photocopying

Photocopying is a reproduction process that creates paper copies of documents by using light to transfer an image onto a photosensitive surface, which is then developed with toner and fused to paper. The technology was developed in the 1930s by Chester Carlson and was popularized by Xerox, giving rise to the common term photocopier for machines that perform the process.

In traditional xerography, an original is placed on a glass platen. Light from an exposure lamp reflects off the document to form a latent electrostatic image on a photoconductive drum. The drum is charged; the light-exposed areas lose charge and attract toner. The toner image is transferred to paper and fused by heat and pressure to form a durable copy. Many office copiers also provide automatic document feeding, duplexing, and finishing options such as stapling.

Digital copying uses scanners and image processing. The original is digitized, stored, and then printed by a laser or LED engine. Digital copiers can produce higher-quality color copies and often function as multifunction devices that scan, print, fax, and email. Resolution and color accuracy vary by device, with typical monochrome copies around 600 dpi and color capable of higher resolutions.

Environmental and regulatory considerations include energy use, disposal of consumables, and emissions standards in some regions. Replacing older devices with energy-efficient models and recycling cartridges reduces environmental impact.

Photocopying remains a common method of document reproduction, especially for quick hard copies and administrative tasks. It complements digital scanning and document management by providing tangible copies when needed.