JP2008235197A - Electrode member, cold cathode lamp, and lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode member capable of securing light-emitting characteristics and life characteristics demonstrated by a conventional cup-shape electrode and capable of reducing the cost of the electrode, and a cold cathode discharge lamp using this electrode member, and a lighting device installed with this cold cathode discharge lamp. <P>SOLUTION: The electrode member 4 is provided with a cup-shape electrode 5 of a bottomed cylindrical shape which is formed by a header machining and of which the periphery of the tip part 52 on the aperture side 51 extends to the inside and a glass sealing wire rod 61 which is welded and connected to the outer end face of the bottom side of the cup-shape electrode 5. A cold cathode discharge lamp L using the electrode member 4 and a lighting device 9A installed with this cold cathode discharge lamp L are provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrode member used for a tube such as a cold cathode fluorescent lamp, a cold cathode discharge lamp using the electrode member, and an illumination device using the cold cathode discharge lamp.

  Recently, liquid crystal display devices such as liquid crystal televisions have been reduced in thickness and color with high brightness, and in association with this, cold cathode fluorescent lamps used as a light source for the backlight of this liquid crystal television are also used for glass tube bulbs and electrodes. Has been promoted to reduce the size and extend the service life.

  With the growing demand for liquid crystal televisions and the like, there is a strong demand for cost reduction of various components used in televisions and light sources for backlights.

  In the cold cathode fluorescent lamp used as the light source, the main components are a glass tube bulb including a phosphor, an electrode member having a cold cathode, a discharge medium, and the like. As a result of various studies on these, the present inventors have found that there is room for improvement in electrode members having relatively high component costs.

  Cold cathode fluorescent lamps have been developed with glass tube bulbs having an inner diameter of 12 mm or less, for example, 5 mm or less, and can be miniaturized as an electrode and have a low cathode fall voltage that does not contribute to light emission, resulting in low power consumption. An electrode member provided with a cup-shaped electrode exhibiting a hollow cathode effect in the shape of a bottomed cylinder that can improve the luminous efficiency by reducing the above is employed.

  This electrode member is, for example, a rolled nickel (Ni) thin plate with a plate thickness of about 0.2 mm punched out into a disk shape by press (deep drawing) processing, an outer diameter of about 2.0 mm, an inner diameter of about 1.6 mm, Consists of a cup-shaped electrode formed in a substantially bottomed cylindrical shape having a length of about 5.0 mm, and a sealing wire made of molybdenum wire having an outer diameter of about 0.8 mm connected to the outer outer end surface of the electrode by welding. Has been.

  The conventional cup-shaped electrode is formed into a cup shape by forcibly deforming the punched disc-shaped plate-like member by press (deep drawing) processing. As the degree of compression increases, the shape of the extension at the periphery of the opening at the tip of the cup is not uniform, and a shape that expands outwardly in a flare shape is formed to remove the convex mold. The extending portion is cut along the circumference and the tip is formed to have a substantially smooth cross-sectional shape.

  A cold cathode fluorescent lamp using an electrode member having a cup-shaped electrode formed by pressing as described above has a hollow cathode effect and can improve light emission characteristics and life characteristics. When a disk-shaped electrode forming material is continuously punched from a sheet-shaped member, the total area of the non-punched portions remaining between the circular punched portions reaches 30 to 40% of the original thin plate material, and the press Including the cut at the tip after molding, there were many parts that would become scraps without being used as electrodes, and the material loss was extremely large.

  Therefore, the present inventors have focused on the fact that the cup-shaped electrode is formed by header processing (forging press) with little material loss during molding.

  However, the cup-shaped electrode made by this header processing (forging press) is formed by extending the bar material, so the peripheral edge of the opening on the opening side of the cup is not uniform. Concavities and convexities were sometimes produced.

