Patent · US Expired

Defect inspection of objects such as electronic circuits

US4056716A · kind A · utility

54Cited by
10References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 30, 1976
Grant dateNov 1, 1977
Priority date
Expiry dateJun 30, 1996

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH05B39/083
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Successive areas of a high-resolution object image are compared with corresponding areas of a low-resolution master pattern to produce signals representing the quality of the object. Comparison is effected by detecting which of a set of features occurs in each area of the object image, detecting which feature of the same set occurs in a larger area of the master pattern, and determining whether these two features are the same.

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