Computer printer
Encyclopedia
In computing, a printer is a peripheral
Peripheral
A peripheral is a device attached to a host computer, but not part of it, and is more or less dependent on the host. It expands the host's capabilities, but does not form part of the core computer architecture....

 which produces a text or graphics of documents stored in electronic
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...

 form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable
Printer cable
Printer cable refers to the cable that carries data between a computer and a printer.There are many different types of cables, for example:*Serial: RS-232, EIA-422*Parallel*FireWire*USB...

 or, in most new printers, a USB cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....

 interfaces, typically wireless
Wireless LAN
A wireless local area network links two or more devices using some wireless distribution method , and usually providing a connection through an access point to the wider internet. This gives users the mobility to move around within a local coverage area and still be connected to the network...

 or Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....

 based, and can serve as a hard copy device for any user on the network. Individual printers are often designed to support both local and network connected users at the same time. In addition, a few modern printers can directly interface to electronic media such as memory card
Memory card
A memory card or flash card is an electronic flash memory data storage device used for storing digital information. They are commonly used in many electronic devices, including digital cameras, mobile phones, laptop computers, MP3 players, and video game consoles...

s, or to image capture devices such as digital camera
Digital camera
A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...

s and scanners
Image scanner
In computing, an image scanner—often abbreviated to just scanner—is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop scanner where the document is placed on a glass...

; some printers are combined with scanners or fax
Fax
Fax , sometimes called telecopying, is the telephonic transmission of scanned printed material , normally to a telephone number connected to a printer or other output device...

 machines in a single unit, and can function as photocopier
Photocopier
A photocopier is a machine that makes paper copies of documents and other visual images quickly and cheaply. Most current photocopiers use a technology called xerography, a dry process using heat...

s. Printers that include non-printing features are sometimes called multifunction printer
Multifunction printer
An MFP , multifunctional, all-in-one , or Multifunction Device , is an office machine which incorporates the functionality of multiple devices in one, so as to have a smaller footprint in a home or small business setting , or to provide centralized document...

s (MFP), multi-function devices (MFD), or all-in-one (AIO) printers. Most MFPs include printing
Printing
Printing is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....

, scanning, and copying among their many features.

Consumer and some commercial printers are designed for low-volume, short-turnaround print job
Print job
In computing, a print job is a file or set of files that has been submitted to be printed.Jobs are typically identified by a unique number, and are assigned to a particular destination, usually a printer...

s; requiring virtually no setup time to achieve a hard copy of a given document. However, printers are generally slow devices (30 pages per minute is considered fast; and many inexpensive consumer printers are far slower than that), and the cost per page is actually relatively high. However, this is offset by the on-demand convenience and project management costs being more controllable compared to an out-sourced solution. The printing press
Printing press
A printing press is a device for applying pressure to an inked surface resting upon a print medium , thereby transferring the ink...

 remains the machine of choice for high-volume, professional publishing. However, as printers have improved in quality and performance, many jobs which used to be done by professional print shops are now done by users on local printers; see desktop publishing
Desktop publishing
Desktop publishing is the creation of documents using page layout software on a personal computer.The term has been used for publishing at all levels, from small-circulation documents such as local newsletters to books, magazines and newspapers...

. Local printers are also increasingly taking over the process of photofinishing as digital photo printers become commonplace. The world's first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage
Charles Babbage
Charles Babbage, FRS was an English mathematician, philosopher, inventor and mechanical engineer who originated the concept of a programmable computer...

 for his Difference Engine
Difference engine
A difference engine is an automatic, mechanical calculator designed to tabulate polynomial functions. Both logarithmic and trigonometric functions can be approximated by polynomials, so a difference engine can compute many useful sets of numbers.-History:...

.

A virtual printer
Virtual printer
A virtual printer is a piece of computer software whose user interface and API resemble that of a printer driver, but which is not connected with a physical computer printer....

 is a piece of computer software whose user interface and API
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

 resembles that of a printer driver, but which is not connected with a physical computer printer.

