Apparatus and method for detecting defect on object
First Claim
1. An apparatus for detecting a defect on an object, comprising:
- an image pickup part for picking up an image of an object to acquire a grayscale inspection image;
a first image generation part for generating a differential image between said inspection image and a grayscale reference image;
a second image generation part for generating an image representing a defect inclusion area which includes a defect, as an image which has less information on a false defect and shape of a defect than information on those in said differential image;
a first evaluation part for performing a provisional evaluation on whether a defect candidate in an area of said differential image which corresponds to said defect inclusion area is true or false; and
a second evaluation part for determining at least one type of feature value which is obtained from said defect candidate in accordance with a result of provisional evaluation performed by said first evaluation part and performing an evaluation on whether said defect candidate is true or false on the basis of said feature value of said defect candidate.
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Accused Products
Abstract
In a defect detection apparatus, data of an inspection image and that of a reference image are inputted from an image pickup part (3) to an operation part (50), and a differential image is thereby generated in a differential image generation part (52) and an image representing a defect inclusion area which includes a defect in an area image generation part (51) as an image which has less information on a false defect and shape of a defect than information on those in the differential image. A first evaluation part (53) performs a provisional evaluation on whether a defect candidate in an area of the differential image which corresponds to the defect inclusion area is true or false. A second evaluation part (54) determines the type of feature values to be obtained from the defect candidate in accordance with a result of provisional evaluation performed by the first evaluation part (53) to obtain the feature values of the defect candidate and performs an evaluation on whether the defect candidate is true or false on the basis of the feature values. With this construction, it is possible to detect a defect on a substrate (9) with high accuracy and high efficiency.
26 Citations
14 Claims
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1. An apparatus for detecting a defect on an object, comprising:
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an image pickup part for picking up an image of an object to acquire a grayscale inspection image;
a first image generation part for generating a differential image between said inspection image and a grayscale reference image;
a second image generation part for generating an image representing a defect inclusion area which includes a defect, as an image which has less information on a false defect and shape of a defect than information on those in said differential image;
a first evaluation part for performing a provisional evaluation on whether a defect candidate in an area of said differential image which corresponds to said defect inclusion area is true or false; and
a second evaluation part for determining at least one type of feature value which is obtained from said defect candidate in accordance with a result of provisional evaluation performed by said first evaluation part and performing an evaluation on whether said defect candidate is true or false on the basis of said feature value of said defect candidate. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for detecting a defect on an object, comprising the steps of:
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a) acquiring a grayscale inspection image of an object;
b) generating a differential image between said inspection image and a grayscale reference image;
c) generating an image representing a defect inclusion area which includes a defect, as an image which has less information on a false defect and shape of a defect than information on those in said differential image;
d) performing a provisional evaluation on whether a defect candidate in an area of said differential image which corresponds to said defect inclusion area is true or false;
e) determining at least one type of feature value which is obtained from said defect candidate in accordance with a result of said provisional evaluation; and
f) obtaining said feature value of said defect candidate and performing an evaluation on whether said defect candidate is true or false on the basis of said feature value. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification