Laser printers use a laser beam to form a pattern of electrostatic dots on a drum inside the printer. The drum reacts to the light to attract the toner and then fuse the toner to the paper. This means the toner will not splatter or smudge on the page. It is also more cost-effective than ink.
Inkjet printers are much more common than laser printers. They can be used on many different types of materials, such as paper, plastic, and even leather. Unlike laser printers, inkjet printers typically are smaller and more portable. These are also cheaper than laser printers. Depending on the type of printer, the price will vary, with the average cost of a black and white page running between 5 and 10 cents. A color page will run between 15 and 25 cents.
Inkjet printing uses a print head that deposits liquid ink onto paper. During printing, the printer’s sensor may stop the printing process if the paper is full of ink or if one color is low. Some inkjet printers offer “ink tanks,” or refillable tanks, that store ink for up to two years. Using refillable tanks allows consumers to print without having to replace ink cartridges.
Unlike inkjet printing, laser printers use a drum. A laser is a highly focused beam of light, which is directed across photoreceptors in the drum. If the image is a dark shade, the toner is able to fuse with the negative charge parts of the drum.
The drum is sensitive, and if it is accidentally touched during a print, the results will not be accurate. For this reason, it is important to not touch the imaging drum while it is being printed. Another disadvantage is that laser printers will eventually need to be replaced with new toner cartridges.
Color laser printers typically use cyan, magenta, yellow, and black inks. The ingredients of color toner differ from manufacturer to manufacturer, but are largely made from a variety of organic compounds. Dye-based inks are more prone to fading and smudging.
The raster memory in the printer holds the bitmap image of the entire page. Usually, a full-color letter-size page will require at least 4 megabytes of memory. At 300 dpi, a full-color page will need at least 90,000 dots per square inch (dpi) to achieve an accurate representation.
The toner is a fine powder, which is bonded to the surface of the paper. When the drum is heated, the toner is fused to the paper. Typically, the toner is replaced after three or four toner cartridges have been used.
Inkjet printers are cheaper, but their printing capabilities vary greatly. They are better for color-rich prints, as well as for photographers. Smaller spaces, such as an office, will benefit from an inkjet, while larger spaces will be better suited to a laser.
While a laser printer is more expensive upfront, it offers a very low cost-per-page. The printer is also able to offer more features, such as copying and scanning.