The mode of operation of the LED printer is comparable to that of the laser printer. In the LED printer, the image is transferredto the light-sensitive image drum by a large number of light-emitting diodes. Depending on the resolution, there may be several thousand light-emitting diodes arranged on an LED strip the width of the print format.
The light-emitting diodes transfer the charge image, which corresponds to the print image, line by line to the roller-shaped image drum by electrostatically charging the surface through exposure. During drum rotation, the electrically charged toner is picked up at the charged points and transferred to the paper. This also becomes electrically charged. The toner is fixed by the application of heat and pressure.
The excess toner is stripped off by a scraper device and collected in the waste toner container.
The print resolution of LED printers is directly dependent on the number of light-emitting diodes and is, for example, about 600 dpi with 5,000 light-emitting diodes. Since LED printers prepare the print image page by page beforehand, they require several megabytes for the print pages, depending on the resolution.