Non-contact object inspection
First Claim
1. A non-contact method of inspecting the topography of an area of an object via analysis of the phase of a pattern projected on the object, comprising:
- i) taking a first image of the object, obtained from a first perspective, on which an optical pattern is projected;
ii) taking a second image of the object, obtained from a second perspective, on which an optical pattern is projected but in which the optical pattern, as it falls on the object, in the second image differs to that in the first image; and
iii) determining data describing the topography of at least a region of the object based on phase data relating to the phase of at least a region of the optical pattern as imaged in the first image in which phase data obtained from a corresponding region of the object as imaged in the second image is used to resolve any ambiguity in the phase or topography data obtained from the first image,wherein the region of the optical pattern as imaged in the first image and the corresponding region of the object as imaged in the second image each comprise a plurality of mutually adjacent pixels that define areas extending substantially in two dimensions.
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Abstract
A non-contact method of inspecting the topography of an area of an object via analysis of the phase of a pattern projected on the object. The method includes taking a first image of the object, obtained from a first perspective, on which an optical pattern is projected, and taking a second image of the object, obtained from a second perspective, on which an optical pattern is projected but in which the optical pattern, as it falls on the object, in the second image differs to that in the first image. The method further includes determining data describing the topography of at least a region of the object based on phase data relating to the phase of at least a region of the optical pattern as imaged in the first image. Phase data obtained from a corresponding region of the object as imaged in the second image is used to resolve any ambiguity in the phase or topography data obtained from the first image.
77 Citations
29 Claims
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1. A non-contact method of inspecting the topography of an area of an object via analysis of the phase of a pattern projected on the object, comprising:
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i) taking a first image of the object, obtained from a first perspective, on which an optical pattern is projected; ii) taking a second image of the object, obtained from a second perspective, on which an optical pattern is projected but in which the optical pattern, as it falls on the object, in the second image differs to that in the first image; and iii) determining data describing the topography of at least a region of the object based on phase data relating to the phase of at least a region of the optical pattern as imaged in the first image in which phase data obtained from a corresponding region of the object as imaged in the second image is used to resolve any ambiguity in the phase or topography data obtained from the first image, wherein the region of the optical pattern as imaged in the first image and the corresponding region of the object as imaged in the second image each comprise a plurality of mutually adjacent pixels that define areas extending substantially in two dimensions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. An apparatus for non-contact inspection of an object, comprising:
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at least one projector configured to project an optical pattern onto the object to be inspected; at least one imager device configured to obtain a first and at least a second image of the object, from first and at least second perspectives, on which the optical pattern is projected; and an analyser configured to determine the topography of at least a region of the object based on phase data relating to the phase of at least a region of the optical pattern as imaged in the first image in which phase data obtained from a corresponding region of the object as imaged in the second image is used to resolve any ambiguity in the phase or topography data obtained from the first image, and in which the optical pattern, as it falls on the object, in the second image differs to that in the first image, wherein the region of the optical pattern as imaged in the first image and the corresponding region of the object as imaged in the second image each comprise a plurality of mutually adjacent pixels that define areas extending substantially in two dimensions.
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29. An apparatus for non-contact inspection of an object, comprising:
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means for projecting an optical pattern onto the object to be inspected; means for obtaining a first and at least a second image of the object, from first and at least second perspectives, on which the optical pattern is projected; and means for determining the topography of at least a region of the object based on phase data relating to the phase of at least a region of the optical pattern as imaged in the first image in which phase data obtained from a corresponding region of the object as imaged in the second image is used to resolve any ambiguity in the phase or topography data obtained from the first image, and in which the optical pattern, as it falls on the object, in the second image differs to that in the first image, wherein the region of the optical pattern as imaged in the first image and the corresponding region of the object as imaged in the second image each comprise a plurality of mutually adjacent pixels that define areas extending substantially in two dimensions.
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Specification