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Blue-LED encoders ‘double signal quality’ at up to 12,000 rpm
Published:  08 May, 2017

By using specially-developed blue-light LEDs, Pepperl+Fuchs claims to have produced a range of incremental rotary encoders with the highest signal quality available. The ENI58IL encoders also offer higher resolutions, improved signal amplitudes, and the ability to operate with absolute accuracy at speeds of up to 12,000 rpm.

“Compared to the long-wave infrared light that is typically used in conventional rotary encoders, the blue light from the new emitter LED has a shorter wavelength while, at the same time, featuring identical splitting width,” explains Stefan Horvatic, head of product management at P+F’s encoder business. “This allows sharper imaging.”

He adds that the BlueBeam technology more than doubles signal quality compared to conventional infrared technology.

The blue light from the LEDs suffers less diffraction than longer-wavelength infrared light, resulting in sharper images. The light also penetrates deeper into the sensing chips, helping to generate sharper contours, and resulting in improved signal amplitudes and reduced edge jitter.

Pepperl+Fuchs’ claims that its blue-light encoder delivers the best signal quality

High-frequency sampling and the use of special circuitry help to protect the encoder against interference. The new technology also keeps signals stable when exposed to mechanical forces such as shock and vibration. Reliability and durability are said to be improved by the use of interlocked bearings which withstand high loads and protect the ball bearing. Another claimed attraction is improved calibration of the code disk.

P+F is offering the encoders with a variety of shaft, flange, and connection options. “With the ENI58IL series, we’re introducing a well-thought-out portfolio of industry-standard encoders covering applications that up to now would have required special devices,” says Horvatic.