User manual

95.08.23.11.29
Color LaserWriter 12/600 PS Basics & Theory 1–55
Step 7:
Toner
Transfer
The paper attracted to the transfer drum is transported in correspon-
dence with the rotation of the transfer drum. At this time, positive
charges are applied to the reverse side of the transfer sheet to transfer
the toner from the photosensitive drum to the paper. This process
repeats sequentially for each color (M, C, Y, K).
The transfer drum consists of an internal aluminum cylinder covered
successively by a conductive elastic sponge layer and an external insu-
lating transfer sheet.
DC bias is applied to the transfer drum. The value of the DC bias varies
in line with the temperature/humidity sensing system.
In full-color mode, as the transfer steps proceed with the first color,
second color, and so on, the transfer force weakens due to the increase
in the number of negatively-charged toner particles on the paper. To
counteract this effect, the transfer bias is gradually increased for the
second and subsequent colors.
Photosensitive Drum
Transfer Drum
Paper
Transfer Sheet
Elastic Sponge Layer
Aluminum Layer
Gripper
Toner
DC bias