Laser Printer

A laser printer is a type of printer that uses a laser beam to apply powdered ink, called toner, to a sheet of paper. A laser printer can print text and shapes at a high resolution, typically 600 dots per inch (dpi) or more. It can also print documents at significantly higher speeds than an inkjet printer, with most models able to print more than 30 pages per minute for simple monochrome documents. However, a laser printer cannot print high-resolution full-color images at the same quality as an inkjet printer, so the best choice depends on the content of the print job.

Laser printers do not use the laser to burn text and other shapes into the paper. Instead, a printer fires a laser at the surface of a rotating cylindrical drum to "draw" the image it is printing. The laser hits the drum's photoreceptive coating and creates a negatively-charged area for positively-charged toner to cling to as the drum rotates past the cartridge. When a sheet of paper moves through the printer, the toner sticks to the paper instead (as it has a slightly stronger charge than the drum). After the paper proceeds past the drum, it passes through rollers that heat the toner and fuse it to the paper.

Since the toner is fused to the paper before it leaves the printer, it won't smear like a fresh page from an inkjet printer. Most laser printers only use black toner, suitable for printing pages of text and other monochrome content. Color laser printers use four colors of toner (cyan, magenta, yellow, and black) and are more expensive, as they are more technically complex and require a separate drum for each color. While a replacement toner cartridge often costs more than an inkjet ink cartridge, a toner cartridge contains enough toner to print thousands of pages, and an ink cartridge may only last a hundred.