Method for the optical inspection of a transparent protective layer and of a colored patterned surface

US7256883B2 · kind B2 · utility

Assignee

• Robert Massen · DE

Inventors

• Igor Detinkin · Konstanz, DE
• Hans-Peter Diehl · Konstanz, DE
• Robert Massen · Schallstadt, DE

Key dates

• Filing date: Jan 15, 2004
• Grant date: Aug 14, 2007
• Expiry date: May 18, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N21/958
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method for the optical inspection of a transparent protective layer and a colored patterned surface which is at least partially covered by the transparent protective layer involves providing a source of illumination and an imaging sensor associated with the source of illumination and illuminating the protective layer with light emitted by the source of illumination in order to recognize defective places inside and beneath the transparent protective layer. The source of illumination emits light in the shortwaved range which is at least partially diffuse and the light striking the surface penetrates at least partially into the protective layer and is scattered at the defective places. Light scattered from the defective places is picked up by the imaging sensor and the defective places are recognized by the local increase in the intensity of the light picked up by the imaging sensor in the area of the defective places.