Wireless power transmission

A wireless power transmission system comprising a power transmitter, which in turn comprises a first light source and means for directing the light emitted by the first light source to a desired direction, and at least one power receiver, Which in turn comprises a first photo-detector for receiving the emitted light and for converting it into electric current, wherein

• the power transmitter further comprises a second light source emitting light of a substantially lower intensity than the light emitted by the first light source, the light being arranged to be transmitted around the light emitted by first light source and substantially parallel to it;
• the power receiver further comprising a second photo-detector for detecting the light emitted by the second light source and transmission means which are responsive to the detection and configured to transmit a control signal to the power transmitter in response to the reception of the light emitted by the second light source,
• the power transmitter being configured to switch on the second light source first and, in response to the reception of the control signal from the power receiver informing of the reception of the light emitted by the second light source, the power transmitter is configured to switch on the first light source.

A power transmitter for wireless power transmission, the transmitter comprising a first light source, means for directing the light emitted by the first light source to a desired direction, and a second light source, the light emitted by which is of a substantially lower intensity than that emitted by the first light source and arranged to be transmitted around the light emitted by the first light source and substantially parallel with it, wherein

• the power transmitter is configured to receive an indication from the power receiver informing of the reception of the light emitted by the second light source,
• the power transmitter is configured to switch on the second light source first and, in response to an indication received from the power receiver informing of the reception of the light emitted by the second light source, the power transmitter is configured to switch on the first light source.

A power receiver which comprises a first photo-detector for receiving light emitted by a first light source and for converting it into electric current, a second photo-detector for detecting the light emitted by a second light source, and transmission means which are responsive to said detection and configured to transmit to the power transmitter an indication informing of the reception of the light emitted by the second light source.