View source for Dot matrix printing

{{Short description|Computer printing process}}
[[File:Tally 5040 Passbook dot matrix printer.jpg|thumb|A dot matrix printer]]

[[File:"Delivery", printed in a bold, large font on a dot matrix printer.jpg|thumb|Sample output from a dot matrix printer|alt=The word "Delivery" as output in a bold, large font by a dot matrix receipt printer, as seen under a low-powered microscope]]

'''Dot matrix printing''',<ref name=NYT.dot>{{cite news |newspaper=The New York Times |title=Getting the most out of a dox matrix printer |author=Peter H. Lewis |date=December 17, 1985 |url=https://www.nytimes.com/1985/12/17/science/peripherals-getting-the-most-out-of-a-dot-matrix-printer.html |access-date=December 12, 2017 |url-status=live |archive-url=https://web.archive.org/web/20171212193238/http://www.nytimes.com/1985/12/17/science/peripherals-getting-the-most-out-of-a-dot-matrix-printer.html |archive-date=December 12, 2017}}</ref> sometimes called '''impact matrix printing''', is a [[computer printing]] process in which ink is applied to a surface using a relatively low-resolution [[dot matrix]] for layout. Dot matrix printers are a type of [[printer (computing)#Impact printers|impact printer]] that prints using a fixed number of pins or wires<ref name="KidBrit1">{{cite web |title=Dot-matrix printer |website=Britannica.com |url=https://kids.britannica.com/students/article/Dot-matrix-printer/321714 |access-date=2017-12-12 |url-status=live |archive-url=https://web.archive.org/web/20171212144651/https://kids.britannica.com/students/article/Dot-matrix-printer/321714 |archive-date=2017-12-12}}</ref><ref name="NYT.dot2">{{cite news |author=Peter H. Lewis |title=Getting the most out of a dot matrix printer |date=December 17, 1985 |newspaper=The New York Times |url=https://www.nytimes.com/1985/12/17/science/peripherals-getting-the-most-out-of-a-dot-matrix-printer.html |access-date=December 12, 2017 |url-status=live |archive-url=https://web.archive.org/web/20171212193238/http://www.nytimes.com/1985/12/17/science/peripherals-getting-the-most-out-of-a-dot-matrix-printer.html |archive-date=December 12, 2017}}</ref> and typically use a print head that moves 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. They were also known as '''serial dot matrix printers'''.<ref name="PCmag.DotM">{{cite web |title=Dot Matrix Printer |website=PCmag.com |publisher=[[Ziff Davis]] |url=https://www.pcmag.com/encyclopedia/term/41904/dot-matrix-printer |access-date=2017-12-12 |url-status=live |archive-url=https://web.archive.org/web/20171212140806/https://www.pcmag.com/encyclopedia/term/41904/dot-matrix-printer |archive-date=2017-12-12}}</ref> Unlike [[typewriter]]s or [[line printer]]s that use a similar print mechanism, a dot matrix printer can print arbitrary patterns and not just specific characters.

The perceived quality of dot matrix printers depends on the vertical and horizontal resolution and the ability of the printer to overlap adjacent dots. 9-pin and 24-pin are common; this specifies the number of pins in a specific vertically aligned space. With 24-pin printers, the horizontal movement can slightly overlap dots, producing visually superior output ([[near letter-quality printing|near letter-quality]] or NLQ), usually at the cost of speed.
[[File:Indian railway suburban rail ticket.jpg|thumb|A [[Kolkata Suburban Railway]] rail ticket printed on by a dot matrix printer]]
Dot matrix printing is typically distinguished from non-impact methods, such as [[inkjet printer|inkjet]], [[thermal printer|thermal]], or [[laser printing]], which also use a [[bitmap]] to represent the printed work. These  other technologies can support higher dot resolutions and print more quickly, with less noise. Unlike other technologies, impact printers can print on [[multipart stationery|multi-part forms]], allowing multiple copies to be made simultaneously, often on paper of different colors.<ref>{{cite web |title=Dot Matrix vs. Inkjet |website=YourBusiness.AZcentral.com |url=https://yourbusiness.azcentral.com/dot-matrix-vs-inkjet-2827.html |access-date=2018-10-17 |url-status=live |archive-url=https://web.archive.org/web/20191012060734/https://yourbusiness.azcentral.com/dot-matrix-vs-inkjet-2827.html |archive-date=2019-10-12 |quote=Dot matrix and inkjet printers share one key characteristic — both make images out of small dots. With a dot matrix printer, a pin presses through a ribbon to make an impact on the page. Inkjet printers have an electrical signal that causes a microscopic quantity of ink to squirt onto the page.}}</ref> They can also employ endless printing using [[continuous paper]] that is fanfolded and perforated so that pages can be easily torn from each other.

==History==
{{History of printing}}

In 1925, [[Rudolf Hell]] invented the [[Hellschreiber]], an early [[fax|facsimile]]-like [[dot matrix]]{{En dash}}based [[teletypewriter]] device,<ref name="Working-paper_1961"/> patented in 1929.

