Patent ID: 6099148
Filing Date: 2000-08-08
Classification: B64F,F21V,F21W,H01K

Abstract:
A luminaire which operates under a power W provided by a power supply the luminaire comprising:a luminaire base;a substantially cylindrical Fresnel lens which attaches to said luminaire base, said substantially cylindrical Fresnel lens having a lens axis and being bounded by a surface of revolution about said lens axis and having a mean lens diameter D;a halogen lamp residing in said substantially cylindrical Fresnel lens, said halogen lamp having a lamp rated voltage V.sub.L which is between about 12 volts and 30 volts and further having,a lamp base,a lamp envelope which attaches to said lamp base,a substantially linear filament residing in said lamp envelope, said substantially linear filament being constructed from a filament wire terminating in a first filament end and a second filament end, with said first filament end being closer to said lamp base than said second filament end,said filament wire having a gauge g and a wire length l.sub.W and being configured such that said substantially linear filament has a filament axis which is substantially parallel to said lens axis and has an effective length l.sub.E which is the linear distance between said first filament end and said second filament end,said substantially linear filament being formed as a helical coil having a coil diameter d and a coil height h, said coil height h being said effective length l.sub.E,the ratio D/d being greater than about 40, and the ratio h/d being greater than about 21/2, andsaid effective length l.sub.E being less than about 1 incha first end filament lead attaching to said first filament end and said lamp base and communicating with the power supply, anda second end support structure attaching to said second filament end and said lamp base and communicating with the power supply; anda lamp bracket attaching to said luminaire base and to said lamp base, said lamp bracket being configured such that said filament axis is substantially coincident with said lens axis.