Analogue and digital copiers - a comparison

Analogue copy machines (which do everything with mirrors, basically) are nowadays outphased by the more modern, digital machines.

A digital copier is a combination scanner/laser printer, often equipped with hard disks, local ram, multiple CPUs and printer/scanner boards.

While analogie copiers have no fixed resolution (the quality of the reproduction depends on the fineness of the toner and the quality of the optics), normal photocopiers work with something like 300,400, 600 and 1200 dpi. One advantage of digital systems is that the scanned image can be stored and manipulated - or printed many times with a single scan. Still - this ability makes digital low-end machines more expensive. On the other hand, high-speed analogue copiers are limited in speed by the capability of the machine to move sheets of paper without jamming.

The main bottleneck in the design of digital copiers is not the paper handling but the time needed to write the image on the photosensitive drum.