Printers of various types. What are printers and what are they for?

A printer is a device used to print electronic information onto paper. In this case, the process of transferring data to paper is called printing, and the result is called printing. A printer can perform several functions, so you should approach the selection process carefully by thoroughly familiarizing yourself with its functions. You need to take into account all the features of printing, for example, an office model for home will not be the best option, since you do not need a large volume of printing, and there is also no need to purchase a universal printing device.

Types of printing devices

Today there are two types of printing devices that differ in their functionality:

• Multifunctional.
• Printers.

The first type is briefly called MFP. It is usually chosen for home use; in addition to printing information on paper, this device can scan documents to save the result in electronic form, you can use it as a regular copier for simple copying of documents, and also as a fax.

Such a complex device will cost less than the cost of a printer, copier and scanner purchased separately. In addition, with such a purchase you will save space on your computer desk, and there will be fewer wires. If you don’t need anything other than printing text on paper, then the second type of device would be the best choice.

Types and features of the device

The range of printers today is very large. They differ in many parameters - purpose, type of ink, number of colors, operating principle, etc. Each type has its own characteristics and auxiliary functions. Let's look at the main types of printers in more detail.

Matrix

This type of printer was developed in Japan in the 60s of the last century.

Its operating principle is to create an image with a special print head, which consists of a matrix, hence the name of this device. The matrix consists of a set of needles driven by electromagnets. The print head moves along the sheet of paper for each line of text, and the needles act on the paper using an ink ribbon, thereby creating a dot print on the sheet.

In different models, the print head can have from 9 to 24 needles. The more needles, the higher the print quality and the clearer the image. Matrix printing devices have almost been replaced by other modern printers, but are still used in some places. For example, sales receipts in stores are printed using a matrix method.

Insufficient quality, like a typewriter, no longer makes it possible to apply matrix technology in other areas. Among the disadvantages of such devices, in addition to poor quality, are noisy operation and low printing speed.

The advantages of this rare design are its ability to function in any conditions; the needle prints are resistant to moisture and abrasion. It is quite difficult to forge a document printed on a dot matrix device.

Jet printer

The principle of operation of an inkjet device is somewhat similar to matrix technology: the image is also formed from dots. Instead of a needle print head, a matrix with liquid inks is used.

It can be fixed in the device body or built into the cartridge. “Struiniki” are divided according to certain typical characteristics.

If we consider their division by type of ink, then they are divided into:

• Water(used in many office and household devices).
• Oily(for marking in industry).
• Solvent(for printing stands, advertising and various posters, resistant to moisture).
• Pigment(the best way to create high-quality images, photographs).
• Thermal transfer(for applying fashionable prints to clothes).
• Alcohol(they dry quickly in the print head, which limits their use).

There are different types of inkjet printers according to their purpose:

• Office(they are equipped with offices for printing small documents).
• Widescreen(for printing advertisements).
• Marking(parts are marked).
• Interior(printing stands, posters, interior elements).
• Photo printers.
• Souvenir(printing images on laser discs, objects with complex surfaces).
• Manicure(painted on nails in beauty salons).

Photo printers and office printing devices are equipped with one head for each color, have high-quality color reproduction, and do not create noise. High image quality can only be achieved by using special paper.

The speed of inkjet printers is slightly higher than that of matrix printers, the image is sensitive to moisture, may smear, depending on the type of ink, and fades over time. An inkjet printer is a capricious device that will work normally if all cartridges are used regularly. If the device has not been turned on for a long time, the ink in the head may dry out.

The main negative factor is the high cost of printing. The ink in the cartridge runs out quickly; periodic replacement is necessary, which is an expensive pleasure. This problem is partially solved by the following device under consideration.

CISS

This device can easily replace the operation of cartridges; its name stands for continuous ink supply system. The operating principle of this system is to supply ink to the cartridge through tubes.

This improves print quality and you can save money without purchasing expensive cartridges. You just need to purchase ink in a timely manner and pour it into containers, which is much cheaper and lasts for a longer time.

To refill this system, you do not need to contact a specialist; you can do everything yourself. Previously, this system was sold separately, but now it is built into many printer models.

Laser technology

It would be more correct to call this printing method electrographic; it arose in 1938, and was then called xerography and electrography. Currently, this method is called laser printing, which is characterized by high quality, efficiency and high speed.

The main element of this device is a photoreceptor that stores an electric current charge on its surface; for each point of the image there is a separate charge. The laser beam hits the photoreceptor, made in the form of a drum, and directs the radiation to individual points from which it removes the charge. A computer connected to a laser printer controls the laser beam and creates a specific image on the drum.

A special powder dye enters the photoreceptor and sticks to its charged areas, creating an image that is then transferred to the paper and baked onto it by heating.

