Printer

A Samsung printer.

A printer is a peripheral computer output device that enables a permanent range of text or graphics from documents stored in an electronic format to be produced by printing them on physical media, typically paper, using print cartridges. ink or laser technology (with toner).

Many printers are used as output peripherals, and are permanently attached to the computer by a cable. Other printers, called network printers, have an internal network interface (typically wireless or Ethernet cable), and can serve as a device to print a document on paper for any network user.

In addition, many modern printers allow direct connection of electronic multimedia devices such as CompactFlash, Secure Digital or Memory Stick cards, flash drives, usb, or image capture devices such as digital cameras and scanners. There are also multifunction devices that consist of printer, scanner or fax machines in a single device. A printer combined with a scanner can basically function as a photocopier.

They are designed to carry out low-volume repetitive jobs that require virtually no configuration time to get a copy of a specific document. However, printers are generally slow devices (10 pages per minute is considered fast), and the cost per page is relatively high.

For larger-volume jobs, there are printers, which are machines that perform the same function as printers but are designed and optimized to carry out large-volume print jobs, such as newspaper printing. Printers are capable of printing hundreds of pages per minute or more.

Classification of printers by mechanism

In general, printers can be divided into categories based on various criteria.

The most common distinction is made between:

• impact printers: are divided into,
  • matrix printers (can be subdivided according to the number of needles containing the print head: 9, 18, 24),
  • margarita printers;
• impactless printers: cover all other types of printing mechanisms, including:
  • thermal printers,
  • injection printers or ink jet printers,
  • laser printers.

In addition, the following criteria can be used to classify printers:

• printing technology,
• formation of the characters,
• transmission method,
• printing method,
• printing capacity.

Character formation

• Features with continuous stroke: the characters formed completely with continuous stroke (the ones produced by a margarita printer, for example).
• Matricial point characteristicsMatritial characters composed of independent point patterns (printers: matrix, injection and thermal).

Technically, laser printers are matrix, but the sharpness of the print and the small size of the dots printed with high density, can be considered that the strokes of its characters are continuous.

Transmission method

This classification refers to the medium used to send the data to the printer:

• Stop it.: transmission byte to byte.
• Series: bit to bit transmission.

Many versions of printers were available in parallel and serial, and even incorporated both options, increasing the flexibility to install them. Currently, the trend is in favor of serial printers, through the USB standard.

Print method

• Character: Character printers are printers:
  • marriages,
  • ink injection,
  • thermals,
  • Margarita.
• Line to line: are frequently used in large installations (e.g.: calculation centers, industrial environments). Line printers are subdivided into printers:
  • tape,
  • chain,
  • drum.
• Page to page: among the page printers are the electrophotographics, such as laser printers.

Print capacity

• Text only: the majority of margarita and ball printers can print only texts, although there are also matrix and laser printers that print only characters.
• Text and graphics: can only reproduce previously engraved characters, in relief or in the form of map of internal characters. Text and graphic printers reproduce all kinds of images by drawing them as point patterns:
  • marriages,
  • ink injection,
  • laser.

Printing speed and print quality

The different types of printers differ in printing speed and the quality of the printed product.

Character printers, such as matrix printers, print at speeds ranging from 200 to 400 characters per second (cps), which is 90 to 180 lines per minute (lpm). Line printers have a wide range of speeds, from 400 to 2000 lines per minute. Page printer speeds range from 4 to 800 pages per minute (ppm) for black-and-white printing, and one-tenth that for color printing.

Print methods

Printer Canon.

The choice of compression engine has a substantial effect on the jobs a printer is intended for. There are different technologies that have different levels of image quality, print speed, cost, noise, and also, some technologies are inappropriate for certain types of physical media (such as carbon paper or transparencies).

Another aspect of printing technology that is often forgotten is resistance to tampering: liquid ink such as from an inkjet head is absorbed by the fibers of the paper, and therefore documents printed with liquid ink are more difficult to alter than those printed by toner or solid ink, which do not penetrate below the surface of the paper.

Toner

Laser printers and thermal printers use this method to adhere toner to the media. They work using the principle of xerography that is at work in most photocopiers: adhering toner to a light-sensitive printing drum, and using static electricity to transfer the toner to the printing medium to which it is attached. it is united thanks to the heat and the pressure.

Laser printers are known for their high-quality printing, good print speeds, and low cost per copy; they are the most common printers for many general purpose office applications. They are less used by the consumer, generally due to their high initial cost. Laser printers are available in both color and monochrome.

The advent of reasonably priced precision lasers has made the toner-based monochrome printer dominant in office applications. Another type of toner-based printer is the LED printer which uses an array of LEDs instead of lasers to cause the toner to adhere to the print drum. Toner, also called dry ink by functional analogy with ink, is a fine powder, usually black, that is deposited on the paper to be printed by means of electrostatic attraction. i>).

Inkjet

Ink jet printers (Ink Jet) spray very small amounts of ink, usually a few picolitres, into the media. For color applications, including photo printing, inkjet methods are dominant, as high-quality printers are inexpensive to produce. Virtually all inkjet printers are color devices; some, known as photo printers, include extra pigments for better reproduction of the color gamut needed for high-quality photo printing (and are additionally capable of printing on photo paper, as opposed to regular office paper).

