Illumination controller

Abstract

An illumination controller is provided. The illumination controller comprises a light sensor device having a first light sensor arrangement configured to sense light within a first spectral range including non-visible light and excluding a sub-range constituted by at least a major part of the visible light, and a second light sensor arrangement configured to sense light within a second spectral range including at least a part of said sub-range. Furthermore, the illumination controller comprises a control unit connected with the light sensor device and arranged to determine an amount of daylight on the basis of an output signal of the first light sensor arrangement and a predetermined function, which characterizes the relationship between the spectral power distribution of the infrared spectrum of daylight and the spectral power distribution of the visible spectrum of daylight, and to determine an amount of artificial light on the basis of an output signal of the second light sensor arrangement and the output signal of the first light sensor arrangement. The illumination controller is arranged to control illumination on the basis of said amounts of daylight and artificial light.