What is the difference between a thermojet printer and an officejet printer?
Thermal Printers
Thermal printers do not use ink to print. A special paper, fittingly called thermal paper, needs to be used with thermal printers. Thermal paper is coated with certain chemicals that make the paper change color when heated. A roller will feed the thermal paper over the thermal print head. Where the print head heats the paper is where the image will show up.
Without the use of ink cartridges or ribbons, the process of thermal printing can be quite simple. The maintenance of a thermal printer is minimal due to the lack of these moving parts. Without these moving parts, thermal printers can be extremely small and portable.
Laser Printers
The word laser can make you think that this technology was taken out of a James Bond film. Adversely, this technology is simple, clever and efficient. The basic principle behind laser jet printing is static electricity.
How does that same buildup of energy that shocks you when you go to open a metal door handle apply to printing? Scientifically speaking, two atoms that are oppositely charged are attracted to each other. The drum inside of the printer is positively charged by a wire or roller with an electrical current running through it. As this drum is revolving, a laser is projected onto the drum to take away the positive charge in certain places. After this occurs the printer then puts a positively charged toner (black powder) on the drum. This positively charged powder will stick to the parts of the drum that are now negatively charged due to the help of the laser.
When the paper goes through the printer, it is given a negative charge by the same wire or roller that took away the charge on the drum. The paper then rolls under the drum attracting the toner from the drum onto the paper (due to its stronger negative charge).
Finally the paper passes through the printer’s fuser. The fuser melts the toner onto the paper and rolls the paper out into the output paper tray. This is the reason why the printer paper is hot when it comes out of a laser printer. This is how the basic concept of static electricity is used to print efficient and great quality prints.
