Xerografia

Xerography is a dry electrostatic copying process used to reproduce images on paper. The method relies on a photoconductive surface that is uniformly charged, then exposed to light to form a latent electrostatic image. Toner particles, bearing an opposite charge, are attracted to the discharged areas and create a visible image. The toner is then transferred to paper and permanently fixed by heat and pressure in a fusing step. The process is non-impact and uses dry powder rather than liquid inks.

Historically, xerography was developed by Chester Carlson in the 1930s. Carlson demonstrated the concept in 1937 and secured patents that led to commercial development. The technology was popularized in the late 1950s and 1960s by the Xerox Corporation, beginning with the Xerox 914 in 1959. The term xerography derives from Greek roots meaning “dry writing,” and is a form of electrophotography, the broader science of using photoconductive surfaces and electrostatic charges to form images.

In modern devices, xerography has evolved from photographic selenium photoconductors to organic photoconductors and hybrid systems. The core principles underpin many contemporary laser printers and photocopiers, where a scanned or digital image is converted into an electrostatic latent image, developed with toner, transferred to paper, and fused for permanence. The technology remains a foundational, widely used method for high-volume document reproduction and is integrated with digital workflows in office equipment.