US 8,264,134 B2 · Ultraminiature broadband light source with spiral shaped filament

Ultraminiature broadband light source with spiral shaped filament

AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration

InventorsMargaret L. Tuma, Joseph S. Collura, Henry Helvajian, Michael D. Pocha, Glenn A. Meyer, Charles F. McConaghy, Barry L. Olsen, William W Hansen

Life of this patent

Estimating the term…

Abstract

An ultraminiature light source using a double-spiral shaped tungsten filament includes end contact portions which are separated to allow for radial and length-wise unwinding of the spiral. The double-spiral filament is spaced relatively far apart at the end portions thereof so that contact between portions of the filament upon expansion is avoided. The light source is made by fabricating a double-spiral ultraminiature tungsten filament from tungsten foil and housing the filament in a ceramic package having a reflective bottom and a well wherein the filament is suspended. A vacuum furnace brazing process attaches the filament to contacts of the ceramic package. Finally, a cover with a transparent window is attached onto the top of the ceramic package by solder reflow in a second vacuum furnace process to form a complete hermetically sealed package.

Claims10

Dependent claims

A light source filament comprising:

first and a second mutually confronting end portions;
a first and a second filament winding extending inwardly towards one another from their respective end portions and spirally confronting one another concentrically along a reducing diameter until joined at a central portion;
a first gap defined as the space between the first and the second filament windings, said first gap having a proximal end at the first end portion and a distal end at the central portion;
a second gap defined as the space between the second and the first filament windings, said second gap having a proximal end at the second end portion and a distal end at the central portion;
and
wherein the width of the first and second gap is reduced by at least 50% from the proximal end through an arc of approximately 180 degrees.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application

12/795,356Filed 7 Jun 2010 · continuation

Priority

22 Jan 2007

Published

US 2011/0006663 A113 Jan 2011

Granted

11 Sep 2012

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

H01K 1/14
Incandescent bodies: characterised by the shape
G01J 3/10
Details: arrangements of light sources specially adapted for spectrometry or colorimetry
H01K 1/18
Details: mountings or supports for the incandescent body
H01K 7/00
Lamps for purposes other than general lighting