Between 1952 and 1954 [[Fritz Karl Preikschat]] filed five patent applications<ref name="DE1006007">{{cite patent |country=DE |number=1006007 |status=patent |title=Umschalteinrichtung für Fernschreiber, bei dem die Schriftzeichen in Rasterpunkte zerlegt sind |gdate=1957-09-12 |fdate=1952-07-29 |pridate=1952-07-29 |inventor=Preikschat, Fritz Karl |inventor-link=Fritz Karl Preikschat |assign=[[Telefonbau und Normalzeit G.m.b.H.]]}}</ref><ref name="DE1006007B">{{cite patent |country=DE |number=1006007 |status=patent |title=Umschalteinrichtung fuer Fernschreiber, bei dem die Schriftzeichen in Rasterpunkte zerlegt sind |pubdate=1957-04-11 |fdate=1952-07-29 |pridate=1952-07-29 |inventor=Preikschat, Fritz Karl |inventor-link=Fritz Karl Preikschat |assign=Preikschat, Fritz Karl}}</ref> for his so-called "PKT printer",<ref name="Working-paper_1961"/> a dot matrix teletypewriter built between 1954 and 1956 in Germany. Like the earlier Hellschreiber, it still used electromechanical means of coding and decoding, but it used a start-stop method ([[asynchronous transmission]]) rather than [[synchronous transmission]] for communication.<ref name="Working-paper_1961"/> In 1956, while he was employed at [[Telefonbau und Normalzeit GmbH]] (TuN, later called [[Tenovis]]), the device was offered to the [[Deutsche Bundespost]] (German Post Office), which did not show interest.
When Preikschat emigrated to the US in 1957 he sold the rights to utilize the applications in any country (except the USA) to TuN. The prototype was also shown to [[General Mills]] in 1957. An improved [[transistorized]] design<ref name="Working-paper_1961">{{citation |author-first=Fritz Karl |author-last=Preikschat |author-link=Fritz Karl Preikschat |title=Working papers on dot matrix teletypewriter |orig-year=1961 |date=2016 |url=https://upload.wikimedia.org/wikipedia/en/f/f6/Working_papers_on_dot_matrix_teletypewriter%2C_1961.pdf |access-date=2016-10-31 |url-status=dead |archive-url=https://web.archive.org/web/20161031121145/https://upload.wikimedia.org/wikipedia/en/f/f6/Working_papers_on_dot_matrix_teletypewriter%2C_1961.pdf |archive-date=2016-10-31}}</ref> became the basis for a portable dot matrix facsimile machine, which was prototyped and evaluated for military use by [[Boeing]] around 1966–1967.<ref name="Boeing_1967">{{citation |title=Facsimile transponder prototype at Boeing |orig-year=1967 |date=2016 |url=https://upload.wikimedia.org/wikipedia/en/8/84/Facsmile_transponder_prototype_at_Boeing%2C_1967.pdf |access-date=2016-10-31 |url-status=dead |archive-url=https://web.archive.org/web/20161031121457/https://upload.wikimedia.org/wikipedia/en/8/84/Facsmile_transponder_prototype_at_Boeing%2C_1967.pdf |archive-date=2016-10-31}}</ref><ref name="Boeing_1966">{{citation |title=Drawings of portable fax machine for Boeing |orig-year=1966 |date=2016 |url=https://upload.wikimedia.org/wikipedia/en/d/d1/Drawings_of_portable_fax_machine_for_Boeing%2C_1966.pdf |access-date=2016-10-31 |url-status=dead |archive-url=https://web.archive.org/web/20161031203820/https://upload.wikimedia.org/wikipedia/en/d/d1/Drawings_of_portable_fax_machine_for_Boeing%2C_1966.pdf |archive-date=2016-10-31}}</ref>
[[File:Epson MX-80.jpg|left|thumb|An [[Epson MX-80]], a classic model that remained in use for many years. [[IBM]] sold it as their IBM 5152.<ref name="NYT.PCdot85">{{cite news |author=Erik Sandberg-Diment |title=Personal Computers; Letter Quality, Almost |date=June 4, 1985 |newspaper=The New York Times |url=https://www.nytimes.com/1985/06/04/science/personal-computers-letter-quality-almost.html |access-date=January 29, 2018 |url-status=live |archive-url=https://web.archive.org/web/20171212193056/http://www.nytimes.com/1985/06/04/science/personal-computers-letter-quality-almost.html |archive-date=December 12, 2017}}</ref>]]

{{Anchor|Wiredot}}
In 1968, the Japanese manufacturer [[OKI (company)|OKI]] introduced its first serial impact dot matrix printer (SIDM), the OKI Wiredot. The printer supported a [[character generator]] for 128 characters with a print matrix of 7 × 5. It was aimed at governmental, financial, scientific and educational markets. For this achievement, OKI received an award from the [[Information Processing Society of Japan]] (IPSJ) in 2013.<ref name="IPSJ_2012">{{cite web |title=Information Processing Technology Heritage - Wiredot printer |date=2012 |publisher=[[Information Processing Society of Japan]] (IPSJ) |url=https://museum.ipsj.or.jp/en/heritage/Wiredot_printer.html |access-date=2016-10-31 |url-status=live |archive-url=https://web.archive.org/web/20161031182147/http://museum.ipsj.or.jp/en/heritage/Wiredot_printer.html |archive-date=2016-10-31}}</ref><ref name="OKI_2013_1">{{cite web |title=OKI's Wiredot Printer Receives Information Processing Technology Heritage Certification in Japan |location=Mount Laurel, New Jersey, USA |date=2013-03-14 |url=http://www.okidata.com/oki-datas-wiredot-printer-receives-heritage-certification |access-date=2016-10-31 |url-status=live |archive-url=https://web.archive.org/web/20130820163044/http://okidata.com/oki-datas-wiredot-printer-receives-heritage-certification |archive-date=2013-08-20}}</ref><ref name="OKI_2013_2">{{cite web |title=OKI Printer aus 1968 als technologisch wertvolles Erbe ausgezeichnet |language=de |date=2013-03-26 |url=http://www.oki.at/press-centre/press-releases/detail.aspx?id=tcm:93-153208-16 |access-date=2016-10-31 |url-status=live |archive-url=https://web.archive.org/web/20161031183409/http://www.oki.at/press-centre/press-releases/detail.aspx?id=tcm%3A93-153208-16 |archive-date=2016-10-31}}</ref>

