Who Invented the Xerox?

The standard photocopier, generally called the Xerox machine, was invented by Chester F. Carlson, who developed the photocopying process in 1938. Although not all photocopiers are actually Xerox machines (since Xerox is a trademarked corporation name), the term is logical to use since most photocopiers operate with a process called xerography, which comes from the Greek word for "dry writing." It took 41 years from the beginning of Carlson's research until the first Xerox copier was created.

History

In 1938, Chester Carlson used Georgi Nadjakov's study of electric polarization with light and darkness to invent a copying method that used dry powder with light and an electric charge to duplicate an image onto paper. The process was called xerography because no moisture was used. It took another nine years for Carlson's invention to catch on, being rejected by 20 companies including IBM and General Electric, until the Rochester-based Haloid Company bought the rights to use his copying process.

Origins

Georgi Nadjakov was a Bulgarian physicist who first developed the process of electrostatic polarization in 1937. Nadjakov discovered that certain insulators (substances that don't conduct electricity) can be electrically polarized when exposed to light within an electric field. The polarization would persist in dark areas and be destroyed in light.

Carlson's Development

Chester Carlson, who had to work to support his ailing parents at an early age, was inspired by Thomas Edison to pursue inventions as a way to improve his economic status. A physics graduate from Cal Tech who studied patent law at New York Law School, his work in the patent office at P. R. Mallory (which would become Duracell) required making multiple copies of patent forms. This drove him to find an easier way to duplicate printing. Studying Nadjakov's research at the New York Public Library, he began to develop the "electrophotography" process, using electrostatic polarization with dry powder. He changed the process name to "xerography" because he thought it sounded better.

The Xerox Name and Machine

The Haloid Company, which specialized in photography equipment at the time, bought the rights to Carlson's patent for the photocopier in 1947. The first public demonstration of the copier came the next year in Detroit at the Optical Society of America's annual meeting. That same year, 1948, they trademarked the name "Xerox," since the copying process was known as xerography. The company became Haloid Xerox in 1958, one year before debuting the Xerox 914 photocopier. The name was shortened to Xerox in 1961. As more companies began making xerographic copiers, they were all generally called Xerox machines by the public, a name that the Xerox company has fought to protect.

Xerography

The process of xerography uses a cylindrical drum that is coated with photoconductive material. The drum's surface is charged with static electricity, and a bright light reflects the original document image onto the drum. The areas of the drum covered by the document's writing and other dark spots become negatively charged. The toner, which is positively charged, is applied and sticks to the negative parts of the drum. The toner is then transferred onto a paper sheet with a higher negative charge, then melted onto the paper through heat and pressure rollers.