High-power metal halide reflector lamp
AssigneeILC Technology, Inc.
InventorsRichard O. Shaffner, John F. Richter
Life of this patent
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Abstract
A metal halide lamp includes a cast ceramic reflector almost completely comprised of alumina. A conventional metal halide bulb is positioned within the reflector. A glaze and then a dielectric coating are applied to the inside surface of the reflector, such that appreciable amounts of infrared radiation from the bulb are absorbed into the glaze and ceramic and not reflected into the beam.
Claims8
An improved metal halide high-pressure discharge lamp system with an inert-gas-filled arc bulb positioned within a reflector to focus outward a beam of light during operation, said reflector comprising:
- a single cast piece of 100% ceramic alumina Al.sub.2 O.sub.3 that forms a substrate of said reflector;
- a glaze on an inside concave surface of said substrate ad with a glassy surface providing for specular reflection of light from said arc bulb;
- and
- an electrically non-conductive dielectric coating on an inside concave surface of the glaze for reflecting non-infrared radiation from said bulb into said beam of light and for passing infrared radiation from said arc bulb into the glaze and the cast ceramic alumina substrate for absorption;
- wherein, the glaze and cast ceramic alumina substrate absorb most of the infrared radiation that is passed through by the dielectric coating from said arc bulb and is converted to heat that may be controlled and removed by a forced air flow.
A method of manufacturing a reflector for a metal halide high-pressure discharge lamp, the method comprising the steps of:
- casting substantially 100% alumina in the shape of a lamp reflector;
- glazing an inside surface of said lamp reflector to obtain a glassy surface of glaze suitable for specular reflection;
- and
- coating said glass surface of said glaze with a dielectric coating such that visible light is reflected by said coating and infrared radiation is absorbed by said glaze and said lamp reflector.
An improved metal halide high-pressure discharge lamp system with a metal halide bulb positioned within a reflector to focus outward a beam of ultraviolet light during operation, said reflector comprising:
- a single cast piece of 100% ceramic alumina Al.sub.2 O.sub.3 that forms a substrate of said reflector;
- a glaze on an inside concave surface of said substrate and with a glassy surface providing for specular reflection of light from said arc bulb;
- and
- an electrically non-conductive dielectric coating on an inside concave surface of the glaze for reflecting ultraviolet radiation from said bulb into said beam of light and for passing visible and infrared radiation from said bulb into the glaze and the cast ceramic alumina substrate for absorption.
A method of manufacturing a reflector for a metal halide high-pressure discharge lamp, the method comprising the steps of:
- casting substantially 100% alumina in the shape of a lamp reflector;
- glazing an inside surface of said lamp reflector to obtain a glassy surface of glaze suitable for specular reflection;
- and
- coating said glass surface of said glaze with a dielectric coating such that ultraviolet light is reflected by said coating and visible and infrared radiation are absorbed by said glaze and said lamp reflector.
Dependencies are inferred from the claim text.