How a Laser Printer Works


Laser printers and photocopiers both work by capturing an image either optically by scanning or electronically from a computer. This image is then projected onto a photosensitive cylinder by a laser beam. When the laser beam hits the surface of the photosensitive cylinder it creates a negative electric charge on the drum in the same pattern as the image that is to be printed.

The photoelectric cylinder then rotates and comes into contact with the toner (ink). The negative charges on the cylinder surface attract the positively charged toner particles. Paper is applied to the cylinder as it rotates, sandwiching the toner in between.

The paper and toner then are compressed against the cylinder by a very hot roller. The heat melts the plastic toner particles into the paper fiber, creating the document. The heat also clears up the charges on the cylinder making it ready for another print. Now you know why the paper feels warm when it comes out of the machine and you can smell melted toner.

Finally, like magic, the copy comes out of the side of the machine and into our lives.