JP2003142028A - Fitting method of cylindrical electrode for cold cathode fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems of the conventional fitting method that when a cylinder having a joint formed by rounding a square metal thin plate is welded to a lead wire inside a cold cathode fluorescent lamp and used as a cylindrical electrode, three inside projections are formed in a lead wire insertion part of the cylindrical electrode, the lead wire thinner than the inner diameter of the cylindrical electrode is held in almost the central part of the cylindrical electrode, and one inside projection is laser-welded to the lead wire, and in this method, the laser-welding is easy to cause imperfect welding, inclination or coming off of the cylindrical electrode is often generated. SOLUTION: This fitting method of the cylindrical electrode is that by two foldin parts 21D formed in the insertion part of a lead wire 1 of the cylindrical electrode 21 and a stepped plane part 21E, the inserted lead wire 1 is held almost at the central part of the cylindrical electrode 21, and then the stepped plane part 21E and the lead wire 1 are laser-welded. Therefore, conventional problems are solved and strong welded state having wide laser-welded area can be obtained.

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a cold cathode fluorescent lamp used for a backlight of a liquid crystal display or the like, and more particularly, to a cold cathode fluorescent lamp. The present invention relates to a method for mounting a cylindrical electrode. 2. Description of the Related Art FIG. 4 shows the structure of a conventional general cold cathode fluorescent lamp, in which a glass tube 4 having a phosphor coating 5 formed on an inner surface thereof and a cylindrical electrode 2 are welded. Lead wire 1
Is welded to a glass bead 3 having a through hole sealed therein to form a tubular bulb, and a sealed gas 6 (neon, argon, mercury) is sealed in a predetermined amount in the tubular bubble. The lighting is performed by applying a predetermined AC voltage to the lead wire 1 from the outside. In the cold cathode fluorescent lamp described above, as a metal material for forming the cylindrical electrode, the following items are usually required. (1) The sputtering rate in the sealed gas must be small. (Prevent blackening of lamp inner wall) (2) Work function is small. (Improvement of lighting efficiency) (3) Having getter function. (Prevention of abnormal discharge) (4) High melting point. (Heat resistance in the lamp manufacturing process) (5) Good moldability. [0004] It is considered that there is no metal that can satisfy the above-mentioned requirements 100%, but molybdenum, zirconium, titanium, and the like are being put to practical use or practical use. is there. The drawback of these metals is that they are hard and have poor moldability, and the lead wire insertion part of a cylindrical electrode with a seam formed by rolling a substantially square metal thin plate,
There is a problem in that it is very difficult to draw a thinner wire in accordance with the thickness of the lead wire smaller than the inner diameter of the cylindrical electrode. Therefore, in the conventional method of attaching a cylindrical electrode, as shown in FIGS. 5 and 6 (a cross-sectional view taken along the line AA in FIG. 5), a joint portion 22 formed by rolling a substantially rectangular metal thin plate is used.
By forming three internal protruding portions 22E in the lead wire 1 insertion portion of the cylindrical electrode 22 having A, while holding the lead wire 1 thinner than the inner diameter of the cylindrical electrode 22 at substantially the center of the cylindrical electrode 22, Laser beam LB is applied to one internal projection 22E.
And the one inner projection 22 </ b> E and the lead wire 1 were laser-welded. In the conventional method of mounting a cylindrical electrode, the laser beam is applied to one of the three internal projections 22E formed on the cylindrical electrode 22. Since the LB was applied and one internal projection 22E and the lead wire 1 were laser-welded, the welded portion was spot-welded, and the laser welding was likely to be incomplete, as shown in FIG. There have been problems such as poor inclination of the cylindrical electrode 22 and poor detachment (not shown). The reason why the laser welding is likely to be incomplete is that, in addition to the point welding, the internal projections 22E and the lead wire 1 are in close contact with each other due to variations in the height of the three internal projections 22E. It is thought that there may not be. According to the present invention, as a specific means for solving the above-mentioned conventional problems, the structure of a cylindrical electrode is changed by connecting a lead wire smaller than the inner diameter of the cylindrical electrode to the cylindrical electrode. While holding at the approximate center, the cylindrical electrode and the lead wire are securely adhered to each other in the welded part where the laser beam
In addition, by adopting a structure in which the welding area is not a point but a large area as much as possible, a strong laser welding state is realized, and the conventional problems are to be solved. An embodiment of the present invention will now be described in detail with reference to the drawings. FIG. 3 shows a substantially square metal sheet, and FIG. 3 shows a state in which a cylinder formed by rolling the metal sheet is processed and attached to a lead wire inside a cold cathode fluorescent lamp as a cylindrical electrode. 1 and 2 (cross-sectional view taken along the line AA in FIG. 1). In FIG. 3, a cutout portion 21B and a cutout portion 21C are provided in a substantially rectangular metal thin plate at a position to be a lead wire insertion portion. And two sides 21
When A is rounded to form a cylinder so that it becomes a joint,
A folded portion 21D having the notch 21B and the notch 21C as two sides can be formed. In FIG. 1 and FIG. 2, two internal projections 21E of the cylindrical electrode 21 are formed at positions opposed to the folded portions 21D of a cylinder formed by rolling the above-described substantially square metal thin plate. It is. Also, the folding part 21
D is obtained by forming two internal projections 21E and then folding the inner projection 21E inside the cylinder. The above is the basic structure of the cylindrical electrode 21 according to the present invention. Next, an embodiment of a method of attaching the cylindrical electrode 21 to the lead wire 1 inside the cold cathode fluorescent lamp will be described. 1 and 2, the cylindrical electrode 2
Although the lead wire 1 thinner than the inner diameter of the cylindrical electrode 21 is held at the approximate center of the cylindrical electrode 21 by the folded portion 21D and the two internal projections 21E, the folded portion 21
D is slightly folded in advance before inserting the lead wire 1 so that the lead wire 1 is press-fitted.
