How does a laser printer work? Easily explained

Laser printers are indispensable in offices and for many prints. This guide explains how a laser printer works exactly.

How does a laser printer work? Building a laser printer

A laser printer consists of various components to bring the data from a document onto paper. In contrast to ink printers, the laser printer works with laser diodes and toner cartridges.

• Image drum: The image drum consists of a special coating that can be charged negatively. The laser neutralizes the negative charge. The charge image, which is represented in the form of pixels, is created on the surface of the image drum.
• Toner: For the color on the paper you need toner cartridges that contain the necessary toner powder. A color laser printer thus has 4 toner cartridges: black, yellow, blue and red.
• Laser: The laser diode directs the laser onto the image drum. The laser hits exactly those areas that are provided with the printer ink.
• Fuser unit: The fuser unit ensures that the toner particles adhere to the paper. The fuser roller is heated to a temperature of around 200 ° C to melt the powder.

How a laser printer works

The operation of the laser printer is based on electrical charges that repel or attract each other. So if two negative charges meet, they repel each other. If a positive charge meets a negative charge, they get dressed.

1. Start process: Once you have started printing, the printer receives important information such as the print resolution and saves it as a whole page. In contrast to ink or dot matrix printers, the laser printer saves entire pages and does not print them out line by line.
2. Rotating image drum: A charging corona or a charging roller negatively charges the image drum. While the drum is rotating, laser beams hit the surface of the drum and thus ensure neutralization. The ink is applied at these neutralized points.
3. Apply toner particles: The neutralized areas pass through the toner, which contains negatively charged powder. The toner powder adheres to the neutralized areas and is repelled by the negatively charged areas.
4. Print color on paper: The paper is charged positively so that the negative particles stick. The charge image corresponding to the side to be printed is on the image drum. The paper runs through the fusing rollers and is printed at a temperature of 200 ° C. At the end of each printing process, the drum is completely exposed and unloaded for the next printing process.

Sweet printer: Now you can even print candy yourself

Next, you should read how to clean the laser printer.