JP3113295U - Cold cathode lead - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent electrical and mechanical stability by filling a gap between a cylindrical body and a rod-shaped body to prevent them from being joined while being inclined and to easily secure a desired welding strength. Provide an excellent cold cathode lead.
A joining member 6 is inserted into a gap c between an outer peripheral portion of a tip end of a rod-like body 3 and an inner peripheral portion of a cylindrical body 2. The joining member 6 is a ring-shaped member having a thickness dimension of 0.05 mm or more, and is made of a material mainly containing at least one of nickel (Ni) and kovar (Co). The laser beam L is irradiated to the outer peripheral surface of the cylindrical body 2 at the same time and in the same amount, and the joining member 6 immediately below the corresponding portion of the cylindrical body 2 is melted by the laser beam L, so that the welded portions 2a and 2b are formed. The cylindrical body 2 and the rod-shaped body 3 are fixed and connected electrically and mechanically.
[Selection] Figure 1

Description

  The present invention relates to a cold cathode lead wire suitable for use as a cold cathode of a cold cathode fluorescent lamp.

  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 cathode fluorescent lamp, or the like is used, and a backlight system in which light is applied from the back of the panel is known. In particular, in displays such as computers, a combination of a cold cathode fluorescent lamp and a light guide plate is the mainstream.

  The cold cathode fluorescent lamp includes 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. First, 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. This ultraviolet light excites the phosphor on the inner wall of the glass tube to emit visible light. With regard to the emission color (color temperature and chromaticity), various emission colors can be created by changing the type of phosphor.

  Here, a conventional example of a cold cathode lead will be specifically described with reference to FIG. In FIG. 2, only one cold cathode lead wire fitted to the glass tube 5 is shown. The cold cathode lead 1 includes a cylindrical body 2 having one end hollow, a conductive rod 3 partially inserted into the other end of the cylindrical body 2, and a tip of the rod 3 And an introduction wire 4 electrically welded to the opposite end.

  The cylindrical body 2 has an inner diameter of about 0.6 to 1.1 mm and an axial length of about 2.0 to 6.0 mm. For example, a sleeve made of nickel (Ni), molybdenum (Mo), or the like. It is a member. The rod-shaped body 3 is a cylindrical rod shape having an outer diameter of about 0.5 to 1.0 mm and an axial length of about 5.0 mm, and is made of a conductive metal such as molybdenum (Mo) or tungsten (W). The portion less than half from the tip, specifically about 2.0 mm from the tip, is inserted into the cylindrical body 2. The lead-in wire 4 is made of MnNi or Du or other various materials.

  In the cold cathode lead wire 1, the laser beam L is irradiated from two points of 180 ° on the outer periphery of the cylindrical body 2 toward the surface of the rod-shaped body 3, and welds 2 a and 2 b are formed by the thermal energy of the laser beam L. Is done. The welds 2a and 2b are formed over the surface of the rod-shaped body 3 through the cylindrical body 2. The cylindrical body 2 and the rod-shaped body 3 are electrically and mechanically connected and fixed by the welded portions 2a and 2b. In addition, since laser welding is performed in a non-contact manner with respect to the cylindrical body 2, there is an advantage that the cylindrical body 2 is not distorted with the welding operation.

Japanese Patent Application No. 2003-132843

  Incidentally, there is a slight gap c between the inner diameter of the cylindrical body 2 and the outer diameter of the rod-shaped body 3. For example, in the example shown in FIG. 2, the difference between the inner diameter of the cylindrical body 2 and the outer diameter of the rod-shaped body 3, that is, the gap c is about 0.1 to 0.4 mm. Considering that the inner diameter of the cylindrical body 2 is 1.0 mm or less, it is difficult to say that the size of the gap c is negligible. The presence of this gap c has the following problems. That is, when the welded portions 2a and 2b are formed by irradiation with the laser beam L, the rod-shaped body 3 is shaken in the cylindrical body 2 by the gap c, and the axis of the cylindrical body 2 and the rod-shaped body There was a risk that the axis 3 would shift. As a result, the rod-shaped body 3 is connected and fixed while being tilted with respect to the cylindrical body 2.

