Optical system for airport semi-flush approach lights
First Claim
1. An optical system suited for an aircraft guidance lighting fixture, comprising a lamp, a reflector, a mirror and an exit prism, said lamp being of the high intensity incandescent type, having an elongated filament of finite length, said lamp and said reflector being mounted in said fixture such that said reflector surrounds said lamp, said reflector having a plurality of ellipsoidal surface portions of differing eccentricities, such that the surface portions are axially displaced relative to each other to reflect light from said lamp in the same general direction, the major axes of each of the ellipsoidal surface portions being coincident and passing through the axis of said elongated filament, a focus of each ellipsoidal surface portion being located on said filament and spaced apart equidistantly from each end of said filament, the ellipsoidal surface portion having the greatest eccentricity being located nearest the filament of said lamp, and the conjugate foci of said ellipsoidal surface portions being coincident in space said mirror lying on said major axes at an adjustable angle of substantially forty five degrees to said axes arranged to reflect light from said lamp through said prism and thus substantially at right angles to said major axes.
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Accused Products
Abstract
This invention relates to a threshold and approach semi-flush light of the type which utilizes a high intensity lamp surrounded by a reflector which concentrates the light emitting from the lamp on a mirror located above the lamp. The mirror reflects the light through a prism in a predetermined pattern. The reflector comprises a pair of ellipsoidal surfaces of differing eccentricities joined together to form a composite reflector, such that the ellipsoidal section nearest the lamp filament has an eccentricity greater than the second ellipsoidal section spaced a greater distance away from the lamp filament.
33 Citations
3 Claims
- 1. An optical system suited for an aircraft guidance lighting fixture, comprising a lamp, a reflector, a mirror and an exit prism, said lamp being of the high intensity incandescent type, having an elongated filament of finite length, said lamp and said reflector being mounted in said fixture such that said reflector surrounds said lamp, said reflector having a plurality of ellipsoidal surface portions of differing eccentricities, such that the surface portions are axially displaced relative to each other to reflect light from said lamp in the same general direction, the major axes of each of the ellipsoidal surface portions being coincident and passing through the axis of said elongated filament, a focus of each ellipsoidal surface portion being located on said filament and spaced apart equidistantly from each end of said filament, the ellipsoidal surface portion having the greatest eccentricity being located nearest the filament of said lamp, and the conjugate foci of said ellipsoidal surface portions being coincident in space said mirror lying on said major axes at an adjustable angle of substantially forty five degrees to said axes arranged to reflect light from said lamp through said prism and thus substantially at right angles to said major axes.
Specification
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- Resources
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Current AssigneeWestinghouse Canada, Inc. (ViacomCBS Incorporated)
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Original AssigneeWestinghouse Canada, Inc. (ViacomCBS Incorporated)
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InventorsSclippa, Ermes
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Primary Examiner(s)Nelson, Peter A.
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Application NumberUS06/252,364Time in Patent Office908 DaysField of Search362/62, 362/135, 362/140, 362/145, 362/297, 362/9, 362/305, 362/304, 362/310, 362/329, 362/339, 362/346, 362/308, 362/328, 362/364, 362/344, 362/350US Class Current362/297CPC Class CodesF21V 7/08 with elliptical curvatureF21W 2111/06 for aircraft runways or the...
