Micro-Epsilon Eltrotec has introduced a colour sensor series. The ColorSensor OT is intended for the recognition of colour nuances and greyscale on shiny and structured surfaces. Unwanted light effects are suppressed through diffuse illumination. The series contains 20 reflex lenses and a fibre-optic lens as well as three versions for the recognition of UV markings.
The different versions of the sensor series enable reliable colour recognition even on shiny and reflective or structured surfaces. Examples include leather, embossed films, fabrics and veneers, as used in automotive engineering, or even large painted parts.
The measuring ranges of the new series typically cover 2 to 800mm, while the switching frequency is 30/35kHz. Eight white-light LEDs, whose brightness can be controlled as required, are used as illuminants for the diffuse illumination. The switching status is displayed by means of five yellow LEDs. The sensors are insensitive to external light and have a true colour detector, which filters RBG values in a similar way to the human eye.
However, the so-called 'best hit mode' uses vector formation to show colours which are so similar that they are almost indistinguishable to the human eye. This provides an unambiguous, process-safe differentiation.
The sensor can be programmed with up to 31 colour values for differentiation, using teach-in buttons or by means of control using a PC or SPS. The connection to the control unit is provided by an RS232 interface; a USB adapter is available as an option. Various algorithms are available for the evaluation. The related software has a function for determining the average value from one to over 32,000 values. The typical colour resolution of the series is delta E> 0.8, which sets new standards in this area. By comparison, the human eye can resolve values of only 1.3 to 1.5.
The OT-3-MA reflex lenses for matt surfaces, available with the sensors, achieve ranges of up to 400mm. They provide focused illumination, which enables the sensors to process rapidly changing object distances. Ranges of 300mm are achieved with the variants GL with shine suppression and HR for reflective and structured surfaces.
The fibre-optic lens LU is suitable for capturing small light spots from 0.5mm in size. Together with offset lenses, this covers working distances from 2mm to 100mm. UV or luminescent markings are used to safeguard against the falsification of documents, securities, bottles or pharmaceutical packaging. For the manufacture of such products, Micro-Epsilon Eltrotec supplies comprehensive advice on identifying luminescent pigments made from rare earths.