Patent ID: 6633338
Filing Date: 2003-10-14
Classification: G01N

Abstract:
A machine-vision system comprising:A) a camera that has a field of view, includes a field-of-view deflector that moves the camera's field of view through positions in which it includes different portions of a target region, and is operable to sense an image of the field of view and generate output signals representative of the sensed image; B) an array of light sources of which each is operable between a lit state, in which that light source shines light into the target region, and an unlit state, in which that light source does not, the light sources being so positioned that: i) if a target surface disposed at an expected target-surface angle in the portion of the target region included in the field of view reflects specularly, the target surface images a viewed subset of the sources into the camera's field of view and images an unviewed subset thereof outside the camera's field of view; and ii) the memberships of the viewed and unviewed subsets change with changes in the position of the camera's field of view; and C) light-control circuitry that, when the camera takes an image, keeps each light source the viewed subset in the unlit state of that light source and permits each light source on the unviewed subset to assume the lit state of that light source.