Oki OKIPAGE 24DX Service Manual page 46

(8) Cleaning
After the end of the transfer, residual toner on the image drum is attracted to the cleaning roller temporarily by static
electricity to clean the image drum surface.
(9) Cleaning of rollers
The charge roller, transfer roller and cleaning roller are cleaned in the following cases:
l
In warming up at power-on time
l
In warming up after the cover is opened and closed
l
When the number of accumulated sheets is 10 or more and the printout operation ends
Changes in bias voltage applied to each roller move adhesive toner from the roller to the image drum and return it to
the developer.
(10) Duplex Unit
When the Duplex Unit receives an instruction for both-sided printing from the unit, the separator will be opened by
the action of a solenoid within Duplex and the route will be shifted to the one into the Duplex after one-sided printing
of papers, which are fed from the tray, are completed. At this time, as the roller (1) rotates in the direction of arrow A,
a sheet is retracted in the rear of the cassette. And then, a given time later after the edge of the sheet passes
through the IN SNS (DUP), the roller will reverse and the roller (1) rotates in the direction of arrow B and sending out
the paper into the Duplex. After that, it passes though the roller (2) and (3), and is fed again into the unit, given
another-sided printing and ejected.