In 1970<ref name="webster">{{cite book |last=Webster |first=Edward C. |title=Print Unchained: Fifty Years of Digital Printing: A Saga of Invention and Enterprise |publisher=DRA of Vermont |year=2000 |isbn=0-9702617-0-5 |location=West Dover, VT}}</ref> [[Digital Equipment Corporation]] (DEC) introduced an impact [[dot matrix printers|dot matrix printer]], the [[DECwriter |LA30]], as did [[Centronics]] (then of [[Hudson, New Hampshire|Hudson]], [[New Hampshire]]): the Centronics 101.<ref name="webster" /><ref>The first '''non'''-impact dot matrix printer was marketed by IBM in 1957: {{cite web |title=History of Computer Printers |url=http://www.inksell.com/tip-printerhistory.html |access-date=2017-12-12 |url-status=dead |archive-url=https://web.archive.org/web/20171212140804/http://www.inksell.com/tip-printerhistory.html |archive-date=2017-12-12}}</ref><ref>{{cite web |author=Mary Brandel |title=1957: IBM introduces the first dot-matrix printer |date=May 12, 1999 |website=[[CNN]] |url=http://www.cnn.com/TECH/computing/9905/12/1957.idg/index.html |access-date=December 12, 2017 |url-status=live |archive-url=https://web.archive.org/web/20090425132250/http://www.cnn.com/TECH/computing/9905/12/1957.idg/index.html |archive-date=April 25, 2009}}</ref> The search for a reliable printer mechanism led it to develop a relationship with [[Brother Industries|Brother Industries, Ltd]] of [[Japan]], and the sale of Centronics-badged Brother printer mechanisms equipped with a Centronics print head and Centronics electronics. Unlike Digital, Centronics concentrated on the low-end [[line printer]] marketplace with their distinctive units. In the process, they designed the [[parallel port|parallel electrical interface]] that was to become standard on most printers until it began to be replaced by the [[Universal Serial Bus]] (USB) in the late 1990s.

DEC was a major vendor, albeit with a focus on use with their PDP minicomputer line.<ref name="MAN50">{{cite book |title=LA50 Printer: Programmer Reference Manual (EK-OLA50-RM-001) |date=1982 |publisher=Educational Services of Digital Equipment Corporation}}</ref> Their LA30 30 character/second (CPS) dot matrix printer, the first of many, was introduced in 1970. In the mid-1980s, dot-matrix printers were dropping in price,<ref name="NYT.dot2"/>{{efn|"they are costing less all the time. In the budget category, a few new machines stand out..."<ref name=NYT.dot/>}} and began to outsell [[daisywheel printer]]s, due to their higher speed and versatility.<ref name="MostCom">{{cite web |title=What Is the Difference Between Impact Printers and Non-Impact Printers? |website=Small Business - Chron.com |url=https://smallbusiness.chron.com/difference-between-impact-printers-nonimpact-printers-56823.html |access-date=2023-05-10 |url-status=live |archive-url=https://web.archive.org/web/20230510174840/https://smallbusiness.chron.com/difference-between-impact-printers-nonimpact-printers-56823.html |archive-date=2023-05-10}}</ref> The Apple [[ImageWriter]] was a popular consumer dot matrix printer in the 1980s until the mid-1990s.

In the 1970s and 1980s, dot matrix impact printers were generally considered the best combination of cost and versatility, and until the 1990s were by far the most common form of printer used with [[personal computer|personal]] and [[home computer]]s.<ref>{{cite web |title=Computer peripheral or Peripheral Devices |date=17 April 2017 |url=https://www.slideshare.net/AdarshkumarYadav/computer-peripheral-or-peripheral-devices-75090737 |access-date=18 October 2018 |url-status=live |archive-url=https://web.archive.org/web/20170424071958/https://www.slideshare.net/AdarshkumarYadav/computer-peripheral-or-peripheral-devices-75090737 |archive-date=24 April 2017 |quote=A report on Computer peripheral devices ... impact printers were generally considered the best combination of expense and versatility, and until the 1990s they were ...}}</ref>

Increased pincount of the printhead from 7, 8, 9 or 12 pins to 18, 24, 27, or 36 permitted superior print quality, which was necessary for success in Asian markets to print legible [[CJKV characters]].<ref name="MX6-4">{{cite book |title=High speed, near letter quality dot matrix printers Popular Science Dec 1983 |date=December 1983 |url=https://books.google.com/books?id=kawCnk4051wC&pg=PA139}}</ref> Epson's 24-pin LQ-series rose to become the new de facto standard, at 24/180&nbsp;inch (per pass – 7.5&nbsp;lpi). Not only could a 24-pin printer lay down a denser dot-pattern in a single pass, it could simultaneously cover a larger area and print more quickly. Although the text quality of a 24-pin was still visibly inferior to a true [[letter-quality printer]] such as a daisy wheel or laser printer, print quality was greatly superior to a 9-pin printer. As manufacturing costs declined, 24-pin printers gradually replaced 9-pin printers.