This technology has proven itself to be very fast compared to inkjet models. The print quality of the laser printer is high, the image is not subject to abrasion, is resistant to moisture, and does not fade, unlike the previous models reviewed. The advantage of laser technology is also the ability to print on any paper with excellent quality.

A laser printer has its drawbacks: high cost, which is offset by cheaper refills and maintenance. The disadvantage also includes some distortion in the printing of letters and images on the edge of the sheet - the dot sometimes turns out to be an oval. Modern models no longer have this problem, through the use of special technological lenses.

LED technology

This method can be considered a type of laser printing, with a difference in the light source. Here, instead of a laser beam, LEDs are used. In the image, all the dots correspond to individual LEDs that do not move like a laser.

This increases operational reliability and is an advantage. Another advantage is high performance - the printing speed can reach 40 sheets per minute, and the print quality is much higher compared to laser printing, since there is no distortion at the edges of the sheet. The only drawback is its high cost.

Rarely used types of printers

There are many different printing technologies that are not widely used or are used for narrow specialization.

• Sublimation the printer is an alternative option for inkjet models; it rarely works in offices, but is successfully used in printing production and has good image quality and color rendition.

• Drums the devices that worked before are no longer in use, their design is outdated, but the printing speed of these devices exceeds all existing types of printers. Its main element is a drum, which has the dimensions of a sheet, and has reliefs of numbers and letters on the surface. The operation of the device is as follows: the drum rotates, and when the desired number or letter passes over the sheet, a special pusher hits the sheet, imprinting the symbol on the paper using ink ribbon. Printed sheets on such a printer can be easily recognized - the font is similar to that of a manual typewriter, with characters “jumping” in height.

• Petal The printer works in a similar way, with the difference that the character set is located on flexible paddles on a rotating disk. The desired petal touches the ink ribbon and a sheet of paper, creating an imprint. Colored text can be obtained by installing a ribbon of a different color.

Throughout the history of development, printing devices have been of the following types: chain, track and ball. They differed in their operating principle, but were not widely used.

• Home or office printer. The only difference between them is the volume of printing. For home use, up to 500 sheets per month are sufficient; for office work, this will clearly not be enough. Therefore, laser models are purchased for the office, while inkjet models are preferable for the home, although everyone chooses for themselves.
• Print quality. This parameter is individual for each user. There is a parameter that determines the clarity and quality of the printout - this is the resolution. For office work, a printing device with a resolution of 600 to 2400 pixels per inch is suitable. Almost all modern devices today have sufficient resolution to work in any conditions.
• Printing cost. When choosing a printer, you need to look at both the price of the device itself and the costs required for its maintenance and refilling. If you only need to print a little, it is better to purchase an inexpensive device designed for small loads. If you need to print a large volume of documents, then the optimal choice would be an expensive printer with a large load capacity. The price also depends on the number of additional functions: built-in memory, auxiliary trays, wireless connection to a computer, etc.

A printer is a computer peripheral device designed to transfer text or graphics to physical media from electronic form.

- Matrix printer- a computer printer that creates images of characters using individual small dots. The print head of a dot matrix printer typically contains 9 to 24 print needles that selectively strike the ink ribbon, creating an image on the paper behind the ink ribbon. For printing on a dot matrix printer, roll or fan-fold perforated paper is used. Although dot matrix printing technologies are often perceived as outdated, dot matrix printers still find use in applications where low-cost, high-volume printing of multi-layer forms (such as airline tickets) or carbon copies is required, and where large quantities of output are required. purely textual information without any special requirements for the quality of the received document (printing sales receipts, labels, labels, data from control and measurement systems); additional savings are achieved through the use of cheap fan-fold or roll paper. Another advantage of matrix printing is the high resource of both the printer itself (8 million lines) and the print head (30 million characters).

- Jet printer. The operating principle of inkjet printers 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 matrix that prints liquid dyes. Dye cartridges come with a built-in print head. To reduce printing costs and improve other printer characteristics, a continuous ink supply system is used.

Laser printer- one of the types of printers that allows you to quickly produce high-quality prints of text and graphics on plain paper. Like photocopiers, laser printers use a xerographic printing process, but the difference is that the image is formed by directly scanning the photosensitive elements of the printer with a laser beam.

Sublimation printer- a printer that prints an image onto dense, hard surfaces by depositing a solid (usually crystalline) dye beneath the surface of the paper. Prints very durable images due to the fact that the ink is hard and is located under the surface of the paper. The protective layer prevents paint from evaporating from under the surface; print higher quality images than inkjet printers at the same resolution level; the quality is also improved due to the ability to mix colors on the image medium in a fairly wide range; the lightest tones are formed in a cloud of dye as naturally as the darker ones; quite expensive, as well as consumables for it; slow photo output (a 10x15 cm photo takes more than 1 minute to print) and the sensitivity of the ink used to ultraviolet radiation. At the moment, the printer is usually used for printing images on plastic cards and on CDs and DVDs.

