JPWO2009025073A1 - Electrode pin for discharge lamp and method for manufacturing the same, electrode structure, cold cathode fluorescent lamp and method for manufacturing the same, lighting device and liquid crystal display device - Google Patents

Abstract

The discharge lamp electrode pin (22) is an electrode pin sealed to the end (10a) of the glass bulb (10), and is formed of the electrode pin body (21) and the surface of the electrode pin body (21). The groove (30) straddling the line (37) along the longitudinal direction (35) of the electrode pin body (21) is provided at a position sealed to the end (10a) of the glass bulb (10).

Description

  The present invention relates to an electrode pin for a discharge lamp and a manufacturing method thereof, an electrode structure, a cold cathode fluorescent lamp and a manufacturing method thereof, an illumination device, and a liquid crystal display device.

Currently, a cold cathode fluorescent lamp (CCFL) is mainly used as a light source of a backlight unit of a liquid crystal display device. The electrode portion of the cold cathode fluorescent lamp is composed of an electrode portion, an electrode pin (sealing wire portion), and an external lead wire (see, for example, Patent Document 1). In recent years, due to the demand for larger screens, thinner screens, higher brightness and lower power consumption in LCD televisions, cold cathode fluorescent lamps are longer (1000 mm or more in the long case) and thinner (in the thin case). Is required to be brighter and more efficient.
Japanese Patent Laid-Open No. 2004-234891

  The electrode pin (encapsulation rod) of the electrode portion in the cold cathode fluorescent lamp is composed of a tungsten rod. Since tungsten has a high melting point, it cannot be formed by a method such as forging, but is manufactured by a so-called powder metallurgy method in which powder is formed and sintered. This sintered body is formed into a rod shape by rolling or drawing, but cracks and streaks in the longitudinal direction are likely to occur during the processing.

  If such longitudinal cracks and streaks are present in the electrode pins, they cannot be completely sealed with glass, so that air flows into the discharge lamp tube through these defects, which contributes to defective products. Usually, such defective electrode pins are essentially eliminated by inspection.

  However, even if the defect rate can be reduced to an error of the order of a few [ppm] by the inspection, cold cathode fluorescent lamps are used for backlights with a few [10] to a dozen [books]. The value of the error of the defect rate increases. In recent years, liquid crystal display devices are used not only for PC monitors but also for many televisions, and require a high degree of reliability that can withstand long-term use for tens of thousands of hours.

  On the other hand, cold cathode fluorescent lamps are required to be manufactured at a low cost, and are in a situation where long life and high reliability must be satisfied without using complicated structures and expensive members. Is the actual situation. As a result of intensive studies under such circumstances, the inventors of the present application have found a configuration that can realize a long life and high reliability with a simple configuration, and have reached the present invention.

  The present invention has been made to solve the above problems, and has a highly reliable discharge lamp electrode pin and method for manufacturing the same, an electrode structure, a cold cathode fluorescent lamp and a method for manufacturing the same, an illumination device, and a liquid crystal display device The main purpose is to provide

  In order to achieve the above object, the present invention employs the following configurations.

[Electrode pins for discharge lamps]
The discharge lamp electrode pin according to the present invention is a discharge lamp electrode pin sealed to an end of a glass bulb. And the electrode pin for discharge lamps concerning this invention is along the longitudinal direction of the said electrode pin main body in the location sealed by the edge part of the said glass bulb | bulb among the electrode pin main body and the surface of the said electrode pin main body. And a groove across the line. Here, as a specific example of the groove, it is possible to adopt a configuration in which the groove pivots around the axis of the electrode pin main body in a substantially circular state.

  In the discharge lamp electrode pin according to the present invention, a configuration in which the groove is formed in a spiral shape on the surface of the electrode pin main body can be adopted.

  In the discharge lamp electrode pin according to the present invention, a configuration in which the spiral groove is formed 2 or more turns on the surface of the electrode pin main body can be adopted.

  Moreover, in the electrode pin for discharge lamps according to the present invention, it is possible to adopt a configuration in which the groove is formed in an annular shape in which one end and the other end are connected on the surface of the electrode pin main body.

  Moreover, in the electrode pin for discharge lamps according to the present invention, it is possible to adopt a configuration in which the annular groove is formed 2 or more on the surface of the electrode pin main body.

  Moreover, in the electrode pin for a discharge lamp according to the present invention, the groove has a recess recessed from the surface of the electrode pin body, and a protrusion connected to the recess and projecting from the surface of the electrode pin body. It is possible to adopt a configuration comprising

  The discharge lamp electrode pin according to the present invention may employ a configuration in which the electrode pin is created by rolling or drawing.

  Moreover, in the electrode pin for discharge lamps according to the present invention, a configuration in which the electrode pin is made of tungsten (W) or molybdenum (Mo) can be employed.

  Moreover, in the electrode pin for discharge lamps according to the present invention, it is possible to adopt a configuration in which the electrode pin is composed of an alloy of iron (Fe) and nickel (Ni).

  In the discharge lamp electrode pin according to the present invention, the groove may be formed by laser processing.

  Further, the discharge lamp electrode pin according to the present invention may employ a configuration in which a lead wire is connected to one end of the electrode pin main body.

Moreover, in the electrode pin for discharge lamps according to the present invention, it is possible to adopt a configuration in which the lead wire is made of nickel.
[Electrode structure]
The electrode structure according to the present invention has the electrode pin for a discharge lamp according to the present invention, a lead wire is connected to one end of the electrode pin body, and a cup electrode is connected to the other end. The configuration can be adopted.

  Moreover, in the electrode structure which concerns on the said invention, the structure that the glass bead is sealed on the surface of the said electrode pin main body is employable.

[Cold cathode fluorescent lamp]
The cold cathode fluorescent lamp according to the present invention includes a glass bulb, a phosphor layer formed on the inner surface of the glass bulb, and the discharge lamp electrode pin according to the present invention.

  Moreover, in the cold cathode fluorescent lamp according to the present invention, it is possible to adopt a configuration in which the glass bulb is made of borosilicate glass.

[Lighting device]
The illumination device according to the present invention includes the cold cathode fluorescent lamp according to the present invention.

[Liquid Crystal Display]
A liquid crystal display device according to the present invention includes the illumination device according to the present invention.