  The discharge of a discharge lamp, such as a cold cathode fluorescent lamp, is performed between opposing electrodes, but the discharge is most likely to occur at the tip of the electrode. If there is a protrusion such as a protrusion at the tip of this electrode, the protrusion There is a problem that the discharge is concentrated and the temperature of this part becomes higher than that of the other part to form a discharge base point, so that stable discharge cannot be sustained or sputtering is caused at an early stage.

  The present invention has been made in view of such circumstances. An electrode member capable of ensuring the light emission characteristics and life characteristics exhibited by a conventional cup-shaped electrode, and reducing the cost by eliminating the loss of the electrode forming material, and the electrode. It is an object of the present invention to provide a cold cathode discharge lamp using a member and an illumination device equipped with the cold cathode discharge lamp.

  The electrode member according to claim 1 of the present invention includes a bottomed cylindrical cup-shaped electrode formed by header processing and having a peripheral edge extending inward on the opening side, and a bottom side of the cup-shaped electrode. And a glass sealing wire that is welded to the outer end surface.

  The cup-shaped electrode with a bottomed cylindrical shape is formed by header processing (cold forging) instead of processing from a plate-like body, so there is almost no loss during molding and material costs are saved. Cost can be reduced.

  In the case of this header processing (cold forging), a rod-shaped material of a predetermined dimension is formed by a pair of concave and convex dies, so that the material extended from the joint of the dies protrudes to the outside, There is little risk of running out of space.

  However, even if there is some unevenness on the periphery of the tip of the molded electrode, by turning the periphery of the tip inward, it becomes a relaxed state inclined more than the sharpened state where the protrusion is upright, and stable discharge can be sustained.

  In the present invention, the cup-like electrode can be formed from a single substance such as nickel (Ni) or niobium (Nb) or an alloy thereof.

  The cold cathode discharge lamp according to claim 2 of the present invention is a glass tube-shaped bulb, the electrode member according to claim 1 in which sealing wire portions are hermetically sealed at both ends of the bulb, and the above And a discharge medium enclosed in a bulb.

  A cold-cathode discharge lamp comprising an electrode member that exhibits the function of claim 1.

  The illumination device according to claim 3 of the present invention includes a housing, the cold cathode discharge lamp according to claim 2 attached to the housing, and a lighting circuit device for the cold cathode discharge lamp. It is characterized by.

  It is an illuminating device provided with the cold cathode discharge lamp which show | plays the effect | action of the said Claim 2.

  According to the first aspect of the present invention, the cup-shaped electrode formed by header processing (cold forging) can be used while obtaining light emission and life characteristics equivalent to those of a conventional cup-shaped electrode formed from a plate-like body. An inexpensive electrode member capable of reducing material loss can be provided.

  Also, a cold cathode discharge lamp is provided that can maintain a stable discharge by extending the periphery of the tip portion inward even when irregularities are formed on the periphery of the opening side of the cup-shaped electrode cup. Can do.

  According to invention of Claim 2, the cold cathode discharge lamp provided with the electrode member which exhibits the effect of the said Claim 1 can be provided.

  According to invention of Claim 3, the illuminating device provided with the cold cathode discharge lamp which exhibits the effect of the said Claim 2 can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a partially cut sectional front view showing a cold cathode fluorescent lamp, FIG. 2 is a partially cut sectional front view showing an electrode member used in the fluorescent lamp in FIG. 1, and FIGS. These are explanatory drawings which show the outline of the manufacturing process of the electrode member shown in FIG.

  The cold cathode fluorescent lamp L shown in FIG. 1 has, for example, a rated power consumption of 5 W or less and about 2.5 W, and the glass tube bulb 1 having a straight tube shape has an outer diameter of about 4.0 mm, an inner diameter of about 3.5 mm, A three-wavelength phosphor film 2 made of a hard glass such as borosilicate glass having a length of about 200 mm is formed on the inner surface of the bulb 1 by mixing and applying phosphors having light emitting areas in blue, green, and red, for example. Yes.

