Mercury free metal halide lamp
AssigneeStanley Electric Co., Ltd.
InventorsMasaaki Muto, Shinya Omori
Life of this patent
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Abstract
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 (mm3), the electric power applied to the arc tube by P (W), and the weight of the indium iodide by X (μg), these parameters are set so as to satisfy a relationship (P/V)(X/V)0.2>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.
Claims18
A mercury-free metal halide lamp comprising:
- an arc tube having a discharge space not containing mercury;
- a pair of electrodes projecting into the discharge space and substantially facing each other;
- xenon gas having a pressure of at least 3 atmospheres at room temperature located in the discharge space;
- and
- at least a metal halide including indium iodide located in the discharge space,
- wherein a relationship (P/V)(X/V)0.2>3.0 is satisfied where V represents the volume of the discharge space in mm3, P represents the electric power applied to the arc tube in W, and X represents the weight of the indium iodide in μg, and a substantially continuous emission spectrum is produced over the entire visible wavelength range.
A mercury-free metal halide lamp comprising:
- an arc tube having a discharge space defining a particular volume and not containing mercury;
- a pair of electrodes projecting into the discharge space and substantially facing each other such that a particular power of electricity can be applied to the pair of electrodes;
- xenon gas having a pressure of at least 3 atmospheres at room temperature located in the discharge space;
- and
- at least a metal halide including a particular weight of indium iodide located in the discharge space,
- wherein the volume of the discharge space, the electric power applied to the arc tube, and the weight of the indium iodide are configured such that a substantially continuous emission spectrum is produced over the entire visible wavelength range by the lamp.
A mercury-free metal halide lamp comprising:
- an arc tube having a discharge space defining a particular volume V and not containing mercury;
- a pair of electrodes projecting into the discharge space and substantially facing each other;
- xenon gas having a pressure of at least 3 atmospheres at room temperature located in the discharge space;
- and
- at least a metal halide including a particular weight X of indium iodide located in the discharge space,
- wherein the volume V in mm3 of the discharge space and the weight X in μg of the indium iodide are configured such that 20≦(X/V)≦60.
Dependencies are inferred from the claim text.