Strobe illumination
AssigneeMitutoyo Corporation
InventorsPaul G. Gladnick, Richard Wasserman
Life of this patent
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Abstract
An illumination technique is provided that adjusts the respective light intensities of each of a plurality of light sources that are strobed at desirable consistent intensities by adjusting a respective light pulse pattern for each respective light source. All the light sources are controlled to illuminate an object throughout a strobe duration period. The light pulse patterns may be micro-strobed light pulse patterns, formed by a variety of methods. The illumination technique is usable to preserve the general shape of the edge intensity profile on an object, and allow precision edge position measurements, regardless of whether the object is moving or not during image acquisition.
Claims16
A method of strobe illumination for acquiring an image of an object, comprising:
- operating a first respective light source according to a first respective light pulse pattern including at least one light pulse while acquiring the image, the first respective light pulse pattern having an overall strobe duration period defined between a start of a first light pulse of the first light pulse pattern and an end of a last light pulse of the first light pulse pattern;
- and
- operating at least a second respective light source according to a second respective light pulse pattern while acquiring the image, the second respective light pulse pattern including at least one more light pulse than the first light pulse pattern, the light pulses of the second respective light pulse pattern distributed over a portion of the overall strobe duration period;
- wherein the respective first and second light pulse patterns at least partially govern the respective time-averaged intensities provided by the respective first and second light sources while acquiring the image.
A method for capturing an image of a workpiece, comprising:
- operating a first respective light source according to a first respective light pulse pattern including at least one light pulse while acquiring the image, the first respective light pulse pattern at least partially governing the respective time-averaged intensity provided by the first respective light source while acquiring the image, and the first respective light pulse pattern having an overall strobe duration period defined between a start of a first light pulse of the first light pulse pattern and an end of a last light pulse of the first light pulse pattern;
- and
- micro-strobing at least a second respective light source to provide a second respective light pulse pattern while acquiring the image, the second respective light pulse pattern including at least one more light pulse than the first light pulse pattern, the second respective light pulse pattern at least partially governing the respective time-averaged intensity provided by the second respective light source while acquiring the image;
- and
- capturing the image of the workpiece over an image integration time of a camera that overlaps the overall strobe duration period.
Dependencies are inferred from the claim text.