Patent attributes
An artificial illumination device for generating natural light similar to that from the sun and the sky comprises a direct-light source comprising a first emitting surface and configured to produce, from primary light, direct light exiting the first emitting surface into a direct-light direction at low divergence, the direct-light source comprising a plurality of pairs of a first light-emitting device positioned upstream the first emitting surface and configured to emit the primary light and a collimator configured to collimate the primary light emitted by the first light-emitting device along the direct-light direction; and a diffused-light generator configured to cause diffused light at a second emitting surface. Both co-operate to form outer light at the outer emitting surface comprising a first light component propagating within a low divergence cone along the direct light direction and a second light component propagating along directions outside the low divergence cone wherein the first light component has a correlated color temperature lower than a CCT of the second light component so that an observer sees, when looking towards the first emitting surface, a bright spot surrounded by a bluish background which mimics the sky.