  When the rod-like body 3 is tilted and fixed to the cylindrical body 2, when the cold cathode lead wire 1 is attached to the glass tube 5, not only the connection failure occurs between both, but the cylindrical body 2 and the glass tube 5 are required. There was a risk of damaging both sides by making strong contact. For this reason, the electrical connection between the glass tube 5 and the cold cathode lead wire 1 becomes unstable, causing various problems such as impeding the flow of a desired current during discharge and shortening the life of the cold cathode fluorescent lamp. It was.

  Further, a high melting point material such as molybdenum (Mo) or tungsten (W) is often used for the material of the cylindrical body 2 or the rod-shaped body 3. Therefore, even if it welds with the laser beam L, welding work is difficult, there exists a possibility that the welding strength of the cylindrical body 2 and the rod-shaped body 3 may not reach a prescribed intensity | strength, and it becomes a problem that dispersion | variation arises in welding strength. It was. Therefore, conventionally, it has been strongly desired to avoid the poor welding strength between the cylindrical body 2 and the rod-shaped body 3 and to stabilize the performance of the cold cathode lead wire 1.

  The present invention has been proposed in order to solve the above-described problems of the prior art, and its purpose is to fill the gap between the cylindrical body and the rod-shaped body so that the two are inclined and joined. An object of the present invention is to provide a cold cathode lead wire that is excellent in electrical and mechanical stability by preventing the occurrence of the damage and easily ensuring a desired welding strength.

  In order to achieve the above object, the invention according to claim 1 is a cold cathode lead provided with a rod-like body partially welded with a lead wire and a cylindrical body into which a tip portion of the rod-like body can be inserted. In the wire, a joining member for joining the rod-shaped body and the cylindrical body is inserted into a gap between the outer peripheral portion of the distal end portion of the rod-shaped body and the inner circumferential portion of the cylindrical body, and the rod-shaped body, The cylindrical body and the joining member are laser welded or resistance welded.

  In the above present invention, by inserting the joining member into the gap between the outer peripheral portion of the rod-shaped body and the inner peripheral portion of the cylindrical body, the deviation of the axis of the rod-shaped body and the cylindrical body that occurs during manufacturing is suppressed, The rod-shaped body is not connected or fixed while being tilted with respect to the cylindrical body. Therefore, when attaching a cold cathode lead wire to a glass tube, both connection failure and damage can be avoided. As a result, the electrical and mechanical stability of the cold cathode lead can be increased.

  According to a second aspect of the present invention, in the cold cathode lead according to the first aspect, the joining member is made of a material mainly containing at least one of nickel and kovar.

  In the invention of claim 2, by using a low melting point material mainly containing at least one of nickel and kovar, not a high melting point material such as molybdenum or tungsten, as a member for joining the rod-shaped body and the cylindrical body, The joining member can be easily melted by laser welding or resistance welding. For this reason, it is possible to ensure a desired welding strength, and to suppress the variation in welding strength between the rod-shaped body and the tubular body, thereby improving the productivity of the cold cathode lead wire.

  As described above, according to the cold cathode lead wire of the present invention, an extremely simple configuration in which a joining member is inserted into a gap between the rod-shaped body and the cylindrical body, and the tilt of the rod-shaped body with respect to the cylindrical body is produced. Defects can be prevented, and the electrical and mechanical stability of the cold cathode lead wire can be increased, contributing to longer life and higher quality of the cold cathode fluorescent lamp in which the cold cathode lead wire is incorporated. It is.

Embodiment of the invention

  Hereinafter, an embodiment of the present invention will be specifically described with reference to FIG. In addition, about the member same as the member shown in the prior art example of FIG. 2, the same code | symbol is attached | subjected and description is abbreviate | omitted.

[Configuration of representative embodiment]
The structural features of the cold cathode lead 1 according to the present embodiment are such that the outer peripheral portion of the distal end portion of the rod-shaped body 3 and the inner periphery of the cylindrical body 2 so as to cover the insertion portion of the rod-shaped body 3 with respect to the cylindrical body 2. The bonding member 6 is inserted into the gap c with the portion. The joining member 6 is a ring-shaped member having a thickness dimension of 0.05 mm or more, and is made of a material mainly containing at least one of nickel (Ni) and kovar (Co).

