JP3114365U - Cold cathode fluorescent lamp electrode cup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode cup for a cold cathode fluorescent lamp excellent in durability and economy, which can improve a sputtering resistance and can surely obtain a desired shape.
SOLUTION: In cups 21 and 22, a bottom portion 7 and a side surface portion 8 adjacent to the bottom portion 7 have a substantially U-shaped thickness which is thicker than a thickness dimension of a side surface portion 10 near an opening portion 9. Portions 7a and 8a are formed. The cups 21 and 22 are manufactured from niobium (Nb), titanium (Ti), nickel (Ni), or a niobium alloy or nickel alloy mainly containing the metal by using impact molding.
[Selection] Figure 1

Description

  The present invention relates to an electrode cup incorporated in a cold cathode fluorescent lamp, and more particularly to the shape and material of the cup.

  Generally, a liquid crystal display can be made thinner and lighter than a CRT display. Therefore, in recent years, it is widely used not only for computers and peripheral devices but also for televisions, mobile phones, digital video cameras and the like. Unlike a self-luminous display device such as a plasma display, this liquid crystal display does not emit light itself, and an external auxiliary light source is required for display. As this auxiliary light source, a light emitting diode, an electroluminescent lamp, a cold cathode fluorescent lamp, or the like is used, and a backlight system in which light is applied from the back surface of the display panel is known. In particular, in displays such as computers, a combination of a cold cathode fluorescent lamp and a light guide plate has become the mainstream.

  The cold cathode fluorescent lamp is composed of a glass tube and cold cathode lead wires fitted to both ends thereof. An appropriate amount of mercury and an inert gas (argon, neon, mixed gas, etc.) are sealed in the glass tube as a discharge medium, and a phosphor that emits light upon stimulation by ultraviolet rays is applied to the inner wall. The light emission mechanism of this lamp is as follows.

  That is, when a high voltage is applied to the cold cathode lead wire, electrons slightly present in the glass tube are attracted to the electrode and collide at high speed. At this time, secondary electrons are emitted and discharge begins. Electrons drawn to the anode by this discharge collide with mercury molecules in the glass tube, and ultraviolet rays are emitted. The emitted ultraviolet light excites the phosphor on the inner wall of the glass tube to emit visible light. Note that the emission color (color temperature and chromaticity) can produce various emission colors by changing the type of phosphor.

  Here, a conventional example of a cold cathode lead will be described in detail with reference to FIG. FIG. 3 shows only one of the cold cathode lead wires fitted to both ends of the glass tube 5. The cold cathode lead wire 1 includes an electrode cup 2, a conductive rod-shaped body (encapsulated wire) 3, and an introduction wire (outer wire) 4. The lead-in wire 4 is attached to the end of the glass tube 5. The lead-in wire 4 is made of MnNi or Du or other various materials.

  The rod-shaped body 3 is electrically welded to the leading end portion of the lead-in wire 4. The rod-shaped body 3 is a cylindrical rod-shaped member having an outer diameter of about 0.5 to 1.0 mm and an axial length of about 2.5 to 5.0 mm, and has a conductive metal such as molybdenum (Mo) or tungsten. (W), made of Kovar (Co), the tip of which is electrically welded to the cup 2.

  4 and 5 are enlarged sectional views of the cups 21 and 22. FIG. The cup 21 in FIG. 4 is a tip-drawing type, and the cup 22 in FIG. 5 is a straight type. As shown in these drawings, the cups 21 and 22 are cylindrical members made of, for example, nickel (Ni) or molybdenum (Mo). The inner diameter of the cup 2 is about 0.6 to 3.0 mm, and the axial length is about 2.0 to 6.0 mm.

