Laser Systems

Glow in the dark materials have the ability to store light energy. One such material is phosphorus. In storing light energy phosphorus also takes on an electrical charge. This charge is a kind of static electricity. A lased light source (laser light) charges the phosphorus coating on a turning drum to resemble the copy sent to the printer/fax/copier. The drum is exposed to a waxy fine powdered pigment called "toner" which sticks to the drum because of the static electrical charge created by the laser light. The drum surface then rolls on a piece of paper causing the toner to transfer onto it. Finally, the paper is squeezed by a hot roller (fuser) which causes the toner to melt into it making the copy permanent. The drum is then discharged, wiped clean of residual toner by a wiper and the process starts over.

Color laser systems operate using the same principles but have three primary color toners (Cyan, Magenta, Yellow) and a black toner. They can share a drum or use sepparate one for each color. Some systems use a solid wax toner stick in place of powdered toner.

Laser printers/faxs/copiers have these elements: toner cartridges, drums and fusers. Toner is used up, drums wear out as the phosphorus gets weaker and will not take on a strong static charge and fusers wear out or the the heater in them fails. Most modern systems use integrated toner cartridges which means the drum is part of the toner cartridge. When a toner is replaced, so is the drum. Fusers can have a very long life. Toner cartridges are rated by how many copies they are designed to make. This is called "yield". Modern toner cartridges are rated from 1500 to 45,000 copies depending on the design. The higher the yeild, the more they cost and larger they become to house a vast store of toner and larger drums.

Laser systems have always been costly to acquire but most major manufacturers have introduced systems in the $100-200 price range usually occupied by ink jet printers. However, it is always prudent to learn the toner cartridge yield and cost before making such an investment. Most low price laser systems use high cost toner cartridges which also have low page yields. As an example, there are several 1000-1500 page toners that cost around $100 when other machines use 2500-5000 page toner cartridges that cost around $50-$75. Low cost color lasers are notoriously expensive to operate using expensive low yield toners. One color laser is sold for $199 but the toner cartridges are $60 each. A full compliment of 4 costs $240 and the yields are around 1000 pages at 5% or less coverage per page; which means text without graphics borders or bold fonts, double spaced.