Printing technology

Printers are routinely classified by the printer technology they employ; numerous such technologies have been developed over the years. The choice of engine has a substantial effect on what jobs a printer is suitable for, as different technologies are capable of different levels of image or text quality, print speed, cost, and noise. Some printer technologies don't work with certain types of physical media, such as carbon paper
Carbon paper
Carbon paper is paper coated on one side with a layer of a loosely bound dry ink or pigmented coating, usually bound with wax. It is used for making one or more copies simultaneous with the creation of an original document...

 or transparencies
Transparency (projection)
A transparency, also known in industrial settings as a "viewfoil" or "foil", is a thin sheet of transparent flexible material, typically cellulose acetate, onto which figures can be drawn. These are then placed on an overhead projector for display to an audience...

.

A second aspect of printer technology that is often forgotten is resistance to alteration: liquid ink
Ink
Ink is a liquid or paste that contains pigments and/or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing and/or writing with a pen, brush, or quill...

, such as from an inkjet head or fabric ribbon, becomes absorbed by the paper fibers, so documents printed with liquid ink are more difficult to alter than documents printed with toner or solid inks, which do not penetrate below the paper surface.

Cheques should either be printed with liquid ink or on special cheque paper with toner anchorage. For similar reasons carbon film ribbons for IBM Selectric typewriters bore labels warning against using them to type negotiable instruments such as cheques. The machine-readable lower portion of a cheque, however, must be printed using MICR
Magnetic ink character recognition
Magnetic Ink Character Recognition, or MICR, is a character recognition technology used primarily by the banking industry to facilitate the processing of cheques and makes up the routing number and account number at the bottom of a check. The technology allows computers to read information off...

 toner or ink. Banks and other clearing houses employ automation equipment that relies on the magnetic flux
Magnetic flux
Magnetic flux , is a measure of the amount of magnetic B field passing through a given surface . The SI unit of magnetic flux is the weber...

 from these specially printed characters to function properly.

Modern print technology

The following printing
Printing
Printing is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....

 technologies are routinely found in modern printers:

Toner-based printers

A laser printer
Laser printer
A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. As with digital photocopiers and multifunction printers , laser printers employ a xerographic printing process, but differ from analog photocopiers in that the image is produced...

 rapidly produces high quality text and graphics. As with digital photocopiers and multifunction printers (MFPs), laser printers employ a xerographic
Xerography
Xerography is a dry photocopying technique invented by Chester Carlson in 1938, for which he was awarded on October 6, 1942. Carlson originally called his invention electrophotography...

 printing process but differ from analog photocopiers in that the image is produced by the direct scanning of a laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

 beam across the printer's photoreceptor
Photodetector
Photosensors or photodetectors are sensors of light or other electromagnetic energy. There are several varieties:*Active pixel sensors are image sensors consisting of an integrated circuit that contains an array of pixel sensors, each pixel containing a both a light sensor and an active amplifier...

.

Another toner-based printer is the LED printer
LED printer
An LED printer is a type of computer printer. LED technology uses a light-emitting diode array as a light source in the printhead. The LED bar pulse-flashes across the entire page width and creates the image on the print drum or belt as it moves past....

 which uses an array of LEDs
Light-emitting diode
A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...

 instead of a laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

 to cause toner adhesion
Adhesion
Adhesion is any attraction process between dissimilar molecular species that can potentially bring them in close contact. By contrast, cohesion takes place between similar molecules....

 to the print drum.

Liquid inkjet printers

Inkjet printers operate by propelling variably-sized droplets of liquid or molten material (ink) onto almost any sized page. They are the most common type of computer printer used by consumers. Today's photo-quality ink jet printers have DPI resolution in the thousands (1200 to 4800dpi). They will give you acceptable quality photo prints of images with 140-200ppi resolution, and high quality prints of images with 200-300ppi resolution.

Solid ink printers

Solid ink
Solid ink
Solid ink is a technology used in computer printers and multifunction devices originally created by Tektronix in 1986. After Xerox acquired the Tektronix Color Printing and Imaging Division in 2000, the solid ink technology became part of the Xerox line of office printing and imaging products....

 printers, also known as phase-change printers, are a type of thermal transfer printer
Thermal transfer printer
A thermal transfer printer is a printer which prints on paper by melting a coating of ribbon so that it stays glued to the material on which the print is applied. It contrasts with direct thermal printing where no ribbon is present in the process...

. They use solid sticks of CMYK
CMYK color model
The CMYK color model is a subtractive color model, used in color printing, and is also used to describe the printing process itself. CMYK refers to the four inks used in some color printing: cyan, magenta, yellow, and key...

