Patent Document ID: 7545971
Application ID: 11209586
Patent Status: 1

Claim One:
1. A computer implemented method for measuring crepe pattern features on a surface of a moving sheet that comprises the steps of: (a) illuminating an area on at least one side of the sheet with radiation and forming an optical image of the illuminated area using at least one lens with the proviso that no stabilizer to constrain the moving sheet to a narrow path is required; (b) obtaining and recording at least one digital image of the optical image of the illuminated area by employing an image detector wherein the digital image comprises a plurality of pixels and a pixel in the digital image represents a dimension in the moving sheet that does not exceed one quarter the nominal crepe pitch of the moving sheet so that the crepe pattern features can be discerned; and (c) calculating the crepe pattern features of the sheet by processing at least one digital image by evaluating at least one spectrum on a linear section through the digital image wherein the at least one spectrum represents physical spacing of the crepe pattern features that are discerned from the digital image wherein the crepe pattern features are characterized as at least one of: (i) an average folding pitch, (ii) a distribution of folding pitches, (iii) an average folding length, (iv) a distribution of folding lengths, and (v) a distribution of folding angles.