[Method of manufacturing electrode pin for discharge lamp]
A method for manufacturing an electrode pin for a discharge lamp according to the present invention is a method for manufacturing an electrode pin for a discharge lamp, the step (a) of preparing an electrode pin body, and the electrode pin body A step (b) of forming a groove across the line along the longitudinal direction. Here, in the method for manufacturing a discharge lamp electrode pin according to the present invention, as a specific example of the recess, it is possible to employ a groove that turns in a state of substantially making a round around the axis.

  In the method for manufacturing a discharge lamp electrode pin according to the present invention, a configuration in which the step (b) is performed by a laser processing method can be adopted.

  In the method for manufacturing an electrode pin for a discharge lamp according to the present invention, a configuration is adopted in which the groove is formed in a spiral shape while rotating the electrode pin main body about the central axis in the longitudinal direction. be able to.

  In the method for manufacturing an electrode pin for a discharge lamp according to the present invention, the groove is formed in an annular shape in which one end and the other end are connected while rotating the electrode pin body about the central axis in the longitudinal direction. It is possible to adopt a configuration of performing.

  In the method for manufacturing an electrode pin for a discharge lamp according to the present invention, the step (a) includes a sub-step of extending the metal material constituting the electrode pin main body by rolling or drawing. Can be adopted.

  Moreover, in the manufacturing method of the electrode pin for discharge lamps concerning the said invention, the structure that the material which comprises the said electrode pin main body is tungsten or molybdenum is employable.

[Cold cathode fluorescent lamp manufacturing method]
In the method for manufacturing a cold cathode fluorescent lamp according to the present invention, the step (a) of preparing the electrode pin main body and the step of forming a groove across the line along the longitudinal direction of the electrode pin main body on the surface of the electrode pin main body. (B), a step of connecting a lead wire to one end of the electrode pin main body, a step of connecting a cup electrode to the other end of the electrode pin main body, and the groove formed in the electrode pin main body. Welding a glass member to the region.

  According to the electrode pin for a discharge lamp according to the present invention, a groove extending over a line along the longitudinal direction of the electrode pin body is formed in a portion sealed on the end of the glass bulb in the surface of the electrode pin body. Therefore, the strength of the sealing portion can be improved, and as a result, a discharge lamp (cold cathode fluorescent lamp) having excellent reliability can be provided.

  In addition, according to the electrode structure according to the present invention, since the discharge lamp electrode pin according to the present invention is employed, the above effect can be obtained as it is.

  According to the cold cathode fluorescent lamp according to the present invention, since the discharge lamp electrode pin according to the present invention is employed, the above effect can be obtained as it is.

  Moreover, according to the illuminating device which concerns on this invention, since the cold cathode fluorescent lamp which concerns on the said invention is employ | adopted, the said effect can be acquired as it is.

  Moreover, according to the liquid crystal display device according to the present invention, since the illumination device according to the present invention is employed as a backlight, high display quality can be ensured.

  According to the method for manufacturing a discharge lamp electrode pin according to the present invention, it is possible to manufacture the discharge lamp electrode pin according to the present invention in which the above-described effects can be obtained without increasing the number of members.

Further, in the method for manufacturing a cold cathode fluorescent lamp according to the present invention, a cold cathode fluorescent lamp is manufactured using the discharge lamp electrode pin manufactured through the same steps as the method for manufacturing the discharge lamp electrode pin according to the present invention. Therefore, it is possible to manufacture the cold cathode fluorescent lamp according to the present invention, which can obtain the above effects, without increasing the number of members.

It is sectional drawing which shows typically the cold cathode fluorescent lamp 100 which concerns on Embodiment 1 of this invention. 3 is an enlarged view of an insertion portion 17 in the cold cathode fluorescent lamp 100. FIG. It is the figure which showed the structure of the electrode pin 22 typically. 3 is a cross-sectional view around a groove 30. FIG. 3 is a cross-sectional view around a groove 30. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. It is a drawing substitute photograph which shows the structure of an experiment sample. It is sectional drawing for demonstrating the structure of an experimental sample. It is a drawing substitute photograph which shows the result of an intensity | strength experiment. It is a drawing substitute photograph which shows the result of an intensity | strength experiment. (A) to (d) are process cross-sectional views for explaining a manufacturing method of the cold cathode fluorescent lamp 100 according to the first embodiment. (A) to (c) are process cross-sectional views for explaining a manufacturing method of the cold cathode fluorescent lamp 100 according to the first embodiment. (A) to (c) are process cross-sectional views for explaining a manufacturing method of the cold cathode fluorescent lamp 100 according to the first embodiment. It is a disassembled perspective view which shows the structure of the illuminating device 400 which concerns on Embodiment 2. FIG. It is a perspective view (partially cutaway sectional view) showing a configuration of lighting apparatus 500 according to Embodiment 3. 10 is a perspective view (partially cutaway cross-sectional view) showing a configuration of a liquid crystal display device 700 according to Embodiment 4. FIG.

Explanation of symbols

10. Glass bulb 10a. End of glass bulb 12. Phosphor layer 15. Bead glass 17. Insertion part 20. Electrode structure 21. Electrode pin body 22. Electrode pin for discharge lamp 24. Cup electrode 26. External lead wire 30. Groove 30. Longitudinal direction 55. Defect 100. Cold cathode fluorescent lamp 400,500. Lighting device 700. Liquid crystal display

In order to improve the adhesion between the electrode pin (encapsulation rod) of the electrode part and the end of the glass bulb in the cold cathode fluorescent lamp (that is, the strength at the part where the bead glass is applied), When a groove is formed on the peripheral surface of a discharge lamp electrode pin made of tungsten or the like by laser processing or the like, the bonding strength between the discharge lamp electrode pin and the glass bulb at the insertion portion is remarkably improved. The present inventors have found that this can be done, and have reached the present invention based on the knowledge.
[Embodiment 1]
Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. In the following drawings, components having substantially the same function are denoted by the same reference numerals for the sake of brevity. In addition, this invention is not limited to the following embodiment.

1. Cold cathode fluorescent lamp 100, electrode structure 20, and discharge lamp electrode pin 22
The cold cathode fluorescent lamp 100, the electrode structure 20, and the discharge lamp electrode pin 22 according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view schematically showing a configuration of a cold cathode fluorescent lamp 100 of the present embodiment (hereinafter simply referred to as “cold cathode fluorescent lamp 100”), and FIG. It is the figure which expanded and showed the edge part 10a sealed with the bead glass 15. FIG. FIG. 3 is a diagram schematically showing the configuration of a discharge lamp electrode pin 22 (hereinafter referred to as “electrode pin 22”) included in the cold cathode fluorescent lamp 100.

