×

Method and apparatus for inspecting surfaces for contrast variations

  • US 5,091,963 A
  • Filed: 05/02/1988
  • Issued: 02/25/1992
  • Est. Priority Date: 05/02/1988
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method of inspecting a surface of an article for isolated contrast variations, comprising:

  • illuminating a surface of an article;

    forming a surface image from the light reflected from said surface, said surface image being composed of a plurality of pixels, said pixels comprising digitized electrical signals each indicative of the relative intensity level of light reflected from a particular portion of said surface;

    comparing the intensity levels of at least some of the pixels to a predetermined intensity threshold to identify pixels corresponding to portions of said surface contrasting with other portions of said surface;

    determining the number of isolated regions of contrast variation on said surface and determining the magnitude of the space occupied by the area of each of said isolated regions of contrast variation from the number of pixels within each isolated region of contrast variation; and

    applying acceptability criteria based upon the number of isolated regions of contrast variation and the magnitudes of the respective areas of the isolated regions of contrast variation to decide whether the article is acceptable for a particular use.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×