  Further, sealing portions 11 and 11 are formed at both ends of the glass tube bulb 1 by sealing electrode members 4 to be described later via beads 3 made of borosilicate glass. Argon ( A cold cathode fluorescent lamp L is configured by sealing a discharge medium composed of about 8 kPa of rare gas such as Ar), xenon (Xe), or neon (Ne) and mercury (Hg).

  The electrode member 4 passes the current in a state where two or three of the bottomed cylindrical cup-shaped electrode 5, the sealing wire 61, and the external lead wire 62 face each other in series. It is completed by generating resistance heat at the contact surface and welding and connecting each other. Further, the glass bead 3 is wound around the sealing wire 61, but the bead 3 is not necessary if the sealing wire 61 is made of a material that is compatible with the glass of the bulb 1.

  Further, the electrode member 4 will be described in detail with reference to FIG. 2 and FIG. 3. The cup-shaped electrode 5 is formed of a nickel (Ni) material by header processing (cold forging), and the opening side 51 tip 52 has a peripheral edge. It extends inward. The cup-shaped electrode 5 has, for example, a bottomed surface having an outer diameter of about 2.1 mm, an inner diameter of the peripheral edge of the opening 51 and a peripheral edge of about 1.4 mm, a side wall thickness of about 0.2 mm, and a length of about 5.0 mm. It is formed in a cylindrical shape.

  The cup-shaped electrode 5 is formed by head processing (cold forging) as shown in the order of steps in FIGS.

First, a billet 7 in which a nickel round bar having an outer diameter of about 0.9 mm is cut into a length of about 2 mm is placed in a concave mold 81 in which concave and convex molds having both center axes are opposed to each other, When the convex mold 82 is struck by a machine or compressed by a hydraulic press toward the billet 7 in the concave mold 81, the billet 7 is pressed and flattened. ((A) Figure)
When the pressing by the convex mold 82 toward the billet 7 is advanced, the central portion of the billet 7 is recessed and the extended portion of the billet is pressed against the inner wall surface of the concave mold 81. It rises to the gap 80 between 81 and the convex mold 82. ((B) Figure)
When the billet 7 is further pressed by the convex mold 82, a bottomed cylindrical cup is formed which extends over the entire gap 80 and is shaped by the two molds 81 and 82. ((C) Figure)
Next, the bottomed cylindrical cup is inserted into the concave mold 83 into which the cup is inserted in the middle, and the bottom side is inserted into the concave mold 83, and the innermost part of the recess 84a is arranged facing the mold 83. The opening side 51 of the cup is inserted into a concave mold 84 whose peripheral edge is formed with a predetermined inclination or curve. (Figure (d))
Then, when at least one of the molds 83 and 84 is pressed, the peripheral edge of the distal end portion 52 of the opening 51 is bent inward by a predetermined angle along the inner wall of the recess 84 a of the mold 84.

  The bending angle (which may be linearly inclined or curved) extending inward of the distal end portion 52 of the opening side 51 is the side surface of the electrode 5 in consideration of the bending workability of the distal end portion 52 and the like. Is the range of 30 to 90 degrees, and the inner diameter of the distal end portion 52 of the opening 51 may be in the range of 50 to 80% of the outer diameter.

  Thereafter, the bottomed cylindrical cup made of nickel taken out from the concave mold 83 or 84 is assembled as the cup-shaped electrode 5 into the electrode member 4 shown in FIG.

  The hitting the billet 7 with the convex mold 82 at the time of the header processing (cold forging) may be one shot or molding by repeated hitting. Further, the pressing by the pair of concave mold 81 and convex mold 82 has a relative relationship, and it is sufficient to drive at least one of them.

  The cup-shaped electrode 5 molded as described above is finished with a rod having a predetermined size by a concave and convex molds 81 and 82 without a discarded material portion. That is, there is no loss in electrode material removal during molding, and the use of the material can be greatly reduced by about 30 to 40% compared to the plate-like body, so that the cost can be reduced.

