Method and apparatus for automatically optimizing optical contrast in automated equipment

A method for automatically adapting illumination light in a vision system to a color of a part feature against a part feature background of a part being viewed by said vision system, comprising:

• selecting at least one of group consisting of a coarse and fine illumination color from a set of available coarse and fine illumination colors;
• setting said illumination light in said vision system to said selected illumination color;
• measuring a contrast level corresponding to the selected illumination color between said part feature and said part feature background;
• determining whether said measured contrast level corresponding to the selected illumination color meets acceptable contrast criteria;
• and
• repeating said selecting step through said determining step if said measured contrast level corresponding to the selected illumination color does not meet said acceptable contrast criteria.

A computer readable storage medium tangibly embodying computer program instructions for automatically adapting illumination light in a vision system to a color of a part feature against a part feature background of a part being viewed by said vision system, comprising the instructions of:

• selecting at least one of group consisting of a coarse and fine illumination color from a set of available illumination colors;
• setting said illumination light in said vision system to said selected illumination color;
• measuring a contrast level corresponding to the selected illumination color between said part feature and said part feature background;
• determining whether said measured contrast level corresponding to the selected illumination color meets acceptable contrast criteria;
• and
• repeating said selecting step through said determining step if said measured contrast level corresponding to the selected illumination color does not meet said acceptable contrast criteria.

An electronic vision system, comprising:

• an illumination light generator capable of generating illumination light of a plurality of different illumination light colors and/or intensities and which illuminates a part feature against a part feature background;
• a camera which images the part feature against the part feature background;
• a contrast tester which measures a contrast level between said part feature and said part feature background;
• and
• an illumination system controller which is responsive to the contrast level and to acceptable contrast criteria to adjust the illumination light generator to illuminate the part feature against the part feature background to one of the plurality of different illumination light colors and/or intensities such that the contrast level meets the acceptable contrast criteria, by at least selecting one of the plurality of different illumination light colors and/or intensities,
• wherein the illumination system controller steps through a set of available coarse illumination colors and selects one of the available coarse illumination colors which meets the acceptable contrast criteria, and then steps through a set of available fine illumination colors within a predetermined range of the selected coarse illumination color and selects one of the available fine illumination colors resulting in a highest contrast level.

An electronic vision system, comprising:

• an illumination light generator capable of generating illumination light of a plurality of different illumination light colors and/or intensities and which illuminates a part feature against a part feature background;
• a camera which images the part feature against the part feature background;
• a contrast tester which measures a contrast level between said part feature and said part feature background;
• and
• an illumination system controller which is responsive to the contrast level and to acceptable contrast criteria to adjust the illumination light generator to illuminate the part feature against the part feature background to one of the plurality of different illumination light colors and/or intensities such that the contrast level meets the acceptable contrast criteria, wherein the illumination system controller adjusts the illumination light generator to illuminate the part feature against the part feature background by:
• selecting one of the plurality of different illumination light colors and/or intensities comprising the illumination system controller stepping through a set of available coarse illumination colors and selecting one of the available coarse illumination colors which meets the acceptable contrast criteria, and then stepping through a set of available fine illumination colors within a predetermined range of the selected coarse illumination color and selecting one of the available fine illumination colors;
• controlling the illumination light generator to illuminate the part feature against the part feature background with the selected illumination light color and/or intensity;
• measuring a contrast level corresponding to the selected illumination light color and/or intensity between the part feature and the part feature background;
• determining whether the contrast level corresponding to the selected illumination light color and/or intensity meets the acceptable contrast criteria;
• and
• repeating the selecting step through the determining step if the contrast level corresponding to the selected illumination light color and/or intensity does not meet the acceptable contrast criteria.