It can be said that the folded portion 21D and the lead wire 1 are in close contact with each other. Also, it can be said that the folded portion 21D and the lead wire 1 are not in point contact but in line contact close to surface contact. Here, the folded portion 21 of the cylindrical electrode 21
The cylindrical electrode 21 is welded to the lead wire 1 over a wide area by applying the laser beam LB to D and laser welding the folded portion 21D and the lead wire 1 to be firmly attached. The present invention is configured as described above, and has the following effects. The folded portion 21D of the cylindrical electrode 21 and the lead wire 1 are in close contact with each other due to the elastic effect of the folded portion 21D, and are not in point contact but in line contact close to surface contact. Since the welding area is large rather than spot welding, the cylindrical electrode 21 and the lead wire 1
Welding is strong and reliable. Since the folded portion 21D and the lead wire 1 are in a welding state close to surface welding, there is no occurrence of a tilt failure or a dropping failure of the cylindrical electrode, which conventionally occurs. Since the notch 21B is provided at the joint 21A of the cylindrical electrode 21, it is easy to fold the inside of the fold 21D. Since the cut portion 21C is provided, even if the lead wire 1 is press-fitted, the joint portion 21A of the cylindrical electrode 21 is formed.
Will not open and become defective.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing a method for mounting a cylindrical electrode of a cold cathode fluorescent lamp according to the present invention. FIG. 2 is a sectional view taken along line AA of FIG. FIG. 3 is an explanatory view showing a substantially square metal sheet in the present invention. FIG. 4 is an explanatory view showing the structure of a conventional general cold cathode fluorescent lamp. FIG. 5 is an explanatory view showing a method of attaching a cylindrical electrode to a conventional cold cathode fluorescent lamp. 6 is a sectional view taken along line AA of FIG. FIG. 7 is an explanatory view showing a tilt failure of a cylindrical electrode. [Explanation of Signs] 1 Lead wire 2 Cylindrical electrode 3 Glass bead 4 Glass tube 5 Phosphor coating film 6 ... Sealed gas 21... Cylindrical electrode 21 </ b> A Seam 21 </ b> B Notch 21 </ b> C Notch 21 </ b> D Folding 21 </ b> E Internal projection 22. Electrode 22A Joint 22E Internal projection LB Laser beam

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[Procedure amendment] [Date of submission] November 28, 2001 (2001.11.
28) [Procedure amendment 1] [Document name to be amended] Description [Item name to be amended] Claim 1 [Correction method] Change [Content of amendment] [Claim 1] A seam formed by rolling a substantially rectangular metal sheet In a mounting method in which a cylindrical member having a cylindrical electrode is welded to a lead wire inside a cold cathode fluorescent lamp and used as a cylindrical electrode, the connecting position of the lead wire (1) of the cylindrical electrode (21) is inserted.
Cut the notch (21B) on both sides of the notch (21A).
Folding part (21C) is provided and this is made into two sides
Notch (21D) is formed in a substantially planar shape, and
(1) Insertion position of the lead wire (1) of the cylindrical wall on the opposite side of the portion (21A)
To form a stepped flat part (21E)
Part (21D) and the inner wall of the stepped flat part (21E)
Therefore, a lead wire thinner than the inner diameter of the cylindrical electrode (21)
While holding (1) substantially at the center of the cylindrical electrode (21),
A laser beam (LB) is applied to the stepped flat part (21E),
A method for mounting a cylindrical electrode of a cold cathode fluorescent lamp, comprising laser welding a stepped flat portion (21E) and a lead wire (1) . In [Amendment 2] [corrected document name] specification [corrected item name] 0009 [correction method] change [Correction contents] [0009] Figure 3, the substantially square sheet metal, a circular cylinder with rounded 2 which becomes seam portion 21A when formed
Cut the notch 21B into the lead wire 1
A recess 21C is provided. Then, the cylindrical electrode 21 is
When formed, the notch 21B and the notch 21C
A substantially flat folded portion 21D having two sides can be formed
It becomes. The portion indicated by the dotted line at the corner of the folded portion 21D
When the folded portion 21D is formed, the lead wire 1
Corner bends that open slightly outward to facilitate insertion
This is a part that forms the part 21F. In [Amendment 3] [corrected document name] specification [corrected item name] 0010 [correction method] change [Correction contents] [0010] Figures 1 and 2, a cylindrical electrode 21
The lead wire 1 insertion portion has substantially flat surfaces on both sides of the seam portion 21A.
