HP 3150 EN - Manual (Page 76)

74 Functional overview EN
Image formation system
Laser printing requires the interaction of several different technologies
(such as electronics, optics, and electrophotographics) to provide a
printed page. Each process functions independently and must be
coordinated with the other printer processes. Image formation
consists of six processes:
● Step 1. Primary charging
● Step 2. Scanning exposure
● Step 3. Developing
● Step 4. Transferring
● Step 5. Separating
● Step 6. Drum cleaning
Figure 11. Image formation block diagram
Toner cartridge
As the heart of the image formation system, the toner cartridge
houses the cleaning, conditioning, and developing steps of the
process. The toner cartridge contains the photosensitive primary
charging roller, developing station, toner cavity, and cleaning station.
Including these components (which wear, degrade, or are consumed)
in the replaceable toner cartridge eliminates the need for a service
call when replacement is required. The special photosensitive
properties of the drum allow an image to be formed on the drum
surface and then transferred to paper.