-coloured ink, similar in consistency to candle wax, which are melted and fed into a piezo crystal operated print-head. The printhead sprays the ink on a rotating, oil coated drum. The paper then passes over the print drum, at which time the image is immediately transferred, or transfixed, to the page. Solid ink printers are most commonly used as colour office printers, and are excellent at printing on transparencies and other non-porous media. Solid ink printers can produce excellent results. Acquisition and operating costs are similar to laser printers. Drawbacks of the technology include high energy consumption
Energy conservation
Energy conservation refers to efforts made to reduce energy consumption. Energy conservation can be achieved through increased efficient energy use, in conjunction with decreased energy consumption and/or reduced consumption from conventional energy sources...

 and long warm-up times from a cold state. Also, some users complain that the resulting prints are difficult to write on, as the wax tends to repel inks from pen
Pen
A pen is a device used to apply ink to a surface, usually paper, for writing or drawing. Historically, reed pens, quill pens, and dip pens were used, with a nib of some sort to be dipped in the ink. Ruling pens allow precise adjustment of line width, and still find a few specialized uses, but...

s, and are difficult to feed through automatic document feeder
Automatic Document Feeder
In multifunction or all-in-one printers, fax machines, photocopiers and scanners, an automatic document feeder or ADF is a feature which takes several pages and feeds the paper one page at a time into a scanner or copier, allowing the user to scan, and thereby copy, print, or fax, multiple-page...

s, but these traits have been significantly reduced in later models. In addition, this type of printer is only available from one manufacturer, Xerox
Xerox
Xerox Corporation is an American multinational document management corporation that produced and sells a range of color and black-and-white printers, multifunction systems, photo copiers, digital production printing presses, and related consulting services and supplies...

, manufactured as part of their Xerox Phaser
Xerox Phaser
Xerox Phaser is the brand name for a line of color and monochrome printers produced and sold by Xerox. Some Phaser printers use Xerox Solid Ink technology...

 office printer line. Previously, solid ink
Solid ink
Solid ink is a technology used in computer printers and multifunction devices originally created by Tektronix in 1986. After Xerox acquired the Tektronix Color Printing and Imaging Division in 2000, the solid ink technology became part of the Xerox line of office printing and imaging products....

 printers were manufactured by Tektronix
Tektronix
Tektronix, Inc. is an American company best known for its test and measurement equipment such as oscilloscopes, logic analyzers, and video and mobile test protocol equipment. In November 2007, Tektronix became a subsidiary of Danaher Corporation....

, but Tek sold the printing business to Xerox in 2001.

Dye-sublimation printers

A dye-sublimation printer (or dye-sub printer) is a printer which employs a printing process that uses heat to transfer dye to a medium such as a plastic card, paper or canvas
Canvas print
A canvas print, also known as a stretched canvas or canvas art, is the result of an image printed onto canvas which is stretched, or gallery-wrapped, onto a frame and displayed...

. The process is usually to lay one colour at a time using a ribbon that has colour panels. Dye-sub printers are intended primarily for high-quality colour applications, including colour photography; and are less well-suited for text. While once the province of high-end print shops, dye-sublimation printers are now increasingly used as dedicated consumer photo printers.

Thermal printers

Thermal printers work by selectively heating regions of special heat-sensitive paper. Monochrome thermal printers are used in cash registers, ATMs
Automated teller machine
An automated teller machine or automatic teller machine, also known as a Cashpoint , cash machine or sometimes a hole in the wall in British English, is a computerised telecommunications device that provides the clients of a financial institution with access to financial transactions in a public...

, gasoline dispensers
Fuel dispenser
A fuel dispenser is a machine at a filling station that is used to pump gasoline, diesel, CNG, CGH2, HCNG, LPG, LH2, ethanol fuel, biofuels like biodiesel, kerosene, or other types of fuel into vehicles...

 and some older inexpensive fax machines. Colours can be achieved with special papers and different temperatures and heating rates for different colours; these coloured sheets are not required in black-and-white output. One example is the ZINK technology.

UV printers

Xerox
Xerox
Xerox Corporation is an American multinational document management corporation that produced and sells a range of color and black-and-white printers, multifunction systems, photo copiers, digital production printing presses, and related consulting services and supplies...

 is working on an inkless printer which will use a special reusable paper coated with a few micrometre
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...

s of UV light
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

 sensitive chemicals. The printer will use a special UV light bar which will be able to write and erase the paper. As of early 2007 this technology is still in development and the text on the printed pages can only last between 16–24 hours before fading.

