Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to define a differentially charged image. The drum then selectively collects electrically charged powdered ink (toner), and transfers the image to paper, which is then heated to permanently fuse the text, imagery, or both, to the paper. As with digital photocopiers, laser printers employ a xerographic printing process. Laser printing differs from traditional xerography as implemented in analog photocopiers in that in the latter, the image is formed by reflecting light off an existing document onto the exposed drum.
HP LaserJet 4200 series printer, installed atop additional 500-sheet paper tray
Gary Starkweather (seen here in 2009) invented the laser printer.
Laser unit from a Dell P1500. The white hexagon is the rotating scanner mirror.
Magnification of color laser printer output, showing individual toner particles comprising 4 dots of an image with a bluish background
Electrostatics is a branch of physics that studies slow-moving or stationary electric charges.
Foam peanuts clinging to a cat's fur due to static electricity. The electric field of the charged fur causes polarization of the molecules of the foam due to electrostatic induction, resulting in a slight attraction of the light plastic pieces to the fur. This effect is also the cause of static cling in clothes.
