How do Laser Printers Work?
The printing of a document on a
laser printer
1. Charging. A wire or a roller projects an electrostatic charge onto a photoreceptor. The photoreceptor is a revolving drum or belt that is photosensitive and can replicate an image.
2. Writing. The next step in the process is the conversion of the image from code the computer understands to code the printer understands. This is called a raster image. Raster images are suitable for scanning onto the photoreceptor. The laser is aimed at a mirror inside the printer that directs the laser beam through a series of lenses. Wherever the laser hits the photoreceptor the electromagnetic charge is reversed and the image from the computer is replicated on the photoreceptor surface.
3. Developing. The image is created once it is exposed to the toner in the laser cartridge. Toner for laser printers consists of a very fine dry plastic powder that is mixed with color.
4. Transferring. The photoreceptor is put through rollers or a presser and this transfers the image to the paper.
5. Fusing. The image is made permanent when it passes through a fuser mechanism. These are a set of rollers that apply heat and pressure (up to 200 degrees Celsius) and the plastic powdered toner is applied to the paper.
6. Cleaning. Once the image is fused it is cleaned by a rubber blade that cleans any excess toner from the photoreceptor and deposits it into a reservoir. Another unit called a discharge lamp also gets rid of any remaining charge in the photoreceptor.
Many printers have a toner-conservation mode, which
can be substantially more economical to use. Using a
laser printer
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