Patent ID: 8462586

Claim:
A direction-controllable lighting unit, comprising a mechanically movable element for directing a light emission into different directions along a light emission output axis; at least two ultrasound transmitter units disposed at said movable element for moving therewith, wherein said at least two ultrasound transmitter units are disposed at said lighting unit in such a way that they differ in at least one of: position, direction of spatial intensity distribution of emission, shape of spatial intensity distribution of emission, direction of spatial distribution of reception sensitivity, or shape of spatial distribution of reception sensitivity and are offset from said light emission output axis, said ultrasound transmitter units are operable to transmit distinguishable ultrasound signals, a mobile control element including at least one ultrasound receiver unit, and control means to evaluate a signal received at the at least one receiver unit, wherein a difference between signals of different transmitter units received at the receiver unit is used to determine a relative direction of said direction controllable lighting unit and said control element, and to control the direction of said controllable lighting unit dependent on said relative direction.