A Xerox copier in a high school library. Xerox Corporation ( (name ˈziːrɒks is a global document management company which manufactures and sells a range of color and black-and-white printers, multifunction High school is the name used in some parts of the world (in particular Scotland, North America and Australia) to describe an institution

A photocopier (or copier) is a machine that makes paper copies of documents and other visual images quickly and cheaply. The history of printing began as an attempt to make easier and reduce the cost of reproducing multiple copies of documents fabrics wall papers and so on The Phaistos Disc ( Phaistos Disk, Phaestos Disc) is a disk of fired Clay from the Minoan palace of Phaistos, possibly dating For the use of the technique in art see Woodcut on the technique and Old master print for the history in Europe and Woodblock printing in Japan. Movable type is the system of Printing and Typography that uses movable components to reproduce the elements of a document (usually individual letters or punctuation Intaglio (pronounced in-TAL-yo ɪn'tælɪəʊ is a family of Printmaking techniques in which the image is incised into a surface known as the matrix or plate A printing press is a mechanical device for applying pressure to an inked surface resting upon a medium (such as paper or cloth thereby transferring an image Lithography is a method for Printing using a plate or stone with a completely smooth surface Offset printing is a commonly used Printing technique where the Inked image is transferred (or "offset" from a plate to a rubber blanket then to the Chromolithography is a method for making multi-color prints. This type of color printing stemmed from the process of Lithography, and it includes all types of lithography A rotary printing press is a Printing press in which the images to be printed are curved around a cylinder Flexography (also called surface printing) often abbreviated to flexo, is a method of Printing most commonly used for packaging (labels tape bags Screen printing is a printing technique that uses a woven mesh to support an ink blocking stencil A dye-sublimation printer (or dye-sub printer) is a Computer printer which employs a printing process that uses heat to transfer dye to a medium such as a plastic Pad printing is a printing process that can transfer a 2-D image onto a 3-D object A laser printer is a common type of Computer printer that rapidly produces high quality text and graphics on plain paper A dot matrix printer or impact matrix printer refers to a type of Computer printer with a print head that runs back and forth on the page and prints by impact striking For the type of printer which uses sparks and aluminised paper (and is sometimes referred to as a "thermal printer" see Spark printer. Inkjet printers operate by propelling variably-sized droplets of liquid or molten material ( Ink) onto almost any sized page Digital printing is the reproduction of Digital images on a physical surface 3D printing is a category of Rapid prototyping technology A three dimensional object is created by layering and connecting successive cross sections of material Paper is thin material mainly used for writing upon printing upon or packaging Most current photocopiers use a technology called xerography, a dry process using heat. Xerography (or electrophotography) is a Photocopying technique developed by Chester Carlson in 1938 and Patented on October 6 (Copiers can also use other output technologies such as ink jet, but xerography is standard for office copying. Inkjet printers operate by propelling variably-sized droplets of liquid or molten material ( Ink) onto almost any sized page )

Xerographic office photocopying was introduced by Xerox in the 1960s, and over the following 20 years it gradually replaced copies made by Verifax, Photostat, carbon paper, mimeograph machines, and other duplicating machines. Xerox Corporation ( (name ˈziːrɒks is a global document management company which manufactures and sells a range of color and black-and-white printers, multifunction The 1960s decade refers to the years from the beginning of 1960 to the end of 1969 The Photostat machine, or Photostat, was an early projection photocopier created in the 1900s by the Photostat Corporation; "Photostat" - which Carbon paper (originally carbonic paper) is Paper coated on one side with a layer of a loosely bound dry Ink or pigmented coating usually bound with Duplicating machines were the predecessors of modern document-reproduction technology The prevalence of its use is one of the factors that prevented the development of the paperless office heralded early in the digital revolution. Historical perspective The paperless office was a Publicist 's slogan meant to describe the Office of the future. This article presents a Timeline of events in the history of Computing from 1950 to 1979

Photocopying is widely used in business, education, and government. There have been many predictions that photocopiers will eventually become obsolete as information workers continue to increase their digital document creation and distribution, and rely less on distributing actual pieces of paper. However, photocopiers are undeniably more convenient than computers for the very common task of creating a copy of a piece of paper.