  By the way, it is known that the inner wall surfaces of the cups 21 and 22 are abraded by electric discharge as the electrodes are sputtered. In particular, the wear of the bottom portions of the cups 21 and 22 and the side portions adjacent to the bottom portions is severe, resulting in a deep wear portion 6 (see FIGS. 6 and 7). Such wear of the cups 21 and 22 makes it difficult for electrons to be emitted, which is a direct factor that impairs the life of the cold cathode fluorescent lamp. In recent years, when the demand for liquid crystal displays for TVs has been increasing, cold cathode fluorescent lamps having a longer life than conventional ones have been desired, and improving the durability of the cups 21 and 22 has become an extremely important technical request.

For example, in the prior art described in Patent Document 1, an emitter layer mainly composed of boride is provided on the cup wall surface, and the thickness dimension of the emitter layer is set to be thicker on the bottom side than on the opening side of the cup. It is a feature. Since the emitter layer has a lower work function than metal, it is effective for reducing power consumption.
JP-A-10-144255

  However, the following problems have been pointed out in the above prior art. That is, the wear parts 6 of the cups 21 and 22 are concentrated in the vicinity of the bottoms of the cups 21 and 22, and the side parts of the cups 21 and 22 are about 1/3 that is closer to the bottom. That is, in the cups 21 and 22, the wear portion 6 does not gradually become deeper from the opening side toward the bottom side.

  For this reason, in the conventional example of Patent Document 1, if the emitter layer is gradually thickened from the opening side toward the bottom side, the emitter layer is somewhat thick even in the vicinity of the opening portions of the cups 21 and 22 that do not wear so much. Sometimes it became. In this case, an emitter layer is formed more than necessary, which is a problem in terms of cost.

  Further, in the conventional example of Patent Document 1, the emitter layer is formed by pouring, drying and sintering on the wall surface after being prepared in the form of a fine powder slurry. For this reason, the formation process of the emitter layer is very troublesome, and in this respect, the manufacturing cost has been increased. Further, a snap-type manufacturing method is usually used for the electrode cup of the cold cathode fluorescent lamp, and it is made by drawing from a plate material. Therefore, the material yield is about 50%, and the material cost is high.

  Thus, with regard to the electrode cup of the conventional cold cathode fluorescent lamp, it has been a problem to improve both durability and economy. The present invention has been proposed to solve the above-described problems, and is a cold cathode excellent in durability and economy that can improve the sputtering resistance and can surely obtain a desired shape. An object is to provide a cup for an electrode of a fluorescent lamp.

  In order to achieve the above object, the present invention provides a cylindrical electrode cup provided at both ends of a glass tube, wherein a bottom portion to which a conductive rod-like body is electrically welded, The electrode cup of a cold cathode fluorescent lamp having openings facing each other is characterized by the following configuration.

  In other words, the invention described in claim 1 is characterized in that a thick part that is thicker than a thickness dimension of the side part in the vicinity of the opening is formed on the bottom part and the side part close to the bottom part. .

  In the invention of claim 1 above, by forming a thick portion so as to be substantially U-shaped on the bottom portion of the cup and the side portion close to the bottom portion, it can withstand a long period of wear due to discharge, Sputter resistance of the cup is improved. As a result, the cup can maintain excellent electron emission characteristics over a long period of time, and can extend the life of the cold cathode fluorescent lamp.

  The invention of claim 2 is the electrode cup of the cold cathode fluorescent lamp according to claim 1, wherein, among the thick portions, the thickness on the bottom side is the thickness on the side surface near the opening. The thickness dimension on the side surface side close to the bottom is 1.5 to 3 times the thickness dimension of the side surface near the opening of the cup.

  In the invention of claim 2, the thickness side of the thick part is 2-5 times the side part near the opening on the bottom side, and 1.5-3 times the side part close to the bottom part. Since the dimensions are optimized, the manufacturing cost can be reduced while sufficiently ensuring the durability of the cup.

  The invention of claim 3 is characterized in that the cold cathode fluorescent lamp electrode cup of claim 1 or 2 is formed by impact molding.

