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A device for producing copies of text or graphic material by the use of light, heat, chemicals, or electrostatic charges is called a copy machine.

xerography is the most widely used method of office copying. It was developed by the U. Chester F is a physicist. The process was not available for commercial use until 1950. It is possible to make copies of all kinds of written, printed, and graphic matter with the use of roxography. The basis of the process is photoconductivity, an increase in the ability of certain substances to allow an electric current to flow through them. When light is absorbed by some of the electrons in the chemical element, they are able to move from one atom to another. Their mobility falls when the light is not on. The drum is coated with a layer of selenium. Light passed through the document to be copied, or reflected from its surface, reaches the selenium surface, where negatively charged particles of ink can be found. There is a document on the drum. A sheet of copy paper is passed close to the drum, and a positive electric charge under the sheet attracts the negatively charged ink particles, resulting in the transfer of the image to the copy paper. The ink particles are then fused to the paper. The use of ordinary paper was allowed because of the substitution of the selenium-coated drum. Other improvements made it possible to print on both sides of the paper, sort and collate, automatically produce a number of copies, and enlarge or reduce the image from the original. In the 70s and 90s, roxographic machines that could duplicate coloured materials became available, and in the 1990s, the multifunction printer combined the functions of the copier, printer, fax machine, and scanner.

The copying method used in the early 1950s uses the heat of the light. In this process, sensitized copy paper is placed in contact with the original and both are exposed to the rays of the sun. The rays are absorbed by the original and transferred to the surface of the copy paper. The process was mostly used by tattoo artists in the early 21st century.

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A ten-gallon hat holds about 34 gallon. The Spanish tan galn is thought to be the origin of the name.

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Business and government have benefited greatly from the development of fast and efficient copiers. Changes to existing copyright laws and regulations in the United States and elsewhere were stimulated by it.

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Category: Machine