How a photocopier works (using xerography)

Main article: Xerography

Schematic overview of the xerographic photocopying process (step 1-4)

1. Charging: The surface of a cylindrical drum is electrostatically charged by either a high voltage wire called a corona wire or a charge roller. Xerography (or electrophotography) is a Photocopying technique developed by Chester Carlson in 1938 and Patented on October 6 The drum has a coating of a photoconductive material. A photoconductor is a semiconductor that becomes conductive when exposed to light. Photoconductivity is an optical and electrical phenomenon in which a material becomes more conductive due to the absorption of electro-magnetic radiation A semiconductor' is a Solid material that has Electrical conductivity in between a conductor and an insulator; it can vary over that
2. Exposure: A bright lamp illuminates the original document, and the white areas of the original document reflect the light onto the surface of the photoconductive drum. The areas of the drum that are exposed to light (those areas that correspond to white areas of the original document) become conductive and therefore discharge to ground. The area of the drum not exposed to light (those areas that correspond to black portions of the original document) remain negatively charged. The result is a latent electrical image on the surface of the drum. (In digital machines, the original document is scanned and digitized and a laser is employed to discharge the drum in a similar fashion)
3. Developing: The toner is positively charged. When it is applied to the drum to develop the image, it is attracted and sticks to the areas that are negatively charged (black areas), just as paper sticks to a toy balloon with a static charge.
4. Transfer: The resulting toner image on the surface of the drum is transferred from the drum onto a piece of paper with a higher negative charge than the drum.
5. Fusing: The toner is melted and bonded to the paper by heat and pressure rollers.
6. Cleaning: The drum is wiped clean with a rubber blade and completely discharged by light.

This example is of a negatively charged drum and paper, and positively charged toner as is common in todays digital copiers. Some copiers, mostly older analog copiers, employ a positively charged drum and paper, and negatively charged toner.

Invention and development

In 1937 Bulgarian physicist Georgi Nadjakov found that, when placed into an electric field and exposed to light, some dielectrics acquire permanent electric polarization in the exposed areas[1]. Year 1937 ( MCMXXXVII) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar. The state of Bulgaria (България transliterated bg-Latn ''Balgaria'' The country preserves the traditions (in ethnic name language and alphabet of the First Bulgarian A physicist is a Scientist who studies or practices Physics. Physicists study a wide range of physical phenomena in many branches of physics spanning Georgi Nadjakov ( December 26, 1896 - February 24, 1981) was a famous Bulgarian Physicist. That polarization persists in the dark and is destroyed in light. Chester Carlson, the inventor of photocopying, was originally a patent attorney, as well as a part-time researcher and inventor. Chester Floyd Carlson ( February 8, 1906 – September 19, 1968) was an American Physicist, Inventor, and A patent attorney is an Attorney who has the specialized qualifications necessary for representing clients in obtaining Patents and acting in all matters and procedures His job at the patent office in New York required him to make a large number of copies of important papers. New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous Carlson, who was arthritic, found this to be a painful and tedious process. Arthritis (from Greek arthro-, joint + -itis, inflammation plural arthritides is a group of conditions involving damage to the Joints of the body As a result, he was motivated to conduct experiments with photoconductivity. Photoconductivity is an optical and electrical phenomenon in which a material becomes more conductive due to the absorption of electro-magnetic radiation Carlson used his kitchen for his "electrophotography" experiments, and, in 1938, he applied for a patent for the process. Xerography (or electrophotography) is a Photocopying technique developed by Chester Carlson in 1938 and Patented on October 6 Year 1938 ( MCMXXXVIII) was a Common year starting on Saturday (link will display the full calendar of the Gregorian calendar. He made the first "photocopy" using a zinc plate covered with sulfur. Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 The words "10-22-38 Astoria" were written on a microscope slide, which was placed on top of more sulfur and under a bright light. A microscope ( Greek: ( micron) = small + ( skopein) = to look or see is an instrument for viewing objects that are After the slide was removed, a mirror image of the words remained. Carlson tried to sell his invention to some companies, but, because the process was still underdeveloped, he failed. At the time, multiple copies were made using carbon paper or duplicating machines, and people did not see the need for an electronic machine. Between 1939 and 1944, Carlson was turned down by over 20 companies, including IBM and GE, neither of which believed there was a significant market for copiers. Year 1939 ( MCMXXXIX) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar. Year 1944 ( MCMXLIV) was a Leap year starting on Saturday (link will display full calendar of the Gregorian calendar. International Business Machines Corporation abbreviated IBM and nicknamed "Big Blue", is a multinational Computer Technology

In 1944, the Battelle Memorial Institute, a non-profit organization in Columbus, Ohio, contracted with Carlson to refine his new process. The Battelle Memorial Institute is a private not-for-profit applied science and technology development company headquartered in Columbus Ohio. Columbus is the Capital and the largest city of the US state of Ohio. Over the next five years, the institute conducted experiments to improve the process of electrophotography. In 1947, Haloid Corporation (a small New York-based manufacturer and seller of photographic paper) approached Battelle to obtain a license to develop and market a copying machine based on this technology.