  In the above invention of claim 3, since the electrode cup is formed by impact molding, the following effects are obtained. Impact molding is a method in which a raw material called coin-shaped slag is placed in a mold, compressed and extruded with a large impact force, and molded into a cylindrical member with a bottom. This molding method has the advantage that the die cost and unit price are low because drawing can be performed in one step. In addition, it is possible to very easily form shapes having different wall thicknesses and bottom thicknesses as compared with plate drawing molding in which it is difficult to set the finished wall thickness. Therefore, it is suitable as a method for forming an electrode cup having a substantially U-shaped thick portion as in the present invention, and the electrode cup can be manufactured with high accuracy and at low cost.

  The invention of claim 4 is an electrode cup for a cold cathode fluorescent lamp according to any one of claims 1 to 3, wherein the cup is made of a material mainly containing at least one of niobium, titanium and nickel. It is said.

  According to the fourth aspect of the present invention, the cup is formed by impact molding reliably by using a material mainly containing at least one of niobium, titanium, and nickel instead of a high-hardness metal material such as molybdenum or tungsten. It becomes possible. Therefore, the material yield can be increased to 100%, and the material cost and the manufacturing cost are greatly reduced, which is economically advantageous.

  As described above, according to the present invention, a substantially U-shaped thick part that is thicker than the thickness of the side part near the opening is formed on the bottom part of the cup and the side part close to the bottom part. By forming by impact molding, a long-lasting and cheap cold cathode fluorescent lamp electrode cup can be obtained.

Embodiment of invention

  Hereinafter, embodiments of the present invention will be specifically described with reference to FIGS. 1 and 2. 1 and 2 are enlarged cross-sectional views of the electrode cup 2 of the cold cathode fluorescent lamp according to this embodiment. The cup 21 in FIG. 1 is a tip type, and the cup 22 in FIG. 2 is a straight type.

[Configuration of representative embodiment]
In the present embodiment, in the cups 21 and 22, the bottom portion 7 and the side surface portion 8 adjacent to the bottom portion 7 have substantially U-shaped meat that is thicker than the thickness dimension of the side surface portion 10 near the opening 9. Thick portions 7a and 8a are formed. At this time, the thickness dimension of the side surface part 10 near the opening 9 is 0.1 to 0.2 mm, and the thickness dimension of the thick part 7a on the bottom part 7 side is 2 to 5 times 0.2 to It is 0.5 mm.

  Further, in the side surfaces of the cups 21 and 22, the thickness dimension of the thick portion 8 a near the bottom portion 7 is 1.5 to 3 times the thickness dimension of the side surface portion 10 near the opening 9. 0.15-0.3 mm. In addition, the cups 21 and 22 of this embodiment are manufactured from niobium (Nb), titanium (Ti), nickel (Ni), or a niobium alloy or nickel alloy mainly containing the metal by using impact molding. .

[Effects of the present embodiment]
In the present embodiment as described above, the thick portions 7a and 8a, which are substantially U-shaped as a whole, are formed on the bottom portion 7 of the cups 21 and 22 and the side surface portion 8 close to the bottom portion 7, so that discharge is caused. It can withstand long wear and the spatter resistance of the cups 21 and 22 is increased. Therefore, the cups 21 and 22 can maintain excellent electron emission characteristics over a long period of time, and as a result, the lifetime of the cold cathode fluorescent lamp in which the cups 21 and 22 are incorporated is extended.

  Further, in the present embodiment, the thick portion 7a on the bottom 7 side where the abrasion is severe is 2 to 5 times the side portion 10 near the opening 9, and the thickness on the side portion 8 side where the abrasion is lighter than the bottom portion 7. The portion 8a is 1.5 to 3 times the side surface portion 10 near the opening 9. For this reason, there is no part which forms a thick part wastefully, and it is possible to increase the durability of the electrode cups 21 and 22 and to manufacture the cups 21 and 22 with a minimum material.

  Further, in this embodiment, the impact molding is used when forming the electrode cups 21 and 22, so that the cups 21 and 22 having the substantially U-shaped thick portions 7a and 8a, that is, the wall thickness and the bottom are formed. Cups 21 and 22 having different shapes can be reliably manufactured with high accuracy. This is because, as described above, impact molding has excellent accuracy as a method of manufacturing a cylindrical member having a shape with a different wall thickness and bottom thickness.

