Electric lamp and discharge devices – With gas or vapor – Having a particular total or partial pressure
Reexamination Certificate
2005-04-12
2005-04-12
Williams, Joseph (Department: 2879)
Electric lamp and discharge devices
With gas or vapor
Having a particular total or partial pressure
C313S631000, C313S634000, C313S637000
Reexamination Certificate
active
06879101
ABSTRACT:
To provide, in a special situation of a mercury-free lamp in which a luminance flicker tends to occur unlike a mercury-containing lamp, a metal halide lamp having an electrode structure modified so as to suppress the luminous flicker that is suitably used as an automotive headlamp, and an automotive headlamp apparatus incorporating the same. A metal halide lamp includes: a hermetic vessel1which is fire resistant and translucent; a pair of electrodes3, 3sealed in the hermetic vessel1with facing each other at a distant of 5 mm or less, the electrodes each having a shaft part3ahaving a diameter of 0.25 mm or more and a tip3b, which originates an arc, having a curved surface having a radius of one-half or less of the diameter of the shaft part; and a discharge medium essentially containing no mercury, sealed in the hermetic vessel1, and containing halides of metals including a light-emitting metal in an amount of 0.005 mg/mm3of an inner volume of the hermetic vessel or more and a xenon gas at 5 atmospheres or higher at a temperature of 25° C., in which the metal halide lamp is turned on with a lamp power of 60 W or lower in a stable state.
REFERENCES:
patent: 2459579 (1949-01-01), Noel
patent: 2716713 (1955-08-01), Noel
patent: 3902090 (1975-08-01), Ekkelboom et al.
patent: 4968916 (1990-11-01), Davenport et al.
patent: 5083059 (1992-01-01), Graham et al.
patent: 5117154 (1992-05-01), Thomas et al.
patent: 5627430 (1997-05-01), Kira et al.
patent: 5789850 (1998-08-01), Iwafuji et al.
patent: 6495962 (2002-12-01), Uemura et al.
patent: 0 978 864 (2000-02-01), None
patent: 1 032 010 (2000-08-01), None
patent: 0 978 864 (2001-11-01), None
patent: 1 172 840 (2002-01-01), None
patent: 1.476.198 (1967-02-01), None
patent: 2001-102001 (2001-04-01), None
Mental et al., “Experimental Investigation of Electrodes for High Pressure Discharge Lamps,” IEEE (2000), 5:3293-3300.
John M Davenport et al., “Xenon-Metal Halide Lamp For Automobile Having Improved Electrode Structure”, Patent Abstracts of Japan of JP 03-163744, Jul. 15, 1991.
R. Botticher et al., “Numerical Modelling of arc Attachment To Cathodes of High-Intensity Discharge Lamps”, J. Phys, D: Appl. Phys. vol. 33, pp. 367-374.
Deguchi Makoto
Hiruta Toshio
Ishigami Toshihiko
Katayama Sakae
Kato Hiroyuki
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Harison Toshiba Lighting Corp.
Quarterman Kevin
Williams Joseph
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