By the dawn of the 1990s, inkjet printers became more common as PC printers.<ref>{{cite web |title=InkJet |website=HPmuseum |url=https://www.hpmuseum.net/exhibit.php?class=5&cat=20 |access-date=2018-10-18 |url-status=live |archive-url=https://web.archive.org/web/20180926140236/http://www.hpmuseum.net/exhibit.php?class=5&cat=20 |archive-date=2018-09-26 |quote=In the early 1990s, inkjet printer sales started a dramatic growth that would last over ten years.}}</ref><ref>{{cite magazine |title=Old Computer Products that refuse to die |date=March 31, 2009 |magazine=PC World |url=https://www.pcworld.com/article/162106/old_computer_products_that_refuse_to_die.html |quote=Beginning in the early 1990s, inkjet printers ...}}</ref>

==Design==
[[File:Dot matrix example text.png|thumb|left|Typical output from a dot matrix printer operating in ''draft'' mode. This entire image represents an area of printer output approximately {{convert|4.5|x|1.5|cm|abbr=on}} in size.]]
[[File:Printer dot matrix EPSON VP-500.jpg|thumb|[[Epson]] VP-500 Printer with its cover removed]]
[[File:Tally Genicom T2240 print head assembly - cross section.jpg|thumb|Tally Genicom T2240, 24-Pin printer head cross section. This print head has 24 solenoids at the top arranged radially inside a circular casing. Each solenoid is connected to a lever, which is connected to a long rod, which acts as a pin at the bottom of the print head.]]

Dot matrix printing uses a print head that moves 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]]. However, unlike a typewriter or [[daisy wheel printer]], letters are drawn out of a dot matrix, and thus, varied fonts and arbitrary graphics can be produced.

Each dot is produced by a tiny metal rod, also called a "wire" or "pin", which is driven forward by the power of a tiny [[electromagnet]] or [[solenoid]], either directly or through small levers (pawls).<ref name=Ink.NotDot/> {{anchor|Butterfly}}Facing the ribbon and the paper is a small guide plate named ribbon mask holder or protector, sometimes also called ''butterfly''<!-- they are officially called butterfly (Schmetterling) at least in the [[NEC Pinwriter]] series --> for its typical shape. It is pierced with holes to serve as guides for the pins. The plate may be made of hard plastic or an artificial jewel such as [[sapphire]] or [[ruby]].

The portion of the printer that contains the pin is called the print head. When running the printer, it generally prints one line of text at a time. The printer head is attached to a metal bar that ensures correct alignment, but horizontal positioning is controlled by a band that attaches to [[sprocket]]s on two wheels at each side which is then driven with an electric motor.<ref>{{cite web |title=MX-70 - User Manual |website=epson.com |url=https://files.support.epson.com/pdf/mx70__/mx70__u1.pdf |access-date=2018-10-17 |url-status=live |archive-url=https://web.archive.org/web/20181018043227/https://files.support.epson.com/pdf/mx70__/mx70__u1.pdf |archive-date=2018-10-18}}</ref> This band may be made of stainless steel, phosphor bronze or beryllium copper alloys, nylon or various synthetic materials with a twisted nylon core to prevent stretching.  Actual position can be found out either by dead count using a [[stepper motor]], [[incremental encoder|rotary encoder]] attached to one wheel, or a transparent plastic band with markings that is read by an optical sensor on the printer head (common on [[inkjet printing|inkjets]]).

Because the printing involves mechanical pressure, dot matrix printers can create [[carbon copy|carbon copies]] and [[carbonless copy paper|carbonless copies]].<ref>{{cite web |title=impact printer |website=AllBusiness.com (Barrons) |url=https://www.allbusiness.com/barrons_dictionary/dictionary-impact-printer-4946840-1.html |access-date=2019-10-12 |url-status=live |archive-url=https://web.archive.org/web/20191012060734/https://www.allbusiness.com/barrons_dictionary/dictionary-impact-printer-4946840-1.html |archive-date=2019-10-12}}</ref>
[[File:Epson dot matrix printer.jpg|right|thumb|Epson LQ 850]]
Although nearly all inkjet, [[thermal printer|thermal]], and [[laser printer]]s also print closely spaced dots rather than continuous lines or characters, it is not customary to call them dot matrix printers.<ref name=Ink.NotDot>{{cite web |title=Dot Matrix vs. Inkjet |website=YourBusiness.AZcentral.com |url=https://yourbusiness.azcentral.com/dot-matrix-vs-inkjet-2827.html |access-date=2019-10-12 |url-status=live |archive-url=https://web.archive.org/web/20191012060734/https://yourbusiness.azcentral.com/dot-matrix-vs-inkjet-2827.html |archive-date=2019-10-12}}</ref>

Dot matrix printers have one of the lowest printing costs per page.{{citation needed|date=October 2023}}

They are able to use fanfold [[continuous paper]] with tractor holes.

Dot matrix printers create noise when the pins or typeface strike the ribbon to the paper,<ref name="AutoX6-5"/> and sound-damping enclosures may have to be used in quiet environments.