LED printer - one of the types of printers, which is a parallel branch of the development of laser printing technology. The fundamental difference between an LED printer and a laser printer is the lighting mechanism of the photosensitive shaft. In the case of laser technology, this is done with one light source (laser), which, using a scanning system of prisms and mirrors, runs over the entire surface of the shaft. In LED printers, instead of a single laser, a line of LEDs is used, located along the entire surface of the shaft. The number of LEDs in the line ranges from 2.5 to 10 thousand pieces, depending on the printer resolution.

Specialized Printers are part of various technical devices and are intended for printing not only on paper, but also on other media - cardboard, fabric, metal, etc.

Hello.

I don’t think I will open America by saying that a printer is an extremely useful thing. Moreover, not only for students (who simply need it to print coursework, reports, diplomas, etc.), but also for other users.

Nowadays you can find various types of printers on sale, the price of which can differ tens of times. This is probably why there are a lot of questions regarding the printer. In this short reference article, I will look at the most popular questions that I get asked about printers (the information will be useful for those who are choosing a new printer for their home). So…

The article has omitted some technical terms and points in order to make it understandable and readable for a wide range of users. Only current user questions that almost everyone faces when searching for a printer are discussed...

1) Types of printers (inkjet, laser, matrix)

Most questions come about this. True, users do not ask the question “types of printers”, but “which printer is better: inkjet or laser?” (For example).

In my opinion, the easiest way to show the pros and cons of each type of printer is in the form of a plate: it turns out very clearly.

My conclusions:

1. If you are buying a printer for printing photos, it is better to choose a regular inkjet printer (preferably a model that can later be installed with a continuous supply of ink - important for those who will print a lot of photos). An inkjet printer is also suitable for those who occasionally print small documents: abstracts, reports, etc.
2. A laser printer is, in principle, a universal machine. Suitable for all users, except those who plan to print high-quality color pictures. A color laser printer is inferior in photo quality (today) to an inkjet printer. The price of the printer and cartridge (including its refill) is more expensive, but in general, if you make a full calculation, the cost of printing will be cheaper than with an inkjet printer.
3. Buying a color laser printer for the home, in my opinion, is not entirely justified (at least until the price drops...).

Important point. Regardless of what type of printer you choose, I would also check one detail with the same store: how much does a new cartridge cost for this printer and how much does it cost to refill it (refillability). Because the joy of the purchase may disappear after the ink runs out - many users will be very surprised to learn that some printer cartridges cost as much as the printer itself!

2) How to connect the printer. Connection interfaces

The vast majority of printers that can be found on sale support the USB standard. As a rule, there are no connection problems, except for one subtlety...

I don’t know why, but often manufacturers do not include a cable with the printer to connect it to the computer. Sellers usually remind you of this, but not always. Many novice users (who are encountering this for the first time) have to run to the store twice: once to get a printer, the second to get a connection cable. Be sure to check the package when purchasing!

The LPT interface is now becoming less and less common (it used to be a standard (very popular interface)). By the way, many PCs are still equipped with this port to be able to connect such printers. There is no point in looking for such a printer for your home these days!

Wi-Fi and Bluetooth

Printers in more expensive price categories are often equipped with Wi-Fi and Bluetooth support. And I have to tell you - the thing is extremely convenient! Imagine walking around your apartment with a laptop, working on a report - then you press the print button and the document is sent to the printer and printed out in a moment. In general, this add-on. The option in the printer will save you from unnecessary wires in the apartment (although it takes longer for the document to be transferred to the printer - but in general, the difference is not so significant, especially if you are printing text information).

3) MFP - is it worth choosing a multifunctional device?

Recently, MFPs have been in demand on the market: devices that combine a printer and a scanner (+ fax, sometimes also a telephone). These devices are extremely convenient for photocopies - you put a sheet of paper and press one button - the copy is ready. As for the rest, I personally don’t see any big advantages (having a separate printer and scanner - you can remove the second one altogether and take it out whenever you need to scan something).

In addition, any normal camera is capable of taking excellent photos of books, magazines, etc. - that is, practically replacing a scanner.

HP MFP: scanner and printer complete with automatic sheet feeder

MFP advantages:

Multi-functionality;

Cheaper than buying each device separately;

Quick photocopy;

As a rule, there is an auto-feed: imagine how much easier this will be if you are copying 100 sheets. With automatic feeding: loaded the sheets into the tray, pressed the button and went to drink tea. Without it, each sheet would have to be turned over and placed on the scanner manually...

Disadvantages of MFPs:

Bulky (relative to a conventional printer);

If the MFP breaks, you will lose both the printer and scanner (and other devices) at once.

