Photocopies

Photocopies are reproductive copies of documents or images created using a photocopying process, most commonly xerography. The term describes both the copies themselves and the devices used to produce them, typically office copiers, multifunction printers, and standalone machines. Copying is widely used for reproducing pages, forms, and illustrations with a result that is a near-identical reproduction.

Most modern photocopiers operate on the xerographic principle. A light source scans the original, forming an electrostatic latent image on a photoconductive drum or belt. The drum is charged, then toner particles, attracted to the latent image, are transferred to plain paper and permanently fixed by heat and pressure. Color copying uses multiple toner colors in separate passes or layers to reproduce color originals. Some machines also scan and print digital copies, or connect to networks to share documents.

Copiers vary in speed, resolution, and features. Common black-and-white devices produce 600×600 to 1200×1200 dpi, while color units offer higher capacity. High-volume machines handle thousands of copies per day, with features such as collating, duplexing, stapling, and finishing. Limitations include potential loss of detail on very light originals, color fidelity challenges, and occasional misalignment.

Historically, xerography was invented by Chester Carlson in 1938 and commercialized by the Haloid Company in the 1950s, leading to the first widely adopted Xerox copiers in 1959. Since then copying technology has evolved into digital, networked, and multifunction devices, reducing the need for separate copying equipment and enabling scanning, email, and cloud storage of copies.

Legal and ethical considerations govern copying of copyrighted materials, with restrictions on reproducing textbooks, manuals, and proprietary content beyond fair use or licenses. Environmentally, copiers consume energy and use toner; modern machines emphasize energy efficiency and toner recycling programs.