Haloid felt that the word "electrophotography" was too complicated and did not have good recall value. After consulting a professor of classical language at Ohio State University, Haloid and Carlson changed the name of the process to "Xerography," which was derived from Greek words that meant "dry writing. The Ohio State University ( OSU) is a Coeducational public Research university in the state of Ohio. Xerography (or electrophotography) is a Photocopying technique developed by Chester Carlson in 1938 and Patented on October 6 Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly " Haloid called the new copier machines "Xerox Machines" and, in 1948, the word Xerox was trademarked. Haloid eventually changed its name to Xerox Corporation. Xerox Corporation ( (name ˈziːrɒks is a global document management company which manufactures and sells a range of color and black-and-white printers, multifunction

In the early 1950s, RCA (Radio Corporation of America) introduced a variation on the process called Electrofax, whereby images are formed directly on specially coated paper and rendered with a toner dispersed in a liquid. An electrofax is an Electrostatic printer and copier technology where the image is formed directly on the paper instead of first on a drum (and then transferred to paper as

During the 1960s and through the 1980s, Savin Corporation developed and sold a line of liquid-toner copiers that implemented a technology based on patents held by the company. Savin was incorporated in 1959 by Max Low (the company was named after Low's brother-in-law and was known primarily for its line of liquid toner photocopiers which set it apart from

In 1949, Xerox Corporation introduced the first xerographic copier called the Model A. Year 1949 ( MCMXLIX) was a Common year starting on Saturday (link will display the full calendar of the Gregorian calendar. Xerox became so successful that, in North America, photocopying came to be popularly known as "xeroxing. " Xerox has actively fought to prevent "Xerox" from becoming a genericized trademark. A genericized trademark (also known as a generic trademark or proprietary eponym) is a Trademark or Brand name that has become the colloquial While the word "Xerox" has appeared in some dictionaries as a synonym for photocopying, Xerox Corporation typically requests that such entries be modified, and that people not use the term "Xerox" in this way.

"Photostat" is an outdated term for a photocopy. Some languages include hybrid terms, such as the widely used Polish term kserokopia ("xerocopy"), even though relatively few photocopiers are of the Xerox brand. Polish ( język polski, polszczyzna) is the Official language of Poland.

Prior to the widespread adoption of xerographic copiers, photo-direct copies produced by machines such as Kodak's Verifax were used. A primary obstacle associated with the pre-xerographic copying technologies was the high cost of supplies: a Verifax print required supplies costing USD $0. 15 in 1969, while a Xerox print could be made for USD $0. 03 including paper and labor. At that time, Thermofax photocopying machines in libraries could make letter-sized copies for USD $0. 25 or more (at a time when the minimum wage for a US worker was USD $1. 65).

Xerographic copier manufacturers took advantage of a high perceived-value of the 1960s and early 1970s, and marketed paper that was "specially designed" for xerographic output. The 1960s decade refers to the years from the beginning of 1960 to the end of 1969 This article is about the Decade 1970-1979 For the Year 1970 see 1970. By the end of the 1970s, paper producers made xerographic "runability" one of the requirements for most of their office paper brands. This article is about the Decade 1970-1979 For the Year 1970 see 1970.

Some devices sold as photocopiers have replaced the drum-based process with inkjet or transfer film technology. Inkjet printers operate by propelling variably-sized droplets of liquid or molten material ( Ink) onto almost any sized page

Among the key advantages of photocopiers over earlier copying technologies are their ability to do the following:

• to use plain (untreated) office paper
• to implement duplex (or two-sided) printing
• to sort and/or staple output

Color photocopiers

Colored toner became available in the 1950s, although full-color copiers were not commercially available until 3M released the Color-in-Color copier in 1968, which used a dye sublimation process rather than conventional electrostatic technology. Duplex printing is a feature of Computer printers and MFPs that allows the automatic printing of a sheet of paper on both sides The 1950s Decade refers to the years of 1950 to 1959 inclusive 3M Company ( formerly Minnesota Mining and Manufacturing Company until 2002 is an American multinational conglomerate corporation with a worldwide Year 1968 ( MCMLXVIII) was a Leap year starting on Monday (link will display full calendar of the Gregorian calendar. A dye-sublimation printer (or dye-sub printer) is a Computer printer which employs a printing process that uses heat to transfer dye to a medium such as a plastic The first electrostatic color copier was released by Canon in 1973. is a Japanese Multinational corporation that specializes in imaging and optical products including Cameras photocopiers and Computer printers Year 1973 ( MCMLXXIII) was a Common year starting on Monday (link will display full calendar of the 1973 Gregorian calendar.

