Patent · US Expired

Optical element inspecting apparatus

US5828500A · kind A · utility

39Cited by
5References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 9, 1996
Grant dateOct 27, 1998
Priority date
Expiry dateOct 9, 2016

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N21/958
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An optical element inspecting apparatus for inspecting optical elements for defects. The optical element inspecting apparatus includes an illuminating unit, an image capturing unit, two polarizers, a rotation device, a controller, and a means for composing a plurality of image data captured by the image capturing unit. The optical element to be inspected is placed between the polarizers and is illuminated by the illuminating unit. The light that passes through the polarizers and the optical element is captured by the image capturing unit and stored in memory. The controller controls the rotation device such that the polarizers are rotated by a predetermined amount and a subsequent image data is captured. In this way, a number of image data are captured and all image data are composed to make a composite image data. The optical element is examined to detect flaws therein by using the composite image data.

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