How laser printer works?

Toner and the Drum


When a laser printer starts a print job, the first thing it does is
apply a positive electrical charge to the drum unit. Afterwards, the
laser system ‘writes’ the page image onto the drum with a negative
charge, creating an electric “virtual negative” of the image.


The Toner


The drum unit rotates, and as the image is written on it, it picks up
toner, the laser