Obsolete and special-purpose printing technologies

The following technologies are either obsolete, or limited to special applications though most were, at one time, in widespread use.

Impact printers rely on a forcible
Force
In physics, a force is any influence that causes an object to undergo a change in speed, a change in direction, or a change in shape. In other words, a force is that which can cause an object with mass to change its velocity , i.e., to accelerate, or which can cause a flexible object to deform...

 impact to transfer ink to the media, similar to the action of a typewriter
Typewriter
A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...

. All but the dot matrix printer
Dot matrix printer
A dot matrix printer or impact matrix printer is a type of computer printer with a print head that runs back and forth, or in an up and down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like the print mechanism on a typewriter...

 rely on the use of formed characters
Typesetting
Typesetting is the composition of text by means of types.Typesetting requires the prior process of designing a font and storing it in some manner...

, letterform
Letterform
A letterform, letter-form or letter form, is a term used especially in typography, paleography, calligraphy and epigraphy to mean a letter's shape.In one sense, letterform applies strictly to the design of individual letters...

s that represent each of the characters that the printer was capable of printing. In addition, most of these printers were limited to monochrome printing in a single typeface at one time, although bolding
Emphasis (typography)
In typography, emphasis is the exaggeration of words in a text with a font in a different style from the rest of the text—to emphasize them.- Methods and use :...

 and underlining of text could be done by "overstriking", that is, printing two or more impressions in the same character position. Impact printers varieties include, typewriter-derived printers, teletypewriter-derived printers, daisy wheel printers, dot matrix printers and line printers. Dot matrix printers remain in common use in businesses where multi-part forms are printed, such as car rental services. An overview of impact printing contains a detailed description of many of the technologies used.

Pen-based plotters were an alternate printing technology once common in engineering and architectural firms. Pen-based plotters rely on contact with the paper (but not impact, per se) and special purpose pens that are mechanically run over the paper to create text and images.

Typewriter-derived printers

Several different computer printers were simply computer-controllable versions of existing electric typewriters. The Friden Flexowriter
Friden Flexowriter
The Friden Flexowriter was a teleprinter, a heavy duty electric typewriter capable of being driven not only by a human typing, but also automatically by several methods including direct attachment to a computer and by use of paper tape....

 and IBM Selectric typewriter
IBM Selectric typewriter
The IBM Selectric typewriter was a highly successful model line of electric typewriters introduced by IBM on July 31, 1961.Instead of the "basket" of individual typebars that swung up to strike the ribbon and page in a traditional typewriter, the Selectric had a type element that rotated and...

 were the most-common examples. The Flexowriter printed with a conventional typebar mechanism while the Selectric used IBM's well-known "golf ball" printing mechanism. In either case, the letter form then struck a ribbon which was pressed against the paper, printing one character at a time. The maximum speed of the Selectric printer (the faster of the two) was 15.5 characters per second.

Teletypewriter-derived printers

The common teleprinter
Teleprinter
A teleprinter is a electromechanical typewriter that can be used to communicate typed messages from point to point and point to multipoint over a variety of communication channels that range from a simple electrical connection, such as a pair of wires, to the use of radio and microwave as the...

 could easily be interfaced to the computer and became very popular except for those computers manufactured by IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

. Some models used a "typebox" that was positioned, in the X- and Y-axes, by a mechanism and the selected letter form was struck by a hammer. Others used a type cylinder in a similar way as the Selectric typewriters used their type ball. In either case, the letter form then struck a ribbon to print the letterform. Most teleprinters operated at ten characters per second although a few achieved 15 CPS.

Daisy wheel printers

Daisy-wheel printers operate in much the same fashion as a typewriter
Typewriter
A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...

. A hammer strikes a wheel with petals, the "daisy wheel", each petal containing a letter form at its tip. The letter form strikes a ribbon of ink
Ink
Ink is a liquid or paste that contains pigments and/or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing and/or writing with a pen, brush, or quill...

, depositing the ink on the page and thus printing a character. By rotating the daisy wheel, different characters are selected for printing. These printers were also referred to as letter-quality printers because, during their heyday, they could produce text which was as clear and crisp as a typewriter, though they were nowhere near the quality of printing press
Printing press
A printing press is a device for applying pressure to an inked surface resting upon a print medium , thereby transferring the ink...

es. The fastest letter-quality printers printed at 30 characters per second.

