Patent ID: 7733033

Claim:
A lighting unit, comprising: at least two light sources of a different color temperature; an operating circuit, comprising: a supply circuit for supplying currents to the two light sources, and a control circuit for controlling the currents supplied by the supply circuit; and a user interface coupled to the control circuit for adjusting the color of the generated light at a number of predetermined color settings by means of adjusting the light outputs of the light sources, wherein the color difference calculated in the CIELAB color space between a first color point corresponding to a first color setting and a nearest color point corresponding to a second color setting is the same for any first color point having the same value of the total light output, and wherein the user interface comprises: a first push button for adjusting the color of the generated light at the predetermined color setting having the next higher value of the color temperature at every push and a second push button for adjusting the color of the generated light at the predetermined color setting having the next lower value of the color temperature at every push.