| 摘要 |
An improved lighting apparatus, suitable for use as part of a lighting fixture, is disclosed, having a plurality of groups of distinct light-emitting devices, e.g., light-emitting diodes, that can be controlled to produce a beam of light having a wide variety of complex luminous flux spectra, including, but not limited, to spectra that closely emulate that of any one of a number of conventional light sources, with or without a conventional chemical dye filter. Each group of light-emitting devices is configured to emit light having a distinct luminous flux spectrum. A controller supplies selected amounts of electrical power to two or more groups of the plurality of groups of light-emitting devices, such that the groups cooperate to produce a composite beam of light having a selected luminous flux spectrum. The spectrum can be controlled to have a normalized mean deviation across the visible spectrum, relative to that of a beam of light to be emulated, of less than about 30%. This a marked improvement over all known lighting fixtures of the kind including multiple groups of distinct light sources. The groups of light-emitting devices are configured to include independently selected quantities of devices. Further, the groups of light-emitting devices are configured to each have a spectral half-width of less than about 40 nanometers (nm) and to have a peak flux wavelength that is spaced less than about 50 nm from that of an adjacent group. |
