Electrodeless fluorescent lamp having a radio frequency gas discharge excited by a closed loop magnetic core
First Claim
1. An improved fluorescent lamp comprising:
- an evacuable, light-transmissive envelope having a substantially globular upper shell;
a closed loop magnetic core contained within said envelope;
means for energizing said core with a radio frequency magnetic field;
a gaseous medium within said envelope adapted to sustain an electric discharge due to an electric field induced therein by said magnetic core and to emit radiation at a first wavelength when sustaining said discharge; and
a luminescent phosphor at least on the interior of said envelope adapted to emit visible light when excited by said first wavelength radiation.
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Accused Products
Abstract
An electrodeless fluorescent lamp adapted for economical substitution in place of existing incandescent lamps comprises an ionizable medium contained within a phosphor coated globular envelope. A closed loop, magnetic core, which may be ferrite, is contained within the ionizable medium to induce an electric field, ionize the medium, and stimulate visible light output. The core, which may be coated with glassy material, is energized by a radio frequency power source in the lamp base structure. Current from the power supply is transmitted to the core by means of a metal rod structure which also serves to transfer heat from within the envelope. A secondary winding on the core provides high starting voltages to initiate a glow discharge.
77 Citations
51 Claims
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1. An improved fluorescent lamp comprising:
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an evacuable, light-transmissive envelope having a substantially globular upper shell; a closed loop magnetic core contained within said envelope; means for energizing said core with a radio frequency magnetic field; a gaseous medium within said envelope adapted to sustain an electric discharge due to an electric field induced therein by said magnetic core and to emit radiation at a first wavelength when sustaining said discharge; and a luminescent phosphor at least on the interior of said envelope adapted to emit visible light when excited by said first wavelength radiation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. An improved fluorescent lamp comprising:
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an evacuable, light-transmissive envelope having a substantially spherical upper shell part and a flat circular base part; an annular magnetic core of rectangular cross section contained within said envelope, the axis of said core lying substantially perpendicular to the plane of said base part; a flat metal ring bonded to the surface of said core nearest to said base part; at least one metallic support rod piercing said base, the ends of said support rods being bonded to said metal ring; at least one metallic connection member piercing said base; a first winding on said core, one end of said winding being connected to one of said metallic support rods, an other end of said winding being connected to one of said metallic connection members; a gaseous medium within said envelope adapted to sustain an electric discharge due to an electric field induced therein by said magnetic core and to emit radiation at a first wavelength when sustaining said discharge; a luminescent phosphor on the surface of said core and on the interior of said envelope adapted to emit visible light when excited by said first wavelength radiation; and means for inducing a radio frequency voltage between said one support rod and said one connection member whereby a radio frequency magnetic field is induced in said core and said electric field is induced in said gaseous medium. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. Fluorescent lamp apparatus comprising:
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a closed loop magnetic core; a mass of a gaseous medium linking said core and adapted to sustain an electric discharge due to an electric field induced therein by said core and to emit radiation at a first wavelength when sustaining said discharge; a substantially spherical, evacuable, light-transmissive envelope containing said mass; a luminescent phosphor on the surface of said envelope, said phosphor being adapted to emit visible light when excited by said first wavelength radiation; and
,means for energizing said core with a radio frequency magnetic field whereby said electric field in induced in said mass. - View Dependent Claims (41, 42)
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43. Apparatus for maintaining an electrical discharge in a gaseous medium contained within an evacuable envelope comprising:
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a closed loop magnetic core contained within said envelope; a winding linking said core and adapted for energizing said core with a radio frequency magnetic field; and means for establising a radio frequency electric current within said winding. - View Dependent Claims (44, 45, 46, 47, 48, 49, 50, 51)
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Specification