Patent ID: 8432500

Claim:
A lighting device comprising: a light source arranged to generate light source light; a luminescent material arranged downstream of the light source and arranged to convert at least part of the light source light into luminescent material light, wherein one or more of the light source and the luminescent material generate heat when the light source generates light source light; and a thermally variable reflecting element, arranged downstream of the light source and the luminescent material, having a first state wherein it is substantially reflecting and a second state wherein it is substantially transparent, and wherein heat induces a chance from the first state to the second state, wherein the thermally variable reflecting element is arranged to transmit at least part of the light source light and/or luminescent material light when being in the second state, and wherein the lighting device is arranged to transport heat generated by one or more of the light source and the luminescent material to the thermally variable reflecting element.