JP2005347227A - Electrode for discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cheap electrode for a discharge lamp reduced in the lowering of strength, and not generating a power loss. <P>SOLUTION: The electrode for a discharge lamp arranged in a discharge lamp glass tube has a first cylinder with a bottom at one end, and a second cylinder extending from the other end of the first cylinder with a diameter larger than that of the first cylinder. An opening of the second cylinder is widened, or the bottom of the first cylinder is dented toward inside. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrode of a discharge lamp.

An electrode of a conventional discharge lamp includes a cylindrical cap-shaped electrode part, a glass tube sealing part, and an external terminal. The electrode part and the support are made of nickel, niobium, tungsten, molybdenum, and kovar. As the external terminal, a zimet wire, a nickel / manganese wire, a nickel wire or the like is used. And each component is joined by welding and the integral electrode is comprised (for example, refer patent document 1).
JP 2002-260578 A

In the conventional discharge lamp, since the respective parts are joined by welding, the joining cost is high and the reliability of the joined portion is problematic.
In addition, there is a problem in that the electrical conductivity of the boundary surface of the joint portion decreases due to an oxidation phenomenon, the power loss of the discharge lamp increases, and the luminance decreases.
In addition, because the wire such as tungsten, molybdenum, and kovar used for sealing is a metal material with low ductility, it is difficult to manage the dies for the drawing process because the drawing process easily causes scratches in the drawing process direction. There is a problem that a polishing step is required after sealing.

  An object of the present invention is to provide an inexpensive electrode for a discharge lamp in which a decrease in strength is small and no power loss is observed.

  The discharge lamp electrode of the present invention is disposed in a discharge lamp glass tube, and has a cylindrical sealing member having a bottom at one end and a cylindrical electrode member having an enlarged diameter from the other end of the sealing member.

  The effect of the discharge lamp electrode according to the present invention is that the diameter of the first cylinder as the sealing member and the second cylinder as the electrode member continuously change stepwise, Since no different member is interposed between them, there is little decrease in strength and no change with time is seen.

Embodiment 1 FIG.
The material for the discharge lamp electrode of the present invention is a metal whose main component is nickel, molybdenum, niobium or tungsten.
The material for the discharge lamp electrode is one in which at least one of 0 to 3% by weight of nickel, 0 to 2% by weight of copper and 0 to 0.2% by weight of iron is added.
Furthermore, in order to increase the brightness and prolong the life, it is a highly reliable shape and material with a lamp for a lamp, in which the tip of the electrode structure is formed in a trumpet shape.

FIG. 1 is a cross-sectional view of a discharge lamp electrode according to Embodiment 1 of the present invention.
The discharge lamp electrode 1 is disposed inside the glass tube 2, is disposed at the end of the cylindrical electrode member 3 having an outer diameter of 2.6 mm and the glass tube 2, and is a cylinder having an outer diameter of 1.6 mm. It is comprised from the sealing member 4 of a shape. The thickness of the cylinder is 0.1 mm. Further, a bottom 5 is provided at one end of the sealing member 4. The length of the electrode 1 is 3 to 10 mm.

The discharge lamp electrode 1 is manufactured by multistage deep drawing of a molybdenum plate having a thickness of 0.25 mm. First, the cylinder is squeezed to a cylinder with an outer diameter of 6 mm, then the cylinder is squeezed to a cylinder with an outer diameter of 2.6 mm, and a part thereof is squeezed into a cylinder with an outer diameter of 1.6 mm. Finally, cut perpendicular to the cylinder so that the openings of the cylinder with an outer diameter of 2.6 mm are aligned.
When manufactured in this way, the bottom of the cylinder with the outer diameter of 1.6 mm remains, and the cylinder with the outer diameter of 2.6 mm and the cylinder with the outer diameter of 1.6 mm are continuously connected by molybdenum.

The sealing member 4 of the discharge lamp electrode 1 is passed through a through-hole 7 provided at the center of the glass bead 6 and inserted into the glass tube 2 so that the electrode member 3 enters inside, thereby melting the glass bead 6. It seals by. As a result of the vacuum leak inspection of the glass tube 2 in which both sides of the glass tube 2 were sealed with the discharge lamp electrode 1, the degree of vacuum was maintained at 1 to 10 × 10 ⁵ Pa.

Embodiment 2. FIG.
FIG. 2 is a cross-sectional view of a discharge lamp electrode according to Embodiment 2 of the present invention.
The discharge lamp electrode 10 is different from the electrode member 3 of the discharge lamp electrode 1 of the first embodiment, and the other parts are the same.
As for the electrode member 11 of the electrode 10 for discharge lamps, the opening opening opened toward the inner side of the glass tube 2 is expanded outwardly in a trumpet shape.
This diameter expansion can be processed by expanding the tip with a conical rod at the end of deepening.

  A discharge lamp provided with such a discharge lamp electrode can reduce luminance unevenness and prolong the life of the lamp.

FIG. 3 is a cross-sectional view of a discharge lamp electrode according to Embodiment 3 of the present invention.
The discharge lamp electrode 20 is the same as the discharge lamp electrode 1 of the first embodiment except that the sealing member 4 is the same, and the other parts are the same.
The sealing member 21 of the discharge lamp electrode 20 is provided with a cylindrical recess inward of the glass tube 2 at the bottom facing the outside of the glass tube 2.
This recess can be processed by squeezing the bottom in the opposite direction at the end of the deepening.

  A discharge lamp provided with such a discharge lamp electrode is provided with a tip of a terminal that can be easily inserted into the bottom surface of the sealing member. Can be improved.

It is sectional drawing of the electrode for discharge lamps concerning Embodiment 1 of this invention. It is sectional drawing of the electrode for discharge lamps concerning Embodiment 2 of this invention. It is sectional drawing of the electrode for discharge lamps concerning Embodiment 3 of this invention.

Explanation of symbols

  1, 10, 20 Electrode for discharge lamp, 2 glass tube, 3, 11 electrode member, 4, 21 sealing member, 5 bottom, 6 glass beads.

Claims (5)

  An electrode for a discharge lamp, which is disposed in a glass tube for a discharge lamp and has a first cylinder with a bottom and a second cylinder whose diameter is expanded from the other end of the first cylinder.   The discharge lamp electrode according to claim 1, wherein an opening of the second cylinder is enlarged.   3. The discharge lamp electrode according to claim 1, wherein the bottom of the first cylinder is recessed inward.   The discharge lamp electrode according to any one of claims 1 to 3, wherein the first cylinder and the second cylinder are made of any one of molybdenum, nickel, and niobium.   The first cylinder and the second cylinder are made of tungsten containing any one of 3% by weight nickel, 2% by weight copper or 0.3% by weight iron. The discharge lamp electrode according to any one of claims 1 to 3.

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