Any printer in which the required image is written by a beam of light onto a photoconductive drum or band that has a uniform electric charge over its surface. The action of the light beam produces a charge pattern on the photoconductor, which is then developed by applying particles of pigment that are attracted to the image but are repelled by the background. The image is then transferred to paper by pressing the paper against the drum or band and applying an electric field. The toner is fixed to the paper by heat and/or pressure or by passing through a solvent vapor bath.
This type of printer can yield very good print quality, forming its image as a fine matrix of dots. It can thus readily produce graphics and a wide variety of typestyles. The most common example is the laser printer.