GB942630A - Downlight and device for varying the spectral quality thereof - Google Patents

Abstract

942,630. Overhead lighting fittings. CENTURY LIGHTING Inc. Feb. 20, 1962, No. 6525/62. Heading F4R. In a light fitting for setting on a ceiling and having an uncoloured electric lamp bulb and an uncoloured reflector surrounding this to direct the light downwards in a cone of predetermined apical angle, an assembly is mounted in and adjacent to the open end of the reflector and includes a sleeve and a set of flat annular baffles, the lowest of which is arranged at the level of the ceiling, the internal surface of the sleeve, the upper surface of the lowest baffle and both surfaces of the remaining baffles being coloured in a limited spectral band within the range 380-700 millimicrons, to create a zone of coloured light above the uncoloured cone, means being provided for joining the assembly detachably in place. In the form shown, the bulb 22 is mounted on the neck 16 of a reflector 10 having a contour to produce a cone of light of 90 degrees apical angle and a downwardly extending skirt terminating in a bead 38 by which the reflector is supported in clips 40 carried by an L-shaped ring 34 secured to tabs 32 embedded in the ceiling. A plate 42 is secured to the horizontal part of ring 34 and has an aperture 46 corresponding to the apical angle of the cone of light. A ring 52 carrying baffle plates 54, 56, 58 having concentric apertures of decreasing diameter in a downward direction rests of the plate 42, the ring and baffles being coloured in the same spectral band. Light from the bulb 22 falling outside the cone of direct light will be reflected one or more times at the coloured surfaces and will create a zone of coloured light outside the cone of direct light.