The HP LaserJet 4 (abbreviated sometimes to LJ4 or HP4) is a group of monochrome laser printers produced in the early to mid-1990s as part of the LaserJet series by Hewlett-Packard (HP). The 4 series has various models, including the standard LaserJet 4 for business use, the 4L for personal use and the 4P for small businesses. Additional models included the 4Si model, created as a heavy-duty business printer, and the 4V model, a B-size printer for desktop publishing and graphic artists. There are also PostScript variants of these machines with the '4M' designation, where M stands for, but is not limited to, usage with an Apple Macintosh. Hewlett-Packard also released an upgraded version of the LaserJet 4/4M known as the 4 Plus ('4+')/4M Plus ('4M+').
The LaserJet 4, especially the 4/4M/4+/4M+ models, have become known for their durability, mainly due to their reliable construction, as well as the printers built-in PCL (and optional PostScript) printer language support which is still used in computers to this day. Hewlett-Packard dominated the laser printing sector during this time in part due to their reliability, relatively affordable pricing, and the spread of LaserJet 4 models from personal use up to heavy business use.
