Direction controllable lighting unit
A direction controllable lighting unit ( 10 ) and use thereof in a lighting system ( 40 ) are described. A lighting unit ( 10 ) has means ( 16 ) for directing the light emission ( 22 ) into different directions. A plurality of light sources ( 20 a , 20 b ) are mounted on a common body ( 14 ). The light sources ( 20 a , 20 b ) are disposed to emit directed light into different directions. The light is modulated to contain identification codes ‘A’, ‘B’, which are unique. Within the lighting system ( 40 ), an optical sensor ( 46 ) is arranged in a region illuminated by the lighting unit ( 10 ). The optical sensor ( 46 ) demodulates the received light according to the identification code. A control unit ( 44 ) is connected to the optical sensor ( 46 ) and to the lighting unit ( 10 ) to control the direction of the lighting unit ( 10 ) based on information from the optical sensor ( 46 ).
1. A controllable lighting system, comprising:
at least one direction controllable lighting unit, comprising:
means for directing a light emission into different directions,
a plurality of light sources mounted on a common body, said light sources disposed to emit directed light emissions differing in at least one of shape, direction or position, and
coding means to drive said light sources such that said light emissions are modulated to contain an identification code (A,B), wherein said codes of said light sources are different;
an optical sensor suited to be arranged in a region illuminated by said lighting unit, where said optical sensor comprises demodulation means to demodulate said indentification codes (A,B), and
a control means connected to said optical sensor and to said lighting unit, where said control mean is disposed to control the direction of a light emission of said lighting unit based on information about said demodulated code.
2. The system according to claim 1 , wherein said direction of said lighting unit is controlled by determining a relative positioning of the light emission direction of said lighting unit and said optical sensor, and wherein said relative positioning is determined by identifying said identification code (A, B).
3. The system according to claim 1 , wherein said sensor is disposed to provide a measurement of intensity of said light modulated with said identification code, and said relative positioning is determined by identifying by said identification code and said measurement of intensity from which of said more light coming from light sources is received.
4. The system according to claim 1 , wherein said control means is disposed to control the direction of said lighting unit by at least one iteration of a closed-loop operation, where in each iteration said lighting unit is driven to change the direction of its light emission, and then said optical sensor is operated to obtain information about said identification codes in the received light, and said information is evaluated according to an evaluation criteria.
5. The system according to claim 1 , said system comprising multiple direction controllable lighting units, wherein each light source of said lighting units emits light modulated to contain a unique identification code.