Editing Printer (computing) (section)

==Technology==
The choice of print technology has a great effect on the cost of the printer and cost of operation, speed, quality and permanence of documents, and noise. Some printer technologies do not work with certain types of physical media, such as [[carbon paper]] or [[transparency (projection)|transparencies]].

A second aspect of printer technology that is often forgotten is resistance to alteration: liquid [[ink]], 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 (printing)|toner]] or solid inks, which do not penetrate below the paper surface.

Cheques can be printed with liquid ink or on special cheque paper with toner anchorage so that alterations may be detected.<ref>{{cite web|url=http://www.abagnale.com/pdf/protection_b.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.abagnale.com/pdf/protection_b.pdf |archive-date=2022-10-09 |url-status=live|title=Protection Against Cheque Fraud|publisher=abagnale.com|author=Abagnale, Frank|author-link=Frank Abagnale|year=2007|access-date=2007-06-27}}</ref> The machine-readable lower portion of a cheque must be printed using [[magnetic ink character recognition|MICR]] toner or ink. Banks and other clearing houses employ automation equipment that relies on the [[magnetic flux]] from these specially printed characters to function properly.

===Modern print technology===

The following [[printing]] technologies are routinely found in modern printers:

====Laser printers and other toner-based printers====
{{main|Laser printing}}

A [[Laser printing|laser printer]] rapidly produces high quality text and graphics. As with digital [[photocopier]]s and multifunction printers (MFPs), laser printers employ a [[xerography|xerographic]] printing process but differ from analog photocopiers in that the image is produced by the direct scanning of a [[laser]] beam across the printer's [[photodetector|photoreceptor]].

Another toner-based printer is the [[LED printer]] which uses an array of [[light-emitting diode|LEDs]] instead of a [[laser]] to cause toner [[adhesion]] to the print drum.

====Liquid inkjet printers====

[[File:Ink-jet-cartridge.jpg|thumb|Liquid ink cartridge from Hewlett-Packard HP 845C inkjet printer]]
[[File:HP Deskjet All in One Printer.jpg|thumb|300px|right|HP Deskjet, an inkjet printer]]
[[Inkjet printing|Inkjet printers]] operate by propelling variably sized droplets of liquid ink onto almost any sized page. They are the most common type of computer printer used by consumers.

====Solid ink printers====
{{main|Solid ink}}

[[Solid ink]] printers, also known as phase-change ink or hot-melt ink printers, are a type of [[thermal transfer printer]], graphics sheet printer or 3D printer . They use solid sticks, crayons, pearls or granular ink materials.  Common inks are [[CMYK color model|CMYK]]-colored ink, similar in consistency to candle wax, which are melted and fed into a piezo crystal operated print-head. A Thermal transfer printhead jets the liquid 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 color office printers and are excellent at printing on transparencies and other non-porous media. Solid ink is also called phase-change or hot-melt ink and was first used by Data Products and Howtek, Inc., in 1984.<ref>{{Cite book|last=Gregory|first=P|title=Editor|publisher=Blackie Academic & Professional for Chapman and Hall|year=1996|isbn=0-7514-0238-9|location=Great Britain|pages=113–138}}</ref>   Solid ink printers can produce excellent results with text and images. Some solid ink printers have evolved to print 3D models, for example, Visual Impact Corporation<ref>{{Cite book|last=Burns|first=Marshall|url=https://www.worldcat.org/oclc/27810960|title=Automated fabrication : improving productivity in manufacturing|date=1993|publisher=PTR Prentice Hall|isbn=0-13-119462-3|location=Englewood Cliffs, N.J.|pages=97|oclc=27810960}}</ref> of Windham, NH was started by retired Howtek employee, Richard Helinski whose 3D patents US4721635 and then US5136515 was licensed to Sanders Prototype, Inc., later named Solidscape, Inc.  Acquisition and operating costs are similar to [[Laser printing|laser printers]]. Drawbacks of the technology include high [[energy conservation|energy consumption]] 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]]s, and are difficult to feed through [[automatic document feeder]]s, but these traits have been significantly reduced in later models. This type of thermal transfer printer is only available from one manufacturer, [[Xerox]], manufactured as part of their [[Xerox Phaser]] office printer line. Previously, [[solid ink]] printers were manufactured by [[Tektronix]], but Tektronix sold the printing business to Xerox in 2001.

