Color Photocopier


A photocopier, also known as copier is a machine that generates paper copies of required documents and visual images cheaply and quickly. Although colored toners became commercially available in 1950s, color photocopier was not available. They became commercially available in 1968. Color photographers that came initially used a dye sublimation process. Color photographers that came in 1973 used conventional electrostatic technology. By using color photocopying, counterfeit currency notes are easier to accomplish. That is why governments of various countries are more concerned about color photocopying.
 Today's highly advanced color photocopier technology can produce accurate copies of any original color document accurate. Some are making wrong use of this perfect color document reproduction capability of photocopiers. People try photocopying of some valuable color documents. The valuable color documents include bond certificates, stock certificates, bank notes, currency and other important documents. Color photocopiers are commonly used in education, government and businesses.

Color monitor has the following components:   Colored toner:  Powder like substance
Paper, drum, cartridges, lubes etc

A color photocopier works in the following manner;
The surface of the drum is charged electrostatically by high voltage wire. The wire is called corona wire. The drum is covered with photoconductive material. Photoconductors, such as semi conductors become conductive when they are exposed to light.

A lamp illuminates original document and white areas of original document reflect light onto the photo conductive drum surface. The drum areas that are fully exposed to light are those areas that also correspond to the white areas of original document.

These areas of drum become conductive and that is why they are discharged to ground.
The drum areas that are unexposed to light are those areas that also correspond to the colored portions of original document. These unexposed drum areas remain negatively charged. Due to this, latent electrical image is created on drum surface.

The colored toner has positive charge in it. When applied to drum, to develop required image, it is attracted towards colored areas as colored areas are negatively charged. The toner sticks to colored areas just as papers stick to toy balloons with static charges.
The resulting image on drum surface is then transferred on to a paper with higher negative charge. The toner is then melted and then bonded to the piece of paper by high pressure and high heat rollers. The drum is then wiped clean with rubber blade and fully discharged by light.