Patent ID: 8402785

Claim:
A method for measuring the shape profile of a surface of a glass sheet comprising: flowing molten glass into a fusion pipe and overflowing the molten glass from the fusion pipe to form a sheet-like flow; receiving the sheet-like flow in a channel and drawing the sheet-like flow into a glass sheet; measuring a shape profile of a surface of the glass sheet while the glass sheet is being drawn, the measuring comprising: positioning an apparatus comprising a light source along or at a bottom of the channel and operating the apparatus to provide an elongated light beam that is incident on the surface of the glass sheet and has elongation in at least one direction; translating the elongated incident light beam substantially linearly over the surface in a predetermined measurement direction such that the elongated incident light beam is incident on the surface of the glass sheet at multiple positions and produces a reflected light beam at each of the multiple positions, wherein a major axis of the elongated incident light beam is perpendicular to a direction in which the elongated incident light beam is translated during the translating; intercepting the reflected light beam produced at each of the multiple positions; receiving information related to the position difference between the intercepted reflected light beams and the incident light beam at each of the multiple positions; and correlating the position difference information to the shape profile of the surface of the glass sheet.