Color photocopying is a concern to governments, as it makes counterfeiting currency easier to accomplish. For the government of parliamentary systems see Executive (government. A counterfeit is an imitation that is made usually with the intent to deceptively represent its content or origins A currency is a unit of exchange, facilitating the transfer of Goods and/or services It is one form of Money, where money is Some countries have introduced anti-counterfeiting technologies into their currency specifically to make it harder to use a color photocopier for counterfeiting. These technologies include watermarks, microprinting, holograms, tiny security strips made of plastic (or other material), and ink that appears to change color as the currency is viewed at an angle. Holography (from the Greek, ὅλος - hólos whole + γραφή - grafē writing drawing is a technique that allows the Some photocopying machines contain special software that can prevent copying currency that contains a special pattern. The EURion constellation is a pattern of Symbols found on a number of Banknote designs since about 1996

Digital technology

In recent years, all new photocopiers have adopted digital technology, thus replacing the older analog technology. A digital system uses discrete (discontinuous values usually but not always Symbolized Numerically (hence called "digital" to represent information for An analog or analogue signal is any continuous signal for which the time varying feature (variable of the signal is a representation of some other With digital copying, the copier effectively consists of an integrated scanner and laser printer. Historical precedent Scanners can be considered the successors of early telephotography input devices consisting of a rotating drum with a single Photodetector at A laser printer is a common type of Computer printer that rapidly produces high quality text and graphics on plain paper This design has several advantages, such as automatic image quality enhancement and the ability to "build jobs" (that is, to scan page images independently of the process of printing them). Some digital copiers can function as high-speed scanners; such models typically offer the ability to send documents via email or to make them available on file servers.

A great advantage of digital copier technology is "automatic digital collation. " When copying a set of twenty pages twenty times, for example, a digital copier scans each page only once then uses the stored information to produce twenty sets. In an analog copier, either each page is scanned twenty times (a total of 400 scans), making one set at a time, or twenty separate output trays are used for the twenty sets.

Low-end copiers also use digital technology, but they tend to consist of a standard PC scanner coupled to an inkjet or low-end laser printer, both of which are far slower than their counterparts in high-end copiers. A digital system uses discrete (discontinuous values usually but not always Symbolized Numerically (hence called "digital" to represent information for However, low-end scanner inkjets can provide color copying at a far lower cost than can a traditional color copier. The cost of electronics is such that combined scanner-printers sometimes have built-in fax machines. (See Multifunction printer. )

Copyright issues

Photocopying material that is subject to copyright (such as books or scientific papers) is subject to restrictions in most countries. Copyright is a legal concept enacted by Governments, giving the creator of an original work of authorship Exclusive rights to control its distribution usually for This is common practice, as the cost of purchasing a book for the sake of one article or a few pages can be excessive. The principle of fair use (in the United States) or fair dealing (in other Berne Convention countries) allows this type of copying for research purposes. Fair use is a doctrine in United States copyright law that allows limited use of copyrighted material without requiring permission from the rights holders such as use for Fair dealing is a Doctrine of Limitations and exceptions to copyright which is found in many of the Common law jurisdictions of the Commonwealth of The Berne Convention for the Protection of Literary and Artistic Works, usually known as the Berne Convention, is an international agreement governing Copyright

In certain countries, such as Canada, some universities pay royalties from each photocopy made at university copy machines and copy centers to copyright collectives out of the revenues from the photocopying, and these collectives distribute resulting funds to various scholarly publishers. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page A university is an institution of Higher education and Research, which grants Academic degrees in a variety of subjects A copyright collective (also known as a copyright collecting agency or copyright collecting society) is a body created by private agreements or by Copyright law In the United States, photocopied compilations of articles, handouts, graphics, and other information called readers are often required texts for college classes. Either the instructor or the copy center is responsible for clearing copyright for every article in the reader, and attribution information must be clearly included in the reader.

