Pilkington Plc

Pilkington Group Limited

Pilkington Automotive Deutschland Gmbh

Simon Peter Aldred

Barry Raymond Hill

Ingo Bartsch

Methods of determining the divergence angle between a primary image and a secondary image generated by a glazing are disclosed. In a first method, a glazing is illuminated with a light source and a primary and a secondary image of the light source, generated by the glazing, are captured using an image capture device. The distance between the primary and the secondary image is determined, and the divergence angle determined from this distance. In a second method, the primary and secondary images are viewed on a target marked with a scale indicating the divergence angle. The divergence angle is read from the scale and the positions the primary and secondary image. In this second method, the light source is located at the center of the target. In both methods, the light source comprises at least one light emitting diode. Preferably, the method is used to examine the edge region of a glazing.

Glazing inspection method

A method of forming a shadowgraph image is described, comprising the steps of illuminating a glazing (), e.g., a vehicle windscreen, with light from a localized light source (), said light being expanded and collimated by a lens optical system () or a mirror optical system, forming a virtual shadowgraph image of the glazing in a virtual image plane (), which may be positioned behind or in front of the glazing: and imaging the virtual image onto a CCD camera (). The glazing may be moving relative to the light source or may be stationary. Furthermore, a method of glazing inspection is described, comprising forming a shadowgraph image as outlined above; processing the shadowgraph image to exclude measurement points corresponding to obscure areas of the glazing as non-valid measurement points: obtaining a processed image by determining an illumination value for each valid measurement point; constructing a reference image by scanning a convolution window point by point over the processed image; and comparing the illumination value of the corresponding point of the reference image.

Glazing inspection

A method of determining the optical quality of a glazing which includes at least one area having a reduced light transmission, involves producing a shadowgraph image of the glazing and measuring the illumination of the glazing at a plurality of measurement points arranged in an array extending over the glazing. The deviation in illumination from a desired value at each measurement point is determined and the at least one area of reduced light transmission is omitted from the array of measurement points.

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Tarleton, United Kingdom

Simon Peter Aldred