  The cold cathode fluorescent lamp 100 includes a glass bulb 10, a phosphor layer 12 formed on the inner surface of the glass bulb 10, and an electrode structure 20. The glass bulb 10 is made of a glass tube whose end 10 a is sealed with a bead glass 15, and mercury (Hg) is sealed inside the glass bulb 10. The phosphor layer 12 is composed of phosphor powder and a binder (binder), for example.

  The electrode structure 20 is a combination of a rod-shaped electrode pin main body 21, an electrode 24 connected to one end of the electrode pin main body 21, and an external lead wire 26 connected to the other end of the electrode pin main body 21. It is configured. In the cold cathode fluorescent lamp 100, the electrode 24 is located inside the glass bulb 100, and the external lead wire 26 is located outside the glass bulb 100. Further, the electrode pin and the external lead wire may be collectively referred to as a discharge lamp electrode pin.

  The electrode pin 22 is fixed to the end 10 a of the glass bulb 10 via the bead glass 15. Specifically, it is provided in a state of penetrating a portion sealed by the bead glass 15, and the end portion 10 a of the glass bulb 10 is formed by attaching the bead glass 15 to the peripheral surface at this portion. It is fixed to. The electrode pin 22 is made of, for example, tungsten (W) or molybdenum (Mo), and the electrode pin 22 included in the cold cathode fluorescent lamp 100 according to the present embodiment is made of tungsten (W) as an example. It is a pin.

  The electrode 24 is made of nickel (Ni), niobium (Nb), molybdenum (Mo), tungsten (W), etc., and the electrode 24 of the cold cathode fluorescent lamp 100 according to the present embodiment is, for example, present. It is a bottom cylindrical cup electrode and is made of nickel (Ni). The external lead wire 26 is made of, for example, nickel (Ni) or dumet, and the external lead wire 26 of the cold cathode fluorescent lamp 100 according to the present embodiment is, for example, a metal made of nickel (Ni). Is a line.

The electrode pin 22 according to the present embodiment has a longitudinal direction 35 of the electrode pin main body 21 in the electrode pin main body 21 and a portion 17 of the surface of the electrode pin main body 21 that is sealed to the end portion 10a of the glass bulb 10. And a groove 30 straddling a line extending along the line (virtual line 37 parallel to the longitudinal direction 35 in FIG. 3). In other words, in the configuration of the present embodiment, the groove 30 is formed in the portion of the surface of the electrode pin main body 21 that is welded by the bead glass.
More specifically, the electrode pin 22 has, for example, a direction 35 (virtual line in FIG. 3) along the central axis in a region of the peripheral surface where the bead glass 15 is attached (sealed portion 17). A groove 30 extending in a direction intersecting with (a direction along 37) is formed. For example, the groove 30 may be configured to extend in a state of substantially making a round of the central axis of the electrode pin main body 21.

  The bead glass 15 is a glass member for sealing the end portion 10a of the glass bulb 10 and for fixing the electrode pin 22 to the end portion 10a of the glass bulb 10, and is made of, for example, borosilicate glass. . In the cold cathode fluorescent lamp 100 according to the present embodiment, the glass bulb 10 is made of borosilicate glass as an example. Borosilicate glass is preferred because it is a glass with a reduced alkali component, and therefore adverse effects on the phosphor layer 12 can be reduced.

The groove 30 formed on the surface of the electrode pin main body 21 is, for example, a spiral groove. The groove 30 is formed by laser processing that irradiates the surface of the electrode pin main body 21 made of tungsten (W) with a laser (for example, a YAG laser or a CO ₂ laser).

  In the example shown in FIGS. 1 to 3, the groove 30 is formed in a spiral shape with respect to the surface of the electrode pin main body 21, and in particular, 2 [winding] or more (for example, 2 [winding], 3 [winding]) 4 [winding], 6 [winding], or more), the surface of the electrode pin body 21 is formed.

In the case of the spiral groove 30, it is formed so as to straddle a line along the longitudinal direction 35 of the electrode pin main body 21. Specifically, for example, it is a direction that intersects with the longitudinal direction 35 of the electrode pin main body 21 and is swung in a state of substantially making a round around the axis.
In addition, as the groove | channel 30, it is also possible to form the cyclic | annular groove | channel which the other end of the groove | channel connected other than the spiral thing as shown in FIGS. 1-3, for example. The annular groove is formed of, for example, 2 [pieces] or more.

  The depth of the groove 30 is, for example, 0.5 [μm] or more. When the groove 30 is formed by laser processing, the depth of the groove 30 can be set to, for example, 3 [μm] to 50 [μm]. Further, the opening width of the groove 30 can be a width that allows the bead glass 15 to easily enter, for example, a width of 5 [μm] or more. In addition, Preferably, the opening width of the groove | channel 30 exists in the range of 5 [micrometers] or more and 70 [micrometers] or less.

  As shown in FIG. 3, the interval d (or pitch) between the spiral grooves 30 can be, for example, 10 [μm] to 500 [μm], and the spiral grooves 30 are formed. The length a (the length along the longitudinal direction 35) of the region can be set to, for example, 0.3 [mm] to 1.5 [mm]. Alternatively, the length a of the region in which the spiral groove 30 is formed may be a predetermined ratio (for example, 10 [%] to 50 [%]) with respect to the length L in the longitudinal direction 35 of the electrode pin main body 21. it can. However, the shape and size (depth, interval d, length a, spiral length, etc.) of the groove 30 are determined according to various conditions (material and shape (diameter, length, etc.) of the electrode pin main body 21 and the sealing portion 17. Any suitable material can be employed in accordance with the welding conditions.

2. Cross-sectional shape of groove 30 formed on the surface of electrode pin main body 21 The cross-sectional shape of groove 30 formed on the surface of electrode pin main body 21 will be described with reference to FIG.

  As shown in FIG. 4, a groove 30 is formed on the surface of the electrode pin main body 21 so as to straddle a line 37 along the longitudinal direction 35 of the electrode pin main body 21. Then, a part of the bead glass 15 is inserted, whereby the sealing strength (sealability) between the electrode pin 22 (or the electrode pin main body 21) and the bead glass 14 can be improved.