4) Which brand should I choose: Epson, Canon, HP...?

There are a lot of questions about the brand. But here it is impossible to answer in monosyllables. Firstly, I would not look at a specific manufacturer - the main thing is that it is a well-known manufacturer of copiers. Secondly, it is much more important to look at the technical characteristics of the device and reviews of real users of such a device (in the age of the Internet - this is easy!). It’s even better, of course, if you are recommended by a friend who has several printers at work and sees the work of each one with his own eyes...

Naming a specific model is even more difficult: by the time you read the article, this printer may no longer be on sale...

That's all for me. I will be grateful for additions and constructive comments. All the best :)

Classification

Based on the ability to print graphic information, printers are divided into alphanumeric (with the ability to print a limited set of characters) and graphic.

Based on the principle of transferring an image to a medium, printers are divided into:

According to the number of printing colors - black and white (monochrome) and color.

By connection to the data source (from where the printer can receive data for printing), or interface:

• via wired channels:
  • via SCSI cable
  • via serial port
  • via parallel port (IEEE 1284)
  • via Universal Serial Bus (USB)
  • via local network (LAN, NET)
  • using two ports, one of the ports controls the CNC drive, the other port sends data to the print heads
• via wireless connection:
  • via infrared (IRDA)

Infrared connection is only possible with a device in direct line of sight, while Bluetooth and Wi-Fi interfaces using radio waves operate at a distance of up to 10-100 meters.

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

Dot matrix printers

Amstrad DMP 3000 dot matrix printer

Epson FX-85 dot matrix printer

The principle of image formation in a dot matrix printer

Dot matrix printers are the oldest types of printers currently in use; their mechanism was invented in 1964 by the Japanese corporation Seiko Epson.

The image is formed by the print head, which consists of a series of needles (a needle array) driven by electromagnets. The head moves line by line along the sheet, while the needles strike the paper through the ink ribbon, forming a dotted image.

The main disadvantages of dot matrix printers are monochrome (although there were also color dot matrix printers, at a very high price), very low operating speed and high noise level, which reaches 65 dB.

Interfaces - One standard bidirectional 8-bit parallel interface with IEEE 1284 nibble mode support, one EIA-232D serial interface.

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

Matrix printers, despite their complete displacement from the household and office sphere, are still quite widely used in some areas (printing sales receipts, banking - printing documents as carbon copies, etc.)

Comparison with other types

• Print quality. Very low, comparable to typewriter quality. However, graphics are possible.
• Color rendition. There were color matrix printers with several ribbons; they did not have plausible color rendition at all. However, in the 1980s it was the only way to print desktop in color.
• Print speed. For conventional 9- and 24-needle printers in text mode - tens of seconds per page, in graphic mode - several minutes. High-speed printers are several times faster. Carbon printing is possible.
• Cost per print. Extremely low (consumable material - ink ribbon). They print excellently on extremely poor quality paper, which further reduces the cost. Non-standard paper formats are possible, this is important for strict reporting forms that are made from high-quality paper (for example, an ACS Express train ticket, 2011).
• Resistance of the print to external influences. Very good; prints are resistant to water and friction. Needle marks make it even more difficult to forge documents. Over time, prints fade (although even after 20 years a document hanging on the wall remains readable).
• Possible print length. Not limited. There may be restrictions on the print spooler (as, for example, in Windows - printing only occurs in pages). Paper feeding can be manual (piece by piece) or roll.
• Environmental friendliness. Loud noise. Low power consumption.
• Easy to maintain. Works in the most spartan conditions. Before it runs out, the cartridge warns about this with non-contrast prints. Unable to buy ribbon, users found ways to color the existing one, inserted typewriter ribbon into the cartridge, etc. When printing from a roll, the paper practically does not jam.
• Main use today. Printing documents. A matrix printer can be found in banks, ticket offices, various bureaus, and as part of cash registers.

Inkjet printers

Epson CX3200 Inkjet Printer

The operating principle of inkjet printers 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 (i.e., a 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 and Lexmark). Other models of office printers use replaceable cartridges; the print head cannot be removed when replacing the cartridge. On most industrial printers, ink is supplied to heads mounted in a carriage through an automatic ink supply system.

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, lengthens or pulls the diaphragm, resulting in a local area of ​​increased pressure 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, developer - Canon, the principle was developed in the late 1970s) - a microscopic heating element is located in the nozzle, which, when an electric current passes, instantly heats up to a temperature of several hundred degrees, when heated Gas bubbles form in the ink. bubbles- hence the name of the technology), which push drops of liquid from the nozzle onto the media.

