| 摘要 |
<P>PROBLEM TO BE SOLVED: To automatically control chromaticity of a white light emitting luminaire regardless of factors which may cause the light output of each color to be changed. <P>SOLUTION: The white light emitting luminaire includes a plurality of LEDs (10, 12 and 14) in each of the colors red, green and blue with a separate power supply for each color and a photodiode (24) arranged to measure the light output of all the LEDs. The light output of each color is measured by an electronic control circuit (30) which turns off the LEDs for colors not being measured in a sequence of time pulses. The measured light output for each color is compared to a desired output, which may be determined by user inputs, and corrections to the current for each color are made accordingly. In between measurements, the current is supplied to all of the LEDs in the array. <P>COPYRIGHT: (C)2008,JPO&INPIT |