They can only print lower-resolution graphics, with limited color performance, limited quality, and lower speeds compared to non-impact printers.<ref>{{cite web |title=Full Color Dot Matrix Is The Art We Need |date=January 19, 2019 |url=https://hackaday.com/2019/01/19/full-color-dot-matrix-is-the-art-we-need/ |access-date=April 20, 2021 |url-status=live |archive-url=https://web.archive.org/web/20210420063410/https://hackaday.com/2019/01/19/full-color-dot-matrix-is-the-art-we-need/ |archive-date=April 20, 2021}}</ref><ref>{{cite web |title=PC Mag |date=24 November 1992 |url=https://books.google.com/books?id=RJBJPJvct40C&q=4+color+ribbon+dot+matrix+pc+mag&pg=PA362}}</ref><ref>{{cite web |title=PC Mag |date=13 November 1990 |url=https://books.google.com/books?id=WIeyaksLI8gC&q=4+color+ribbon+dot+matrix+pc+mag&pg=PT374}}</ref>

==Variations==
[[File:Epson Wide Carriage 9-pin printer - with legal paper 8.5x14.jpg|thumb|left|An example of a wide-carriage printer, designed for paper 14 inches wide, shown with legal paper loaded (8.5"×14")]]
[[File:Tally Genicom T2240 print head pins.jpg|thumb|upright|Print head of a 24-pin printer (Tally Genicom T2240)]]
[[File:9 nadel druckkopf-star nl10--hinnerk ruemenapf vs01-p50.jpg|thumb|upright|Print head of a 9-pin printer (Star NL10)]]

The common serial dot matrix printers use a horizontally moving print head.<ref>{{cite web |title=10 Rules You Should Know To Keep Your Dot Matrix Printer Operational |website=MicomData.com |url=https://www.midcomdata.com/wp-content/uploads/2014/05/10_Rules_You_Should_Know_To_Keep_Your_Dot_Matrix_Printer_Operational.pdf |access-date=2018-10-17 |url-status=live |archive-url=https://web.archive.org/web/20181018043509/http://www.midcomdata.com/wp-content/uploads/2014/05/10_Rules_You_Should_Know_To_Keep_Your_Dot_Matrix_Printer_Operational.pdf |archive-date=2018-10-18}}</ref> The print head can be thought of featuring a single vertical column of seven or more pins approximately the height of a character box. In reality, the pins are arranged in up to four vertically or/and horizontally slightly displaced columns in order to increase the dot density and print speed through interleaving without causing the pins to jam. Thereby, up to 48 pins<ref>{{cite web |title=Dot Matrix printers |website=MindMachine.co.uk |url=https://mindmachine.co.uk/book/print_06_dotmatrix.html |access-date=2018-10-17 |url-status=live |archive-url=https://web.archive.org/web/20191012060733/https://mindmachine.co.uk/book/print_06_dotmatrix.html |archive-date=2019-10-12}}</ref> can be used to form the characters of a line while the print head moves horizontally. The printing speed of serial dot matrix printers with moving heads varies from 30<ref>DEC LA30</ref> to 1550 [[printing speed|characters per second (cps)]].<ref>{{cite web |title=Epson DFX-9000 |url=https://www.epson.de/products/printers/dot-matrix-printers/epson-dfx-9000#specifications |archive-url=https://web.archive.org/web/20160505034554/http://www.epson.de/products/printers/dot-matrix-printers/epson-dfx-9000#specifications |archive-date=2016-05-05}}</ref>

In a considerably different configuration, so called line dot matrix printers<ref>{{cite web |title=Dot Matrix Printing is defined here as a labelling term |url=https://www.labelplanet.co.uk/glossary-of-label-terms/dot-matrix-printing.php |access-date=2018-10-17 |url-status=dead |archive-url=https://web.archive.org/web/20181018043357/https://www.labelplanet.co.uk/glossary-of-label-terms/dot-matrix-printing.php |archive-date=2018-10-18}}</ref> or [[line matrix printer]]s use a fixed print head almost as wide as the paper path utilizing a horizontal line of thousands of pins for printing. Sometimes two horizontally slightly displaced rows are used to improve the effective dot density through interleaving. While still line-oriented, these printers for the professional heavy-duty market effectively print a whole line at once while the paper moves forward below the print head. Line matrix printers are capable of printing much more than 1000 cps, resulting in a throughput of up to 800 pages per hour.

A variation on the dot matrix printer was the cross hammer dot printer, patented by Seikosha in 1982.<ref>{{cite patent |country=US |number=4462705 |title=Cross hammer dot printer |inventor1-first=Hayashi |inventor1-last=Mikio |inventor2-first=Mizutani |inventor2-last=Seiki |pubdate=1984-07-31}}</ref> The smooth cylindrical roller of a conventional printer was replaced by a spinning, fluted cylinder. The print head was a simple hammer, with a vertical projecting edge, operated by an electromagnet. Where the vertical edge of the hammer intersected the horizontal flute of the cylinder, compressing the paper and ribbon between them, a single dot was marked on the paper. Characters were built up of multiple dots.

==Manufacturers and models==
{{Summarize section|date=May 2023}}

===DEC===
{{Main|DECwriter}}
Unlike the [[#LA30|LA30]]'s 80-column, uppercase-only 5 x 7 dot matrix, DEC's product line grew. New models included:
* LA36 (1974): supported upper and lower case, with up to 132 columns of text (also 30 CPS)
* LA34: a lower-cost alternative to the LA36
* LA38: an LA34 with more features
* LA180: 180 CPS
* LS120: 120 CPS
* LA120: 180 CPS (and some advanced features)
* LA12: a portable terminal – the [[DECwriter#DECwriter Correspondent|DECwriter Correspondent]]<ref>{{cite magazine |title=DEC Introduces New 'Correspondent' |date=April 1982 |magazine=Hardcopy |page=13}}</ref>