Inkjet printer printheads are created using the following types of ink supply:

Classification

By type of printed material:

• Roll - equipped with systems for rewinding and rewinding roll material, designed for printing on self-adhesive paper, canvas, banner fabric

• Solid sheet - for printing on PVC, polystyrene, foam cardboard. The sheet of material is fixed to the frame using a vacuum clamp or clamps. The carriage (equipped with a drive for movement along the X axis) is mounted on a portal, which, together with the carriage, moves over the material (along the Y axis).

• Souvenir - movement of the workpiece relative to the head, along the Y axis, is ensured 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). They are used for printing on disks, phones, and for marking parts.

• Sheet flexible - for printing on paper and film of standard formats (A3, A4, etc.). Equipped with a mechanism for capturing and rewinding sheet material.

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

By type of ink used:

• Water-based based on water-soluble dye. They are used in the vast majority of household and office inkjet printers and in some interior wide-format printers. The main disadvantage is poor light fastness, that is, rapid fading in the sun.
• Solvent ink. Solvent inks are used in large format and interior printing. They are characterized by very high resistance to water and precipitation. They are characterized by the viscosity of the solvent, grain size and the pigment dye fraction used.
• Alcohol inks are not widely used, since heads that print with alcohol ink dry out very quickly.
• Oil-based - used in industrial marking systems and for testing print heads.
• Pigment - used to obtain high-quality images in interior and photo printing.
• UV-curable ink - used as an environmentally friendly replacement for solvent ink and for printing on rigid materials.
• Thermal transfer ink - a distinctive feature of thermal transfer ink is the ability, using a heat press, to transfer the printed image from the substrate to the product. Used to apply logos to clothing.

By purpose:

• 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 print speed (from 20 m² per hour), and not the highest optical resolution.
• Interior - scope of interior printing - printing of interior design elements, printing of posters, information stands, drawings. The main format is 1600 mm. Main manufacturers of interior printers: Roland, Mimaki.
• Photo printers - designed for printing photographs; they print on small format materials (usually on rolls 1000 mm wide). The color model is no worse than CMYK+Lc+Lm (six-color printing), sometimes the color model is supplemented with orange, white paint, silver (to obtain metallic effects), etc.
• Souvenir - used for printing on small parts, for printing on disks, and blanks of complex shapes. Manufactured by many companies: TechnoJet, Epson, Canon, HP, etc.
• Office printers differ from photo printers in the absence of light and sheet-fed material. Major manufacturers of office printers: Epson, HP, Canon, Lexmark.
• Marking - included in production lines. The print head, fixedly mounted above the conveyor belt, applies markings to moving products.
• Manicure - used for applying complex designs to nails in nail art salons.

By ink supply system:

• Continuous, with the location of 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 canisters → pump → filter → flexible path → carriage → check valve → subtank equipped with ink level sensors → head.

• Continuous, with subtanks, 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 → check valve → subtank equipped with ink level sensors and connected to a vacuum system → heads.

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

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

The main characteristic of a printer, on which optical resolution most strongly depends, is the type, number and location of print heads on the carriage.

Photo 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 calibrating and mixing them.

Wide-format and interior printers are equipped with two to four heads for each color.

To ensure effective drying and prevent material sticking, inkjet printers are equipped with bed heating systems.

In office printers, 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” ink supply system. The cartridge plays the role of a damper.

Currently, inkjet printers in A4 and A3 formats 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 of color laser printers, which comes down to replacing toner and rollers only.

The most significant advantage of inkjet printing over laser printing is the length of the continuous print, limited only by the length of the roll material. On laser printers, the length of the print is limited by the circumference of the intermediate media - the shaft or ribbon. On the largest laser printers, print lengths can reach up to a meter. On office inkjet printers, due to the extremely narrow specialization and automation of printers, low productivity Print Manager(Windows), the high cost of programs that replace the Print Manager, such as FlexiSign, Caldera, etc. and the complete lack of mechanisms necessary for printing on roll media, in most cases, it is impossible to implement continuous printing of unlimited length.

Sublimation Printers

Thermal sublimation (sublimation) is the rapid heating of the dye once the liquid phase has passed. Steam immediately forms 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 Mylar ribbon (thermal sublimation printers from Mitsubishi Electric). The final color is printed in several passes: each tape is sequentially pulled under a tightly pressed thermal head, consisting of many thermal elements. These latter, heating up, sublimate the dye. Thanks to the short distance between the head and the carrier, the dots are positioned stably and are obtained in a very small size.

Serious problems with sublimation printing include the sensitivity of the ink used to ultraviolet radiation. If the image is not covered with a special layer that blocks ultraviolet light, the colors 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 withstand humidity, sunlight and even aggressive environments, but the price of photographs increases. For the full-color quality of sublimation technology, you have to pay for the long printing time of each photo (printing one 10x15 cm photo with a Sony DPP-SV77 printer takes about 90 seconds). Manufacturers write about a photographic color width of 24 bits, which is more desirable than actual. In reality, photographic color latitude is no more than 18 bits.

