×

Surface relief measuring equipment

  • US 4,433,386 A
  • Filed: 12/08/1980
  • Issued: 02/21/1984
  • Est. Priority Date: 10/01/1980
  • Status: Expired due to Term
First Claim
Patent Images

1. Apparatus for measuring the thickness of a coating comprising:

  • a turntable for supporting and rotating a flat substrate bearing a regularly sectored coating pattern, wherein in use, the centers of the coating pattern and the turntable are substantially coincident;

    tracking means for bearing on a top surface of the patterned substrate, the tracking means vertically moveable in a direction perpendicular to the substrate;

    means for moving the tracking means radially of the turntable;

    a transducer operably connected to the tracking means for generating an electrical signal in response to vertical movement thereof;

    a band pass filter for passing a component of the transducer electrical output at a frequency corresponding to the frequency of traversal of the pattern sectors by the tracking means;

    and means for measuring amplitude of the filtered signal to provide an indication of coating thickness.

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