Patent ID: 7199884
Filing Date: 2007-04-03
Classification: G01B

Abstract:
1. A system for measurement of a thickness of a web having a first surface and a second surface, comprising: a first sensor head that includes (i) means for projecting a pattern onto the first surface of the web and (ii) means for detecting an image of the projected pattern and converting the detected image into an electrical signal corresponding to an electronic image; means for analyzing the electronic image to determine a distance between the first sensor head and a first selected location on the first surface of the web; a second sensor head that includes means for measuring a distance from the second sensor head to a second selected location on the second surface of the web; means for measuring a distance from the first sensor head to the second sensor head; means for measuring a tilt angle of the web; means for measuring a relative misalignment of the first and second sensor heads; and means for calculating the thickness of the web using the tilt angle of the web and the relative misalignment of the first and second sensor heads.