US 6,983,066 B2
Machine vision
James Mahon, Dublin (Ireland); Niall Burke, Sallins (Ireland); Adrian Boyle, Monasterevin (Ireland); Karl Stanley, Dublin (Ireland); Brian Farrell, Dublin (Ireland); and Peter Conlon, Dublin (Ireland)
Assigned to MV Research Limited, Dublin (Ireland)
Filed on Apr. 12, 2002, as Appl. No. 10/120,382.
Application 10/120382 is a continuation of application No. PCT/IE00/00130, filed on Oct. 17, 2000.
Claims priority of application No. 990870 (IE), filed on Oct. 18, 1999; and application No. 99650103 (EP), filed on Nov. 05, 1999.
Prior Publication US 2002/0114505 A1, Aug. 22, 2002
Int. Cl. G06K 9/00 (2006.01)
U.S. Cl. 382—141 16 Claims
OG exemplary drawing
 
1. An illumination unit for a machine vision system, the illumination unit comprising:
means for illuminating a target with monochrome illumination for sufficient time for a camera to capture a monochrome image,
means for subsequently illuminating the target with a different monochrome illumination at substantially the same angle for sufficient time for a camera to capture a different monochrome image of the same target whereby the sequentially captured monochrome images are superimposed by an image processor to provide a colour or near colour image,
wherein each monochrome illumination means comprises a plurality of light emitting diodes of the same wavelength,
wherein the diodes are arranged in a ring, and
wherein the diodes of different monochrome illumination means are distributed to provide a similar illumination intensity and distribution for each monochrome image.