Discharge lamp with improved light distribution characteristics
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsShiro Iida, Noriyuki Uchida, Kenji Nakano, Tatsuhiro Yabuki
Life of this patent
Estimating the term…
Abstract
Disclosed is a discharge lamp with enhanced vertical illuminance and accordingly improved light distribution characteristics that is easy to manufacture and suitable for mass production. For a discharge lamp in which a discharge path with a double helix configuration is formed or a discharge lamp in which a plurality of U-shaped tubes are placed on an arc tube holder to form a single tortuous discharge path, a width of a turning part 106 is specified so as to narrow spaces formed in an arc tube top part, or swelling parts are provided in a vicinity of the arc tube top part so as to narrow the spaces.
Claims8
A discharge lamp, comprising:
- an arc tube holder;
- and
- a double helical arc tube whose both ends are held by the arc tube holder, and that includes a turning part at a top thereof and two helical parts, the turning part joining the two helical parts together,
- wherein a tube diameter of the turning part gradually increases toward a middle of the turning part, in such a direction that narrows a non light-emitting region formed between the turning part and a neighboring portion of each helical part at the top of the arc tube.
A discharge lamp, comprising:
- an arc tube holder;
- and
- a double helical arc tube whose both ends are held by the arc tube holder, and that has a turning part at a top thereof and two helical parts, the turning part joining the two helical parts together,
- wherein the turning part has a swelling part, to narrow a non light-emitting region formed between the turning part and a neighboring portion of each helical part at the top of the arc tube.
A discharge lamp, comprising:
- an arc tube holder;
- and
- a double helical arc tube whose both ends are held by the arc tube holder, and that has a turning part at a top thereof and two helical parts, the turning part joining the two helical parts together,
- wherein at the top of the arc tube, a swelling part is provided on each helical part, to narrow a non light-emitting region formed between the turning part and a neighboring portion of each helical part at the top of the arc tube.
A discharge lamp, comprising:
- an arc tube holder;
- and
- an arc tube that includes a plurality of U-shaped tubes placed on the arc tube holder, predetermined ones of the U-shaped tubes being connected together, to form a single discharge path therein,
- wherein each U-shaped tube has a swelling part at a top thereof that is an opposite side to the arc tube holder, to narrow a non light-emitting region surrounded by tops of the plurality of U-shaped tubes.
Dependencies are inferred from the claim text.