What Is a Printer Drum Unit?

Most drum units are monochrome, meaning that they print in black only.

A printer drum unit is one of the key components of a laser printer. It is one of the critical differences between a laser style and an inkjet printer.

Wet versus Dry

An inkjet printer literally contacts the paper with wet ink, whereas a laser printer does not. Instead, heat and pressure are used in a laser printer to transfer the desired image onto the page. The ink for a laser printer is actually in a dry, powdered form. This is why the drum comes is needed.

The Drum

First, the drum receives a charge. It is then exposed to the toner. In most laser printers, we find a monochrome setup because more than one color becomes quite expensive. The drum contains an exact image of the document that needs to be printed. When it is given toner, the document can then be sent from the drum and "fused" to the paper.

Prices

Many vendors sell drum units in stores or on the Internet. Prices may vary depending on the brand and the age of the laser printer. For example, a run-of the-mill Brother drum unit will cost slightly less than $90 and an authentic printer drum from IBM, which was the first company to come out with a laser printer in 1975, may cost more than $600.

References

• Laser Printer