Patent · US Expired

Surface defect inspection system

US4403294A · kind A · utility

53Cited by
10References
12Claims
0Family size

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Key dates

Filing dateNov 28, 1980
Grant dateSep 6, 1983
Priority date
Expiry dateNov 28, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06T2207/30164
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A surface defect inspection system comprises an image pick-up device for picking up an image by sequentially scanning the surface of an object two-dimensionally, a threshold circuit for quantizing the image signal produced from the image pick-up device as a binary code, a pattern feature extracting device for making calculations for extracting the features of image patterns from the quantized signal in synchronism with the scanning, and for temporarily storing the result of the calculations, a pattern region end decision device for deciding that individual pattern regions have ended in one direction, and a defect decision device for reading out from the pattern feature extracting device the result of the calculations on the pattern features corresponding to the positions each of the patterns in the direction perpendicular to the one direction each time of the decision that each pattern region has ended, so that the feature of each pattern scanned is compared with a predetermined reference, thus deciding and an indication of producing the presence or absence of a defect.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.