Lexmark 4200 Series - Manual (Page 35)

Diagnostic aids 3-1
4413-XXX
3. Diagnostic aids
Theory of mechanism
Scanner mechanism
The scanner mechanism consists of components which feed, scan,
and eject the documents that are to be copied or transmitted to a
remote facsimile unit. These components and their functions are
explained below.
Drive feed roller assembly
The drive feed roller assembly, consisting of various rollers, rubber
pad, and springs, automatically separates and feeds the pages of a
document over the scanning area and stacks them on the document
exit tray.
Documents up to 15 pages can be placed in the drive feed roller
assembly for scanning. The leading edge of the document moves
the document detect sensor lever when the operator slides the stack
into the drive feed roller assembly. The scan motor starts to rotate
when the document detect sensor detects the leading edge of the
document. The roller feeds the first page of the document into the
feeder.
The scan motor stops when the leading edge of the page actuates
the document scan sensor. The page is now in the scan position.
The drive feed roller assembly rubber pad prevents multiple sheets
from being fed. A spring provides force that the pad places on the
document pages for proper separation.
The scan motor is turned on when the machine is ready to scan the
document and drives the feed roller at a speed determined by the
resolution selected. The scan motor stops after a set period of time
when the trailing edge of the page releases the document scan
sensor. If another page is detected as the trailing edge of the page
releases the document scan sensor, the next page feeds to the scan
position. The exit roller pushes the page out onto the document exit
tray where it is stacked.