  Moreover, it is not a hard metal material such as molybdenum (Mo) or tungsten (W), but niobium (Nb), titanium (Ti), nickel (Ni), or a niobium alloy or nickel alloy mainly containing the metal. By using as, it becomes possible to implement impact molding reliably. For this reason, the material yield can be increased to 100%, which is twice that of the prior art, and the material cost and the manufacturing cost can be greatly reduced to ensure excellent economic efficiency.

[Other embodiments]
In addition, this invention is not limited to said embodiment, The magnitude | size and shape of each part, a material, a part of manufacturing method, the use of a product, etc. can be changed suitably. For example, the materials of the cups 21 and 22 can be used as appropriate. The shape of the cups 21 and 22 may be a prismatic cylindrical member, and the rod-like portion 3 is a shape corresponding to the shape of the inner diameter portion of the cylindrical portion and can be selected as appropriate. Is also free. Furthermore, the types of the cups 21 and 22 can be replaced as long as they have electron emission characteristics.

  The surface of the cups 21 and 22 can also be configured by applying and coating a substance that enhances the light emission characteristics, such as lanthanum boride (LaB6). Further, the shape of the lead-in wire 4 is not limited to the above, and may be bent in advance according to the connection target. In addition, as a cold cathode fluorescent lamp to which the present invention is applied, for example, a straight tube, a W-shaped tube, a U-shaped tube, a U-shaped tube, an L-shaped tube, etc. Anything is applicable. The emission color can be various, and is not limited to a specific color. Furthermore, an apparatus to which the present invention is applied is not limited to a cold cathode fluorescent lamp, and can be widely used as an electrode for discharge.

The expanded sectional view of the cup for electrodes of the cold-cathode fluorescent lamp which concerns on typical embodiment which concerns on this invention (first-drawing type). The expanded sectional view (straight type) of the electrode cup of the cold cathode fluorescent lamp concerning this embodiment. The top view of the cold cathode lead wire in the conventional cold cathode fluorescent lamp. The expanded sectional view of the cup for electrodes in the conventional cold cathode fluorescent lamp (first-drawing type). The expanded sectional view (straight type) of the cup for electrodes in the conventional cold cathode fluorescent lamp. The expanded sectional view of the conventional electrode cup which showed the abrasion state (pointing type). The expanded sectional view (straight type) of the conventional cup for electrodes which showed the abrasion state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cold cathode lead wire 2, 21 and 22 ... Electrode cup 3 ... Rod-shaped body 4 ... Lead-in wire 5 ... Glass tube 6 ... Wearing part 7 ... Bottom part 8 ... Side face part 7a, 8a close to bottom part 7 ... Thickness Part 9: Opening part 10: Side surface part near the opening part 9

Claims (4)

A cylindrical electrode cup provided at both ends of a glass tube, the electrode cup of a cold cathode fluorescent lamp having a bottom portion into which a conductive rod-like body is inserted and an opening facing each other in the glass tube In
An electrode cup for a cold cathode fluorescent lamp, wherein a thick portion that is thicker than a thickness of a side portion near the opening is formed on the bottom portion and a side portion close to the bottom portion.   Among the thick portions, the thickness on the bottom side is 2 to 5 times the thickness on the side near the opening, and the thickness on the side near the bottom is the opening of the cup. 2. The electrode cup for a cold cathode fluorescent lamp according to claim 1, wherein the thickness is set to 1.5 to 3 times the thickness of the side surface in the vicinity of the portion.   3. The cold cathode fluorescent lamp electrode cup according to claim 1, wherein the cup is formed by impact molding.   The electrode cup for a cold cathode fluorescent lamp according to any one of claims 1 to 3, wherein the electrode cup is made of a material mainly containing at least one of niobium, titanium and nickel.

Images