  More specifically, since the electrode pin main body 21 (for example, a pin made of tungsten (W)) and the bead glass 15 have different coefficients of thermal expansion, they are invisible levels between them. However, a slight gap can occur. Due to the influence of the gap, there is an increased possibility that a leak (that is, communication between the inside of the glass bulb 10 and the atmosphere) 50 of the sealing portion 17 occurs. However, if the groove 30 is formed on the surface of the electrode pin main body 21, the groove Since the bead glass 15 is inserted into the 30 recesses, the occurrence of the leak 50 can be prevented or reduced.

  In particular, when the groove 30 is formed by laser processing, the groove 30 is formed by melting a metal (for example, tungsten (W)). Therefore, as shown in FIG. It can be provided. That is, the groove 30 has a shape including a concave portion that is recessed from the surface of the electrode pin main body 21 and a convex portion that is connected to the concave portion and protrudes from the surface of the electrode pin main body 21 with respect to the center of the cross section. be able to. By adopting such a configuration, the effect of suppressing the occurrence of leak 50 between the electrode pin main body 21 and the bead glass 15 can be improved.

3. Discharge lamp electrode pins 22 and grooves 30
Next, the discharge lamp electrode pin 22 and the groove 30 of the cold cathode fluorescent lamp 100 according to the first embodiment will be further described with reference to FIGS. 6 to 10 are perspective views schematically showing the configuration of the electrode pin 22.

  As described above, when the electrode pin 22 (or the electrode pin body 21) is made of tungsten (W) or molybdenum (Mo), the electrode pin 22 (or the electrode pin body 21) is made of tungsten (W). Alternatively, it is produced by extending molybdenum (Mo) by rolling or drawing. In this case, as shown in FIG. 6, a defect 55 (for example, a micro crack parallel to the drawing direction) 55 extending along the longitudinal direction 35 of the electrode pin main body 21 may exist on the surface 21 a of the electrode pin main body 21. . When this defect 55 exists, there is a high possibility that a leak due to a gap due to this defect 55 occurs.

  In the cold cathode fluorescent lamp 100 according to the present embodiment, as shown in FIG. 7, a spiral groove 30 (that is, a line 37 along the longitudinal direction 35 of the electrode pin main body 21 is formed on the surface 21 a of the electrode pin main body 21. Since the straddling groove 30) is formed, the defect 55 extending along the longitudinal direction 35 of the electrode pin main body 21 can be cut off by the groove 30. As described with reference to FIGS. 4 and 5, the bead glass 15 as a part of the glass bulb 10 enters the inside of the groove 30.

  Therefore, in the cold cathode fluorescent lamp 100 according to the present embodiment, by forming the groove 30 on the surface of the electrode pin main body 21, a leak 50 (for example, a leak over time after completion of the product) caused by the defect 55 is generated. Can solve the problem of slow leak).

  In view of the role of the groove 30 for cutting the defect 55 extending along the longitudinal direction 35 of the electrode pin main body 21, as shown in FIG. 8, the effect of preventing or suppressing the leak 50 can also be obtained by the annular groove 30. it can.

  If the defect 55 can be cut effectively, the effect of the present embodiment can be obtained even if the discontinuous groove 30 is formed as shown in FIG.

  On the other hand, as shown in FIG. 10, even a groove having a recess on the surface 21 a of the electrode pin main body 21 is a groove 32 parallel to the longitudinal direction 35 of the electrode pin main body 21 (that is, along the longitudinal direction 35. In the case of the groove 32) not intersecting with the line 37, the defect 55 extending along the longitudinal direction 35 of the electrode pin main body 21 cannot be cut off, so that the effect of preventing the leak 50 of the present embodiment cannot be obtained.

4). Sealing Strength Next, with reference to FIG. 11 to FIG. 14, the improvement of the sealing strength according to the configuration of the present embodiment will be described.

  The inventors of the present application formed an experimental sample shown in FIG. 11 for the experiment on the sealing strength, and measured the strength. As shown in FIG. 11, the experimental sample has a configuration in which the bead glass 15 is attached to the region where the groove 30 is formed on the surface of the electrode pin main body 21. The electrode pin 22 includes an electrode pin main body 21 in which a groove 30 is formed, and a lead wire (external lead wire) 26 connected to one end of the electrode pin main body 21. The diameters of the electrode pin main body 21 and the external lead wire 26 are each 0.8 [mm].

  Specifically, as shown in FIG. 12, after the electrode pin main body 21 and the external lead wire 26 are connected to each other by welding, the bead glass 15 is inserted so as to be supported by the welding hump 25 (arrow 60). Subsequently, the bead glass 15 is fused (attached) to the electrode pin main body 21. In this way, the experimental sample shown in FIG. 11 is produced. The electrode pin body 21 used in this experiment is made of tungsten (W), and the external lead wire 26 is made of nickel (Ni).

  The results of the sealing strength experiment are shown in FIG. 13 and FIG. In order to measure the sealing strength (adhesion strength) of the experimental sample shown in FIG. 11, when the external lead wire 26 is pulled to remove the bead glass 15 from the electrode pin main body 21, the bead glass 15 is detached. Previously, it was found that the nickel (Ni) external lead wire 26 was cut.

  A sample A shown in FIG. 13 has a spiral groove 30 (groove depth 10 [μm]) having 6 turns. Sample B has a spiral groove 30 with a turn number 3 (groove depth 10 [μm]), and sample C has a spiral groove 30 with a turn number 3 (groove depth 5). [Μm]) is formed.

  As a comparative example, the adhesion strength of an experimental sample in which no groove was formed on the surface of the electrode pin main body was examined. As shown in FIG. 14, when the external lead wire 26 was pulled, the bead glass 15 was removed from the discharge lamp electrode pin. The external lead wire 26 was not cut. The breaking strength at this time (breaking strength of the comparative example) was an average strength of 192.7 [N] (Weibull coefficient 22.9). Therefore, the breaking strength when the groove 30 is formed is much higher than that (actually, the adhesive strength was excellent enough to cause the external lead wire 26 to be cut, so the breaking strength could not be measured. ).

