Colour discriminating sensor now offers analogue output

Citation

(2001), "Colour discriminating sensor now offers analogue output", Sensor Review, Vol. 21 No. 3. https://doi.org/10.1108/sr.2001.08721cad.021

Colour discriminating sensor now offers analogue output

Colour discriminating sensor now offers analogue outputKeywords: Colour, Sensors

Omron has introduced an analogue output version of its E3MC RGB colour sensor (Plate 20). Able to accurately discriminate not just different colours but also shades of the same colour, the sensor provides three separate analogue outputs (0-10V) for the three primary colours of red, green and blue, from which the actual colour detected can be deduced. The sensor discriminates colour without being influenced by changes in ambient temperature, brightness or positioning of sensing objects.

Plate 20 Omron's colour discriminating sensor now offers analogue output

The analogue colour sensor is ideally suited to quality control tasks and manufacturing processes where colour is a crucial element. The analogue output provides the control system both with verification that the detected colour is within tolerance, and with a real-time indication of potential problems as colour drifts towards the limits of tolerance and beyond. This gives users an effective tool for continuous process improvement and pre-emptive maintenance.

The E3MC detects colours by making use of the fact that the reflection ratio of a primary colour reflected by an object varies with the chromaticity of the object. Using Omron's FAO (free angle optics) technology, built around a multi-layer polarised filter, the E3MC emits red, green and blue light on a single optical axis. The RGB content of the received light is processed on board the sensor to discriminate the colour of the object. A monitor photodiode compensates for any LED output variation that might be caused by temperature change.

Options for the analogue E3MC RGB sensors include models with built-in amplifiers for long distance setting, and versions with fibre heads for tiny spot sensing. Sensing distance for the built-in amplifier version is specified at 60mm, and the device will tolerate a ±10mm variation in the sensing surface, assuming stable detection. The optical fibre variant offers a 20mm sensing distance with a ±4mm threshold. All models are protected to IP66 for reliable operation in the most arduous of environments.

For further information, please contact: Paul Borrett at Omron Electronics Ltd, 1 Apsley Way, Staples Corner, London NW2 7HF, UK. Tel: +44 (0)20 8450 4646.