A photoplotter is a specialized electro-opto-mechanical machine that exposes a latent image on a medium, usually high-contrast monochromatic (black-and-white) photographic film, using a light source being controlled by a computer.
[7][8]: 244- Early machines used a xenon flash lamp, and projected an image mounted in a rotating aperture wheel onto the photosensitive surface of the film or glass plate.
[9]: 54 The imaging head assembly traversed over the surface of the media without touching it to produce draws and flashes.
Draws are vectors or arcs created by continuous illumination as the imaging head moves over the photosensitive surface.
[8]: 234 Modern photoplotters are generally raster-scan devices that use a laser beam focused to one or more spots, modulated at multi-megahertz rates to form the image.