Uses of Static Electricity (the crackly stuff on jumpers)

Static Electricity  Is an electric charge built up on an insulated body  Oppositely charged atoms attract each other  A charged atom will attract an uncharged atom  Atoms with the same charge repel

Laser Printers  Use a ‘photoreceptor’ – a drum made of a material which when charged up can be discharged by photons (light)  The drum is first given a positive charge by a corona wire  A laser is then used to trace the image on the rotating drum – where the laser hits, the static is lost.

Laser Printers

Laser Printers  The toner powder is given a positive charge and blown onto the drum.  As the toner and the drum have the same charge, the toner only sticks to the uncharged areas.  The drum continues to turn.

Laser Printers  The toner is ‘pulled’ from the drum by negatively charged paper – this has a stronger attraction than the neutral areas on the drum.  The toner is melted onto the paper by the hot ‘fuser’ rollers.

Laser Printers  The drum is then discharged by the discharge lamp  The uncharged drum is now ready to be charged to have a new image placed on it.