Laser printers

A laser printer works similar to the photocopy machine. The main difference is that, while the photocopier creates a copy of a real image, a laser printer makes a copy of the digital computer image.

When the data arrives at printer from the computer, the encoded image is stored in the memory of printer. The memory stores one page of data, and then sends it to the laser and other devices. Some of the printers use a light emitting diode (LED) matrix, instead of a single laser. These printers are called as LED printers.  For practical purposes, LED printers are equivalent to the laser printers. 

The laser blinks rapidly while it scans a cylindrical drum. The drum has special properties that cause it to attract the printing chemical, called toner, in some places but not others, creating an image pattern that will ultimately appear on the paper. A sheet of paper is pulled past from the drum and also past an electrostatic charger. Toner from the drum is attracted to the paper. The image hence goes onto the paper, although it has not yet been permanently fused, or bonded, to paper. The fuser, a hot pair of roller/squeezers, does this job, completing printing process.The main advantage of laser printers is their excellent print and graphics quality. The im- age resolution of a laser printer ranges from about 300 dots per inch (DPI) for older units to 1200, 2400, or even more DPI in state of the art machines. As far as the untrained eye can tell, 600 DPI is as high-quality as a photograph. Laser printers handle graphics and text both well. If an image is rendered on the photocopy machine, it can be rendered as well on the laser printer. Another asset of laser printers is that they make almost no noise. Yet another good feature is that this type of printer is relatively fast. The best high end machines can generate a couple of dozen copies per minute.

The laser printer is best device for rendering high resolution hard copy text and graphics. If you are doing desktop publishing, presentation graphics, or anything else which requires top grade or high volume hard copy, you will want a laser printer. Ask some friends for their opinions, and if printing is important to you, do not cut corners. A good laser printer is the geek’s equivalent of the reliable truck.