  Next, the inventors of the present application produced a cold cathode fluorescent lamp 100 having electrode pins 22 and performed an evaluation experiment in which thermal stress was applied to the cold cathode fluorescent lamp 100. This experiment was performed as follows.

  First, the external lead wire 26 portion of the cold cathode fluorescent lamp 100 is immersed in solder held at 350 [° C.] for 30 [seconds] and then cooled to room temperature by natural cooling 10 [times] repeatedly. It was. After repeatedly applying thermal stress to the sealing part 17 in this way, the lamp 100 was held in the atmosphere of 10 [atmospheric pressure] for 48 [hours]. Then, the lighting experiment of the cold cathode fluorescent lamp 100 was conducted. As a result, it was found that in the cold cathode fluorescent lamp 100 provided with the electrode pin 20 of the present embodiment, all the samples are turned on and show the designed brightness and emission spectrum. On the other hand, in the cold cathode fluorescent lamp according to the prior art in which no groove is formed on the surface of the electrode pin main body (comparative example), the lighting does not occur at a rate of 1 [lines] to 3 [lines] in 100 [lines]. A sample was seen.

  Furthermore, the present inventors conducted an evaluation experiment in which bending stress is applied to the external lead wire 26 of the cold cathode fluorescent lamp 100 according to the present embodiment. This experiment was performed as follows. First, bending stress was applied to the sealing portion 17 by bending the external lead wire 26 of the cold cathode fluorescent lamp 100 at a right angle to the longitudinal direction 35 of the electrode pin body. Thereafter, the lamp 100 was kept in the atmosphere of 10 [atmospheric pressure] for 48 [hours], and a lighting experiment of the cold cathode fluorescent lamp 100 was performed in the same manner as described above. As a result, it was found that the cold cathode fluorescent lamp 100 provided with the electrode pins 22 of the present embodiment turned on all the samples and exhibited the designed brightness and emission spectrum. On the other hand, in the cold cathode fluorescent lamp according to the prior art in which no groove is formed on the surface of the electrode pin main body (comparative example), the lighting is not performed at a rate of 1 [lines] to 4 [lines] in 100 [lines]. A sample was seen.

5). Manufacturing Method of Cold Cathode Fluorescent Lamp 100 and Electrode Structure 20 Next, a manufacturing method of the cold cathode fluorescent lamp 100 and the electrode structure 20 according to the present embodiment will be described with reference to FIGS. 15 and 16. 15 and 16 are process cross-sectional views for explaining the manufacturing method according to the present embodiment.

  First, as shown in FIG. 15A, the electrode pin 22 having the groove 30 formed on the surface of the electrode pin main body 21 is produced. The electrode pin 22 in which the groove 30 is formed is prepared by preparing the electrode pin main body 21 and then forming the groove 30 across the line along the longitudinal direction 35 of the electrode pin main body 21 on the surface of the electrode pin main body 21. The The groove 30 is formed by laser processing (for example, using a YAG laser or a CO2 laser). However, as long as the groove 30 straddling the line along the longitudinal direction 35 of the electrode pin main body 21 can be formed, the method may be chemical etching or machining.

  The groove 30 can be obtained, for example, by forming a concave portion on the surface of the electrode pin main body 21 while rotating the electrode pin main body 21 around the central axis in the longitudinal direction. As described above, the groove 30 may be a spiral groove, an annular groove, or another shape. The electrode pin body 21 can be obtained by extending a constituent metal material (for example, tungsten (W)) by drawing or the like and cutting it to a predetermined length. Since the defect 55 along the longitudinal direction 35 of the electrode pin main body 21 may occur during the drawing process, it is preferable to execute the configuration of the present embodiment (formation of the groove 30).

  For example, in the electrode pin main body 21 made of an alloy of Fe and Ni, a defect 55 along the longitudinal direction 35 of the electrode pin main body 21 may be generated, so that the technique of adopting the configuration of the present embodiment is employed. There is a significant significance.

  Next, as shown in FIG. 15B, the external lead wire 26 is disposed at one end (for example, one end face) of the electrode pin main body 21 in which the groove 30 is formed. Next, as shown in FIG. 15C, the electrode pin main body 21 and the external lead wire 26 are connected by welding. Note that a welding hump 25 may be formed on one end side of the external lead wire 26 (on the electrode pin main body 21 side) by welding. Further, if the groove 30 is formed at a central portion in the longitudinal direction of the electrode pin main body 21, the connection direction between the electrode pin main body 21 and the external lead wire 26 is set to one end side and the other end side of the electrode pin main body 21. It is possible to obtain a merit in the manufacturing process that any of the above can be performed.

  Thereafter, as shown in FIG. 15D, the bead glass 15 is inserted into the electrode pin main body 21 in which the groove 30 is formed. At this time, the bead glass 15 is inserted so as to cover the groove 30. In the manufacturing method according to the present embodiment, the welding hump 25 is caused to function as a positioning member for the bead glass 15.

  Next, as shown in FIG. 16A, the bead glass 15 and the electrode pin main body 21 are welded. This welding is performed by heating the bead glass 15. Next, as illustrated in FIG. 16B, the electrode 24 is connected to the other end (for example, the other end surface) of the electrode pin main body 21 by welding to obtain the electrode structure 20.

  Although the degree of adhesion between the bead glass 15 and the electrode pin main body 21 may be reduced due to heat during welding of the electrode 24, the groove 30 is formed on the surface of the electrode pin main body 21 in the configuration according to the present embodiment. Therefore, the degree of adhesion is improved, and even when heat is generated during such welding, a decrease in the degree of adhesion between the bead glass 15 and the electrode pin main body 21 can be effectively suppressed.

  Next, as shown in FIG. 16C, the electrode structure 20 is inserted into the glass bulb 10 with the electrode 24 at the tip. Thereafter, the bead glass 15 and the glass bulb 10 provided in the electrode structure 20 are melted by heating, and both are brought into close contact and welded at the sealing portion 17, whereby the cold cathode fluorescent lamp according to the present embodiment. 100 is obtained.

  Before and after the step of inserting the electrode structure 20 into the glass bulb 10, the step of forming the phosphor layer 12 on the inner surface of the glass bulb 10, the step of introducing mercury into the glass bulb 10, the step of introducing enclosed gas, etc. Is executed.

6). Variation on Manufacturing Method of Cold Cathode Fluorescent Lamp 100 The cold cathode fluorescent lamp 100 according to the present embodiment can also be manufactured as shown in FIG.

