Developing Unit - Printronix L5000 Series Maintenance Manual

The developer compound coats the developer roller, which has a positive charge. As
the photoconductive drum rotates past the developer roller, the positivly charged
toner sticks to the negatively charged carrier beads. Remember, all areas that were
exposed to LEDs hold low positive charges and thus contain latent images.
The positively charged toner leaves the developer roller and adheres to the areas of
the drum that were exposed by the LEDs. The heavy carrier beads stay in the
developer unit. (Carrier beads are never used up—they recycle. However, as the
developer unit ages, the carrier beads inside it smooth out and become less effective.
When you install new developer, it will, of course, contain new carrier beads.)
At this point the drum surface contains an image (in the form of toner on the
photoconductive drum surface) of the information or image being printed.

Developing Unit

The developing mechanisms of the printer are integrated into a single unit, which is
constructed as shown below.
Principles of Operation 5–11