Method and device for controlled illumination of an object for improving identification of an object feature in an image of the object

摘要

In a method and apparatus wherein components and/or markings applied to substrates are illuminated with illumination devices and imaged via a camera, adequate contrast between useful and unwanted structures is achieved even in the case of highly disparate optical properties of different materials for the substrates, components and markings by the use of an illumination device composed of a number of illumination units that respectively emit light in spectral ranges different from one another and which are thereby separately varied in intensity. This illumination with variable spectral distribution assures an adequate contrast even given the employment of different materials for the illuminated items.