Canon LBP-860 Service Manual page 57

3. Transfer stage
In the transfer stage. the toner image is
transferred from the drum surface to the
paper.
Step 4 Transfer
Transfer chargmg roller
Figure 2-25
A posilive charge applied to the back of the
paper attrarls the negatively charged toner
particles to the paper.
accomplishes transfer by using lhe
charging roller
compared with the corona transfer method
are as follows:
. Low transfer voltage that is less than half
that for corona transfer
. Less ozone generation
The paper is supported by the transfer
charging roller and photosensitive drum,
so feed is more stable.
Reference:
If the image on the photosensitive drum
is not completely transferred to the paper
due to jamming, etc., the toner may
adhere to the transfer charging roller.
The printer removes the toner from the
transfer charging roller by switching the
transfer voltage between positive and
negative in sequence. During wait, initial
rotation, and last rotation, the printer
sets the primary DC voltage to zero, and
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The printer
method. Advantages
the charge on the drum to zero. In
this case, the transfer voltage is made
negative to remove the negatively-
charged toner on the transfer charging
roller to the drum. The transfer charging
roller is thus cleaned.
Step 5 Separation
eliminator
The stiffness of the paper causes it to
separate from the drum. (Curvature
separation)
To stabilize the paper feed and prevent
small white circles from appearing in the
printed image at low temperature and
humidity, the charge on the back of the
paper is reduced by the static charge
eliminator after transfer.
Transfer charging roller