LaserJet
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LaserJet is the brand name used by the American computer company Hewlett-Packard (HP) for their line of dry electrophotographic (DEP) laser printers.
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[edit] Technology
HP 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 Corporation, among many other suppliers.
[edit] History
[edit] 1980s
The first laser printer for IBM Compatible personal computers was introduced in 1984 by HP as the LaserJet (now called LaserJet Classic). It was a 300-dpi, 8 ppm printer that sold for $3,495.
It featured a 8 MHz processor and the Courier typeface. Due to the high cost of memory, the first LaserJet only had 28 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 and dot matrix 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 November 1985, priced at $3,995. It introduced "soft fonts," treatments like bold and italic 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 March 1986, HP introduced the LaserJet 500, which featured high-capacity duty cycle of 1,000 pages a month. 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.
HP introduced the world's first mass market laser printer, the LaserJet series II, in March 1987, list priced at $2,695. Many 20-year-old LaserJet II's (and its successor, the mechanically-similar LaserJet III) remain in use as reliable workhorses in offices and publishing houses; corroboration may be found by noting that a LaserJet II toner cartridge remains one of the most popular toner cartridges at a stationary store. Also in March 1987, the LaserJet 2000 was launched. A high-end, networkable workhorse, the LaserJet 2000 offered a duty cycle of 70,000 pages per month and the standard 300-dpi output. Priced at $19,995.
In June 1988, HP shipped its 1 millionth LaserJet printer.
In September 1989, HP introduced the first "personal" version of the HP LaserJet printer series, the LaserJet IIP. Priced at $1,495 by HP, it was half the size and price of its predecessor, the LaserJet II. It offered 300-dpi output and 4 ppm printing with PCL 4 enhancements such as support for compressed bitmapped fonts and raster images. Retailers predicted a street price of $1000 or less, making it the world’s first sub-$1,000 laser printer. The LaserJet IIP (and its successor, the IIIP) were extremely reliable except for scanner failures, diagnosable by the lack of the familiar "dentist drill" whine and a "50" error displayed on the control panel; aftermarket replacement scanner assemblies remain readily available to this day.
[edit] 1990s
In March 1990 the newest model, the LaserJet III, priced at $2,395, was introduced with two new features: Resolution Enhancement technology (REt), which dramatically increased print quality, and HP PCL 5. Thanks to PCL 5, text scaling was easy, and thus customers were no longer restricted to 10 and 12-point type sizes. This had a dramatic effect on word processing software market.
The world's first network printer, the HP LaserJet IIISi, was introduced in March 1991. Priced at $5,495, it featured a high-speed, 17 ppm engine, 5MB of memory, 300-dpi output, REt and such paper handling features as job stacking and optional duplex printing. The LaserJet IIISi also was HP’s first printer to offer onboard Adobe PostScript as opposed to the font-cartridge solution offered on earlier models.
In October 1992, HP introduced its first printer with 600-dpi output and Microfine toner, the LaserJet 4, bringing publication-quality printing to the desktop. It was also the first LaserJet to ship with TrueType fonts, which ensured the printer fonts exactly matched the fonts displayed on the computer screen. Priced at $2,199.
In April 1994, HP shipped its 10 millionth LaserJet printer.
In September 1994 HP introduced the Color LaserJet, HP's first color laser printer. The printer had an average cost per page of less than 10 cents. The Color LaserJet offered 2 ppm color printing and 10 ppm for black text, 8MB of memory, 45 built-in fonts, a 1,250 sheet paper tray and enhanced PCL 5 with color. Priced at $7,295.
In April 1996, HP introduced the LaserJet 5 family of printers. They offered HP PCL 6, an improved printer language for noticeably faster output – especially with complex, graphics-intensive documents. They also featured 600-dpi output with REt, and a 12 ppm engine. Prices started from $1,629.
The world’s first mass-market all-in-one laser device, the HP LaserJet 3100 was introduced in April 1998. Users could print, fax, copy, and scan with a single appliance.
In July 1998, HP shipped its 30 millionth LaserJet printer.
In February 1999, HP introduced the LaserJet 2100 printer series – the world’s first personal laser printers in their class to offer high-quality 1200 x 1200-dpi resolution without significant performance loss.
[edit] 2000s
In December 2000, HP celebrated the shipment of the 50 millionth LaserJet printer.[1]
In September 2001, HP entered the low-end laser printer market with the introduction of the LaserJet 1000. It was the first sub-$250 LaserJet and the lowest priced monochrome HP LaserJet printer to date. Offered 10 ppm, HP Instant-on fuser, 600-dpi with HP REt boosting output effectively to 1200dpi, 2.5 cent cost per page, and 7,000-page monthly duty cycle.