Dot-matrix printers

In the general sense many printers rely on a matrix
Matrix (mathematics)
In mathematics, a matrix is a rectangular array of numbers, symbols, or expressions. The individual items in a matrix are called its elements or entries. An example of a matrix with six elements isMatrices of the same size can be added or subtracted element by element...

 of pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....

s, or dots, that together form the larger image. However, the term dot matrix printer
Dot matrix printer
A dot matrix printer or impact matrix printer is a type of computer printer with a print head that runs back and forth, or in an up and down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like the print mechanism on a typewriter...

 is specifically used for impact printers that use a matrix of small pin
Pin
A pin is a device used for fastening objects or material together.Pin may also refer to:* Award pin, a small piece of metal or plastic with a pin attached given as an award for some achievement...

s to create precise dots. The advantage of dot-matrix over other impact printers is that they can produce graphical
Graphic design
Graphic design is a creative process – most often involving a client and a designer and usually completed in conjunction with producers of form – undertaken in order to convey a specific message to a targeted audience...

 images in addition to text; however the text is generally of poorer quality than impact printers that use letterforms (type).

Dot-matrix printers can be broadly divided into two major classes:
  • Ballistic wire printers (discussed in the dot matrix printer
    Dot matrix printer
    A dot matrix printer or impact matrix printer is a type of computer printer with a print head that runs back and forth, or in an up and down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like the print mechanism on a typewriter...

    s article)
  • Stored energy printer
    Stored energy printer
    A stored energy printer is a type of computer printer that uses the energy stored in a spring or magnetic field to push a hammer through a ribbon to print a dot...

    s


Dot matrix printers can either be character
Character (computing)
In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language....

-based or line-based (that is, a single horizontal series of pixels across the page), referring to the configuration of the print head.

At one time, dot matrix printers were one of the more common types of printers used for general use, such as for home and small office use. Such printers would have either 9 or 24 pins on the print head. 24-pin print heads were able to print at a higher quality. Once the price of inkjet printers dropped to the point where they were competitive with dot matrix printers, dot matrix printers began to fall out of favor for general use.

Some dot matrix printers, such as the NEC P6300, can be upgraded to print in colour. This is achieved through the use of a four-colour ribbon mounted on a mechanism (provided in an upgrade kit that replaces the standard black ribbon mechanism after installation) that raises and lowers the ribbons as needed. Colour graphics are generally printed in four passes at standard resolution, thus slowing down printing considerably. As a result, colour graphics can take up to four times longer to print than standard monochrome graphics, or up to 8-16 times as long at high resolution mode.

Dot matrix printers are still commonly used in low-cost, low-quality applications like cash register
Cash register
A cash register or till is a mechanical or electronic device for calculating and recording sales transactions, and an attached cash drawer for storing cash...

s, or in demanding, very high volume applications like invoice
Invoice
An invoice or bill is a commercial document issued by a seller to the buyer, indicating the products, quantities, and agreed prices for products or services the seller has provided the buyer. An invoice indicates the buyer must pay the seller, according to the payment terms...

 printing. The fact that they use an impact printing method allows them to be used to print multi-part documents using carbonless copy paper
Carbonless copy paper
Carbonless copy paper , non-carbon copy paper, or NCR paper is an alternative to carbon paper, used to make a copy of an original, handwritten document without the use of any electronics...

, like sales invoices and credit card
Credit card
A credit card is a small plastic card issued to users as a system of payment. It allows its holder to buy goods and services based on the holder's promise to pay for these goods and services...

 receipts, whereas other printing methods are unusable with paper of this type. Dot-matrix printers are now (as of 2005) rapidly being superseded even as receipt printers.

Line printers

Line printers, as the name implies, print an entire line of text at a time. Three principal designs existed. In drum printers, a drum carries the entire character set of the printer repeated in each column that is to be printed. In chain printers, also known as train printers, the character set is arranged multiple times around a chain that travels horizontally past the print line. In either case, to print a line, precisely timed hammers strike against the back of the paper at the exact moment that the correct character to be printed is passing in front of the paper. The paper presses forward against a ribbon which then presses against the character form and the impression of the character form is printed onto the paper.

