum printer). The first printer, called UNIPRINTER, was created in 1953 by Remington Rand for the UNIVAC computer. The main element of such a printer was a rotating drum, on the surface of which there were relief images of letters and numbers. The width of the drum corresponded to the width of the paper, and the number of alphabet rings was equal to the maximum number of characters per line. Behind the paper was a line of hammers powered by electromagnets. At the moment of passing the desired symbol on the rotating drum, the hammer hit the paper, pressing it through the ink ribbon to the drum. Thus, in one revolution of the drum, it was possible to print the entire line. Then the paper moved one line and the machine printed further. In the USSR, such machines were called alphanumeric printing devices (ATsPU). Their printouts are recognizable by their typewriter-like font and letters that "jump" across the line. The output speed of a drum printer was and remains the highest among all known printing devices, but it was far from being the limit of the technology's capabilities. Printing was done on roll paper, which is why the system engineers called the result of the printout a “sheet”.

Chamomile (petal) printers (daisywheel printer) according to the principle of operation were similar to drum printers, but they had one set of letters located on the flexible petals of a plastic disk. The disk rotated, and a special electromagnet pressed the desired petal against the ink ribbon and paper. Since there was only one character set, the print head had to move along the line, and the print speed was noticeably lower than that of drum printers. By replacing the disk with symbols, it was possible to get a different font, and by inserting a non-black tape, you could get a “color” print.

Ball printers (IBM Selectric) are similar in principle to daisy-wheel printers, but the type carrier (print head) was shaped like a ball with raised letters. This image formed the basis of the Wikipedia logo.

Caterpillar printers (train printer). A set of letters is attached to the caterpillar chain;

Chain printers. They differed in the placement of printing elements on plates connected in a chain;

Teletype printers consisted of an electromechanical part, repeating an electric typewriter, and a modem. That is, an electric keyboard, an electromechanical lever character printer and a device for receiving and transmitting information via a communication channel were combined into one unit. Additionally, a device for recording and reading punched tape, usually 5-row (5-bit), was connected.

Thermal printers from Xerox. They are characterized by consumables - a paraffin-based substance that melts at 60 degrees. Celsius.

The most environmentally friendly printer. The Japanese company PrePeat seriously thought about protecting the environment and released a printer that does not require any ink, toner or paper to work. Printed using thin white plastic. The sheet is automatically cleaned in the printer before reprinting.

Internet printer

Recently, printers have appeared on the office equipment market, the software of which supports a direct connection to the Internet (usually through a router), which allows such a printer to function independently of a computer. This connection provides a number of additional features:

• print documents or web pages directly from the printer display;
• print documents or web pages from any web device (including remote) without the need to install a printer driver on it;
• view printer status and manage print jobs from any browser, no matter where you are;
• operational automatic update software printer.

The market offers a wide range of printing devices. Knowing what types of printers exist and how they differ will help you make the right choice. Each type of device has its pros and cons. Having familiarized yourself in detail with the types of printers, you can choose the type that is most suitable for you for home use or for solving problems in the office.

Manufacturers of equipment produce various models peripherals for printing, which may differ technical specifications, appearance, dimensions, features of work. Depending on the technology used, the work is based on the following main types of printers:

• matrix;
• jet;
• laser;
• LED.

The varieties of printers can also include an MFP - a multifunctional device that performs several options. Each type has its own characteristics and characteristics, and also copes with various tasks. Before heading to the store for a new device, learn more about the types of printers and their characteristics.

These are the first devices for printing, the peak of popularity of which was more than 10 years ago. Now more modern models have taken their place, so the production of matrix devices has practically ceased.

Principle of operation

Dot matrix printers work in much the same way as a typewriter. The operation of the device is based on a matrix, which consists of needles (usually there are 9, 18 or 24 of them). Now only devices with a 24-needle matrix are produced, which allows you to get the highest print quality. Between the paper, which moves on the shaft, and the printing unit (matrix), there is an ink ribbon. When the needles hit it, the dots from them are transferred to the paper. Print codes for characters, letters, and numbers are stored in the machine's memory.

Advantages and disadvantages

These printers offer the following benefits:

• low price of the device;
• simultaneous printing up to 3 copies (between the paper it is necessary to lay a copy paper);
• printing on roll paper;
• low cost per sheet.

Dot-matrix printers cannot provide high quality printing, and they are quite noisy. Printers of this type are an excellent option for businesses that do not have the conditions for more modern models or copies of documents are made in large volumes, but there are no high quality requirements. They are not suitable for home use due to poor print quality and noise.

Over the past decade, inkjet printers have made great progress in development. They allow you to get high quality color printing. Black and white models of such devices are no longer available.

Principle of operation

Inkjet printers print by spraying ink through very small nozzles. The image is made up of small dots. For printing, quick-drying inks of four colors are used:

• Black (black);
• Cyan (blue);
• Magenta (magenta);
• Yellow (yellow).

