Although Inkjet printers are fast, the less expensive Inkjet models on the market today are not speedy enough to keep up with the demands of a busy office, where performance and reliable paper handling are a must- you will need a more expensive, high-end Inkjet printer for office use. Inkjet ink tends to smear when wet. Finally, Inkjet printers tend to suffer from banding on large areas of black or a single color. If you have ever tried to print a large illustration using solid black on an Inkjet or dot matrix printer, you have seen this effect: visible bands running horizontally across the image. Because the print head can apply only a small rectangle of ink, any misalignment of the paper or minute difference in the ink mixture results in a band. These disadvantages may not be tremendously important to the owner of a home PC, but office workers need the best possible print quality, and they need those pages yesterday. For this reason, either a high-end inkjet printer or laser printers are better suited for a networked office environment. Laser printers have been around for years now, but most of us remember why they were not popular for home or small office use. As little as five years ago, the least expensive laser printer available would still set you back at least $1,000. Prices have dropped to the point where that same $1,000 will buy you an office- quality laser printer that delivers pages at 16 pages per minute at 1,200 dpi- And, in fact, prices for many "personal" laser printers have dropped to less than $400, making them affordable for the home user who wants best monochrome and grayscale documents.

In this section lets discuss the inner workings of both monochrome and color laser printers, as well as other features you will find on most lasers that make them the right choice for an office setting.

How Do Laser Printers Work?

Is a laser printer the same as a laser copier? Not really instead of scanning input from a hard copy document, a laser printer accepts its input of the original image as a series of codes from your computer. Your laser printers microprocessor uses these codes to build an image of the page in the printers internal memory, which it then transfers to the printed page. (This is why you often see the RAM or buffer memory listed in advertisements for laser printers.)

Your laser printer also uses toner instead of ink. Toner is a very fine black powder that is very sensitive to electric charges. Luckily, you usually dont have to pour toner into your printer; as with an inkjet, you simply replace a cartridge to add more toner to virtually all laser printers. Laser toner cartridges use a roller to spread a wide, continuous layer of toner over the length of the cartridge.

But how does that toner stay on the paper, and what arranges it to form text and graphics? Lets follow the laser printing process step by step:

A roller moves across the face of a turning cylinder inside your laser printer; the charging roller transfers an electrical charge to the cylinder, which is called photoconductor. As mentioned earlier, toner powder is very sensitive to electrical charges, and this charge repels the toner powder away from the photoconductor. The photoconductor cylinder keeps turning, which next brings it into contact with a laser beam. (It had to be called a "laser printer" for some reason.) The laser beam is controlled by the printers microprocessor brain, which turns the beam on and off as it sweeps back and forth across the surface of the phtoconductor. Areas struck by the laser beam reverse the electrical charge, so the toner sticks to just the imaged areas of the photoconductor cylinder. The next stop for the photoconductor cylinder is another roller - this one is the tone roller, which dispenses an even line of toner across the face of the photoconductor. Those areas of the cylinder that have been hit by the laser beam attract toner, while the rest of the toner still repels it. In effect, the cylinder now carries an image of the page, but it hasnt yet been transferred to the paper. As the photoconductor continues to turn, it comes in contact with the transfer roller - paper from the paper tray is simultaneously fed between the two surfaces. The transfer roller applies a slight electrical charge to the paper, so the toner that remains on the photoconductor cylinder now sticks to the paper. (At this point, however, the toner is not actually affixed to the page; it would fall off if you shook the page.) Now our attention turns to the paper - it passes trough another two rollers. The top roller, which is on the same side of the paper as the toner, is called the fuser roller; its heated by the printer, so the toner partially melts and sticks to the page for a permanent bond. To provide pressure, another roller simultaneously presses the paper against the fuser roller. As the two rollers turn, the paper is drawn through them and moves outside the machine to the paper collection tray. Now that the photoconductor cylinder has transferred the image to the page, it must be cleaned before the process can repeat. As the cylinder continues to turn, it passes under a cleaning brush or a scraper blade that removes any stray particles of toner. Finally the photoconductor cylinder completes the cycle by returning to the charging roller; if another page has to be printed, the entire process is repeated. Color laser printers follow this same general process, but they use four color toners instead of one.(Sometimes these colors are added as individual cartridges or poured individually into the unit, while other printers combine all of the separate color toner cartridge.) The photoconductor cylinder in a color printer makes four complete passes to transfer each of the four base colors to the page before it passes to the fuser roller. As you can imagine, these printers are far more complex and require more internal memory to hold four separate images of the same page, so even with the drop in monochrome laser prices, a color laser printer can still set you back several thousand dollars.

The office choice

Traditionally, laser printers have been the top sellers for office environments (although inkjet printers are rapidly growing in popularity as technology improves). Besides the advantages listed earlier in this section, laser printers also have a number of other features that make them especially attractive for heavy printing traffic:

High printing speed. Although inkjet technology is improving in speed, high-performance laser printers can still double the output speed of even the best inkjet printer in monochrome printing, making laser printers the favorite in nay office that requires a high volume of printing.

Network capable. Most laser printers have an option for a network connection, which simplifies their use as a network printer. (Some high-end inkjet printers also offer built-in network support.)

Improved paper handling. Laser printers can usually hold more paper than an average inkjet printer, meaning the paper supply lasts longer and requires less intervention. Many models (as do most inkjets) also come with accessory trays that enable you to use legal and European paper sizes.

Resident fonts and font cartridges. Many older models of laser printers can be upgraded with additional on-board fonts through font cartridges, while todays models are upgraded with internal font memory cards; because windows doesnt have to download these fonts to your printer each time you print a document. On-board fonts can save you anywhere from 15 to 30 seconds of printing time. The more you use a specific font in your documents, the more youll benefit if you add that font cartridge to your laser printer.

Warning

The fuser roller is exposed on many laser printers when you open the cover, and if the printer has been running, this roller is often hot. Its important not to touch the fuser roller, and pay close attention to any warning labels or stickers inside your laser printer when your replacing toner cartridges or cleaning the interior mechanism.