An older technology than inkjet, laser printers are another popular alternative to legacy impact printing. Laser printers are known for their high volume output and low cost-per-page. Laser printers are often deployed in enterprises as a workgroup or departmental print center, where performance, durability, and output requirements are a priority. Because laser printers service these needs so readily (and at a reasonable cost-per-page), the technology is widely regarded as the workhorse of enterprise printing.
Laser printers share much of the same technologies as photocopiers. Rollers pull a sheet of paper from a paper tray and through a charge roller, which gives the paper an electrostatic charge. At the same time, a printing drum is given the opposite charge. The surface of the drum is then scanned by a laser, discharging the drum's surface and leaving only those points corresponding to the desired text and image with a charge. This charge is then used to force toner to adhere to the drum's surface.
The paper and drum are then brought into contact; their differing charges cause the toner to then adhere to the paper. Finally, the paper travels between fusing rollers, which heat the paper and melt the toner, fusing it onto the paper's surface.
7.4.1. Color Laser Printers
Color laser printers aim to combine the best features of laser and inkjet technology into a multi-purpose printer package. The technology is based on traditional monochrome laser printing, but uses additional components to create color images and documents. Instead of using black toner only, color laser printers use a CMYK toner combination. The print drum either rotates each color and lays the toner down one color at a time, or lays all four colors down onto a plate and then passes the paper through the drum, transferring the complete image onto the paper. Color laser printers also employ fuser oil along with the heated fusing rolls, which further bonds the color toner to the paper and can give varying degrees of gloss to the finished image.
Because of their increased features, color laser printers are typically twice (or several times) as expensive as monochrome laser printers. In calculating the total cost of ownership with respect to printing resources, some administrators may wish to separate monochrome (text) and color (image) functionality to a dedicated monochrome laser printer and a dedicated color laser (or inkjet) printer, respectively.