Patent ID: 8207676

Claim:
Solid-state based light source for emitting light, comprising one or more light source elements for generating light, a first sensor for receiving light emitted by the light source elements and ambient light and for generating a first sensor signal representing the received light, a second sensor for only receiving ambient light and for generating a second sensor signal representing the received ambient light, a third sensor protected from light for generating a third sensor signal representing darkness for use as a reference; a control unit for receiving the first and the second sensor signals and for generating control signals for controlling the light source elements based on the difference between the first and the second sensor signals to compensate for the influence of the ambient light, wherein the control unit further receives the third sensor signal for generating control signals for controlling the light source elements taking into account the third sensor signal; and directing means for selectively directing the ambient light together with the light generated by the light source elements to the first sensor and the ambient light alone to the second sensor.