  First, after performing the process shown in FIG. 15C, the cup electrode 24 is connected to the other end portion (for example, the other end surface) of the electrode pin main body 21 by welding as shown in FIG. 17A.

  Next, as shown in FIG. 17B, the bead glass 15 is welded to the electrode pin main body 21. Thereafter, as shown in FIG. 17C, the electrode structure 20 is inserted into the glass bulb 10 and welded to each other by the sealing portion 17, whereby the cold cathode fluorescent lamp 100 according to the present embodiment. Is obtained.

  Further, during the process of assembling the backlight from the cold cathode fluorescent lamp, a stress is applied to the external lead wire 26 of the cold cathode fluorescent lamp, and thereby, between the surface of the electrode pin main body 21 in the sealing portion 17 and the bead glass 15. Leakage may occur, but in the configuration according to the present embodiment, the groove 30 is formed on the surface of the electrode pin main body 21, thereby improving the adhesion strength at the sealing portion 17. The problem can be solved.

  In addition, in the configuration in which the lifetime of the backlight, and hence the life of the liquid crystal display device, is determined by the leakage of the cold cathode fluorescent lamp, in the configuration according to this embodiment, the life of the backlight and the life of the liquid crystal display device are determined. Can be improved.

  Furthermore, in the configuration according to the present embodiment, since the strength of the sealing portion 17 is improved by forming the groove 30, long life and high reliability can be achieved without using a complicated configuration or an expensive member. As a result, the technical value including the cost is very large.

Although the present invention has been described with reference to the preferred embodiment, such description is not a limitation, and various modifications can of course be made.
[Embodiment 2]
Illumination apparatus 400 according to Embodiment 2 of the present invention will be described with reference to FIG.

  As shown in FIG. 18, an illumination device 400 according to Embodiment 2 of the present invention is a direct-type backlight unit, and has a rectangular parallelepiped housing 401 having one surface opened, and the interior of the housing 401. A plurality of lamps 100, a socket 402 for electrical connection to a lighting circuit (not shown) for lighting the lamp 100, and an optical sheet 403 covering the opening of the housing 401. I have.

  Note that the cold cathode fluorescent lamp 100 according to the first embodiment is employed as the lamp 100 of the illumination device 400 according to the present embodiment.

  The casing 401 is made of, for example, polyethylene terephthalate (PET) resin, and a reflection surface 404 is formed on the inner surface thereof by vapor deposition of a metal such as silver (Ag).

  Note that as the material of the housing 401, a material other than a resin material, for example, a metal material such as aluminum (Al) or a cold-rolled material (for example, SPCC) can be used. Further, as the reflective surface 404 on the inner surface, in addition to the metal vapor-deposited film, for example, a reflective sheet whose reflectance is increased by adding calcium carbonate, titanium dioxide or the like to polyethylene terephthalate (PET) resin is attached to the housing 401. Things can also be used.

  Inside the casing 401, a socket 402, an insulator 405, and a cover 406 are disposed. The sockets 402 are provided at predetermined intervals in the lateral direction (vertical direction) of the housing 401 corresponding to the arrangement of the lamps 100. The socket 402 is formed by processing a plate material made of stainless steel or phosphor bronze, for example, and has a fitting portion 402a into which the external lead wire 104b is fitted. And the lead wire 103 is elastically deformed and fitted so as to push the fitting portion 402a. As a result, the external lead wire 103a fitted in the fitting part 402a is pressed by the restoring force of the fitting part 402a and is difficult to come off. As a result, the external lead wire 103a can be easily fitted into the fitting portion 402a, and can be made difficult to come off after being fitted at one end.

  The socket 402 is covered with an insulator 405 so as not to short-circuit between adjacent sockets 402. The insulator 405 is formed using, for example, polyethylene terephthalate (PET) resin.

  Note that the insulator 405 is not limited to the above structure.

  Since the socket 402 is disposed in the vicinity of the electrode 102 that is relatively hot during the operation of the lamp 100, the insulator 405 is preferably formed using a heat-resistant material. For example, a polycarbonate (PC) resin, silicone rubber, or the like can be used as a material for the heat-resistant insulator 405.

  Inside the housing 401, a lamp holder 407 may be provided at a place where necessary. The lamp holder 407 that fixes the position of the lamp 100 inside the housing 401 uses, for example, polycarbonate (PC) resin and has a shape that conforms to the outer surface shape of the lamp 100.

  Here, the “location as necessary” in the above is a case where the lamp 100 is long, for example, exceeding the total length of 600 [mm], such as near the center in the longitudinal direction of the lamp 100. In addition, this is a place necessary for eliminating the bending of the lamp 100.

  The cover 406 divides the socket 402 from the space inside the housing 401, and is made of, for example, polycarbonate (PC) resin. The cover 406 keeps the periphery of the socket 402 warm, and at least the housing 401 side. By making the surface highly reflective, a decrease in luminance at the end of the lamp 100 can be reduced.

  The opening of the housing 401 is covered with a translucent optical sheet 403 and is sealed so that foreign matter such as dust and dirt does not enter inside. The optical sheets 403 are configured by laminating a diffusion plate 408, a diffusion sheet 409, and a lens sheet 410.

  The diffusion plate 408 is, for example, a plate-like body configured using polymethyl methacrylate (PMMA) resin, and is disposed so as to close the opening of the housing 401. The diffusion sheet 409 is configured using, for example, a polyester resin. The lens sheet 410 is configured by, for example, pasting an acrylic resin and a polyester resin. These optical sheets 403 are disposed so as to be sequentially superimposed on the diffusion plate 408.

As described above, the illumination device 400 according to Embodiment 2 of the present invention is excellent in reliability.
[Embodiment 3]
An illumination device 500 according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 19 is a perspective view (partially cutaway view) of lighting apparatus 500 according to Embodiment 3 of the present invention.

  As shown in FIG. 19, an illumination device 500 according to Embodiment 3 of the present invention is an edge light type backlight unit, which includes a reflector 501, a lamp 100, a socket (not shown), a light guide plate 502, A diffusion sheet 503, a prism sheet 504, and the like are included.

