History and Commercial Use of Photocopiers
- Chester Carlson invented photocopying and applied for a patent in 1938.
- He made the first photocopy using a zinc plate covered with sulfur.
- Carlson was turned down by over 20 companies before partnering with Battelle Memorial Institute.
- In 1947, Haloid Corporation obtained a license to develop and market a copying machine based on Carlson’s technology.
- Haloid changed the name of the process to xerography and trademarked the term Xerox in 1948.
- Photocopying gradually replaced other duplicating machines in the business, education, and government sectors.
- Despite predictions of obsolescence, photocopiers continue to be widely used as of 2015.
- High-end machines evolved into multi-function printers that combine photocopying, faxing, scanning, and printing.
- Low-end color photocopiers became dominant in the home-office market during the 1990s.
- High-end color photocopiers for heavy-duty handling and large-format printing are primarily found in print and design shops.
Xerography and Other Technologies
- Most modern photocopiers use xerography, a dry process that uses electrostatic charges and toner particles.
- Xerography is standard for office copying, but copiers can also use inkjet technology.
- Xerographic copiers offered significant cost advantages over pre-xerographic technologies.
- Xerographic output became a requirement for most office-paper brands by the end of the 1970s.
- Some photocopiers have replaced drum-based processes with inkjet or transfer-film technology.
- Colored toner became available in the 1950s, but full-color copiers were commercially available in 1968.
- Xerox introduced the first electrostatic color copier in 1973.
- Color photocopying raised concerns about counterfeiting currency and documents.
- The 3M Color-in-Color copier used dye sublimation technology instead of electrostatic technology.
- New photocopiers increasingly implement digital technology, replacing analog technology.
- Digital copiers consist of an integrated scanner and laser printer.
- Advantages of digital copying include automatic image-quality enhancement and the ability to build jobs.
- Digital copiers can function as high-speed scanners and offer document sharing options.
- Automatic digital collation is a significant advantage of digital copier technology.
Copyright Issues, Counterfeiting, Health Issues, and Forensic Identification
- Photocopying copyrighted material is restricted in most countries.
- Fair use or fair dealing allows copying for certain purposes.
- Universities may pay royalties for photocopying.
- Copyright clearance is required for readers used in college classes.
- Attribution information must be included in readers.
- Anti-counterfeiting technologies are used in currency.
- Color copying raises concerns for document forgery.
- Some licenses and transcripts have anti-copying watermarks.
- Special software can prevent copying of currency.
- Holograms and security strips are used in currency.
- Exposure to ultraviolet light is a concern.
- Photocopiers with certain light sources emit ultraviolet rays.
- Emissions from photocopy machines can include ozone and fumes.
- Concerns have been expressed about selenium in photocopy machines.
- Filters used in early photocopiers removed ultraviolet light.
- Mechanical tolerances cause banding, which can identify devices.
- Some printers and copiers embed identification codes into pages.
- Imperfections in output can help identify the manufacturer and brand.
- Xerox and Canon are known for embedding identification codes.
- EFF has investigated and documented printer tracking schemes.
- Printer forensics can aid in tracing counterfeiters.
- Color laser printer technology is used by the government to track documents.
- Dutch authorities track counterfeits through printer serial numbers.
- Printers may have the capability to spy on users.
- Some printers display tracking dots.
A photocopier (also called copier or copy machine, and formerly Xerox machine, the generic trademark) is a machine that makes copies of documents and other visual images onto paper or plastic film quickly and cheaply. Most modern photocopiers use a technology called xerography, a dry process that uses electrostatic charges on a light-sensitive photoreceptor to first attract and then transfer toner particles (a powder) onto paper in the form of an image. The toner is then fused onto the paper using heat, pressure, or a combination of both. Copiers can also use other technologies, such as inkjet, but xerography is standard for office copying.
Photocopying is widely used in the business, education, and government sectors. While there have been predictions that photocopiers will eventually become obsolete as information workers increase their use of digital document creation, storage, and distribution and rely less on distributing actual pieces of paper, as of 2015, photocopiers continue to be widely used. During the 1980s, a convergence began in some high-end machines towards what came to be called a multi-function printer: a device that combined the roles of a photocopier, a fax machine, a scanner, and a computer network-connected printer. Low-end machines that can copy and print in color have increasingly dominated the home-office market as their prices fell steadily during the 1990s. High-end color photocopiers capable of heavy-duty handling cycles and large-format printing remain a costly option found primarily in print and design shops.