Stanley Electric Co., Ltd

Masaaki Muto

Shinya Omori

Yasuhisa Yaguchi

Takashi Futami

Toshiyuki Nagahara

Hiroharu Shimada

Isamu Sato

Yoshifumi Takao

Naoyuki Matsubara

Kimihiro Iritono

Masatoshi Hirohashi

Shigeru Shibayama

Aiko Kanegae

A discharge lamp can be configured to include a glass tube bulb; a pair of discharge electrodes arranged within the glass tube bulb; and metal foils enclosed within sealing portions at both axial ends of the glass tube bulb so as to connect the discharge electrodes and externally extending lead wires. The metal foils can be provided with cuts and/or holes of various shapes and sizes acting as a stress alleviating portion for alleviating stress due to temperature variations.

Discharge lamp and method of making same

In a metal halide lamp, xenon gas having a pressure of at least 3 atmospheres at room temperature and at least a metal halide including indium iodide are sealed in a discharge space not containing mercury. If the volume of the discharge space is denoted by V (mm), the electric power applied to the arc tube by P (W), and the weight of the indium iodide by X (&#x3bc;g), these parameters are set so as to satisfy a relationship (P/V)(X/V)&#x3e;3.0. A continuous emission spectrum can thereby be produced by indium over the entire visible wavelength range, thus obtaining a mercury-free metal halide lamp that is usable as an excellent white light source suitable for data projectors, automobile lamps, headlights, and other systems and devices.

Mercury free metal halide lamp

The invention provides an arc tube with improved chromaticity and start-up characteristics that does not contain mercury, and provides a vehicle headlamp equipped with a metal halide lamp that contains no mercury in the arc tube. Among other improvements, the evaporation of low melting point metal halides is promoted and the start-up characteristics of the arc tube are improved.

Discharge lamp

A metal halide discharge lamp can include a light emitting tube having a discharge chamber formed in the light emitting tube and containing no mercury. A pair of electrodes can be provided with a portion, which projects into the discharge chamber. The discharge chamber can include a buffer gas, which also acts as a starter gas, of xenon (Xe) in an amount of 7-20 atmospheres at room temperature, and at least one kind of metal halide. The light emitting tube can have a positive resistance range in current-voltage characteristics relative to a varying input electric power. In the positive resistance range, the light emitting tube can be driven by an electric power which is less than or equal to a rated power supplied during steady lighting. In the metal halide lamp of the invention, even if the input electric power to the light emitting tube is varied, sudden unintentional extinguishment does not occur, and varying range of light color can be narrowed.

Mercury-free metal halide lamp, with contents and electric power control depending on resistance properties

A high pressure electric discharge lamp adapted to utilize dielectric barrier discharges can include an arc tube having a discharge space that contains at least a rare gas and an outer tube airtightly surrounding the arc tube. At least one material selected from Ne, Ar, Kr, Xe, F , Cl , Br , I and N or a mixture thereof that are apt to produce a dielectric barrier discharge can be filled in the space between the arc tube and the outer tube at pressure preferably between 1.3 and 100 &lsqb;kPa&rsqb; and more preferably between 40 and 80 &lsqb;kPa&rsqb;. The type and the pressure of the rare gas contained in the space is selected as to make the dielectric barrier discharge starting voltage in the space lower than the discharge starting voltage in the discharge space.

High pressure electric discharge lamp

A lamp bulb for a high pressure discharge lamp that includes a pair of opposing electrodes that projects a predetermined distance into a discharge chamber, molybdenum foils, lead wires, and a bulb, the lamp bulb includes a discharge chamber filled with a metal halide and a rare gas, the discharge chamber including at least a concave surface curving inwardly with respect to a Z-axis of the automotive high pressure discharge lamp, a discharge chamber portion surrounding the discharge chamber, including at least a convex surface curving outwardly along the Z-axis of the discharge lamp, tapered portions tapering towards the discharge chamber, sealed ends in which are located the molybdenum foils, the electrodes, and the lead wires, and sealed portions substantially free from substantial curvature change, the sealed portions being located between the discharge chamber and the sealed ends.

Discharge lamp for automobile having a convex surface in the discharge chamber

A high pressure discharge lamp used as a light source for an automobile headlight and a method of forming the high pressure discharge lamp are disclosed. The high pressure discharge lamp includes a discharge chamber portion defining a discharge chamber filled with metal halide and rare gas, a pair of opposing electrodes, a portion of each electrode respectively projecting a predetermined distance into the discharge chamber, molybdenum foils, lead wires, and a bulb. The bulb includes a tapered portion, a sealed portion, and a sealed end having portions of a molybdenum foil, an electrode, and a lead wire disposed therein.

Metal halide lamp with specific internal electrode seal detail

A discharge lamp for an automotive vehicle including a discharge bulb and an outer cover tube for covering the discharge bulb. The discharge bulb is composed of a discharge chamber portion, a pair of seal portions for sealing both ends of the discharge chamber portion, and a pair of discharge electrodes held in respective ones of the seal portions. At the end of each seal portion adjacent to the discharge chamber portion, a taper portion is provided, which is narrowest near the discharge chamber portion, and which defines an angle with respect to a tube axis of the discharge bulb of 45 degrees or less. A curvature of a tube wall of the discharge chamber portion, is substantially constant. A ratio of the minimum thickness to the maximum thickness of the tube wall measured within that angle is between 1 and 0.8. The discharge bulb and the outer cover tube are in contact, with the portion of said discharge chamber portion having the maximum outer diameter being in contact with the outer cover tube.

Discharge lamp for an automotive vehicle

In a method for manufacturing small tubular lamps, a moving amount of a tube stock is adjusted according to a wall thickness thereof to make the stock-guide amount uniform, and the internal pressure during the stock-guide step is also adjusted so as to produce a suitable dimension of the outside diameter thereof, whereby the working amount in the succeeding step is reduced to decrease errors in dimensional tolerances, particularly in wall thickness and internal volume.

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Tokyo, Japan

Masaaki Muto