Patent · US Expired

Surface-defect detecting device

US4095905A · kind A · utility

16Cited by
2References
26Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 17, 1976
Grant dateJun 20, 1978
Priority date
Expiry dateAug 17, 1996

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01B11/303
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A surface-defect detecting device including: illuminating means for illuminating a minute peripheral or annular zone on the surface of a material to be inspected, such as the circumferential surface of a cylindrical body; at least a pair of reflecting mirrors having ellipsoidal or spheroidal surfaces and first focal points positioned at the minute annular zone so as to focus the light reflecting from the aforesaid minute annular zone on the circumferential surface of the body; and photoelectric elements positioned at second the other focal points of the reflecting mirrors, respectively; whereby when a defect is not present in the minute annular zone on the circumferential surface of the body, the light is regularly reflected on the surface of the body to be inspected, so as not to be received by the photoelectric elements, and on the other hand, when a defect is present on the minute annular zone on the circumferential surface of the body, the light is irregularly reflected on the minute annular zone to be received by photoelectric elements, so that the body may be inspected for a defect on its surface according to signals obtained from the photoelectric elements, and the defect th…

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