====LA30====
The DECwriter LA30 was a 30 character per second dot matrix [[printing terminal]] introduced in 1970 by [[Digital Equipment Corporation]] (DEC) of [[Maynard, Massachusetts]].<ref>{{cite book |title=PDP-11 Processor Handbook |date=1973 |publisher=[[Digital Press]], [[Digital Equipment Corporation]] (DEC) |pages=1–4 |quote=Digital Equipment Corporation (DEC) designs and manufacturers many of the peripheral devices offered with PDP-11's. As a designer and manufacturer of peripherals, DEC can offer extremely reliable equipment... The LA30 DECwriter, a totally DEC-designed and built teleprinter, can serve as an alternative to the Teletype.}}</ref>

It printed 80 columns of uppercase-only 7 × 5 [[dot matrix]] characters across a unique-sized paper. The printhead was driven by a [[stepper motor]] and the paper was advanced by a noisy [[solenoid]] [[ratchet (device)|ratchet]] drive. The LA30 was available with both a [[parallel interface]] (LA30-P) and a [[serial interface]] (LA30-S); however, the serial LA30 required the use of [[fill character]]s during the carriage-return. In 1972, a receive-only variation named LA30A became available.

====LA36====
The LA30 was followed in 1974 by the LA36,<ref>{{cite web |title=The DEC LA36 Dot Matrix Printer Made Business Printing Faster |url=https://biztechmagazine.com/article/2017/03/dec-la36-dot-matrix-printer-made-business-printing-faster-and-more-efficient |access-date=2018-10-18 |url-status=live |archive-url=https://web.archive.org/web/20181018122252/https://biztechmagazine.com/article/2017/03/dec-la36-dot-matrix-printer-made-business-printing-faster-and-more-efficient |archive-date=2018-10-18 |quote=DEC brought the LA36 to market in 1974}}</ref> which achieved far greater commercial success,<ref name="UK2">{{cite web |title=Digital DECWriter II |website=ComputingHistory.org.uk |url=https://www.computinghistory.org.uk/det/3367/Digital-DECWriter-II |access-date=2018-10-18 |url-status=live |archive-url=https://web.archive.org/web/20181018122258/http://www.computinghistory.org.uk/det/3367/Digital-DECWriter-II |archive-date=2018-10-18 |quote=The LA36 DECwriter II was the companys first commercially successful ... The printer mechanism uses a dot-matrix technique to print 132 columns of text across standard 14 inch computer forms}}</ref> becoming for a time the standard dot matrix computer terminal. The LA36 used the same print head as the LA30 but could print on forms of any width up to 132 columns of mixed-case output on standard [[line printer#green bar paper|green bar fanfold paper]].<ref name="UK2"/> The carriage was moved by a much-more-capable [[servo drive]] using a [[DC electric motor]] and an optical encoder / [[tachometer]]. The paper was moved by a stepper motor. The LA36 was only available with a serial interface but unlike the earlier LA30, no fill characters were required. This was possible because, while the printer never communicated at faster than 30 characters per second, the mechanism was actually capable of printing at 60 characters per second. During the carriage return period, characters were ''buffered'' for subsequent printing at full speed during a catch-up period. The two-tone buzz produced by 60-character-per-second catch-up printing followed by 30-character-per-second ordinary printing was a distinctive feature of the LA36, quickly copied by many other manufacturers well into the 1990s. Most efficient dot matrix printers used this buffering technique.

Digital technology later broadened the basic LA36 line into a wide variety of dot matrix printers.

====LA50====
The DEC LA50 was designed to be a "compact, dot matrix"<ref name="MAN50"/> printer. When in graphic mode (as opposed to text mode), the printhead can generate graphic images. When in ([[bitmap]]) graphics mode, the LA50 can receive and print [[Sixel]]{{efn|short for "six pixels:" a pattern six [[pixel]]s high and one wide, resulting in 64 possible patterns.}} graphics format.
[[File:Sixel Wikipedia logo.png|thumb|The Wikipedia logo, converted to [[Sixel]] format]]

===Centronics 101===
{{Main|Centronics#Centronics 101}}
The [[Centronics#Centronics 101|Centronics 101]]<ref>Centronics and Digital Equipment corporation launch the dotmatrix printers, Centronics 101 and LA30 respectively. Centronics claimed to be the first..." {{cite book |author=Raveesh Mayya.K |title=BLITZ-THE IT QUIZ BOOK |date=2012 |publisher=Sapna Book House (P) |isbn=978-8128005800 |url=https://books.google.com/books?isbn=8128005804}}</ref> (introduced 1970) was highly innovative and affordable at its inception. Some selected specifications:
* Print speed: 165 characters per second
* Weight: 155 pounds (70.3&nbsp;kg)
* Size: 27 ½" W x 11 ¼" H x 19 ¼ D (approx. 70&nbsp;cm x 29&nbsp;cm x 49&nbsp;cm)
* Shipping: 200 pounds (approx. 91&nbsp;kg), wooden crate, unpacked by removal of 36 screws
* Characters: 62: 10 numeric, 26 upper case, and 26 special characters (no lower case)
* Character size: 10 characters per inch (10 "''pitch''")
* Line spacing: 6 lines per inch (6 LPI)
* Vertical control: punched tape reader for top of form and vertical tab
* Forms thickness: original plus four copies
* Interfaces: Centronics parallel, optional RS-232 serial