  The reflection plate 501 is disposed so as to surround the periphery of the light guide plate 502 excluding the liquid crystal panel side (arrow Q), and includes a bottom surface portion 501 a that covers the bottom surface, and a curved lamp side surface portion 501 c that covers the periphery of the lamp 100. The light irradiated from the lamp 100 is reflected from the light guide plate 502 to the liquid crystal panel (not shown) side (arrow Q). The reflector 501 is made of, for example, a film-like polyethylene terephthalate (PET) vapor-deposited with silver (Ag) or a laminate of metal foil such as aluminum.

  The socket (not shown) has substantially the same configuration as the socket 402 used in the lighting device 400 according to the second embodiment.

  The light guide plate 502 guides the light reflected by the reflection plate 501 to the liquid crystal panel side. The light guide plate 502 is made of, for example, translucent plastic, and is laminated on the reflection plate 501 a provided on the bottom surface of the lighting device 500. ing. As a constituent material, polycarbonate (PC) resin, cycloolefin-based resin (COP), or the like can be used.

  The diffusion sheet 503 is for expanding the visual field, and is made of, for example, a film having a diffusion transmission function made of polyethylene terephthalate resin or polyester resin, and is laminated on the light guide plate 502.

  The prism sheet 504 is for improving luminance, and is made of, for example, a sheet obtained by bonding an acrylic resin and a polyester resin, and is laminated on the diffusion sheet 503. Note that a diffusion sheet 503 may be further stacked on the prism sheet 504.

  In the illumination device 500 according to Embodiment 3 of the present invention, a reflection sheet (not shown) is provided on the outer surface of the glass bulb 10 except for a part in the circumferential direction of the lamp 100 (the light guide plate 502 side when inserted into the illumination device 500). Aperture-type lamps provided with).

As described above, the illumination device 500 according to Embodiment 3 of the present invention is excellent in reliability.
[Embodiment 4]
A configuration of a liquid crystal display device 700 according to Embodiment 4 of the present invention will be described with reference to FIG.

  As shown in FIG. 20, a liquid crystal display device 700 according to the fourth embodiment of the present invention is, for example, a 32 [inch] liquid crystal television, and includes a liquid crystal screen unit 701 including a liquid crystal panel and the second embodiment. The lighting device 400 according to the above and a lighting circuit 702 are configured.

  The liquid crystal screen unit 701 is a known one and includes a liquid crystal panel (color filter substrate, liquid crystal, TFT substrate, etc .; not shown), and forms an image based on an image signal input from the outside.

  The lighting circuit 702 is a circuit for driving and driving the lamp 100 in the lighting device 400. The lamp 100 operates at a lighting frequency of 40 [kHz] to 100 [kHz] and a lamp current of 3.0 [mA] to 25 [mA].

  In the fourth embodiment of the present invention, the illumination device 400 is applied as an example of the illumination device of the liquid crystal display device 700. However, for example, the illumination device 500 can also be applied.

  As described above, in the liquid crystal display device 700 according to Embodiment 4 of the present invention, high display quality can be ensured.

  INDUSTRIAL APPLICABILITY The present invention is useful for realizing a discharge lamp (cold cathode fluorescent lamp), an illuminating device, and a liquid crystal display device having a simple configuration and excellent reliability.

  The present invention relates to an electrode pin for a discharge lamp and a manufacturing method thereof, an electrode structure, a cold cathode fluorescent lamp and a manufacturing method thereof, an illumination device, and a liquid crystal display device.

  Currently, a cold cathode fluorescent lamp (CCFL) is mainly used as a light source of a backlight unit of a liquid crystal display device. The electrode portion of the cold cathode fluorescent lamp is composed of an electrode portion, an electrode pin (sealing wire portion), and an external lead wire (see, for example, Patent Document 1). In recent years, due to the demand for larger screens, thinner screens, higher brightness and lower power consumption in LCD televisions, cold cathode fluorescent lamps are longer (1000 mm or more in the long case) and thinner (in the thin case). Is required to be brighter and more efficient.

Japanese Patent Laid-Open No. 2004-234891

  The electrode pin (encapsulation rod) of the electrode portion in the cold cathode fluorescent lamp is composed of a tungsten rod. Since tungsten has a high melting point, it cannot be formed by a method such as forging, and is manufactured by a so-called powder metallurgy method in which powder is formed and sintered. This sintered body is formed into a rod shape by rolling or drawing, but cracks and streaks in the longitudinal direction are likely to occur during the processing.

If such longitudinal cracks and streaks are present in the electrode pins, they cannot be completely sealed with glass, so that air flows into the discharge lamp tube through these defects, which contributes to defective products. Usually, such defective electrode pins are essentially eliminated by inspection.
However, even if the defect rate can be reduced to an error of the order of a few [ppm] by the inspection, cold cathode fluorescent lamps are used for backlights with a few [10] to a dozen [books]. The value of the error of the defect rate increases. In recent years, liquid crystal display devices are used not only for PC monitors but also for many televisions, and require a high degree of reliability that can withstand long-term use for tens of thousands of hours.

On the other hand, cold cathode fluorescent lamps are required to be manufactured at a low cost, and are in a situation where long life and high reliability must be satisfied without using complicated structures and expensive members. Is the actual situation. As a result of intensive studies under such circumstances, the inventors of the present application have found a configuration that can realize a long life and high reliability with a simple configuration, and have reached the present invention.
The present invention has been made to solve the above problems, and has a highly reliable discharge lamp electrode pin and method for manufacturing the same, an electrode structure, a cold cathode fluorescent lamp and a method for manufacturing the same, an illumination device, and a liquid crystal display device The main purpose is to provide

In order to achieve the above object, the present invention employs the following configurations.
[Electrode pins for discharge lamps]
The discharge lamp electrode pin according to the present invention is a discharge lamp electrode pin sealed to an end of a glass bulb. And the electrode pin for discharge lamps concerning this invention is along the longitudinal direction of the said electrode pin main body in the location sealed by the edge part of the said glass bulb | bulb among the electrode pin main body and the surface of the said electrode pin main body. And a groove across the line. Here, as a specific example of the groove, it is possible to adopt a configuration in which the groove pivots around the axis of the electrode pin main body in a substantially circular state.

In the discharge lamp electrode pin according to the present invention, a configuration in which the groove is formed in a spiral shape on the surface of the electrode pin main body can be adopted.
In the discharge lamp electrode pin according to the present invention, a configuration in which the spiral groove is formed 2 or more turns on the surface of the electrode pin main body can be adopted.