Health issues

Ultraviolet exposure is a concern. In the early days of photocopiers, the sensitizing light source was filtered green to match the optimal sensitivity of the photoconductive surface. This filtering conveniently removed all ultraviolet [2]. Currently, a variety of light sources are used. As glass transmits ultraviolet rays between 325 and 400 nanometers, copiers with ultraviolet-producing lights such as fluorescent, tungsten halogen, or xenon flash expose documents to some ultraviolet [3]. Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many

Concerns about emissions from photocopy machines have been expressed by some in connection with the use of selenium and emissions of ozone and fumes from heated toner [4] [5]. Selenium (səˈliniəm is a Chemical element with the Atomic number 34 represented by the chemical symbol Se, an atomic mass of 78 OZONE is an object oriented Operating system written in the C programming language. These concerns, however, can be a result of misunderstanding or exaggeration [6]

Forensic identification

Main article: Printer steganography

Similar to forensic identification of typewriters, computer printers and copiers can be traced by imperfections in their output. Printer steganography is a type of Steganography produced by Color printers including HP and Xerox brand color Laser printers, where Forensic Identification is the application of forensic science and technology to identify specific objects from the Trace evidence they leave often at a Crime A typewriter is a mechanical or Electromechanical device with a set of "keys" that when pressed cause characters to be printed on a medium The mechanical tolerances of the toner and paper feed mechanisms cause banding, which can reveal information about the individual device's mechanical properties. It is often possible to identify the manufacturer and brand, and, in some cases, the individual printer can be identified from a set of known printers by comparing their outputs. [7] [8]

Some high-quality color printers and copiers steganographically embed their identification code into the printed pages, as fine and almost invisible patterns of yellow dots. Steganography is the art and science of writing hidden messages in such a way that no one apart from the sender and intended recipient even realizes there is a hidden message Some sources identify Xerox and Canon as companies doing this [9] [10]. Xerox Corporation ( (name ˈziːrɒks is a global document management company which manufactures and sells a range of color and black-and-white printers, multifunction is a Japanese Multinational corporation that specializes in imaging and optical products including Cameras photocopiers and Computer printers The Electronic Frontier Foundation (EFF) has investigated[11] this issue and documented how the Xerox DocuColor printer's serial number, as well as the date and time of the printout, are encoded in a repeating 8×15 dot pattern in the yellow channel. The Electronic Frontier Foundation ( EFF) is an international non-profit advocacy and legal organization based in the United States with the stated purpose of being dedicated EFF is working to reverse engineer additional printers. The Electronic Frontier Foundation ( EFF) is an international non-profit advocacy and legal organization based in the United States with the stated purpose of being dedicated The US government has been reported to have asked these companies to implement such a tracking scheme, so that counterfeiting can be traced. A counterfeit is an imitation that is made usually with the intent to deceptively represent its content or origins

Current copier brands

• Canon

• Gestetner, owned by Ricoh
• Hewlett Packard
• Konica Minolta
• Kyocera Mita, including its Copystar brand
• Lanier, owned by Ricoh
• Océ. is a Japanese Multinational corporation that specializes in imaging and optical products including Cameras photocopiers and Computer printers The Gestetner, Named for its Inventor David Gestetner, is a Duplicating machine. is a Japanese manufacturer of office equipment Medical imaging, Graphic imaging, Optical devices and Measuring instruments The company is a Japanese company based in Kyoto, Japan. The company was founded as in 1959 by Kazuo Inamori. Océ NV is a Netherlands -based company that manufactures and sells production printing and copying hardware and related software including its Océ Imagistics brand
• Oki Electric Industry, OKI Printing Solutions brand
• Panasonic
• Rex-Rotary, owned by Ricoh
• Ricoh
• Savin, owned by Ricoh
• Sharp
• Toshiba
• Xerox / Fuji Xerox partnered companies with non-overlapping marketing areas

Further reading

• R. Océ NV is a Netherlands -based company that manufactures and sells production printing and copying hardware and related software ( is a Japanese electronics company founded (as Meikosha Ltd in January 1881 by Kibataro Oki ( or Ricoh, is a Japanese company that was established on 6 February 1936 as Riken Kankoshi Co Savin was incorporated in 1959 by Max Low (the company was named after Low's brother-in-law and was known primarily for its line of liquid toner photocopiers which set it apart from () is a Japanese Electronics manufacturer founded in 1912 It takes its name from one of its founder's first inventions the Ever-Sharp Mechanical pencil, which ( is a multinational conglomerate manufacturing company headquartered in Tokyo, Japan. Xerox Corporation ( (name ˈziːrɒks is a global document management company which manufactures and sells a range of color and black-and-white printers, multifunction is a Joint venture partnership between the Japanese photographic firm Fuji Photo Film Co Schaffert: Electrophotography. Focal Press, 1975
• Owen, David (August 2004). Copies in Seconds : How a Lone Inventor and an Unknown Company Created the Biggest Communication Breakthrough Since Gutenberg: Chester Carlson and the Birth of the Xerox Machine. New York: Simon and Schuster. ISBN 0743251172.  

See also

• Duplicating machines
• List of duplicating processes
• Multifunctional copier
• Negative photocopy
• Printing
• Risograph

External links

• Detailed description and simulation of the electrophotographic print process
• How a colour copier works