| 主权项 |
1. Wake-up lamp system, comprising:
a light source for producing light output with a light output intensity and a colour point in a CIE 1931 xy chromaticity diagram, the light source having a nominal light output intensity (Lmax); a clock device generating a clock signal; and a control device for controlling the light source, the control device being coupled to receive said clock signal from the clock device; wherein the control device is adapted to operate in a wake-up mode; wherein the control device, when operating in the wake-up mode, controls the light source such that the light output intensity is made to gradually increase from a minimum intensity value (Lmin) to a maximum intensity value (Lmu) and such that the colour point of the light output is made to travel a predefined chromaticity path in said chromaticity diagram, said chromaticity path having a starting point associated with the minimum intensity value (Lmin) and an end point associated with the nominal intensity value (Lmax), the control device being designed to set a position of the colour point on said chromaticity path as a function of the light output intensity; wherein said starting point has a colour temperature between 400 K and 1500 K and wherein said end point has a colour temperature higher than 2700 K; wherein each colour point on said chromaticity path has an associated colour temperature T, with a maximum colour temperature Tmax associated with the nominal intensity value (Lmax), and wherein the control device is designed, when varying the light output intensity of the light source, at least for values of the light output intensity higher than a predefined threshold level Lth, to simultaneously vary the position of the colour point on said chromaticity path such that a derivative dT/dL(L) of the colour temperature T of the light output is derivative dT/dL(L) for a black body radiator having at said nominal intensity value (Lmax) a colour temperature equal to said maximum colour temperature Tmax. |
