Patent · US Expired

Apparatus for inspecting the surface of materials

US5298963A · kind A · utility

49Cited by
12References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 26, 1992
Grant dateMar 29, 1994
Priority date
Expiry dateFeb 26, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2201/103
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An apparatus for inspecting the surface of a sheet-like object has a movable stage with an object mounted thereon; a source for lighting the object on the stage, particularly by making a plurality of illumination lights respectively having different wavelengths incident on the surface of the object from respective predetermined directions; image pickup device for fetching the image of the object under illumination of the light as image data or the images of parts of the object as image data obtained on the respective different wavelengths; image data processing device for inspecting the image data for defects; and a device for synchronizing control either for flashing the light at a predetermined time interval just after the stage commences its movement, synchronously with fetching the image data or for flashing the light and simultaneously fetching the image data obtained on the respective different wavelengths, synchronously with the object on the stage reaching respective predetermined positions while moving the stage.

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