Modern inkjet photo printers use 6 colors, which allows you to increase the brightness and saturation of colors. Features of the printing technology of different manufacturers may have slight differences.

Advantages and disadvantages

This type of printer is popular among users because it has the following advantages:

• affordable cost of the device;
• high quality color printing;
• the ability to print photos using special photo paper;
• almost silent operation;
• economy in terms of energy consumption;
• the ability to print on paper, film and other materials.

The advantages also include the versatility of some models, for example, you can print photos from a camera without connecting to a computer.

The disadvantages include:

• high cost of printing;
• slow print speed (when compared with laser models);
• high cost of maintenance (purchase of ink cartridges and special paper).

Inkjet devices are suitable for those who want to print high quality photo and color documents. The low cost of models of this type captivates many users, but keep in mind that the cost of consumables will be high. If the device is rarely used for printing, the ink may dry out and the cartridges may need to be replaced.

Today, printers that use laser technology are the most common, as they provide high print quality and performance. In most cases, printers of this type provide monochrome printing, but there are also color models.

Principle of operation

At the heart of the laser printer is a movable drum, as in a copier. Printing consists of several stages. First, a laser beam applies an image to a sheet of paper that moves on a drum. After that, the toner, a powder of electrically charged particles, falls on the applied image and is fixed by sintering when passing through a heated roller. The technology provides high-quality printing, which is not afraid of water and the sun's rays.

Advantages and disadvantages

Many users opt for laser printers for their advantages:

• high performance;
• low cost of printing;
• high speed printing;
• high-quality printing, resistant to water and ultraviolet;
• low noise level.

The radiation level is minimal, so the device does not cause harm to human health. Can be used for printing high volume documents.

The main disadvantage of such devices is the high price compared to models based on inkjet technology.

LED printers

The new generation of LED printers is still very expensive, so not everyone can afford such a model.

Principle of operation

LED printing technology is in many ways similar to laser printing. The light source in such devices is not a laser beam, but a strip of LEDs. Application of this modern technology allows for high quality printing.

Advantages and disadvantages

LED devices, like other types of printers, have their advantages and disadvantages. The main pluses are:

• high quality printing;
• high speed;
• silent operation;
• performance.

Due to the high cost, this technique is still inferior in popularity to other types of printers.

A multifunctional device (MFP) is used for printing documents and photos, scanning and copying, receiving or sending faxes, as it combines the options of several peripheral devices at once.

Great for small offices with limited space as well as home use. Combining multiple peripherals in one saves usable space.

Principle of operation

The operation of the MFP can be based on inkjet or laser technology, and models that work on LEDs are also appearing on the market. Features of the operation of the device depend on the technology used.

Advantages and disadvantages

If you are interested in what types of printers are currently available, you have familiarized yourself with the main varieties. According to many consumers, the MFP is a great option for home use and small offices. It has the following advantages:

• combines several peripheral devices;
• it is much cheaper compared to purchasing each device separately;
• allows you to save space;
• differs in low cost of the press;
• can print on both sides;
• has high performance.

Depending on the model, some MFPs can be used to print documents and photos, at the same time, such devices have their drawbacks:

• if the MFP fails, the work of the entire office will stop;
• when the toner runs out, the scanner may not work;
• slower copy speed and higher copy cost.

Knowing all the main types of printers, you will be able to make a rational choice. It is impossible to answer unequivocally the question of how to choose the type of device, since it is necessary to take into account the tasks set (how often and how much you plan to print), the required quality, operating conditions, financial capabilities and other factors. Do not forget to consider the features, disadvantages and advantages of each type.

State educational institution

Belgorod State National Research University

Law Institute

Legal support of national security

Informatics essay

Types of printers and their characteristics

Made by student gr.01001312

Logvinenko D.O.

Teacher:

Belgorod

INTRODUCTION 3

CHAPTER 1. PRINTERS: CONCEPT, TYPES 4

1.1. Printer: concept, history of creation 4

1.2. Classification of printers 7

CHAPTER 2. CHARACTERISTICS OF THE MAIN TYPES OF PRINTERS 9

2.1. Dot matrix (dot) printer 9

2.2. Inkjet printer 10

2.3. Laser printer 12

CHAPTER 3. PRINTER OPERATION 16

3.1. How dot matrix printers work 16

3.2. How Inkjet Printers Work 16

3.3. How laser printers work 17

CHAPTER 4. ADVANTAGES AND DISADVANTAGES OF THE MAIN TYPES OF PRINTERS 18

4.1. Advantages and disadvantages of dot matrix printers 18

4.2. Advantages and disadvantages of inkjet printers 19

4.3. Advantages and disadvantages of laser printers 19

CONCLUSION 20

REFERENCES 22

INTRODUCTION

Printers are classified as peripheral or external devices.

Peripheral devices are devices located outside system block and involved at a certain stage of information processing. First of all, these are devices for fixing output results: printers, plotters, modems, scanners, etc.

