Photocopying is a phenomenon which creates copies of paper documents or other graphic images in a very quick time and at a low cost. The first of its kind was introduced by Xerox in 1960s. By 1980s, Photocopying machines gradually replaced copies made by carbon paper, mimeograph machines and other substitute products that were used at that time. If will not be wrong to say that due to this usage preference the development of paperless offices was prevented in the initial years of digital revolution.

Today, Photocopying machines are used on a large scale in almost every business, institutes and government offices. Although, there has been talk about the extinction of photocopiers as more and more people are embracing to digital technology for creation of important documents. Even distribution of such documents is preferred through digital technology than sending the actual piece of paper. But still a photocopier is more convenient than a computer for creating a normal copy of a written document.

Let's look at the working of a photocopier step by step:-

1. First and foremost, the surface of a drum is supplied with an electro-static charge produced by a high-voltage wire called a corona wire. A semiconductor material named selenium or germanium is used to coat the drum.

2. Secondly, a light (thin strips format) is beamed onto the image, which is only reflected by the white areas of the paper. The light is then directed towards the drum, which is specially designed to make it photoconductive. This is done to neutralize the positive charges from the light.

3. As a result, the charges have become opposite i.e. the white areas of the picture have become neutral and the black areas have become positive.

4. The toner is negatively charged. Hence, when it is in contact with the drum, it gets attached with the areas that are positively charged, just like paper sticks to a charged balloon.

5. The toner is then attracted onto a positively charged piece of paper.

6. The toner is nothing but a dry ink substance. If paper came out of the photocopier covered in dry toner it would just brush off, so the toner is heated to make it melt and to bind it to the paper.

Articles Source - Free Articles
About the Author

Jatin Chawla is a freelance journalist. Jatin writes for http://headings.internettollfree.com, offering valuable information on Copying Machine Supply.