The most well-known manufacturers of heat-sublimation printers are Canon and Sony.

Comparison with other types (for photo printing)

• Print quality. A good image, without a raster (to produce a light color, the printer evaporates less ink). The lineature is close to that of a magazine photograph.
• Color rendition. Very good.
• Print speed. About a minute per 10x15 photo. Professional printers 6-15 seconds.
• Cost per print. On a household printer, 13-15 rubles per print. On a professional one - less than 5 rubles.
• Resistance of the print to external influences. Covered with film after printing. Water and fade resistant.
• Possible print length. Only in photo format, usually 10x15.
• Environmental friendliness. Low noise.
• Easy to maintain. More reliable than inkjet; Downtime is not a problem for sublimation printers. They are afraid of dust.
• Main use today. Photo printing.

Laser printers

HP LaserJet 4100TH 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 the technology was as follows. On the surface of the photodrum with a corotron (scorotron) charge ( charge shaft) the static charge is evenly distributed, after which the LED laser (in LED printers - an LED line) removes this charge in the right places - thereby placing a latent image on the surface of the photodrum. Next, toner is applied to the photodrum. The toner is attracted to the discharged areas of the drum surface that retain the latent image. The image drum is then rolled over the paper and the toner is transferred to the paper by a transfer coronator ( transfer shaft). After this, the paper passes through fusing unit(stove) to fix the toner, and the photodrum is cleaned of toner residues and discharged in cleaning unit.

The first laser printer was EARS (Ethernet, Alto, Research character generator, Scanned Laser Output Terminal), invented and created in 1971 by the Xerox Corporation, and their mass production began in the second half of the 1970s. The Xerox 9700 printer could be purchased at that time for 350 thousand dollars, but it printed at a speed of 120 ppm.

Comparison with other types

• Print quality. High, in expensive models it approaches offset printing (resolution is limited to approximately 1200 dpi).
• Color rendition. The toner produced on the basis of paraffins has stable characteristics. Since the printing unit for each color is bulky (similar to a conventional black and white cartridge), the number of inks cannot be increased indefinitely, as in inkjet printers. So they make do with the standard four, and the photographic image is obtained with a large raster (about 80 lpi), especially in light colors.
• Print speed. Even a personal printer produces 10-20 pages per minute. But first, a few tens of seconds to warm up.
• Cost per print. Low (a few US cents per page for black and white printing and tens for color). Refilling is expensive, but it lasts a long time (in personal printers - from 1.5 to 3 thousand pages).
• Resistance of the print to external influences. They hold color well and are water resistant, but do not withstand friction at all. Therefore, documents issued for a long time (for example, a passport) are printed either on other types of printers, or in a very bold and clear font.
• Possible print length. Laser printing is a continuous process and the document must be buffered and prepared in the printer's memory; This is limited to printing on black and white printers. On color ones - also the length of the transfer ribbon on which all four toners are combined. Paper feeding is automatic, piece by piece only.
• Environmental friendliness. Almost silent. They pollute the air with ozone and toner.
• Easy to maintain. Works reliably in normal home and office environments. The printer usually “warns” about the imminent replacement of the cartridge with stripes on the printout. However, toner gets dirty and is difficult to wash, so you should not refill an empty cartridge at home. The print drum (usually one for several refills; in cheap printers it is built into the cartridge) and automatic paper feeder rollers also require regular replacement. Contains an electric heating element and therefore cannot be operated from a UPS.
• Main use today. An indispensable assistant in any office. In the 2000s, the prices dropped so much that they became available to home users. Because of their high-quality single-color images, laser printers are used in printing for phototypesetting.

Thermal printers

The printing process consists of “burning” dots onto special heat-sensitive paper. They are simple and cheap, do not require a dye, but the printing quality is low.

Comparison with other types

• Print quality. Extremely low, comparable to dot matrix printers.
• Color rendition. Only black and white.
• Print speed. Very fast, faster than dot matrix and inkjet printers.
• Cost per print. Thermal printers that print in A4 format are not currently produced, so comparisons with other printers can only be made per square meter of print. 1 m² of cash register tape costs approximately twice as much as 1 m² of office paper, which, however, is cheaper than laser prints.
• Resistance of the print to external influences. Prints are not resistant to friction and pressure; fade quickly (within a few months).
• Possible print length. Limited by software only.
• Environmental friendliness. There is virtually no noise or pollution.
• Easy to maintain. Extremely reliable; The only consumable material is thermal paper.
• Main use today. They are still used in small-format and small-sized printing devices: faxes, cash registers, ATMs, service terminals.

