Importance

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Abstract

A joystick 50 comprising: a control shaft 52; first and second reflecting surfaces, the surfaces each having a reflectivity that varies along a notional line on the surface; a first sensor assembly 70 comprising a first emitter operable to illuminate the first reflecting surface along said line with radiation, and a first detector arranged to detect radiation emitted by the first emitter and reflected by the first reflecting surface; and a second sensor assembly 72 comprising a second emitter operable to illuminate the second reflecting surface along the line with radiation, and a second detector arranged to detect radiation emitted by the second emitter and reflected by the second reflecting surface; wherein movement of said shaft 52 provides a relative movement between emitters of the first and/or second sensor assemblies 70, 72 and respective associated reflecting surfaces to vary the intensity of radiation reflected, and the detectors of the first and second sensor assemblies are each operable to output a voltage that is dependent on the intensity of radiation detected.

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First Claim