====Dye-sublimation printers====
{{main|Dye-sublimation printer}}

[[File:RGB dye sublimation panels.jpg|thumb|300px|A disassembled dye sublimation cartridge]]
A dye-sublimation printer (or dye-sub printer) is a printer that employs a printing process that uses heat to transfer dye to a medium such as a [[plastic card]], paper, or [[canvas print|canvas]]. The process is usually to lay one color at a time using a ribbon that has color panels. Dye-sub printers are intended primarily for high-quality color applications, including color 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====

[[File:Twitter receipt printer.jpg|thumb|Receipt printer printing an X timeline]]
[[Thermal printing|Thermal printers]] work by selectively heating regions of special heat-sensitive paper. Monochrome thermal printers are used in cash registers, [[Automated teller machine|ATMs]], [[Fuel dispenser|gasoline dispensers]] and some older inexpensive fax machines. Colors can be achieved with special papers and different temperatures and heating rates for different colors; these colored sheets are not required in black-and-white output. One example is [[Zink (technology)|Zink]] (a portmanteau of "zero ink").

=== Obsolete and special-purpose printing technologies ===
[[File:Epson MX-80.jpg|thumb|[[Epson]] [[Epson MX-80|MX-80]], a popular model of dot-matrix printer in use for many years]]

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

====Impact printers====
{{anchor|Impact_printers}} Impact printers rely on a forcible impact to transfer ink to the media. The impact printer uses a print head that either hits the surface of the ink ribbon, pressing the ink ribbon against the paper (similar to the action of a [[typewriter]]), or, less commonly, hits the back of the paper, pressing the paper against the ink ribbon (the [[IBM 1403]] for example).  All but the [[dot matrix printer]] rely on the use of ''fully formed characters'', [[letterform]]s that represent each of the characters that the printer was capable of printing. In addition, most of these printers were limited to monochrome, or sometimes two-color, printing in a single typeface at one time, although [[emphasis (typography)|bolding]] and [[underlining]] of text could be done by "overstriking", that is, printing two or more impressions either in the same character position or slightly offset. Impact printers varieties include typewriter-derived printers, teletypewriter-derived printers, daisywheel printers, dot matrix printers, and line printers. Dot-matrix printers remain in common use <ref>{{cite web| url = https://www.printersbuddy.com/uses-of-printer/| title = Uses of Printer?| work = PrintersBuddy.com| access-date = 7 June 2022| archive-date = 17 January 2023| archive-url = https://web.archive.org/web/20230117222607/https://www.printersbuddy.com/uses-of-printer/| url-status = usurped}}</ref> in businesses where multi-part forms are printed. ''An overview of impact printing''<ref>{{cite journal | url=http://www.research.ibm.com/journal/rd/416/zable.pdf | url-status=dead | title=An overview of impact printing | journal=IBM Journal of Research and Development | author1=J. L. Zable | author2=H. C. Lee | pages=651–668 | volume=41 | issue=6 | date=November 1997 | doi=10.1147/rd.416.0651 | issn=0018-8646 | access-date=29 December 2008 | archive-date=9 October 2022 | archive-url=https://ghostarchive.org/archive/20221009/http://www.research.ibm.com/journal/rd/416/zable.pdf }}{{subscription required}}</ref> contains a detailed description of many of the technologies used.

=====Typewriter-derived printers=====
{{main|Friden Flexowriter|IBM Selectric typewriter}}
[[File:IBM Selectric typeball.jpg|thumb|left|Typeball print element from IBM Selectric-type printer]]

Several different computer printers were simply computer-controllable versions of existing electric typewriters. The [[Friden Flexowriter]] and [[IBM Selectric typewriter|IBM Selectric-based]] printers 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=====
{{main|Teleprinter}}

The common [[teleprinter]] could easily be interfaced with the computer and became very popular except for those computers manufactured by [[IBM]]. 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=====
[[File:Triumph-Adler Daisy wheel Cubic PS-92800.jpg|thumb|left|"Daisy wheel" print element]]
{{main|Daisy wheel printer}}
Daisy wheel printers operate in much the same fashion as a [[typewriter]]. 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]], 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 they could produce text which was as clear and crisp as a typewriter. The fastest letter-quality printers printed at 30 characters per second.

