Method of inspecting a workpiece surface including a picturing system with a shortened focal plane
First Claim
1. A method of inspecting a workpiece surface for detecting a defective portion on the workpiece surface by using an optical inspecting apparatus having a projector for radiating a detecting light towards the workpiece surface and a picturing means for receiving a reflected light from the workpiece surface, said method comprising the steps of:
- picturing with the picturing means the reflected light in a condition in which a focal plane of the picturing means is positioned between the workpiece surface and the picturing means such that the focal plane does not intersect the workpiece surface anywhere in an inspecting region of the workpiece surface from which the picturing means can receive the reflected light; and
processing an image to detect the defective portion on the workpiece surface in the inspecting region from a dark portion which appears on the image of the picturing means.
1 Assignment
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Accused Products
Abstract
A workpiece surface is measured to detect a defective portion with a projection and a depression on the workpiece surface by using an optical inspecting apparatus having a projector for radiating a detecting light towards the workpiece surface and a picturing device for receiving a reflected light from the workpiece surface. A reflected light from the workpiece surface is pictured in a condition in which a focal surface of the picturing device is positioned away from the workpiece surface to the side of the picturing device relative to an entire region of that effective inspecting range of the workpiece surface from which the picturing device can receive the reflected light. The defective portion on the workpiece surface is detected from a dark portion which appears on the image of the picturing device.
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Citations
5 Claims
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1. A method of inspecting a workpiece surface for detecting a defective portion on the workpiece surface by using an optical inspecting apparatus having a projector for radiating a detecting light towards the workpiece surface and a picturing means for receiving a reflected light from the workpiece surface, said method comprising the steps of:
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picturing with the picturing means the reflected light in a condition in which a focal plane of the picturing means is positioned between the workpiece surface and the picturing means such that the focal plane does not intersect the workpiece surface anywhere in an inspecting region of the workpiece surface from which the picturing means can receive the reflected light; and processing an image to detect the defective portion on the workpiece surface in the inspecting region from a dark portion which appears on the image of the picturing means. - View Dependent Claims (2, 3, 4, 5)
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Specification