Patent ID: 7256883
Filing Date: 2007-08-14
Classification: G01N

Abstract:
1. A method for the optical inspection of a transparent protective layer and of a colored patterned surface, whereby the transparent protective layer at least partially covers the colored patterned surface, said method using a first source of illumination and a first imaging sensor associated with the first source of illumination, said method comprising the steps of: illuminating said protective layer with light emitted by the first source of illumination in order to recognize defective places inside and beneath the transparent protective layer, said first source of illumination emitting shortwaved light in the range that is visible for the first imaging sensor and that is at least partially diffuse, the light striking said surface penetrating at least partially into the protective layer and scattering at the defective places; picking up light scattered back from the defective places with the first imaging sensor; and recognizing the defective places by the local increase in the intensity of the light picked up by the first imaging sensor in the area of the defective places.