Printers are designed to output information on solid media, mostly on paper. There are a large number of different printer models that differ in principle of operation, interface, performance and functionality. According to the principle of operation, they are distinguished: dot-matrix, inkjet and laser printers.

The purpose of the work is to study the types of printers, their principles of operation, as well as their advantages and disadvantages.

To achieve the goal set in the work, it is necessary to solve the following tasks:

1) Define the concept of "printer", consider the history of its creation;

2) Consider the classification of printers;

3) Describe the main types of printers;

4) To study the principle of operation of printers;

5) Consider the advantages and disadvantages of the main types of printers.

Chapter 1. Printers: concept, types

1.1. Printer: concept, history of creation

Printer (from the English printer - printer) - a device for converting information stored on storage devices (text, graphics) into a hard copy, usually on paper. This process is called printing, and the resulting document is a printout.

Charles Babbage thought about the need to put the results of calculations on paper when he developed his Analytical Engine - a mechanical prototype modern computers. As a result, he also came up with the first printer in the history of mankind, called the Difference Engine (Difference Engine).

Unfortunately, this device was never created during the life of the author. True, 150 years after the death of the author, this printer was nevertheless assembled by the London Science Museum, under the guidance of its director Doron Suod (Fig. 1). The resulting device consisted of 8,000 parts, and weighed about 5 tons. It should be noted that during the development of this Difference Engine, Babbage came up with many ideas that are still used today.

When computers appeared, at first information was either written down manually or printed out on a typewriter (special personnel were even hired for this). The first printing device that could be connected to a computer was created in 1953 by Remington-Rand. The device, according to the principle of operation, is very reminiscent of a typewriter, was called UNIPRINTER. The main part of the printer was a disk with many "petals", each of which was a letter (a relief image of letters, numbers and special characters). A special impact mechanism hit the petal, which, through the printed tape, hit the paper. At the same time, the idea of ​​color printing was born - for it, a printed ribbon of various colors was used. The UNIPRINTER print speed was about 80,000 characters per minute! In the future, printers of this type were called "leaf printers". There have also been attempts to replace the petals with special drums and ribbons. This technology also came to the USSR, where such machines were called alphanumeric printing devices - ATsPU. These printers had a number of significant drawbacks - they were unreliable, very noisy, did not allow graphics to be printed, and always printed in the same font.

Dot matrix printing was developed by Seyko Epson in 1964. But the first dot matrix printer appeared in 1970. It was developed by Centronics Data Computer. For printing, it used a matrix of 7 needles (hence the name of the type of printers). The printer was called Model 101. Thanks to dot matrix printers, it became possible to print graphics in the same way. The technology has rapidly developed and become cheaper. So, already in 1983, the first printer appeared on sale, which could well have been purchased by a home user - its cost was about $ 700 (for example, the cost of Model 101 was about $ 3,000). This printer was the Image Writer, the brainchild of C.ltoh Electronics. The arrival of dot matrix printers in the house gave an additional impetus to the development of technology. But matrix printers also have a number of disadvantages, the main of which are poor print quality and noise. However, due to their exceptionally low cost, and very high reliability, dot matrix printers have survived to this day.

The disadvantages of dot matrix printers forced researchers to look for new ways to print. The first inkjet printers appeared not much later than dot matrix printers - in 1976, IBM introduced the first working model, called the Model 6640. However, it was still quite a few years before inkjet printers appeared on the desktops of home users. The main role in the development of inkjet printers was played by Canon, Epson and Hewlett-Packard, who developed their own printing technologies (BubbleJet, piezoelectric method and drop-on-demand, respectively).

The first color inkjet printer was developed by Hewlett-Packard, which introduced a printer in the early 90s that could mix inks with each other, thereby obtaining different colors and shades.

As for laser printers, it should be noted that the technology used in laser printing (electrography) appeared long before the appearance of the first dot matrix printers - back in 1938. It was developed by the American scientist Chester Carlson. Since then, it has been repeatedly improved and refined. However, only Xerox guessed to use it to create a printer, which decided to use copier technology to create a printer. As a result, in 1971, the EARS apparatus appeared, which never left the walls of the laboratory. The very first commercial model of a laser printer appeared in 1977. It was called the Xerox 9700 Electronic. IBM, Apple and Hewlett-Packard are joining the development of laser printers. However, for a long time, these devices were too expensive - their price was about several thousand dollars. The first printer that cost less than $1,000 was created by Hewlett-Packard, which created the LaserJet IIP model in the early 90s. A modern laser printer used at home is a relatively inexpensive (still an order of magnitude more expensive than an inkjet printer) device, with a very low cost of printing.

There are several other types of printing - sublimation, thermal ... But they are either not used at home at all, or are used extremely rarely.

To date, three technologies (matrix, inkjet and laser) are the most used and widespread. Constantly improving and developing, in essence they have remained unchanged since the moment of creation. But who knows, maybe in the very near future, a technology will appear that will make a real revolution in the world of printers.