Other printers

• Drum printers 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 in a line. Behind the paper was a line of hammers driven by electromagnets. At the moment the desired symbol passed 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 the entire line could be printed. Then the paper was shifted one line and the machine continued printing. In the USSR, such machines were called alphanumeric printing devices (ADP). Their printouts can be recognized by their typeface-like font and the letters “jumping” across the line. The output speed of the drum printer was and remains the highest among all known printing devices, but it was far from the limit of the capabilities of this technology. Printing was done on roll paper, which is why system specialists called the printing result a “sheet.”

• Daisy type printers (petal printers)

According to the principle of operation, they were a hybrid of a drum drum and a typewriter. They had one set of letters, located on flexible petals of a plastic disk. The disk rotated, and a special electromagnet pressed the desired petal to the ink ribbon and paper. Since there was only one set of characters, it was necessary to move the print head along the line, and the printing speed was noticeably lower than that of drum printers. By replacing the disk with symbols, you could get a different font, and by inserting a non-black tape, you could get a “color” print. To do this, the “pause” command could be present in the printer’s command set.

In addition to the daisy, the lettering piece could be in the shape of a thimble, a (truncated) ball, or even a caterpillar chain ( chain printer).

• Teletype printers consisted of an electromechanical part, replicating 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 writing and reading punched tape, usually 5-row (5-bit), was connected.

Internet printers

Printer manufacturers recommend refilling their printers with their own ink/toner, however, it is technically difficult to prevent the use of ink/toner from third-party manufacturers (just like making a car run only on gasoline from the car manufacturer). Buying so-called branded cartridges is more expensive than refilling cartridges with ink or toner from third-party manufacturers.

There is a whole industry of ink manufacturers that supply them to printer manufacturers under OEM agreements, as well as directly to users under their own brand, for example, inktec, ink-mate. Modern Canon printer models use Fine cartridges with a built-in chip that controls the supply and level of ink consumption. But this does not prevent the refilling of such cartridges, even without reprogramming the chip; if after refilling there remains information that the ink has run out, the printer does not refuse to print, it only reports a refill.

Cartridges allow repeated refilling, subject to certain requirements (either compatible ink is required, or washing the cartridge and head, for inkjet printers).

In addition to the cartridge refill system, for inkjet printers there is also a system for supplying ink from an external vessel (the so-called CISS).

Printhead

The print head is the mechanism by which the dye is actually applied to the surface of the material.

Print queue

Famous manufacturers

• Kyocera. Kyocera Corporation also owns the Mita brand (no longer used)
• Ricoh. Also known under the brands Nashuatec, Rex Rotary and Gestetner (NRG Group; since 2007 - part of the Ricoh Company corporation)
• TallyGenicom

Non-traditional uses

• Even before the advent of matrix (graphics) printers, people wanted to print at least a semblance of graphics. This could be done even on a drum or other character printer using the so-called. ASCII graphics. Even now, some applications (for example, the graphics editor GIMP) have the option to output the image in ASCII text file format, suitable for printing on a character printer.

• Many printers leave printed sheets

Printers (printing devices) are devices for outputting data from a computer, converting information ASCII codes into corresponding graphic symbols (letters, numbers, signs, etc.) and fixing these symbols on paper.

Printers are the most developed group of PC devices, numbering up to 1000 different modifications. Printers differ from each other in various ways:

Color (black and white and color);

Method of forming characters (character printing and character synthesizing);

Operating principle (matrix, thermal, inkjet, laser);

Printing methods (stressed, unstressed) and line formation (sequential, parallel);

Carriage width (with wide (375 - 450 mm) and narrow (250 mm) carriage);

Length of the printed line (80 and 132 - 136 characters);

Character set (up to the full ASCII character set);

Print speed;

Resolution, the most common unit of measurement is dpi (dots per inch) - the number of dots per inch.

Within a number of groups, several types of printers can be distinguished; For example, matrix character-synthesizing printers widely used in PCs can be impact, thermographic, electrographic, electrostatic, magnetographic, etc., based on their operating principle.

Among impact printers, letter, spherical, petal (daisy-type), needle (matrix), etc. are often used.

Printers can print character-by-character, line-by-line, or page-by-page. Printing speed varies from 10 - 300 characters/s (impact printers) to 500 - 1000 characters/s and even up to several tens (up to 20) pages per minute (impactless laser printers); resolution - from 3 - 5 dots per millimeter to 30 - 40 dots per millimeter (laser printers).

Many printers allow efficient output of graphical information (using pseudographic characters); service printing modes: dense printing, double-width printing, with underlining, with superscripts and subscripts, highlighted printing (each character is printed twice), two-pass printing (the second time the character is printed with a slight shift) and multi-color (up to 100 different colors and shades) printing.