===IBM 5103===
[[File:IBM 5103 printer in Tekniska museet (1).jpg|thumb|IBM 5103 printer in [[Swedish National Museum of Science and Technology|Tekniska museet]]]]
The IBM 5103<ref>{{cite book |title=IBM 5103 printer |date=April 1979 |url=https://www.computerhistory.org/collections/catalog/102621955 |access-date=2021-07-15 |url-status=live |archive-url=https://web.archive.org/web/20210715210729/https://www.computerhistory.org/collections/catalog/102621955 |archive-date=2021-07-15}}</ref> was the only IBM printer that could be attached to the [[IBM 5100]], an early day portable computer. Printing was 8 DPI, 10 pitch, 6 LPI, and capable of printing bidirectionally from a 128-character set. Two models were offered:<ref>{{cite web |title=IBM Archives: IBM 5120 Computing System |date=23 January 2003 |website=[[IBM]] |url=https://www.ibm.com/ibm/history/exhibits/pc/pc_6.html |access-date=15 July 2021 |url-status=dead |archive-url=https://web.archive.org/web/20210516205203/https://www.ibm.com/ibm/history/exhibits/pc/pc_6.html |archive-date=16 May 2021 |quote=two previously announced products: the IBM 5103 models 11 and 12 bidirectional, matrix printers}}</ref> 80 and 120 characters per second.<ref>{{cite web |title=IBM 5103 Dot matrix printer |website=computermuseum.informatik.uni-stuttgart.de |url=https://computermuseum.informatik.uni-stuttgart.de/dev/ibm_5110/technik/en/5103.html |access-date=2021-07-15 |url-status=live |archive-url=https://web.archive.org/web/20210715210729/http://computermuseum.informatik.uni-stuttgart.de/dev/ibm_5110/technik/en/5103.html |archive-date=2021-07-15}}</ref>

====Near Letter Quality (NLQ)====
{{Main|Near letter-quality printing}}
''Near Letter Quality'' mode—informally specified as almost good enough to be used in a business letter<ref name="MX6-3">{{cite book |title=Dot Matrix, InfoWorld Jul 28, 1986 |date=28 July 1986 |url=https://books.google.com/books?id=Vy8EAAAAMBAJ&q=dot%20matrix%20letter%20quality&pg=PA40}}</ref>—endowed dot-matrix printers with a simulated typewriter-like quality. By using multiple passes of the carriage, and higher dot density, the printer could increase the effective resolution. In 1985, ''The New York Times'' described the use of "''near letter-quality,'' or NLQ" as "just a neat little bit of hype"<ref name="NYT.dot2"/> but acknowledged that they "really show their stuff in the area of fonts, print enhancements and graphics."

NLQ printers could generally be set to print in "draft mode", in which case a single pass of the print head per line would be used. This produced lower quality print at much higher output speed.

==PC usage==
In 1985, ''PC Magazine'' wrote "for the average personal computer user dot matrix remains the most workable choice".<ref name="NYT.PCdot85"/> At the time, IBM sold [[Epson]]'s [[Epson MX-80|MX-80]] as their IBM 5152.<ref>Subhead: "Note that the IBM 5152 is a rebadged Epson MX-80." {{cite web |title=IBM 5152 - Documentation Pointers |url=https://www.minuszerodegrees.net/5152/doco/5152_documentation.htm |access-date=2017-12-12 |url-status=live |archive-url=https://web.archive.org/web/20180921184049/http://minuszerodegrees.net/5152/doco/5152_documentation.htm |archive-date=2018-09-21}}</ref>

Another technology, [[inkjet printing]], which uses the [[razor and blades model|razor and blades business model]] (give away the razor handle, make money on the razor blade)<ref>"Printer makers, led by [[Hewlett-Packard]] Co., have long used the razor-and-blade pricing model, in which the hardware is sold for little or no profit." {{cite news |title=Kodak's Strategy For First Printer -- Cheaper Cartridges |newspaper=The Wall Street Journal |url=https://www.wsj.com/articles/SB117073503026399219 |access-date=2018-01-29 |url-status=live |archive-url=https://web.archive.org/web/20171213010339/https://www.wsj.com/articles/SB117073503026399219 |archive-date=2017-12-13}}</ref> has reduced the value of the low cost for the printer: "a price per milliliter on par with liquid gold" for the ink/toner.<ref name="CW.ink">{{cite news |author=Robert L. Mitchell |title=HP explains why printer ink is so expensive |date=May 24, 2010 |newspaper=Computerworld |url=https://www.computerworld.com/article/2469251/emerging-technology/hp-explains-why-printer-ink-is-so-expensive.html |access-date=December 12, 2017 |url-status=live |archive-url=https://web.archive.org/web/20171212193146/https://www.computerworld.com/article/2469251/emerging-technology/hp-explains-why-printer-ink-is-so-expensive.html |archive-date=December 12, 2017}}</ref>

===Personal computers===
In June 1978, the [[Epson]] TX-80/TP-80,<ref>{{cite magazine |title=Epson America, Inc. |department=Peripherals at NCC |magazine=Computerworld |volume=XIII |issue=22 |date=28 May 1979 |publisher=IDG Enterprise |via=Google Books |url=https://books.google.com/books?id=BO24urtO-OoC&pg=RA1-PA32}}</ref> an 8-pin dot-matrix printer mainly used for the [[Commodore PET]] computer, was released. This and its successor, the 9-pin [[Epson MX-80|MX-80/MP-80]] (introduced in 1979–1980),<ref>{{cite web |title=Epson Corporate Information U.S. History |website=epson.com |url=http://www.epson.com/cgi-bin/Store/AboutCorpHistory.jsp |url-status=dead |archive-url=https://web.archive.org/web/20130802071715/http://www.epson.com/cgi-bin/Store/AboutCorpHistory.jsp |archive-date=2013-08-02}}</ref> sparked the popularity of impact printers in the personal computer market.<ref>{{cite web |title=MX-80 - Epson |url=http://global.epson.com/company/corporate_history/milestone_products/11_mx80.html |access-date=2017-12-12 |url-status=dead |archive-url=https://web.archive.org/web/20171218204310/http://global.epson.com/company/corporate_history/milestone_products/11_mx80.html |archive-date=2017-12-18}}</ref> The MX-80 combined affordability with good-quality text output (for its time). Early impact printers (including the MX) were notoriously loud during operation, a result of the hammer-like mechanism in the print head. The MX-80's low dot density (60 dpi horizontal, 72&nbsp;dpi vertical) produced printouts of a distinctive "computerized" quality. When compared to the crisp typewriter quality of a daisy-wheel printer, the dot-matrix printer's legibility appeared especially bad. In office applications, output quality was a serious issue, as the dot-matrix text's readability would rapidly degrade with each [[photocopier|photocopy]] generation.

