| 摘要 |
Light source circuitry comprises a first group of one or more light emitting diodes operable to emit light of a first color, a second group of one or more light emitting diodes operable to emit light of a second color, and a third group of one or more light emitting diodes operable to emit light of a third color, wherein the first, second and third groups of light emitting diodes are arranged such that, when a fixed current arrives at the light source circuitry, the fixed current is shared between the first, second and third groups, and wherein the circuitry is configured such that a proportion of the fixed current that flows through each of the first and second groups is controllable in dependence on a received control signal and such that the remainder of the fixed current flows through the third group. The light source circuitry allows the chromaticity of the combined light emissions of the light source circuitry to be varied gradually across a range using a single control signal and also without requiring the use of pulse width modulation (PWM) |