=====Dot-matrix printers=====
{{main|Dot matrix printer}}

[[File:Dot matrix example text.png|thumb|right|Sample output from  9-pin dot matrix printer (one character expanded to show detail)]]
The term [[dot matrix printer]] is used for impact printers that use a matrix of small [[pin]]s to transfer ink to the page.<ref>{{cite book
 |author1=David W. Beskeen |author2=Carol Cram |author3=Jennifer Duffy |author4=Lisa Friedrichsen |author5=Elizabeth Eisner Reding
 |title=Microsoft Office 2007 illustrated: Introductory
 |url=https://archive.org/details/microsoftofficew00jenn_1|url-access=registration|date=2008|publisher=Thomson Course Technology|location=Boston, Mass.|isbn=978-1418860479
 |edition=Windows XP}}</ref> The advantage of dot matrix over other impact printers is that they can produce [[graphic design|graphical]] 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
* [[Stored energy printer]]s

Dot matrix printers can either be [[character (computing)|character]]-based or line-based (that is, a single horizontal series of pixels across the page), referring to the configuration of the print head.

In the 1970s and '80s, 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 normally had either 9 or 24 pins on the print head (early 7 pin printers also existed, which did not print [[descender]]s). There was a period during the early home computer era when a range of printers were manufactured under many brands such as the [[Commodore International|Commodore]] VIC-1525 using the [[Seikosha]] '''Uni-Hammer''' system.  This used a single solenoid with an oblique striker that would be actuated 7 times for each column of 7 vertical pixels while the head was moving at a constant speed. The angle of the striker would align the dots vertically even though the head had moved one dot spacing in the time.  The vertical dot position was controlled by a synchronized longitudinally ribbed platen behind the paper that rotated rapidly with a rib moving vertically seven dot spacings in the time it took to print one pixel column.<ref>{{cite web|title=VIC-1525 Graphics Printer User Manual|url=http://www.classiccmp.org/cini/pdf/Commodore/VIC-1525%20Printer%20User%27s%20Manual.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.classiccmp.org/cini/pdf/Commodore/VIC-1525%20Printer%20User%27s%20Manual.pdf |archive-date=2022-10-09 |url-status=live|publisher=Commodore Computer|access-date=22 February 2015}}</ref> 24-pin print heads were able to print at a higher quality and started to offer additional type styles and were marketed as [[Dot matrix printing#Near Letter Quality .28NLQ.29|Near Letter Quality]] by some vendors. 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 favour for general use.

Some dot matrix printers, such as the NEC P6300, can be upgraded to print in color. This is achieved through the use of a four-color 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. Color graphics are generally printed in four passes at standard resolution, thus slowing down printing considerably. As a result, color 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 such as [[cash register]]s, or in demanding, very high volume applications like [[invoice]] printing. Impact printing, unlike laser printing, allows the pressure of the print head to be applied to a stack of two or more forms to print [[Multipart stationery|multi-part documents]] such as sales invoices and [[credit card]] receipts using [[continuous stationery]] with [[carbonless copy paper]]. It also has security advantages as ink impressed into a paper matrix by force is harder to erase invisibly. Dot-matrix printers were being superseded even as receipt printers after the end of the twentieth century.