  And the said electrode member 4 arrange | positions the cup-shaped electrode 5 and 61 parts of sealing wire materials along the substantially central axis in the glass tube valve 1 end part which formed the fluorescent substance film 2, and 61 parts of sealing wire materials respond | correspond The glass tube bulb 1 is heated from the outside with a gas burner, etc., the glass of the bulb 1 and the bead 3 are softened and melted, and the glass on the bulb 1 side is reduced in diameter to be fused with the surface of the bead 3. Do.

  Thereafter, the inside of the glass tube bulb 1 is evacuated through an exhaust pipe (not shown), a discharge medium composed of a rare gas and mercury is sealed inside, the exhaust pipe is sealed, and a base is joined to the end of the bulb 1 as necessary. Thus, the cold cathode fluorescent lamp L is completed.

  Accordingly, the cost of the cold cathode fluorescent lamp L using the cup-shaped electrode 5 can also be reduced. Moreover, even if the electrode 5 is manufactured by header processing (cold forging) and there is some unevenness on the periphery of the electrode tip 52, the discharge is stabilized by making the relaxed state inclined from the sharpened state where the protrusion is upright. Therefore, since the electrode is a hollow electrode, a large current per area can be obtained, and light emission characteristics and life characteristics similar to those of a cold cathode fluorescent lamp including a cup-shaped electrode formed from a plate-like body can be obtained.

  The cold cathode fluorescent lamp L is used as an illumination device (light source) for a backlight of a television or a personal computer using liquid crystal, for example. That is, the cold cathode fluorescent lamp L is incorporated in an illumination device as shown in FIGS. 4 (a) and 4 (b). FIG. 4A is a partial cross-sectional perspective view showing an embodiment of a light guide type illumination device 9A.

In FIG. 4A, 91 is a housing that also serves as a bowl-shaped reflecting mirror with a U-shaped cross section, to which a cold cathode fluorescent lamp L is mounted, 92 is a light guide plate made of acrylic resin, and 93 and 94 are light guide plates 92. A reflection sheet 95 is formed on the bottom and side surfaces and in the housing case (not shown) of the light guide plate 92, and 95 is a light diffusing plate disposed on the upper surface side of the light guide plate 92. It is incorporated with a lighting circuit device (not shown).

  In this light guide type illumination device 9A, the direct light from the cold cathode fluorescent lamp L and the reflected light from the reflecting mirror 91 are incident on the light guide plate 92 and transmitted through the light guide plate 92 to reach the bottom surface or side surface. The light is reflected by the reflection sheets 93 and 94 toward the upper surface of the light guide plate 92. The light incident on the light diffusion plate 95 from the upper surface of the light guide plate 92 is diffused from the upper surface of the light diffusion plate 95 and is emitted toward the liquid crystal panel P, for example.

  4B is an exploded perspective view of the reflector type illumination device 9B. A plurality of cold-cathode fluorescent lamps L,... Are mounted and disposed in a housing 96 also serving as a reflecting mirror. A light diffusing plate 95 is placed in the opening, and these are incorporated together with a lighting circuit device in an appliance main body (not shown).

  In the illuminating device 9B, the direct light from the cold cathode fluorescent lamps L,... And the reflected light from the reflecting mirror 96 are incident on the light diffusion plate 95 and diffused and emitted from the upper surface of the light diffusion plate 95.

  The lighting devices 9A and 9B are used as a light source unit for a backlight of a display panel on which a liquid crystal display device such as a personal computer or a liquid crystal television or a predetermined display device is formed, or as a general lighting fixture.

  And since these illuminating devices 9A and 9B use the cold cathode fluorescent lamp L in which cost reduction was achieved, cost reduction can be performed, maintaining the quality performance equivalent to the past.

