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3: Operation
Colorwriter LSR 2000 Printer
Service Guide
3-35
Step 3: Developing
The toner (developer) used by the Colorwriter is a single-
component non-magnetic toner composed of resin. This toner is
unique for its insulating property, and is charged with negative
potential by friction between the rotating cylinder and the blade
surface.
The toner comes in four colors - magenta, cyan, yellow and black -
each contained in its own toner cartridge. Each toner cartridge is
housed within the developing rotary and is sequentially directed to
the photosensitive drum in line with the rotation of the rotary (see
“Developing unit control” on page 3-58).
Because the laser-beam-irradiated area on the photosensitive drum
is higher in potential than the toner negatively charged on the
cylinder, the toner jumps across and adheres to the drum surface
due to the difference in potential.
This effect is called toner projection development and makes the
electrostatic latent image on the photosensitive drum surface visible.
AC bias is applied to the developing cylinder for ease in projecting
toner to the photosensitive drum surface and to improve the
contrast of the output image. DC bias varies in response to image
maximum density correction control (see “Maximum density
control” on page 3-69) and the operation of the Density Control
Panel.
Note:
For reference purposes, Figure 3-25 on page 3-36 shows the
light area of the photosensitive drum, which actually has negative
potential, as having positive potential to indicate that it is higher in
potential than that of the cylinder.