Comb printers, also called line matrix printer
Line matrix printer
A line matrix printer is a computer printer that is a compromise between a line printer and a dot matrix printer. Basically, it prints a page-wide line of dots. It builds up a line of text by printing lines of dots.-Applications:...

s, represent the third major design. These printers were a hybrid of dot matrix printing and line printing. In these printers, a comb of hammers printed a portion of a row of pixels at one time, such as every eighth pixel. By shifting the comb back and forth slightly, the entire pixel row could be printed, continuing the example, in just eight cycles. The paper then advanced and the next pixel row was printed. Because far less motion was involved than in a conventional dot matrix printer, these printers were very fast compared to dot matrix printers and were competitive in speed with formed-character line printers while also being able to print dot matrix graphics.

Line printers were the fastest of all impact printers and were used for bulk printing in large computer centres. They were virtually never used with personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

s and have now been replaced by high-speed laser printer
Laser printer
A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. As with digital photocopiers and multifunction printers , laser printers employ a xerographic printing process, but differ from analog photocopiers in that the image is produced...

s. The legacy of line printers lives on in many computer operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

s, which use the abbreviations "lp", "lpr", or "LPT" to refer to printers.

Pen-based plotters

A plotter is a vector graphics
Vector graphics
Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...

 printing device which operates by moving a pen over the surface of paper. Plotters have been used in applications such as computer-aided design
Computer-aided design
Computer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...

, though they are rarely used now and are being replaced with wide-format conventional printers, which nowadays have sufficient resolution to render high-quality vector graphics using a rasterized print engine. It is commonplace to refer to such wide-format printers as "plotters", even though such usage is technically incorrect. There are two types of plotters, flat bed and drum.

Sales

Since 2005, the world's top selling brand of inkjet and laser printer
Laser printer
A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. As with digital photocopiers and multifunction printers , laser printers employ a xerographic printing process, but differ from analog photocopiers in that the image is produced...

s has been HP which now has 46% of sales in inkjet and 50.5% in laser printers.

Other printers

A number of other sorts of printers are important for historical reasons, or for special purpose uses:
  • Digital minilab
    Minilab
    A minilab is a small photographic developing and printing system, as opposed to large centralized photo developing labs. Many retail stores use minilabs to provide on-site photo finishing services....

     (photographic paper
    Photographic paper
    Photographic paper is paper coated with light-sensitive chemicals, used for making photographic prints.Photographic paper is exposed to light in a controlled manner, either by placing a negative in contact with the paper directly to produce a contact print, by using an enlarger in order to create a...

    )
  • Electrolytic printers
    VT52
    The VT52 was a CRT-based computer terminal produced by Digital Equipment Corporation introduced in September, 1975 . It provided a screen of 24 rows and 80 columns of text and supported all 95 ASCII characters as well as 32 graphics characters. It supported asynchronous communication at baud rates...

  • Spark printer
    Spark printer
    A spark printer is an obsolete form of computer printer which uses a special paper coated with a layer of aluminium over a black backing, which is printed on by using a pulsing current onto the paper via two styli that move across on a moving belt at high speed. They were introduced in the late 1960s...

  • Barcode printer
    Barcode printer
    A barcode printer is a computer peripheral for printing barcode labels or tags that can be attached to physical objects. Barcode printers are commonly used to label cartons before shipment, or to label retail items with UPCs or EANs....

     multiple technologies, including: thermal printing, inkjet printing, and laser printing barcode
    Barcode
    A barcode is an optical machine-readable representation of data, which shows data about the object to which it attaches. Originally barcodes represented data by varying the widths and spacings of parallel lines, and may be referred to as linear or 1 dimensional . Later they evolved into rectangles,...

    s
  • Billboard / sign paint spray printers
  • Laser etching (product packaging) industrial printers
  • Microsphere (special paper)

Printing mode

The data received by a printer may be:
  • A string of characters
    Plain text
    In computing, plain text is the contents of an ordinary sequential file readable as textual material without much processing, usually opposed to formatted text....

  • A bitmapped image
    Raster graphics
    In computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...

  • A vector image
    Vector graphics
    Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...



