XEROX

A Xerox® copier, generically known as a photocopier, essentially works on the principles of ststic electricity. Electrical charges can be either positive or negative, which is somewhat similar to the poles of magnets. The negative end of a magnet will stick instantly to the positive end of another magnet, but two negatives or positives will repel each other. The same thing happens with negative and positive electrical charges; a negatively charged comb will attract positively charges flakes of pepper or grains of salt.

What a Xerox® copier does is take advantage of this natural electrical attraction or repulsion. What we see as a document to be copied is actually viewed as nothing more than black or white spaces to a Xerox® copier. When the document is placed on the glass tray for copying, a number of processes happen all at once. This is where the science of photocopying begins.

Beneath the transparent glass tray lies a flet belt or round drum called a photoreceptor. The surface of this photoreceptor is made from special materials which can be negatively and positively charged in different areas at the same time. An electrical element known as a Corona wire moves across the photoreceptor and gives the entire surface a positive electrical charge, much like rubbing a latex balloon or running a comb through hair. Once the entire surface of the photoreceptor is positively charged, an intensely bright light moves across the surface of the original document to be copied.