On Photocopier

Published:2011/3/3 2:19:00 Author:LiuQiaoyan From:SeekIC

Photocopier is a machine that copies documents and other visual images quickly and cheaply. Most current photocopiers for office copying use a technology called xerography, a dry process using heat. Photocopying is widely used in education, government, and business areas. Many people predict that photocopiers will become dated as information workers no longer create and distribute their documents on the paper. But at present,copier is still playing an indispensable role in our daily life.
There are four processes when a xerographic copier is working. First of all is the charging. Charge the cylindrical drum that covers with a photoconductive material with a high voltage wire called a charge roller. The drum will become conductive when exposed to light. The second step is exposure. As a bright lamp illuminates the original document, and the white areas of the original document reflect the light onto the surface of the photoconductive drum, the areas of the drum that are exposed to light become conductive and therefore discharge to ground. The part not exposed to light remain charged negatively. As a result, a latent electrical image appears on the surface of the drum. The third one is developing. Charge the toner positively, when it is applied to the drum to develop the image, it is attracted and sticks to the areas that are negatively charged just as paper sticks to your hair with a static charge. The fourth one is transfer. The toner image on the surface of the drum is transferred onto a piece of paper with a higher negative charge than the drum.
Color photocopier is a concern to government as it facilitates counterfeiting currency. Some countries even express terms to make it harder to use technologies include microprinting, watermarks,holograms, tiny security strips made of plastic, and ink that appears to change colors as the currency is viewed at an angle.
The newly develop trend of copy machines is to adopt digital technology. With digital copying, the copier effectively consists of an integrated scanner and laser printer. This design has several advantages. Some digital copiers can function as high-speed scanners that made them being able to send documents via email.
When people selecting the equipment, factors like volume, copying speed, paper size, price, features and performance should be taken into consideration. The related integrated circuit is NCV4264-2.


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