Optical imaging with optimized illumination efficiency and uniformity

A method for imaging a scan line on a media sheet, comprising:

• defining an optical path from a media sheet to a sensor for receiving and converting a light image derived from that media sheet to an electrical signal;
• selecting a predetermined scan line position which is substantially aligned with the optical path;
• emitting a light beam from a high performance diffusing light source whereby a portion of the light beam illuminates a first portion of the predetermined scan line and a portion of the light beam is reflected from a reflector to illuminate a second, opposed portion of the predetermined scan line position, thereby uniformly illuminating substantially an entirety of the predetermined scan line position;
• and
• collecting at least a portion of the light beam reflected from or transmitted through the media sheet in the sensor to image the portion of the media sheet defined by the predetermined scan line position.

An optical imaging module for uniformly illuminating a predetermined scan line position of a media sheet, comprising:

• a diffusing light source for emitting a light beam and a light reflector for reflecting at least a portion of that light beam, said diffusing light source and light reflector cooperating to uniformly illuminate at least a predetermined scan line position on a media sheet to be imaged;
• and
• a sensor array for receiving a light image derived from the media sheet and for converting the light image to an electrical signal;
• wherein the diffusing light source and light reflector are arrayed on opposed sides of an optical path defined between the scan line position and the sensor array, to uniformly distribute a light beam about at least the predetermined scan line position.