The first
laser printer was demonstrated in
1969. An
engineer named Gary Starkweather, who was working at the
Xerox Palo Alto Research Center, figured out a way to combine a laser and
Xerox's tried and true
xerography process. This process allowed for a printer that could print graphics type rather than just
fixed-width characters.
And now for some technical geeky stuff:
Now, regular xerography works like this: A photo-sensitive drum is charged with electrons, and then an image of the paper you want to produce is reflected on it, then ink is put on the drum, the paper is put on the drum, and then the paper is fused by putting it over a heated roller.
Now, with a laser printer, instead of reflecting an image onto the the drum, a high-intensity laser beam is used. A mirror that spins at high speed, spreads the beam out so that it can write the image onto the drum quickly.