Tuesday, July 3, 2012

Printer Work

Introduction








Several manufacturers are making and selling printers. However, there are only three different types of printers: laser, ink-jet and dot matrix. Laser printers are clearly the fastest of the three and have the better print quality. Just like each print job is different, each type of printer has its own specialty and benefit. Each printer functions differently, with its own set of parts and procedures. In this article, we will learn about the laser printer and how it works.


About Laser Printers


When a print job is sent to a laser printer by the operating system, it is instructed to print a page at a time. That is why it was originally called the "page printer." Unlike other printer types that print a dot at a time, the laser printer is able to produce entire pages with remarkable quickness. The incredible print quality by these high-end printers accounts for their expensive price tag.


The laser printer combines six different mechanisms to function: electricity, optics, chemistry, heat, friction and magnetism.


Parts


The parts that make up the printer are just as important because they provide the mechanisms the printer needs to function. The parts and their duties in the printing process are:


The paper feeder. This feeds the paper into the printer using friction. Paper is either held in a paper tray or is contained vertically above the feeder.


Paper transport path. This device moves the paper through the printer. This device ensures that only one piece of paper is fed into the machine at a time by using several sets of rollers. The rollers are synchronized with the entire process to ensure that each piece of paper loads at the exact time that it is needed.








Toner cartridge. This contains three elements that are significant to the print process: toner, print drum and cleaning blade. The toner is the laser printer's version of ink. It is made up of carbon, polyester and iron particles. The carbon outlines the image with its black chalk-like substance. The carbon is helped by the polyester that controls the flow. The iron is responsible for heating the carbon with electrical charges so that it melts onto the paper.


Print drum. This is a photosensitive cylinder that holds the electromagnetic charge given by the iron particles. The drum loses the charge when it is exposed to direct light.


Cleaning blade. This removes an excess toner that builds up on the print drum. This ensures that each print job will continue to have amazing quality and not be loaded with built-up toner.


Fuser. This melts the toner onto the paper. It heats up the Teflon-coated roller by using a halogen lamp. Another rubber roller works with the Teflon-coated one to melt the iron and toner onto the paper by pressing together as the paper passes through.


The Printing Process


The process begins when the printer receives the request from the computer's operation system for a new print job. The print drum is then charged negatively to -600Vdc. When the drum is effectively charged, the laser moves in a strobe-like manner to reflect off the mirror located on the drum. The drum spins as the light creates the image out of the pattern that was sent. After the image is printed on the drum, the toner is supplied to the drum. The paper is then fed into the printer and travels through the paper transport path. The paper is given a positive charge (+600Vdc) that is directly opposite of the negative one that the drum holds. The negative charge of the drum and the positive charge of the paper is how the image is transferred from the drum to the paper. The image is then fused into the paper by the fuser as it moves through the heated rollers.


The end of the printing process is the cleaning of the drum so that it is ready for the next printing job.

Tags: laser printer, onto paper, print drum, drum paper, drum This