LaserJet is the brand name used by the American computer company Hewlett-Packard (HP) for their line of xerography (DEP) laser printers.
LaserJets employ electro-photographic laser marking engines sourced from the Japanese company Canon. Most early printers used internal firmware, controllers, associated software, and drivers developed internally by HP and were considered their "value add" to the standard printer engines. Beginning with the LaserJet 4000, HP has nearly completely outsourced this work to Oak Technology, now Zoran, among many other suppliers.
The first mass market laser printer for IBM Compatible personal computers was introduced in 1984 by HP as the LaserJet. It was an 8ppm printer that sold for $3495.
Due to the high cost of memory, the first LaserJet only had 128 kilobytes of memory, and a portion of that was reserved for use by the print engine. This rendered the LaserJet nearly useless for direct graphical image printing, with it only capable of printing a low-resolution 75-dpi image about 1 inch square before running out of memory. It took approximately two minutes for the first page to print out.
Instead the first LaserJet was primarily intended for use as a high-speed professional replacement for text-only daisy-wheel impact printers. By using control codes it was possible to change the printed text style using font patterns stored in permanent ROM in the printer.
The LaserJet Plus followed in 1985, introducing "soft fonts" and other features including a parallel (Centronics) interface. It also included 512 kilobytes of memory, which was just enough to print graphics at 300 dpi that covered about 70% of the letter-size page area.
In 1986, Desktop Publishing came to the world of IBM PC's and compatibles, after its origin on the Apple Macintosh and Apple LaserWriter. The HP LaserJet, along with Aldus Pagemaker and Microsoft Windows, was central to the PC-based solution, and while lacking the perceived elegance of Apple's approach, this multi-vendor solution was available to a mass audience for the first time.
In May 2006 HP announced the 100 millionth LaserJet shipment.