The Basic Science of Laser Printing

Laser PrintingAnyone on the market for a fast printer that can handle the pace of a busy office and large daily volumes will find the best match with a laser printer.  Though inkjet printers are reliable and deliver precise resolutions, laser machines tend to offer faster speeds and sharper text, but how does a laser printer actually work? Let us look at the laser printing process, and some of the science behind it.

The basic science behind laser printing is the use of static electricity, which is combined with heat. The photoreceptor or drum is a large cylindrical object that can hold a static charge. At the start of the printing process, the drum is given an entirely positive charge from a component called a corona wire. As the drum rotates, the laser points at the drum in precise patterns, discharging the static charge wherever it is pointed. This gives these areas a negative charge.

Toner powder

Toner powder.

The toner is positively-charged, and attracted to the negatively-charged portions. When it is released, it is drawn to the drum in the areas of negative charge. The drum then rolls across the paper and releases the toner particles onto the paper in the same pattern. Color printers use multiple drums: one for each color of cyan, magenta, yellow, and black. This is a continuous process, where the laser is etching portions of the image at the same time that some particles are being attracted, while at the same time others are being transferred, so there is a lot of coordination required.

Once the toner particles are aligned on the page, the paper goes through the printer fuser assembly, which contains one or more heated rollers. The fuser applies the heat necessary to melt the toner particles, so that they are fused to the paper. This is the reason pages that come out of a laser printer often feel warm.

The technical aspects of getting all of the components to work perfectly together is quite a feat of engineering, but the basic science is fairly easy to understand. A laser printer can produce a wide variety of text and images with the use of static electricity and heat, and at a very high rate of speed.

Here is a video that illustrates the process of laser printing:


Robyn Warner
Robyn Warner has been writing since she learned how to hold a pen. She wrote her first book of poems before the age of 10. Though creative writing is her preference, she is enjoying life in the technical blog world. Robyn’s goal in her 30s is to use her writing to inspire fellow cancer survivors and have a job that gives her the flexibility to live anywhere and never wear shoes.

3 Responses to “The Basic Science of Laser Printing”

  • […] printing and edible printing, as the toxins from printer ink should never be consumed.  Also, laser toner printers are not yet able to print edible images. If you cannot purchase a printer specifically for […]

  • […] Though it is not commonly discussed in the printing process, an OPC drum is imperative to delivering high quality documents using laser technology. […]

  • […] and for good reason. In fact, there is very little difference between the two when it comes to the basic science of how the two types work. They both use static electricity applied to a drum, which helps to apply […]