Defect inspection apparatus
AssigneeHitachi High-Tech Corporation
InventorsYasuhiro Yoshida, Masayoshi Ishikawa, Toshinori Yamauchi, Kosuke Fukuda, Hiroyuki Shindo
Life of this patent
Estimating the term…
Abstract
A defect inspection apparatus includes: a feature value calculation unit calculating a feature value based on a captured image of a sample; an image information reduction unit generating a latent variable by reducing an information quantity of the feature value; a statistic value estimation unit estimating an image statistic value that can be taken by a normal image based on the latent variable; and a defect detection unit detecting a defect in an inspection image based on the image statistic value and the inspection image of the sample.
Claims14
A defect inspection apparatus for improving robustness to process and imaging variations and increasing inspection throughput by generating per-pixel normal-image statistics from a vector-quantized latent representation, the apparatus comprising:
- an imaging subsystem configured to capture, from a sample, an inspection image;
- and
- one or more processors and a non-transitory memory storing instructions that, when executed by the one or more processors, cause the apparatus to:
- compute, from a captured image of the sample, a feature representation;
- generate a latent variable by reducing an information quantity of the feature representation,
- estimate, based on the latent variable, an image statistic value that can be taken by a normal image, and
- detect a defect in the inspection image based on the image statistic value and the inspection image of the sample.
Dependencies are inferred from the claim text.