Abstract: A switch arrangement comprises a photoconductor to be illuminated. The switch arrangement also comprises a conductor which is intended to further transmit light escaping from the photoconductor and directed to the conductor by a local contact, wherein the conductor and the photoconductor are further under the control of an external force, arranged to move in relation to each other and to cause the development, loss or change of the contact in such a way that a detectable change is caused in the light guided through it.

Abstract: The present invention relates to proximity sensors. It also relates to proximity sensors in electronic devices using lightguides. More specifically the invention relates to a simple self monitoring of optical proximity sensors. This can be achieved according to one embodiment of the present invention by a system of lightguides for the use in proximity sensor. The lightguide system comprises a transceiver lightguide to direct-transmitter to a predefined direction, and a receiver lightguide to direct transmitter light reflected from an object towards a receiver, where the transceiver and receiver lightguides comprise diffracting surfaces to direct a part of-the light from the transmitter as a self monitoring beam in a direction towards a receiver.

Abstract: The invention relates to a switch arrangement comprising photoconductor means to be illuminated. The switch arrangement also comprises conductor means which are intended to further transmit light escaping from the photoconductor means and directed to the conductor means by means of a local contact, wherein said conductor means and said photoconductor means are further, under the control of an external force, arranged to move in relation to each other and to cause the development, loss or change of said contact in such a way that a detectable change is caused in the light guided through it.

Abstract: The present invention relates to proximity sensors. It also relates to proximity sensors in electronic devices using lightguides. More specifically the invention relates to a simple self monitoring of optical proximity sensors. This can be achieved according to one embodiment of the present invention by a system of lightguides for the use in a proximity sensor. The lightguide system comprises a transceiver lightguide to direct transmitter to a predefined direction, and a receiver lightguide to direct transmitter light reflected from an object towards a receiver, where the transceiver and receiver lightguides comprise diffracting surfaces to direct a part of the light from the transmitter as a self monitoring beam in a direction towards a receiver.