Patent ID: 8049879

Claim:
An apparatus for measuring optical distortion in a glass sheet including: a digital camera, a background screen including a matrix of spaced apart dots positioned on a contrasting background, a glass stand for receiving and maintaining the glass sheet in the path between the camera and the background screen, at least one light source mounted in a position to illuminate the surface of the glass sheet so that the camera captures an image of the surface of the glass sheet when the glass sheet surface is illuminated, at least one light source mounted in a position to illuminate the background screen so that the camera captures an image of the matrix transmitted through the glass sheet, and a computer including logic for receiving the captured image data and (1) analyzing at least the surface image data to determine whether there are any surface marks or elements on the glass sheet that should not be considered in the optical distortion analysis, (2) locating and isolating the data corresponding to any such surface marks or elements in the image of the matrix, and (3) determining a magnification and lens power associated with each point of interest on the matrix without considering the isolated data.