Some printers can process all three types of data, others not.
  • Character printers, such as daisy wheel printer
    Daisy wheel printer
    Daisy wheel printers use an impact printing technology invented in 1969 by David S. Lee at Diablo Data Systems. It uses interchangeable pre-formed type elements, each with typically 96 glyphs, to generate high-quality output comparable to premium typewriters such as the IBM Selectric, but two to...

    s, can handle only plain text data or rather simple point plots.
  • Pen plotter
    Plotter
    A plotter is a computer printing device for printing vector graphics. In the past, plotters were widely used in applications such as computer-aided design, though they have generally been replaced with wide-format conventional printers...

    s typically process vector images. Inkjet based plotters can adequately reproduce all three.
  • Modern printing technology, such as laser printer
    Laser printer
    A laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. As with digital photocopiers and multifunction printers , laser printers employ a xerographic printing process, but differ from analog photocopiers in that the image is produced...

    s and inkjet printer
    Inkjet printer
    An inkjet printer is a type of computer printer that creates a digital image by propelling droplets of ink onto paper. Inkjet printers are the most commonly used type of printer and range from small inexpensive consumer models to very large professional machines that can cost up to thousands of...

    s, can adequately reproduce all three. This is especially true of printers equipped with support for PostScript
    PostScript
    PostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...

     or PCL
    Page description language
    A page description language is a language that describes the appearance of a printed page in a higher level than an actual output bitmap. An overlapping term is printer control language, but it should not be confused as referring solely to Hewlett-Packard's PCL...

    , which includes the vast majority of printers produced today.


Today it is common to print everything (even plain text) by sending ready bitmapped images to the printer, because it allows better control over formatting.  Many printer driver
Printer driver
In computers, a printer driver or a print processor is a piece of software that converts the data to be printed to the form specific to a printer...

s do not use the text mode at all, even if the printer is capable of it.

Monochrome, colour and photo printers

A monochrome
Monochrome
Monochrome describes paintings, drawings, design, or photographs in one color or shades of one color. A monochromatic object or image has colors in shades of limited colors or hues. Images using only shades of grey are called grayscale or black-and-white...

 printer can only produce an image
Image
An image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...

 consisting of one colour, usually black. A monochrome printer may also be able to produce various tones of that color, such as a grey-scale
Grayscale
In photography and computing, a grayscale or greyscale digital image is an image in which the value of each pixel is a single sample, that is, it carries only intensity information...

. A colour printer can produce images of multiple colours. A photo printer is a colour printer that can produce images that mimic the colour range
Gamut
In color reproduction, including computer graphics and photography, the gamut, or color gamut , is a certain complete subset of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circumstance, such as within a given color space or by a...

 (gamut) and resolution
Image resolution
Image resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail....

 of prints made from photographic film
Photographic film
Photographic film is a sheet of plastic coated with an emulsion containing light-sensitive silver halide salts with variable crystal sizes that determine the sensitivity, contrast and resolution of the film...

. Many can be used on a standalone basis without a computer, using a memory card
Memory card
A memory card or flash card is an electronic flash memory data storage device used for storing digital information. They are commonly used in many electronic devices, including digital cameras, mobile phones, laptop computers, MP3 players, and video game consoles...

 or USB
Universal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....

 connector.

The printer manufacturing business

Often the razor and blades business model
Freebie marketing
Freebie marketing, also known as the razor and blades business model, is a business model wherein one item is sold at a low price in order to increase sales of a complementary good, such as supplies or software...

 is applied. That is, a company may sell a printer at cost, and make profits on the ink cartridge
Ink cartridge
An ink cartridge or inkjet cartridge is a replaceable component of an inkjet printer that contains the ink that is deposited onto paper during printing....

, paper, or some other replacement part
Spare part
Spare Parts may also refer to:* Spare Parts , by Status Quo* Spare Parts is a Doctor Who audio drama.* Spare Parts , by Servotron* "Spare Parts" , by Bruce Springsteen* "Spare Parts"...

. This has caused legal disputes regarding the right of companies other than the printer manufacturer to sell compatible
Computer compatibility
A family of computer models is said to be compatible if certain software that runs on one of the models can also be run on all other models of the family. The computer models may differ in performance, reliability or some other characteristic...

 ink cartridges. To protect their business model, several manufacturers invest heavily in developing new cartridge technology and patenting it.

Other manufacturers, in reaction to the challenges from using this business model, choose to make more money on printers and less on the ink, promoting the latter through their advertising campaigns. Finally, this generates two clearly different proposals: "cheap printer – expensive ink" or "expensive printer – cheap ink". Ultimately, the consumer decision depends on their reference interest rate
Interest rate
An interest rate is the rate at which interest is paid by a borrower for the use of money that they borrow from a lender. For example, a small company borrows capital from a bank to buy new assets for their business, and in return the lender receives interest at a predetermined interest rate for...

 or their time preference
Time preference
In economics, time preference pertains to how large a premium a consumer places on enjoyment nearer in time over more remote enjoyment....