====PC software====
Initially, third-party printer enhancement software offered a quick fix to the quality issue. General strategies were:
* doublestrike (print each line twice), and
* double-density mode (slow the print head to allow denser and more precise dot placement).

Some newer dot-matrix impact printers could reproduce [[bitmap]] images via "dot-addressable" capability. In 1981, Epson offered a retrofit [[EPROM]] kit called [[Graftrax]] to add this to many early MX series printers. Banners and signs produced with software that used this ability, such as [[Broderbund]]'s [[The Print Shop|Print Shop]], became ubiquitous in offices and schools throughout the 1980s.

As carriage speed increased and dot density increased (from 60 dpi up to 240 dpi), with some adding color printing, additional typefaces allowed the user to vary the text appearance of printouts. Proportional-spaced fonts allowed the printer to imitate the non-uniform character widths of a typesetter, and also darker printouts. 'User-downloadable fonts' gave until the printer was powered off or soft-reset. The user could embed up to two [[#Near Letter Quality (NLQ)|NLQ]] custom typefaces in addition to the printer's built-in (ROM) typefaces.
[[File:Ink cartridge and inside zoom.jpg|thumb|Upper: [[Inmac]] ink [[ribbon]] cartridge with black ink for a dot matrix printer. Lower: Inked and folded, the ribbon is pushed back into the cartridge by the roller mechanism to the left.]]

===Contemporary use===
The desktop impact printer was gradually replaced by the [[inkjet printer]]. When [[Hewlett-Packard]]'s {{cite patent |country=US |number=4578687 |status=patent}} expired on steam-propelled photolithographically produced ink-jet heads in 2004, the inkjet mechanism became available to the printer industry. For applications that did not require impact (e.g. carbon-copy printing), the inkjet was superior in nearly all respects: comparatively quiet operation, faster print speed, and output quality almost as good as a laser printer. By 1995, [[inkjet technology]] had surpassed dot matrix impact technology in the mainstream market and relegated dot matrix to niche applications.<ref name="Dyszel">{{cite journal |last1=Dyszel |first1=William |title=Hammering On |date=7 November 1995 |journal=PC Magazine |location=New York |publisher=Ziff-Davis |volume=14 |issue=19 |pages=285–296 |url=https://books.google.com/books?id=qxIpLj9BmV8C&pg=PA285 |access-date=27 April 2020}}</ref>

{{As of|2021}}, dot matrix impact technology remains in use in devices and applications such as:{{citation needed|date=October 2023}}
* [[Cash register]]s,
* [[Automatic Teller Machine|ATMs]],
* Banking, passbook and cashier's checks,
* Time cards and parking stubs,
* Multi-layer contracts for signature,
* [[Fire alarm system]]s,
* Point-of-sale terminals,
* British and Irish fire stations for turnout sheets,
* Applications requiring continuous output on fan-fold paper.

[[Thermal printing]] is gradually supplanting them in some of these applications, but full-size dot-matrix impact printers are still used to print [[carbonless copy paper|multi-part stationery]]. For example, dot matrix impact printers are still used at bank tellers and auto repair shops, and other applications where use of [[continuous stationery|tractor feed paper]] is desirable such as [[data logging]] and [[aviation]]. Most of these printers now come with USB interfaces as a standard feature to facilitate connections to modern computers without legacy ports.

==Notes==
<references group="lower-alpha" responsive="1"></references>

==See also==
* [[Daisy wheel printing]]
* [[ESC/P]]
* [[Dye-sublimation printer]]
* [[IBM Proprinter]]
* [[Typeball printer]]

==References==
{{Reflist|refs=
<ref name="AutoX6-5">{{cite web |title=Panasonic KX-P2123 |website=atarimagazines.com |url=https://www.atarimagazines.com/compute/issue144/G10_Panasonic_KXP2123.php |access-date=2021-06-11 |url-status=live |archive-url=https://web.archive.org/web/20210611232846/https://www.atarimagazines.com/compute/issue144/G10_Panasonic_KXP2123.php |archive-date=2021-06-11}}</ref>
}}

==External links==
{{Commons category|Dot matrix printers}}
* {{cite web |last=Tomash |first=Erwin |title=The U.S. Computer Printer Industry |website=jacques-andre.fr |url=https://jacques-andre.fr/chi/chi90/tomash.html |access-date=2023-11-21}}

[[Category:Dot matrix printers]]
[[Category:American inventions]]
[[Category:20th-century inventions]]
[[Category:Computer-related introductions in 1970]]
[[Category:Printing technology]]

[[fr:Imprimante#Imprimante à aiguilles ou imprimante matricielle]]