Messehighlight 20. Februar 2024

Multispectral lights for vision systems have been used for many years. The typical and most used configuration is a halogen light, very similar to the solar spectrum, with band-pass filters on the camera in order to have only the required wavelengths. The typical applications are:

• optical sorting in machine vision;
• waste recycling;
• chemical analysis of material composition;
• food safety and inspection;
• medical & healthcare;
• pharmaceutical manufacturing;
• semiconductor & photovoltaic;
• mineralogy & mining.

The technique consists in the lighting of the object to inspect, using only the wavelength selected to highlight and identify the target, for example the presence of water in a solid object or to select the types of plastic on the basis of the optical answer of a specific wavelength. The typical disadvantages of these applications are:

• low duration of the light source (+/- 1000 hours);
• overheating and instability of the light source;
• slowness in the replacement of the optical filters on the camera with the rotating mechanism;
• limited number of optical filters;
• light power that can not improve on many wavelengths;
• complicated use of this solution in environments with water, dust and vibrations.