  In the present embodiment, similarly to the conventional example shown in FIG. 2, laser light L is emitted from a laser welding apparatus (not shown) from two points on the outer periphery of the cylindrical body 2 at an angle of 180 °. The laser beam L collected by the condenser lens is irradiated to the outer peripheral surface of the cylindrical body 2 at the same time and in the same amount. At this time, the joining member 6 immediately below the corresponding portion of the cylindrical body 2 is melted by the thermal energy emitted by the laser light L, and welds 2a and 2b are formed, so that the cylindrical body 2 and the rod-shaped body 3 are electrically Fixed and connected mechanically.

[Operational effects of this embodiment]
In the present embodiment as described above, since the joining member 6 is inserted into the gap c between the outer peripheral portion of the rod-like body 3 and the inner peripheral portion of the cylindrical body 2, the cylinder is used when performing laser welding. The rod-shaped body 3 is not shaken in the rod-shaped body 2, and there is no fear that the axis of the cylindrical body 2 and the axis of the rod-shaped body 3 are shifted. Therefore, the cylindrical body 2 and the rod-shaped body 3 can be connected and fixed in a parallel state. For this reason, when the cold cathode lead wire 1 is attached to the glass tube 5, it is possible to avoid both poor connection and damage. As a result, the electrical and mechanical stability of the cold cathode lead wire 1 can be improved, which contributes to extending the life and quality of the cold cathode fluorescent lamp in which the cold cathode lead wire 1 is incorporated.

  In the present embodiment, a material mainly containing at least one of nickel (Ni) and kovar (Co) is used as the material of the joining member 6. This material is a low melting point material having a melting point lower by 1000 ° C. or more than molybdenum (Mo) or tungsten (W). Therefore, the joining member 6 can be easily melted by laser welding. Therefore, variation in the welding strength between the rod-like body 3 and the cylindrical body 2 can be suppressed, and a stable welding strength can always be secured to improve the productivity of the cold cathode lead wire 1.

[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 material of the joining member 6 is not limited to a material mainly containing at least one of nickel and kovar, and various materials can be used. Further, the shape of the bonding agent 6 can also be freely selected, and for example, it may be a wedge shape whose thickness dimension decreases in the insertion direction.

  Further, the cylindrical portion 2 may be a prismatic cylindrical portion, and the rod-like portion 3 and the joining member 6 can be appropriately selected in a shape corresponding to the shape of the inner diameter portion of the cylindrical portion, The diameter of these members is also free. Further, the type of the cylindrical body 2 can be replaced as long as it has electron emission characteristics. In addition, the surface of the cylindrical body 2 may be configured by applying and coating a substance that enhances the light emission characteristics, such as lanthanum boride (LaB6).

  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. Moreover, 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, the 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.

  In the above embodiment, the welded portions 2a and 2b are provided at two positions at an angle of 180 ° within 1.0 mm from the tip E of the cylindrical body 2 in consideration of the accuracy of electrical and mechanical connection. However, this setting location may be within the range where the cylindrical body 2 and the rod-shaped body 3 overlap, that is, within the range indicated by the arrow R in FIG. 1. The number is not limited to two, and may be one or three or more. Furthermore, the cylindrical body 2, the rod-shaped body 3, and the joining member 6 may be fixed and connected not by laser welding but by resistance welding.

1 is a plan view of a representative embodiment according to the present invention. The top view of the conventional cold cathode lead wire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cold cathode lead wire 2 ... Cylindrical body 3 ... Rod-shaped body 4 ... Lead-in wire 5 ... Glass tube 6 ... Joining member L ... Laser beam c ... Gap

Claims (2)

In the cold cathode lead wire provided with a rod-like body welded to a part of the lead wire and a cylindrical body into which the tip of the rod-like body can be inserted,
A joining member for joining the rod-shaped body and the cylindrical body is inserted into a gap between the outer peripheral portion of the tip of the rod-shaped body and the inner circumferential portion of the cylindrical body,
The cold cathode lead wire, wherein the rod-like body, the cylindrical body, and the joining member are laser-welded or resistance-welded.   2. The cold cathode lead according to claim 1, wherein the joining member is made of a material mainly containing at least one of nickel and kovar.

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