  The present invention is not limited to the above embodiment. Cold cathode discharge lamps to which the present invention can be applied include not only fluorescent lamps but also rare gas emission lamps and ultraviolet radiation lamps, and glass tube bulbs are made of hard materials such as borosilicate glass, aluminosilicate glass, and quartz glass. What consists of soft glass, such as glass or soda-lime glass, can be used.

  The shape of the bulb (lamp) is not limited to a straight tube shape, but may be a bent shape such as a U-shape, a W-shape, or a ring shape, or a shape formed by connecting a plurality of straight tubes in series. The attachment part is not limited to the one that is performed through the bead, but is formed by drawing sealing that uses a burner or the like to reduce the diameter of the glass tube that directly seals the sealing wire with the bulb, or by crushing sealing using a mold. The reflective film, the colored film, the protective film, etc. may be formed on the inner or outer surface of the bulb.

  The material of the bottomed cylindrical cup-shaped electrode forming the electrode member is not limited to nickel (Ni), but can also be made of niobium (Nb) or an alloy containing these metals as a component, and its cross-sectional shape is It is not limited to a cylindrical shape, and may be a rectangular tube shape. In addition, by attaching or filling an easy-electron radioactive substance or getter material to the cup-shaped electrode, it is possible to facilitate the occurrence of discharge and enhance the starting characteristics or the working characteristics.

  In addition, the material form for forming the cup-shaped electrode is not limited to the one made of nickel or the like in the form of a rod, but header processing (cooling) such as filling powder into a concave mold and pressing it with a convex mold. The electrode may be formed by intermediate forging.

  The material of the sealing wire is not limited to molybdenum (Mo), but tungsten (W), alloys containing these metals, or jumet (DX) or Kovar (KOV-iron (Fe) approx. 54% by mass, nickel (Ni) approx. 29 mass% and cobalt (Co) of about 17 mass%)), and the selection of the wire can be made in accordance with the material and thermal expansion coefficient of the glass tube bulb used.

  The external lead wire connected to the other end of the sealing wire is nickel (Ni), iron (Fe), iron (Fe) / nickel (Ni) alloy, nickel (Ni) / manganese (Mn) It may be a wire made of nickel (Ni) or iron (Fe) / nickel (Ni) alloy whose surface is coated with copper (Cu).

  Also, the sealing wire and the external lead wire are not separate from each other, and the sealing wire and the external lead wire may be the same integrated body by extending the sealing wire to form an external lead wire. .

  Furthermore, the illumination device according to the present invention is mounted on a backlight for a liquid crystal display device, a liquid crystal television, a decoration device, etc., as well as a reading device such as a facsimile, an exposure device for a copying machine, or a normal illumination device or lamp. Can be used.

1 is a partially cut-away front view showing an embodiment of a cold cathode fluorescent lamp of the present invention. FIG. 2 is a partially cutaway sectional front view showing an electrode structure used in the fluorescent lamp in FIG. 1. Drawing (a)-(d) is an explanatory view showing the outline of the manufacturing process of the electrode member shown in Drawing 2 in order in the section in order. FIGS. 1A and 1B are partially cutaway cross-sectional views showing an embodiment of the illumination device of the present invention.

Explanation of symbols

L: Cold cathode fluorescent lamp 1: Glass tube bulb 11: Sealing part 4: Electrode member 5: Cup-like electrode 51: Opening side 52: Tip part 61: Sealing wire 9A, 9B: Lighting device

Claims (3)

A bottomed cylindrical cup-shaped electrode formed by header processing and having a peripheral edge at the opening side extending inward;
A glass sealing wire connected by welding to the bottom side outer end surface of the cup-shaped electrode;
An electrode member comprising: A glass tube valve;
The electrode member according to claim 1, wherein the sealing wire portions are hermetically sealed at both ends of the valve;
A discharge medium enclosed in the bulb;
A cold cathode discharge lamp comprising: A housing;
A cold cathode discharge lamp according to claim 2 attached to the housing;
This cold cathode discharge lamp lighting circuit device;
A lighting device comprising:

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