Patent ID: 7893922

Claim:
An input organ, comprising means for detecting the touch of a fingertip, a key stem movable in response to detecting the touch of a fingertip by the means for detecting, a switch arranged to be operated in response to movement of the key stem, means for providing a tactile feedback to the fingertip to acknowledge an activation of said input organ, and wherein said means for providing a tactile feedback comprises elongate shape memory metal; wherein the elongate shape memory metal comprises a first muscle wire arranged to be energised when the organ is touched by a fingertip to such an extent that said first muscle wire contracts and tactile feedback in the form of mechanical energy resulting from said contraction is mediated to a touch surface of said means for detecting arranged to make contact with the fingertip; wherein the elongate shape memory metal comprises a second muscle wire, said first and a second muscle wires being independently controllable, wherein the first muscle wire is arranged to convey a motion of said touch surface towards the fingertip, and the second muscle wire is arranged to convey a motion of said touch surface away from said fingertip; and wherein said conveying of a motion is achieved by the first muscle wire being arranged under and generally parallel to the touch surface as a taut string between two supports in position for the key stem contacting the first muscle wire approximately at the middle of its length whereby the increased tension in the first muscle wire is conveyed toward the touch surface, and wherein said conveying of a motion is achieved by the second muscle wire being arranged under and generally parallel to the touch surface as a taut string between two supports in position for the key stem contacting the second muscle wire approximately at the middle of its length whereby increased tension in the second muscle wire is conveyed away from the touch surface.