Patent ID: 9010148
Filing Date: 2015-04-21
Classification: G01N

Abstract:
1. A method of reducing distortion in a glass sheet, comprising the steps of: forming a glass ribbon in a glass manufacturing process; separating a glass sheet from the glass ribbon, the glass sheet having a substantially flat surface; measuring a retardation value through the surface of the glass sheet at a plurality of locations of the glass sheet; determining an average retardation value of all of the measured retardation values; cutting the glass sheet into a plurality of sub-sheets; measuring a distortion of the sub-sheets; defining a distortion parameter indicative of the distortion of the sub-sheets; determining a correlation between the average retardation value and the distortion parameter such that a distortion parameter of sub-sheets of a subsequent glass sheet can be predicted based on the correlation; and modifying the glass manufacturing process such that an average retardation value of the subsequent glass sheet is adjusted to thereby reduce a distortion of the sub-sheets from the subsequent glass sheet based on the correlation.