There are two methods for injecting ink:

1. Thermal method. An electrical impulse produces a temperature increase (approx. 480 °C during microseconds) that makes a small amount of ink inside a chamber forming a steam bubble that forces its output by the injectors. When going outside, this steam condenses and forms a tiny drop of ink on paper. Then the resulting vacuum drags new ink into the camera. This method has the inconvenience of greatly limiting the lives of injectors, so these injectors are found in ink cartridges.
2. Piezoelectric method. Each injector is made up of a piezoelectric element that, by receiving an electrical impulse, changes sharply the pressure inside the head causing the injection of an ink particle. Your injection cycle is faster than the heat.

Solid ink

Solid ink printers, also called phase change printers, are a type of thermal transfer printer but use solid bars of CMYK color ink (similar in consistency to candle wax). The ink melts and feeds a print head operated by a piezoelectric crystal (eg quartz). The head distributes the ink in a greased drum. The paper then passes over the drum as the image is transferred to the paper.

They are commonly used as color printers in offices, as they are excellent at printing transparencies and other non-porous media, and can achieve great results. The costs of acquisition and use are similar to laser printers.

The disadvantages of this technology are the high energy consumption and the long waiting periods (heating up) of the machine. There are also some users who complain that writing is difficult on solid ink prints (wax tends to repel ink from ballpoint pens), and they are hard to feed paper automatically, although these traits have been significantly reduced in the Latest models. Also, this type of printer can only be obtained from a single manufacturer, Xerox, as part of their Xerox Phaser line of office printers. Previously solid ink printers were made by Tektronix, but it sold its printing division to Xerox in 2000.

Impact

Printing daisy.

Printing balls.

Impact printers or slam printers rely on the force of impact to transfer ink to the medium, similar to typewriters, they are generally limited to reproducing text. At the time they dominated the print quality. There are two main types:

1. Margarita printer, so called for having the types contained radially on a wheel, hence its appearance of a margarita.
2. Wheel printer, so called for having all the types contained in a sphere. This is the case of IBM Selectric electric typewriters.

Impact printers work with a head in which there are needles, these needles hit a tape, similar to that of a typewriter, which generates the print of the letter.

Dot matrix

In the general sense, many printers are based on a matrix of many pixels or dots that together make up the largest image. However, the term matrix or dot is used specifically for impact printers that use an array of small pins to create precise dots. These printers are known as dot matrix. The advantage of dot matrix over other impact printers is that they can produce graphic images in addition to text. However, the text is generally of poorer quality than type impact based printers.

Some sub-classifications of dot matrix printers are ballistic wire printers and stored energy printers.

Dot matrix printers can be either character based or line based, referring to the configuration of the print head.

Dye Sublimation

Dye-sublimation printers employ a printing process that uses heat to transfer ink to media such as plastic cards, paper, or canvas. The process usually consists of putting on one color at a time using a tape that has colored panels. These printers are primarily intended for high-quality color applications, including color photography, and are less recommended for text. First used in copy shops, they are increasingly targeting consumer photo printers.

Thermal

Thermal printers are based on a series of hot needles that run through the thermosensitive paper that turns black on contact. Due to their low cost, they are widely used in ATMs and supermarkets.

Printer memory

Printers carry internal memory. They range from 6 KB on matrix printers to at least 2 MB on laser printers.

Currently, lasers sell independent memory modules to expand their capacity.

Memory is used as a buffer and as permanent and semi-permanent storage. In addition, its use is necessary because the treatment of vector graphics and the design of bitmap fonts consume memory.

The buffer is used to hold active print jobs and the persistence is used to store font layout and data.

Printer connection

The connection of the printer with the computer has been evolving leading to the improvement of printing performance and user comfort.

The oldest form of connection was through a serial port where the transfer was done bit by bit, allowing long distances with slow speeds that did not exceed 19,200 bytes/second.

It rose to the parallel port connection in which the transfers were byte by byte allowing 8 parallel connections achieving a faster speed between ½ MB/second up to 4 MB/second. The drawback was the limitation of the distance of the cable that connects the printer with the computer since it does not allow a length greater than 2 meters.

Another form of connection was achieved by putting the printer on an Ethernet network using RJ-45 connections based on the IEEE 802.3 standard. Achieved speeds exceed 10 Mb/sec based on packet handling. It should not be confused with a shared printer, since network printers operate as a network element with its own IP address.

Another more current connection method is through USB ports (Universal Serial Bus). The speed improves again with 480Mb/second with the advantages that the USB port brings: compatibility with several systems and the possibility of using it in portable devices.

Finally, Wi-Fi wireless connection, through the IEEE 802.11 protocol, is being the newest. It reaches 300 Mb/second and works for both inkjet, laser or multifunction printers.

Although it achieves less speed than those connected by USB, Wi-Fi provides advantages such as autonomy, mobility and freedom for the user without the use of cables. For correct use and avoid unwanted access we must encrypt the network.

