Patent · US Expired

Detection of subsurface defects by reflection interference

US4302108A · kind A · utility

35Cited by
11References
14Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJan 29, 1979
Grant dateNov 24, 1981
Priority date
Expiry dateJan 29, 1999

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N21/8901
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A process for detecting defects in a multiply layered light transmitting structure, comprising illuminating the surface of the structure with a beam of light at an angle of incidence to the structure at which at least a portion of the beam will be reflected, and detecting the intensity of the reflected beam to locate subsurface as well as surface anomalies in the structure.

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