Copier Parts

It’s a good idea to keep spare parts

There are numerous parts inside a photocopier; actually too many to mention and explain. Working parts such as cleaning blades, bearings, gears, rubber parts, fans, coolers, tubes, vacuums and filters, can be confusing to the layman. We’ll stick to the most important parts that carry out the main functions of copying; the drum or belt, corona wires, lamp and lenses, toner, and the fuser.

The photoreceptor drum is really the main part of a copier however some models use a belt instead of a drum. The drum is actually a metal roller that is covered by a layer of photoconductive material such as selenium, germanium or silicon. When the photoconductive material is struck by light, the energy of the photons enables a current to pass through it. These electrons neutralize the positive charge that coats the drum to form a latent image.

The drum rotates when a copy is being made and it can create an image strip by strip. After one strip of light is focused onto a part of the drum, the drum rotates to expose a fresh area of the photoconductor while the previously exposed area of the drum comes into contact with the toner, and then the paper. The drum needs to be cleaned, recharged with ions, exposed to photons, and covered with toner several times to make a copy. There are various types of drums and belts available and they are replaceable.

To make a copy, a field of positive charges has to be created on the drum and the copy paper. The charges are generated by corona wires. The wires are subjected to a high voltage, which are then transferred to the drum and paper as static electricity. One wire runs parallel to the drum and charges its photoconductive surface with positive ions. The other corona wire is coats the surface of the paper as the paper travels toward the drum.

The copier needs a source of light that has enough energy to take electrons out of the photoconductive atoms. This source is an incandescent or fluorescent bulb which flashes light onto the original document. When the lamp is on, it moves across the inside of the copier and lights up one strip of paper at a time. A mirror that is attached to the lamp then guides the reflected light through a lens onto the turning drum. The lens enables a copy of the image to be focused in a specific area. The lens can’t actually make the image appear sharper, but it can magnify and reduce the size of the original image on the copy.

The toner is a negatively charged, plastic based powder which is kept in a cartridge. When toner-coated beads are rolled over the drum, the particles of toner are attracted to the positively charged ions on the unexposed parts of the drum. The toner is also drawn to the electrostatically charged paper. The toner is then melted and fused to the copy paper. You can buy black toner along with colored toner for color copiers.

This melting process is carried out by the fuser, which melts and presses the toner into the paper to create text and/or images. The fuser also has to make sure the toner and paper doesn’t stick to it. The process is carried out by quartz tube lamps and Teflon-coated rollers. The paper goes through the rollers, which press down on the page to embed the toner into the paper. The lamps are on inside the rollers to create enough heat to melt the toner. The Teflon coating makes sure the toner and paper doesn’t stick to the rollers. Fuser rollers can also be easily replaced.

To find out how these parts create a copier, read our How a Photocopier Work section. It’s a good idea to buy some spare parts for your copier in case of a break down or in the case of plain old wear and tear. Copiers also have outside replaceable parts such as automatic document feeders, paper trays, the lid and glass.