Colour Laser Printer components

Drum Unit:

The purpose of the drum unit in a laser printer is to transfer an image to the paper.

A laser printer places toner on the roller called the “Photosensitive Drum” by electrical charge. The image is then rolled out onto the paper. Toner and paper is then super heated for a few milliseconds and under pressure sealed into the paper.

Designs differ between manufacturers.

Types of Drum Units:

A seperate drum and toner recognises that a drum roller only needs replacing at certain intervals to keep printing to an acceptable standard. Drum units usually last for the life of four toner cartridges, which reduces the overall cost to the printer owner. Brother have kept this design in most of their laser printers, some HP and Lexmark printers have also adopted the design.

Kyocera have adopted ceramic drum units, that have an expected life of the printer which effectively reducing the total cost of ownership. This benefits the owner as the only item to be replaced is the toner cartridge.

Other printers will have a combined drum and toner cartridge. This type of design works on the principle of keeping everything to a replaceable minimum. It is very easy to just replace the toner cartridge with these printers.

Some printers have a different style of drum called a an image belt. The image belt is usually long lasting and really does the same job as the drum.

If your printer displays a message to replace the drum or belt unit, replace this within a reasonable period of time to ensure the printer keeps working. The printer will alert you several times.

Follow the instructions to reset the counter in some printers. Intsructions are usually provided with the replacement items and apply to the specific models of printers.

Example C: Brother monochrome laser model

Example D: Colour laser drum

Toner cartridge

Toner is a heat sensitive powder used to create images and text on paper.

Referred to as a consumable, toner is the main usable component of the printing process. Toner is stored ready for use in cartridges, always replace the toner cartridge when running low or print quality becomes poor because of toner deterioration.

Removal and Re-install

Pull out the drum and toner cartridge from your printer.

On either side of the drum unit press down on the blue or green lever (as shown in Example D). The toner cartridge can now be removed.

Place the toner into the new drum unit.

Reinsert the drum and toner back into the printer.

Example E The toner cartridge clips into the drum unit