. From an economics
Economics
Economics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek from + , hence "rules of the house"...

 viewpoint, there is a clear trade-off
Trade-off
A trade-off is a situation that involves losing one quality or aspect of something in return for gaining another quality or aspect...

 between cost per copy and cost of the printer.

Printing speed

The speed of early printers was measured in units of characters per second. More modern printers are measured in pages per minute. These measures are used primarily as a marketing tool, and are not as well standardised as toner yields
ISO/IEC 19752
ISO/IEC 19752 is an ISO standard method for the determination of toner cartridge yield for monochrome laser printers, introduced in June 2004.Traditionally, printer manufacturers did not employ a standard, well-defined methodology for measuring toner cartridge yield...

. Usually pages per minute refers to sparse monochrome office documents, rather than dense pictures which usually print much more slowly, especially colour images. PPM are most of the time referring to A4 paper
ISO 216
ISO 216 specifies international standard paper sizes used in most countries in the world today. It defines the "A" and "B" series of paper sizes, including A4, the most commonly available size...

 in Europe and letter
Letter (paper size)
Letter or US Letter is the most common paper size for office use in several countries, including the United States, Canada, Mexico, Bolivia, Colombia, Venezuela, the Philippines, and Chile. It measures 8.5 by 11 inches ....

 paper in the United States, resulting in a 5-10% difference.

Printer steganography


Printer steganography is a type of steganography
Steganography
Steganography is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity...

 produced by color printers, including Brother
Brother Industries
is a diversified Japanese company that produces or imports a wide variety of products including printers, sewing machines, large machine tools, label printers, and typewriters, fax machines, and other computer-related electronics. It markets its multifunction printers as Multi-Function Centers...

, Canon, Dell, Epson, HP, IBM, Konica Minolta
Konica Minolta
is a Japanese manufacturer of office equipment, medical imaging, graphic imaging, optical devices, and measuring instruments. It is headquartered in the Marunouchi Center Building in Marunouchi, Chiyoda, Tokyo, with a Kansai office in Nishi-ku, Osaka, Osaka Prefecture...

, Kyocera, Lanier, Lexmark, Ricoh, Toshiba and Xerox
Xerox
Xerox Corporation is an American multinational document management corporation that produced and sells a range of color and black-and-white printers, multifunction systems, photo copiers, digital production printing presses, and related consulting services and supplies...

 brand color laser printers, where tiny yellow dots are added to each page. The dots are barely visible and contain encoded printer serial numbers, as well as date and time stamps.

See also

  • 3D printing
    3D printing
    3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable, and easier to use than other additive manufacturing technologies. However, the term 3D printing is...

  • Cardboard modeling
  • List of printer companies
  • Print (command)
    Print (command)
    In computing, print is a command in the command line interpreters of DOS, OS/2 and Microsoft Windows. It is used to add a text file to the print queue...

  • Print screen
    Print screen
    Print screen is a key present on most PC keyboards. It is typically situated in the same section as the break key and scroll lock key...

  • Print server
    Print server
    A print server, or printer server, is a device that connects printers to client computers over a network. It can accept print jobs from the computers and send the jobs to the appropriate printers....


  • Printable version
    Printable version
    A printable version of an Internet HTML page is a simplified version of the webpage, rendered without navigation tools such as on-screen menus. In a printable version pages generally consist of plain text and pertinent images. Inline hyperlinks become ordinary text, links on the margins may or may...

  • Printer friendly
    Printer friendly
    Printer friendly is a term used on the Internet to describe a version of a web page formatted for printing. Normally, web pages include information and navigation content that is only useful while browsing the website...

  • Printer point
    Printer point
    In photography, a printer point is a unit of relative exposure, in printing a negative, equal to a 1/12 of a stop or 0.025 Log unit of exposure ratio ....

  • Printer (publishing)
  • Printmaking
    Printmaking
    Printmaking is the process of making artworks by printing, normally on paper. Printmaking normally covers only the process of creating prints with an element of originality, rather than just being a photographic reproduction of a painting. Except in the case of monotyping, the process is capable...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK