Patent · US Expired

Coarse flaw detector for printed circuit board inspection

US4707734A · kind A · utility

24Cited by
6References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 17, 1985
Grant dateNov 17, 1987
Priority date
Expiry dateJun 17, 2005

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06T2207/30141
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A system for detecting flaws in printed circuit boards. The circuit board is scanned by a video camera to provide a serial stream of bits each indicative of a picture element within a particular scan line. The serial stream of bits is formulated into binary numbers each representative of a contiguous path of picture elements composed of n.times.n picture elements. Each of these binary numbers are compared with a corresponding one of a set binary numbers stored in memory representative of a perfect master printed circuit board. Failure of the printed circuit board to match the stored master indicates a flaw. The invention also includes means to generate overlapping patches to insure detection of defects which occur in adjacent patches.

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