Infrared halogen lamp with improved efficiency
View Patent ↗Methods for improving the efficiency of infrared (IR) halogen lamps and IR halogen lamps having improved efficiency are disclosed. In a method of aligning a filament in a lamp body, the lamp body having the filament therein is rotated, and tubular end portions are heated and necked down which may assist in positioning the filament within the lamp and reduce end losses. IR halogen lamps formed from glass tubes having an OD less than 5 mm are also disclosed. The reduced diameter of the glass tubing increases the surface area for IR energy reflection and reduces end losses. Spuds or beads may be used to position the filament within the lamp.
1. A double ended infrared (IR) halogen lamp comprising:
a lamp body having a light emitting chamber intermediate sealed tubular end portions; and
a filament assembly including:
a refractory metal wire positioned in said chamber and extending axially through each of said end portions;
a pair of metal foils, each foil being connected at a respective distal end of said wire; and
a pair of beads, each bead ensheathing a portion of said wire extending in an end portion of said lamp body, said beads being positioned interior of and spaced from said metal foil connected to the distal end of said wire.
2. The lamp of claim 1 wherein said beads are cylindrical or spherical.
3. The lamp of claim 2 wherein said beads have a diameter of 2 mm or less.
4. The lamp of claim 1 wherein said beads are formed from glass or quartz.
5. A double-ended infrared halogen lamp comprising:
a lamp body formed from quartz having a light emitting chamber intermediate a pair of sealed end portions; and
a filament assembly including:
a refractory metal wire positioned in said chamber and extending axially through each of said end portions;
a pair of metal foils, each foil being connected at a respective distal end of said wire;
wherein each of said sealed end portions being hermetically sealed around a metal foil and at least a portion of the refractory wire of said filament assembly; and
wherein said lamp body comprises a pair of necked down portions having an inner wall in contact with said filament assembly, each of said necked down portions being positioned between said chamber and a respective sealed end portion, said necked down portions having a lateral dimension smaller than any lateral dimension of said sealed end portion proximate thereto.
6. The lamp of claim 5 wherein each necked down portion has a generally circular cross section.
7. The lamp of claim 5 further comprising an IR reflective coating on an outer surface of the lamp body forming said light emitting chamber.
8. The lamp of claim 7 wherein said IR reflective coating covers the outer surface of the lamp body in an area extending from the longitudinal center of the lamp body beyond each necked down portion of said body.
9. The lamp of claim 5 wherein said light emitting chamber is ellipsoidal or spherical.
10. The lamp of claim 5 wherein the end portions comprise tubular portions having an outside diameter of 5 mm or less.
11. The lamp of claim 10 wherein the end portions comprise tubular portions having an outside diameter of 4 mm or less.