A laser printer works using the same basic technology that a photocopier does; however, a laser printer uses a laser beam scanning system. Whenever a person prints something from his or her computer through a laser printer, the first thing that happens is the transmission of data.
Millions of bytes or characters of data move from the computer to the printer. Then the electronic circuit present in the printer must figure out how to print the data that it has received. This is where the printer determines how to print the data so that it looks correct on the page. This is also when the electronic circuit activates the corona wire, which is a high-voltage wire. The corona wire gives off a static electric charge and effectively charges the photoreceptor drum.
Once the photoreceptor drum is charged up, it will gain a positive charge across its surface. While this is happening, the circuit will bring the laser to life. It will ask the laser to draw the image of the page on the drum. The laser does not have to move as it will bounce its laser beam off of a moving mirror, which is then run over the drum. Soon the whole image will appear on the drum and then the ink roller will touch the drum. Now the toner has a positive electrical charge so it can stick to the negative electrical charge parts on the photoreceptor drum. A sheet of paper is fed through the printer and the piece is printed.