=====Line printers=====
{{main|Line printer}}
Line printers print an entire line of text at a time. Four principal designs exist.
[[File:Drum-printer.jpg|thumb|left|Print drum from drum printer]]
* '' Drum printers'', where a horizontally mounted rotating drum carries the entire character set of the printer repeated in each printable character position.  The [[IBM 1132]] printer is an example of a drum printer.<ref>{{cite web|archive-date=2022-10-09|archive-url=https://ghostarchive.org/archive/20221009/https://www.cs.auckland.ac.nz/~alan/courses/r&rtc/773notes/01.0.1p.pdf|quote=drum. 120 print wheels. Hammer. Print wheels. Paper. Ribbon. ... 1132|title=Computer Science 773 Robotics and Real-time Control THE IBM 1132|url=https://www.cs.auckland.ac.nz/~alan/courses/r&rtc/773notes/01.0.1p.pdf|url-status=live}}</ref> Drum printers are also found in adding machines and other numeric printers (POS), the dimensions are compact as only a dozen characters need to be supported.<ref>{{cite web|access-date=22 February 2015|archive-date=26 March 2015|archive-url=https://web.archive.org/web/20150326180608/http://www.johnwolff.id.au/calculators/Tech/Logos240/Logos240.htm|author=John Wolff|publisher=John Wolff's Web Museum|title=The Olivetti Logos 240 Electronic Calculator - Technical Description|url=http://www.johnwolff.id.au/calculators/Tech/Logos240/Logos240.htm|url-status=live}}</ref>

[[File:PrinterIBM1403 090325.jpg|thumb|IBM 1403 line printer]]
* ''Chain or train printers'', where the character set is arranged multiple times around a linked chain or a set of character slugs in a track traveling horizontally past the print line.  The [[IBM 1403]] is perhaps the most popular and comes in both chain and train varieties.  The ''band printer'' is a later variant where the characters are embossed on a flexible steel band.  The LP27 from Digital Equipment Corporation is a band printer.
* ''Bar printers'', where the character set is attached to a solid bar that moves horizontally along the print line, such as the [[IBM 1443]].<ref>{{cite book|last=IBM Corporation|title=IBM 1443 PRINTER for 1620/1710 Systems|url=http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/1620/A26-5730-2_1443_printer_for_1620.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/1620/A26-5730-2_1443_printer_for_1620.pdf |archive-date=2022-10-09 |url-status=live}}</ref>
* A fourth design, used mainly on very early printers such as the IBM 402, features independent type bars, one for each printable position. Each bar contains the character set to be printed.  The bars move vertically to position the character to be printed in front of the print hammer.<ref>{{cite book|last=IBM Corporation|title=IBM 402, 403 and 419 Accounting Machines Manual of Operation|year=1963|url=http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/punchedCard/AccountingMachine/224-1614-13_402-403-419.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/punchedCard/AccountingMachine/224-1614-13_402-403-419.pdf |archive-date=2022-10-09 |url-status=live}}</ref>

In each 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.  Each system could have slight timing issues, which could cause minor misalignment of the resulting printed characters.  For drum or typebar printers, this appeared as vertical misalignment, with characters being printed slightly above or below the rest of the line.  In chain or bar printers, the misalignment was horizontal, with printed characters being crowded closer together or farther apart.  This was much less noticeable to human vision than vertical misalignment, where characters seemed to bounce up and down in the line, so they were considered as higher quality print.
* ''Comb printers'', also called ''[[line matrix printer]]s'', represent the fifth major design. These printers are a hybrid of [[dot matrix printing]] and line printing. In these printers, a comb of hammers prints 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 can be printed, continuing the example, in just eight cycles. The paper then advances, and the next pixel row is printed. Because far less motion is involved than in a conventional dot matrix printer, these printers are very fast compared to dot matrix printers and are competitive in speed with formed-character line printers while also being able to print dot matrix graphics.  The [[Printronix]] P7000  series of line matrix printers are still manufactured as of 2013.

Line printers are the fastest of all impact printers and are used for bulk printing in large computer centres. A line printer can print at 1100 lines per minute or faster, frequently printing pages more rapidly than many current laser printers.  On the other hand, the mechanical components of line printers operate with tight tolerances and require regular [[preventive maintenance]] (PM) to produce a top quality print. They are virtually never used with [[personal computer]]s and have now been replaced by high-speed [[Laser printing|laser printer]]s.  The legacy of line printers lives on in many [[operating system]]s, which use the abbreviations "lp", "lpr", or "LPT" to refer to printers.

