The very short answer is, yes, they do use lasers.
The not-quite-as-short answer is that when you hit the print button, you send a large stream of electronic data to your laser printer. An electronic circuit in the printer interprets the data and uses it to determine what the finished product needs to look like. The printer uses a laser beam to scan back and forth across a drum inside the printer, building up a pattern of static electricity. Toner is applied to the drum. Paper is applied to the drum. Finally, as in a copier, a fuser unit bonds the toner to the paper.
If you’re still with us, and would like more detail – the long and more detailed answer is this:
1. Millions of bytes (characters) of data are sent to the printer from your computer.
2. An electronic circuit in the printer, running the driver software, figures out how to print this data so it looks correct on the page.
3. The electronic circuit activates a corona wire – a high-voltage wire that gives a static electric charge to anything nearby.
4. The corona wire lends a charge to the photoreceptor drum, so that the drum gains a positive charge which is spread uniformly across its surface.
5. The circuit activates a laser, which draws the image of the page onto the drum by bouncing off a moving mirror that scans it over the drum. Where the laser beam “touches” the drum, it erases that portion of the positive charge and creates an area of negative charge instead. Where the page needs to be white, there are areas with a positive charge; where the page should be black, there are areas of negative charge.
6. An ink roller coats then coats the drum with tiny particles of powdered ink (toner). The toner has been given a positive electrical charge, so it sticks to the parts of the photoreceptor drum that have a negative charge. No toner is attracted to the parts of the drum that have a positive charge. An image of the page builds up on the drum.
7. A sheet of paper is pulled from a drawer and fed toward the drum. As it moves, the paper is given a strong positive electrical charge by another corona wire.
8. When the paper nears the drum, its positive charge attracts the negatively charged toner particles away from the drum. The image is transferred from the drum onto the paper.
9. The inked paper passes through the fuser unit, a set of two hot rollers. Heat and pressure from the rollers fuse the toner particles permanently into the fibers of the paper.
10. The paper is ejected and deposited into the print tray.
11. You hand the finished product to the boss, who immediately promotes you, gives you the second-best parking spot and keys to the executive ski chalet.
For more information on how a laser printer can improve your workflow (not to mention your future), please contact us.