Dot matrix printers. In matrix printers, an image is formed from dots using the impact method, so it is more correct to call them impact-matrix printers, especially since other types of character-synthesizing printers also most often use matrix formation of characters, but in a non-impact method. Nevertheless, “matrix printers” is their generally accepted name, so we will stick to it.

Dot matrix printers can work in two modes - text and graphic.

In text mode, character codes are sent to the printer to be printed, with character outlines selected from the printer's character generator.

In graphics mode, codes are sent to the printer that determine the sequence and location of image dots.

In needle (impact) dot matrix printers, dots are printed using thin needles striking the paper through an ink ribbon. Each needle is controlled by its own electromagnet. The printing unit moves horizontally, and the characters in the line are printed sequentially. Many printers print in both forward and reverse strokes. The number of pins in the print head determines the print quality. Inexpensive printers have 9 needles. The character matrix in such printers has a dimension of 7x9 or 9x9 pixels. More advanced dot matrix printers have 18 or even 24 needles.

The print quality of dot matrix printers is also determined by the ability to output dots during the printing process with partial overlap in several passes of the print head.

For text printing, in general, there are the following modes, characterized by different print quality:

Draft mode (Draft);

Printing mode close to typographical (NLQ - Near-Letter-Quality);

Mode with typographic print quality (LQ - Letter-Quality);

Super-quality mode (SLQ - Super Letter-Quality).

Note. LQ and SLQ modes are only supported by inkjet and laser printers.

In printers with different numbers of needles, these modes are implemented differently. In 9-pin printers, Draft printing is done in one pass of the print head along the line. This is the fastest printing mode, but has the lowest quality. The NLQ mode is implemented in two passes: after the first pass of the head, the paper is pulled to a distance corresponding to half the size of the dot; then a second pass is made with partial overlap of the dots. In this case, the printing speed is halved.

Dot matrix printers usually support several fonts and their varieties, among which roman (small typewriter font), italic (italic), bold-face (bold), expanded (stretched), elite (semi-compressed), condensed ( compressed), pica (straight font ≈ cicero), courier (courier), san serif (sans serif font), serif (serif), prestige elite (prestige elite) and proportional font (the width of the field allocated for the character depends on the width character).

Switching the operating modes of dot matrix printers and changing fonts can be done both software and hardware by pressing the keys available on the devices and/or setting the switches accordingly.

The performance of matrix printers when printing text in Draft mode is in the range of 100-300 characters/s, which corresponds to approximately two pages per minute (including sheet changes).

Thermal printers. In addition to matrix needle printers, there is also a group of matrix thermal printers, equipped with a thermal matrix head instead of a needle print head and using special thermal paper or thermal carbon when printing (which, of course, is their significant drawback).

Inkjet printers. In the print head of these printers, instead of needles, there are thin tubes - nozzles, through which tiny droplets of dye (ink) are thrown onto the paper. These are impactless printing devices. The print head matrix usually contains from 12 to 64 nozzles. In recent years, significant progress has been made in their improvement: inkjet printers have been created that provide a resolution of up to 20 dots/mm and a printing speed of up to 500 characters/s with excellent print quality, approaching the quality of laser printing. Color inkjet printers are available.

Laser printers. They use the electrographic method of image formation, which is used in copiers of the same name. The laser is used to create an ultra-thin light beam that draws the contours of an invisible dot electronic image on the surface of a pre-charged photosensitive drum - the electric charge flows from the points on the surface of the drum illuminated by the laser beam. After developing the electronic image with dye powder (toner). sticking to the discharged areas, printing is performed - transferring the toner from the drum to the paper and fixing the image on the paper by heating the toner until it melts.

Laser printers provide the highest quality printing with a resolution of up to 50 dots/mm (1200 dpi) and print speeds of up to 1000 characters/s. Color laser printers are widely used. For example, the Tektronix (USA) Phaser 550 laser printer has a horizontal and vertical resolution of 1200 dpi; color printing speed - 5 A4 pages per minute, monochrome printing speed - 14 ppm.

Printers can be connected to MP via both parallel and serial ports. Parallel ports are used to connect parallel printers (receiving information one byte at a time). For example, adapters like Centronics allow you to connect up to three printers simultaneously. Serial ports (2 pcs.) are used to connect sequentially operating (perceiving information sequentially 1 bit at a time) printers, for example, RS-232C type adapters (connection C2). A serial printer does not mean it is slow. Most printers use parallel ports.

Many high-speed printers have their own buffer memory with a capacity of up to several hundred kilobytes. In conclusion, it should be noted that the most popular PC printers (their share is at least 30%) are produced by the Japanese company Seiko Epson (Table 4.11). The control language for these printers (ESC/P) has become a de facto standard. Printers from Star Micronics, Hewlett Packard, Xerox, Mannesmann, Citizen, Panasonic, etc. are also widely used.