==== Liquid ink electrostatic printers ====
Liquid ink electrostatic printers use a chemical coated paper, which is charged by the print head according to the image of the document.<ref>{{cite web |url=http://www.mif.pg.gda.pl/homepages/frank/sheets/138/c/CK1366.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.mif.pg.gda.pl/homepages/frank/sheets/138/c/CK1366.pdf |archive-date=2022-10-09 |url-status=live |publisher=[[Raytheon|Raytheon Company]]  |title= ''CK1366 CK1367 Printer-type cathode ray tube'' data sheet |date=1 November 1960 |access-date=29 July 2017 }}; {{cite web |url=http://www.mif.pg.gda.pl/homepages/frank/sheets/138/c/CK1368.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.mif.pg.gda.pl/homepages/frank/sheets/138/c/CK1368.pdf |archive-date=2022-10-09 |url-status=live |publisher=[[Raytheon|Raytheon Company]]  |title= ''CK1368 CK1369 Printer-type cathode ray tube'' data sheet |date=1 November 1960 |access-date=29 July 2017 }}</ref> The paper is passed near a pool of liquid ink with the opposite charge. The charged areas of the paper attract the ink and thus form the image. This process was developed from the process of [[electrofax|electrostatic copying]].<ref>{{cite web |url=http://cms.ironk12.org/TeacherWebsites/RyanDurfee/USHistory/HistoryStudentsWebsites/MadisonAlgerHISTORYWEBSITE/electrostaticprinter.html |title=Madison's website on Renn Zaphiropoulos |publisher=Cms.ironk12.org |access-date=2012-11-02 |url-status=dead |archive-url=https://web.archive.org/web/20121201153330/http://cms.ironk12.org/TeacherWebsites/RyanDurfee/USHistory/HistoryStudentsWebsites/MadisonAlgerHISTORYWEBSITE/electrostaticprinter.html |archive-date=2012-12-01 }}</ref> Color reproduction is very accurate, and because there is no heating the scale distortion is less than  ±0.1%. (All laser printers have an accuracy of ±1%.)

Worldwide, most survey offices used this printer before color inkjet plotters become popular. Liquid ink electrostatic printers were mostly available in {{convert|36|to|54|in}} width and also 6 color printing. These were also used to print large billboards. It was first introduced by Versatec, which was later bought by [[Xerox]]. [[3M]] also used to make these printers.<ref>{{cite web |url=http://www.wide-format-printers.org/3M_Scotchprint_Printer_2000/3M_Scotchprint_2000_signs.htm |title=Introduction to the 3M Scotchprint 2000 electrostatic printer |publisher=Wide-format-printers.org |access-date=2012-11-02 |archive-date=15 May 2012 |archive-url=https://web.archive.org/web/20120515052623/http://www.wide-format-printers.org/3M_Scotchprint_Printer_2000/3M_Scotchprint_2000_signs.htm |url-status=live }}</ref>

==== Plotters ====
{{main|Plotter}}
[[File:Calcomp 565 drum plotter.jpg|thumb|right|A Calcomp 565 drum plotter]]
Pen-based [[plotter]]s 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. Since the pens output continuous lines, they were able to produce technical drawings of higher resolution than was achievable with dot-matrix technology.<ref>{{Cite web|url=http://www.hpmuseum.net/exhibit.php?class=4&cat=24|title=HP Computer Museum|website=www.hpmuseum.net|access-date=10 June 2014|archive-date=3 July 2014|archive-url=https://web.archive.org/web/20140703013250/http://hpmuseum.net/exhibit.php?class=4&cat=24|url-status=live}}</ref>  Some plotters used roll-fed paper, and therefore had a minimal restriction on the size of the output in one dimension. These plotters were capable of producing quite sizable drawings.

=== Other printers ===
[[File:Brother QR printer QL-500.JPG|thumb|right|[[Brother Industries|Brother]] QL-500 label printer ]]
A number of other sorts of printers are important for historical reasons, or for special purpose uses.
* [[Minilab|Digital minilab]] ([[photographic paper]])
* [[VT52|Electrolytic printers]]
* [[Spark printer]]
* Barcode printer multiple technologies, including: [[thermal printing]], [[inkjet printing]], and [[laser printing]] [[barcode]]s
* Label printer
* Billboard / sign paint spray printers
* Laser etching (product packaging) industrial printers
* Microsphere (special paper)