A dust tolerant scanner without a transparent plate to support objects
scanned by its media scan assembly. Other dust or debris collecting
surfaces in the optical path of the scanner are positioned as far away as
possible from an object focal plane of the media scan assembly. The media
scan assembly includes upper and lower document feeder portions which
define a media path adjacent to a reference surface of the upper portion.
The lower document feeder portion includes a media conformance member
which positions pieces of media against the reference surface as the
pieces of media are advanced along the media path. The media conformance
member includes ramp portions and an aperture which provides an optical
path between the object focal plane and a sensor focal plane within the
scanner.