Page Description Languages and Printing Formats

A “page description language” (PDL) is a means of encoding each element of a document so that it can be transmitted to the printer for printing. It is the medium that defines the characteristics and composition that would describe a printed document within a data stream. There are several types of PDL:

• PostScript
• Printer Command Language (PCL), printer control language
• HPGL, for plumbing

Character definition formats: Truetype

It was created by Apple to be technologically independent of Adobe's PostScript fonts, but its quality turned out to be inferior. It was bought by Microsoft which has contributed to its not disappearing. The main strength of TrueType is that it gives font designers a great degree of control over the way their fonts display at different sizes.

The problem with most programs is that they don't normally use truetype. They generally load fonts in Postscript style and all hints are discarded; this is a big loss for sources with high quality. Aside from font design, there are two other keys to font quality to consider: character profile and hint. Only a few foundries currently produce fonts that fully exploit the hinting potential of truetype. Now there are applications that convert a Type 1 of Postscript to a truetype, but they are better than auto-generated scripts.

Image Tracer

The plotters are used to make drawing prints of architectural, engineering, industrial design plans, etc., for printing sheets, posters, photographic enlargements, billboards, signs on routes, public roads, signage, etc. There are two kinds of plotters depending on the use of their inks, water-based or solvent-based. A particular case is the cutting plotter, which cuts an adhesive medium that will then be attached to another surface, from T-shirts to bodywork.

Color or photo printers

There are devices such as cell phones, which are used in photo developing houses or at home. These devices are often known as a photo printer, photo quality printer, or photo printer docks. These devices print in color, producing images that mimic the range of colors and resolutions of photographic developing methods prior to this technology.

The printer business

The business model of razors and razors is often used in the printing business. Companies can sell a printer below cost, and make a profit on ink cartridges, paper, or other parts that are replaced. This has caused legal disputes regarding the right of companies other than the printer manufacturer to sell compatible or alternative ink cartridges. To protect the business model of razors and razors, many manufacturers invest considerable sums in the development of new technologies and their patents.

Other manufacturers, reacting to the challenges this business model brings, are aiming to make more profit from printers and less from ink cartridges, promoting lower cartridge prices through advertising campaigns. This generates two very different proposals: "cheap printer - expensive ink" or "expensive printer - cheap ink". Finally, the consumer's decision depends on his reference interest rate or his intertemporal preference.

Cartridges, ink and paper

Both the cartridges, as well as the ink and the paper are 3 essential elements to be able to make copies with a printer, and knowing how to choose the most appropriate element depending on the type of printing that is intended to be done can increase the performance of our printer to unsuspected limits.

Cartridges

In the case of laser printers, the life of the cartridge depends on the amount of toner it contains and when the toner runs out, the cartridge must be replaced. In the event that the cartridge and the OPC (photoconductive sensitive organ) are in separate compartments, when the toner runs out, only the cartridge is replaced, but in the event that the OPC is inside the cartridge, both must be changed, increasing the expense considerably. The situation is more critical in the case of color laser printers.

In inkjet printers the life of the cartridge depends on the life of the ink, although many cartridges can be refilled, which helps to reduce the expense of buying a new one although the excessive use of a cartridge may cause you to make your prints with lower quality.

Ink

There are two types of ink for printers:

1. Slow-drying penetrating ink: is mainly used for monochromatic printers.
2. Fast-drying ink: used in color printers, as in these printers, inks of different colors are mixed and these have to dry quickly to avoid distortion.

The objective of all printer ink manufacturers is that their inks can print on any medium and for this they develop new types of ink with different chemical compositions almost daily.

Paper

Today, when you want to make a high-quality copy on a printer, you have to use high-quality glossy paper. This paper is quite expensive and in the case of wanting to make many copies in photographic quality, its cost would be very high. For this reason, manufacturers develop new printers that allow high-quality prints to be obtained on common paper.

Some manufacturers, such as Epson, make their own paper.

Potential printing problems

Problems with paper

If care is not taken when selecting the right type of paper for the printer or when loading the paper, small problems may appear. It may be that the wrong positioning of the paper causes the printer not to detect the paper, for which it will be enough to reposition it correctly. This misplacement or a poor choice of paper can also cause a jam to occur during printing because the printer has taken several sheets at the same time, so you must be careful when placing the paper in tray and should not overload this tray with too much paper.

Ink Problems

Sometimes when printing documents or photographs, horizontal bands may appear that make the print quality worse. Although this problem can occasionally be related to a poor choice of printing paper, it is usually due to ink problems with inkjet prints. One possible cause is the print quality setting, since the document may require a higher quality setting from the printer. Other possible causes could be that the cartridge is running out of ink or that the printheads are dirty.

Other printers

Some other classes of printers are important for historical reasons or for special uses, including the following:

• Ink sublimation printers, sometimes used for high-quality prints in color or photo.
• Teletype
• Thermal printer (heat-sensitive paper)
• Wax thermal printer (Xerox/Tektronix)
• Thermal printer on metallic paper (Sinclair ZX Printer, designed for Sinclair ZX80, Sinclair ZX81 and Sinclair ZX Spectrum)
• Microsphere (special paper)
• Multifunction photocopier