Method for producing lamp filaments of increased radiative efficiency
AssigneeGeneral Electric Company
InventorLionel M. Levinson
Life of this patent
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Abstract
A method for fabricating incandescent lamp filaments having surface features of submicron-to-micron sized cross sections which increase the radiative efficiency of the filament comprises depositing at least one enveloping mask layer on the filament and cutting a selected pattern into the filament by ablation with a beam of radiated energy. The desired surface features are formed on the filament by a process that includes stenciling through the selected pattern.
Claims20
A method for increasing the radiative efficiency of an incandescent lamp filament, comprising the steps of:
- depositing at least one enveloping mask layer on said filament;
- ablating said at least one mask layer with a beam of radiated energy to cut a selected pattern through the full thickness of said layer;
- forming surface features on said filament arranged in a pattern that corresponds substantially to said selected pattern and including cavities of submicron-to-micron size, said last recited step including stenciling through said selected pattern to the structure immediately subjacent to said at least one mask layer;
- and
- removing mask material remaining after the formation of said surface features to fully uncover the surface of said filament.
A method for increasing the radiative efficiency of light from an incandescent lamp filament comprising the steps of:
- depositing a first enveloping mask layer on the surface of said filament;
- depositing a second enveloping mask layer on said first mask layer;
- ablating said second mask layer with a beam of radiated energy to cut a selected pattern through the thickness of said second mask layer;
- etching said first mask layer through said selected pattern in said second mask layer, said etching step being effective to cut a pattern through the thickness of said first mask layer corresponding substantially to said selected pattern;
- removing the remaining portions of said second mask layer to expose said first mask layer;
- selectively depositing a filament-compatible refractory material through the pattern in said first mask layer onto said filament surface, said refractory material forming boundary walls on said filament surface in a pattern corresponding substantially to said selected pattern, said walls defining cavities of predetermined size therebetween;
- and
- removing the remaining portions of said first mask layer to fully uncover said filament surface.
A method for increasing the radiative efficiency of an incandescent lamp filament, comprising the steps of:
- depositing an enveloping mask layer on the surface of said filament;
- ablating said mask layer with a beam of radiated energy to cut a selected pattern through the thickness of said mask layer;
- etching said filament surface through said selected pattern in said mask layer to form cavities in said filament surface, said cavities having predetermined dimensions in the submicron-to-micron range and being arranged in a pattern corresponding substantially to said selected pattern;
- and
- removing all remaining mask material after ablation of said enveloping mask layer to fully uncover said filament surface.
Dependencies are inferred from the claim text.