In 2003, HP shipped its 75 millionth LaserJet printer.
In November 2003, HP entered the $24 billion copier market with the LaserJet 9055/9065/9085 MFPs, a copier-based line of high-volume multi-function printers.
In May 2004, HP celebrated the 20th anniversary of the original LaserJet and ThinkJet printers.
In May 2006 HP announced the 100 millionth LaserJet shipment.[2]
As of 2007, HP has several lines of monochrome (black and white) and color printers and multi-function products (copy, scan, and/or fax included) that range from 20-55 ppm and range in price from $149 to several thousands of dollars.
[edit] Evolution of the LaserJet control panel
The 1992 LaserJet 4L marked the transition between a control panel designed for an informed operator and one designed for a casual user. The 4L's predecessor, the IIIP, had an array of buttons and a cryptic numerical LCD display. The 4L was shipped with 4 LEDs, each with an icon to indicate a different condition, and a single pushbutton whose purpose varied depending on context (ie. Hold down during printing, the printer will cancel the job. Hold down when off, the printer will power up and print a test page including total number of pages printed. A short press would provide a form feed or tell the printer to resume from a paper jam or out-of-paper condition. The actual application of the button is far more intuitive than any possible written description - basically, the button tells the printer "Whatever you're doing now, do the next most logical thing".). A 4L's four status LEDs will also light in unusual patterns to indicate service requirements; for example, a lit error light and a lit ready light would indicate a fuser problem (usually just needs to be reseated - most 4L problems can be resolved by simply disassembling the printer, cleaning it, then reassembling it). Interestingly, the 4L used early light pipes, with surface-mounted LEDs on the control board on the left side of the printer, and plastic channels to conduct light from the lit status LEDs to the top of the printer. To this day, professional-grade LaserJets retain more comprehensive displays.
Before the 4L, the control panel typically had buttons with names like Online, Menu, Shift, Continue, Reset, +, -, and Form Feed. This interface was loved only by engineers, since it also included seemingly conflicting status indicators like Online and Ready. A printer that is offline but ready does not print, though this is not immediately clear to new users. (As a consolation, even prior to Office Space, PC Load Letter was a commonly confusing error message mocked as a monument to poor user interface design and was commonplace on LaserJets prior to the 4L. "PC Load Letter" means, "Paper Cartridge - Load (insert) Letter (8.5"x11") paper" - for very minimal costs, the message could have probably alternated between "OUT OF LETTER / TOP CASSETTE / FEED ME!" )
When a LaserJet is controlled by a Windows PC, the Form Feed button usually never does anything when pressed. It had a small indicator light, and was only used with very simple DOS programs that did not eject the last page after sending data to the printer. The Form Feed button would print whatever was remaining in memory and prepare the printer to accept any new data as if it were being typed at the top of a new blank sheet of paper.
Also, the Online button was a poorly named toggle switch, such that if the printer was already online, pressing Online actually makes the printer go offline and could be used to stop a runaway print job. Pressing Shift-Reset would then clear the remainder of the unwanted document from the printer's memory. None of this complexity of operation was obvious to new users unfamiliar with the printer.
This was in stark contrast with the original Apple LaserWriter which had no buttons at all, and just three status lights: Ready, Busy, and Paper Jam. The only user interaction with the LaserWriter was to open it to clear paper jams, and when closed the printer would immediately auto-resume without further prompting. All other control, including canceling print jobs, was done from the Macintosh computer. Apple continued the tradition of buttonless controls and only status lights on up through the LaserWriter II product line, while the HP LaserJet models continued to bristle with unusual buttons, intended for users of simple DOS software incapable of sophisitcated automatic printer management and monitoring.
But by 1999 the PC was now firmly into the Windows 95 era with DOS fading fast. Many of the original manual control buttons like Form Feed were no longer necessary, because the Windows 95 print-spooler subsystem offered even simple Windows applications a much greater control over the printer than was available to DOS applications, which had to constantly rebuild and re-engineer basic printer management systems from scratch. This new Windows-oriented interface was highly intuitive and obvious to the casual user, who needed little familiarization with the printer to use it effectively.
[edit] Key innovations
- Spring 1984 – First HP LaserJet
- Fall 1994 – First HP Color LaserJet
- Spring 1997 – First printer-based multifunction device
- Spring 2006 – World’s smallest footprint LaserJet
[edit] Industry firsts
- Spring 1984 – Personal laser printing
- March 1991 – Network printing
- April 1993 – Web Jetadmin
- November 2005 – Universal Print Driver
[edit] See also
- Series and models