Folded portion 21D is formed, and seam portion 2D is formed.
A stepped flat portion 21E is formed on the cylindrical wall on the opposite side of 1A.
And the inner wall of the two folded portions 21D and the stepped flat portion 21
A lead wire 1 thinner than the inner diameter of the cylindrical lightning pole 21 with the inner wall of E
Is held at a substantially central portion of the cylindrical electrode 21.
It is. The above is the basic structure of the cylindrical electrode 21 according to the present invention.
It is. [Procedure amendment 4] [Document name to be amended] Description [Item name to be amended] 0011 [Correction method] Change [Content of amendment] Next, the cylindrical electrode 21 is connected to the lead wire 1 inside the cold cathode fluorescent lamp. An embodiment of a method for attaching to a vehicle will be described. 1 and 2, 2 Tsuno析Ri
The insertion part 21D is slightly deep inside before the lead wire 1 is inserted.
It is folded. Therefore, the insertion of the lead wire 1 is called press fitting.
It will be. The corners of the two folds 21D
A corner bent portion 21F that opens to the outside of the cylinder is formed.
Therefore, the lead wire 1 slides on the corner bent portion 21F to accommodate the lead wire.
Press-fitting is easy. Leads pressed in this way
The line 1 has a stepped flat due to the elastic effect of the folded portion 21D.
It comes into close contact with the inner wall of the surface portion 21E. [Procedure amendment 5] [Document name to be amended] Specification [Item name to be amended] 0012 [Correction method] Change [Content of amendment] Here, stepped flat portion 21 of cylindrical electrode 21
A laser beam LB is applied to E, and the stepped flat portion 21E and the lead
The cylindrical electrode 21 is re-welded by laser welding
Wide welding instead of spot welding in close contact with lead wire 1
Laser welding is performed firmly on the
No problems and no defects occur, completely solving conventional problems
The Rukoto. [Procedure amendment 6] [Document name to be amended] Specification [Item name to be amended] 0014 [Correction method] Change [Content of amendment] Lead wire 1 inserted into cylindrical electrode 21
Is stepped flat due to the elastic effect of the two folded portions 21D.
The laser is held in close contact with the inner wall of the surface portion 21E.
The distance between the stepped flat portion 21E and the lead wire 1 by the beam LB.
Laser welding is assured and poor welding occurs almost
do not do. [Procedure amendment 7] [Document name to be amended] Description [Item name to be amended] 0015 [Correction method] Change [Contents of amendment] The stepped flat portion 21E and the lead wire 1
Laser welding is performed over a large welding area instead of welding.
Laser welding becomes stronger and the cylindrical electric
Completely solves conventional problems without poor pole inclination or dropout
Can be solved. [Procedure amendment 8] [Document name to be amended] Description [Item name to be amended] Explanation of sign [Correction method] Change [Details of amendment] [Explanation of sign] 1 ... Lead wire 2 ... Cylindrical electrode 3 ...
…… Glass Bead 4 ………… Glass Tube 5 ………
… Phosphor coating film 6… Enclosed gas 21… Cylindrical electrode 21A… Seam part 21B… Notch 21C… Cut
21D: Folded portion 21E: Stepped flat portion 2
1F: Square bent portion 22: Cylindrical electrode 22A: Joint portion 22E: Internal projection LB
…… Laser beam [Procedure amendment 9] [Document name to be amended] Drawing [Item name to be amended] All drawings [Correction method] Change [Contents of amendment] [Fig.1] FIG. 2 FIG. 3 FIG. 4 FIG. 6 FIG. 7 FIG. 5

Claims (1)

Claims: 1. A method for mounting a cylindrical cylinder having a seam formed by rolling a substantially square metal sheet into a lead wire inside a cold cathode fluorescent lamp and using it as a cylindrical electrode. A notch (21B) and a notch (21C) are provided at the insertion position of the lead wire (1) at the joint (21A) of the cylindrical electrode (21), and a fold (21D) having the two notches is provided. At the same time, two internal projections (21E) are formed at positions facing the folds (21D), and the folds (21D) and the two internal projections (21) are formed.
With E), the lead wire (1) thinner than the inner diameter of the cylindrical electrode (21) is held at substantially the center of the cylindrical electrode (21),
A laser beam (LB) is applied to the folding part (21D),
A method for mounting a cylindrical electrode of a cold cathode fluorescent lamp, comprising laser welding a folded part (21D) and a lead wire (1).