Moreover, in the electrode pin for discharge lamps according to the present invention, it is possible to adopt a configuration in which the groove is formed in an annular shape in which one end and the other end are connected on the surface of the electrode pin main body.
Moreover, in the electrode pin for discharge lamps according to the present invention, it is possible to adopt a configuration in which the annular groove is formed 2 or more on the surface of the electrode pin main body.

Moreover, in the electrode pin for a discharge lamp according to the present invention, the groove has a recess recessed from the surface of the electrode pin body, and a protrusion connected to the recess and projecting from the surface of the electrode pin body. It is possible to adopt a configuration comprising
The discharge lamp electrode pin according to the present invention may employ a configuration in which the electrode pin is created by rolling or drawing.

Moreover, in the electrode pin for discharge lamps according to the present invention, a configuration in which the electrode pin is made of tungsten (W) or molybdenum (Mo) can be employed.
Moreover, in the electrode pin for discharge lamps according to the present invention, it is possible to adopt a configuration in which the electrode pin is composed of an alloy of iron (Fe) and nickel (Ni).
In the discharge lamp electrode pin according to the present invention, the groove may be formed by laser processing.

Further, the discharge lamp electrode pin according to the present invention may employ a configuration in which a lead wire is connected to one end of the electrode pin main body.
Moreover, in the electrode pin for discharge lamps according to the present invention, it is possible to adopt a configuration in which the lead wire is made of nickel.
[Electrode structure]
The electrode structure according to the present invention has the electrode pin for a discharge lamp according to the present invention, a lead wire is connected to one end of the electrode pin body, and a cup electrode is connected to the other end. The configuration can be adopted.

Moreover, in the electrode structure which concerns on the said invention, the structure that the glass bead is sealed on the surface of the said electrode pin main body is employable.
[Cold cathode fluorescent lamp]
The cold cathode fluorescent lamp according to the present invention includes a glass bulb, a phosphor layer formed on the inner surface of the glass bulb, and the discharge lamp electrode pin according to the present invention.

Moreover, in the cold cathode fluorescent lamp according to the present invention, it is possible to adopt a configuration in which the glass bulb is made of borosilicate glass.
[Lighting device]
The illumination device according to the present invention includes the cold cathode fluorescent lamp according to the present invention.

[Liquid Crystal Display]
A liquid crystal display device according to the present invention includes the illumination device according to the present invention.
[Method of manufacturing electrode pin for discharge lamp]
A method for manufacturing an electrode pin for a discharge lamp according to the present invention is a method for manufacturing an electrode pin for a discharge lamp, the step (a) of preparing an electrode pin body, and the electrode pin body on the surface of the electrode pin body A step (b) of forming a groove across the line along the longitudinal direction. Here, in the method for manufacturing a discharge lamp electrode pin according to the present invention, as a specific example of the recess, it is possible to employ a groove that turns in a state of substantially making a round around the axis.

In the method for manufacturing a discharge lamp electrode pin according to the present invention, a configuration in which the step (b) is performed by a laser processing method can be adopted.
In the method for manufacturing an electrode pin for a discharge lamp according to the present invention, a configuration is adopted in which the groove is formed in a spiral shape while rotating the electrode pin main body about the central axis in the longitudinal direction. be able to.

In the method for manufacturing an electrode pin for a discharge lamp according to the present invention, the groove is formed in an annular shape in which one end and the other end are connected while rotating the electrode pin body about the central axis in the longitudinal direction. It is possible to adopt a configuration of performing.
In the method for manufacturing an electrode pin for a discharge lamp according to the present invention, the step (a) includes a sub-step of extending the metal material constituting the electrode pin main body by rolling or drawing. Can be adopted.

Moreover, in the manufacturing method of the electrode pin for discharge lamps concerning the said invention, the structure that the material which comprises the said electrode pin main body is tungsten or molybdenum is employable.
[Cold cathode fluorescent lamp manufacturing method]
In the method for manufacturing a cold cathode fluorescent lamp according to the present invention, the step (a) of preparing the electrode pin main body and the step of forming a groove across the line along the longitudinal direction of the electrode pin main body on the surface of the electrode pin main body. (B), a step of connecting a lead wire to one end of the electrode pin main body, a step of connecting a cup electrode to the other end of the electrode pin main body, and the groove formed in the electrode pin main body. Welding a glass member to the region.

According to the electrode pin for a discharge lamp according to the present invention, a groove extending over a line along the longitudinal direction of the electrode pin body is formed in a portion sealed on the end of the glass bulb in the surface of the electrode pin body. Therefore, the strength of the sealing portion can be improved, and as a result, a discharge lamp (cold cathode fluorescent lamp) having excellent reliability can be provided.
In addition, according to the electrode structure according to the present invention, since the discharge lamp electrode pin according to the present invention is employed, the above effect can be obtained as it is.

According to the cold cathode fluorescent lamp according to the present invention, since the discharge lamp electrode pin according to the present invention is employed, the above effect can be obtained as it is.
Moreover, according to the illuminating device which concerns on this invention, since the cold cathode fluorescent lamp which concerns on the said invention is employ | adopted, the said effect can be acquired as it is.
Moreover, according to the liquid crystal display device according to the present invention, since the illumination device according to the present invention is employed as a backlight, high display quality can be ensured.

According to the method for manufacturing a discharge lamp electrode pin according to the present invention, it is possible to manufacture the discharge lamp electrode pin according to the present invention in which the above-described effects can be obtained without increasing the number of members.
Further, in the method for manufacturing a cold cathode fluorescent lamp according to the present invention, a cold cathode fluorescent lamp is manufactured using the discharge lamp electrode pin manufactured through the same steps as the method for manufacturing the discharge lamp electrode pin according to the present invention. Therefore, it is possible to manufacture the cold cathode fluorescent lamp according to the present invention, which can obtain the above effects, without increasing the number of members.

It is sectional drawing which shows typically the cold cathode fluorescent lamp 100 which concerns on Embodiment 1 of this invention. 3 is an enlarged view of an insertion portion 17 in the cold cathode fluorescent lamp 100. FIG. It is the figure which showed the structure of the electrode pin 22 typically. 3 is a cross-sectional view around a groove 30. FIG. 3 is a cross-sectional view around a groove 30. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. 3 is a perspective view schematically showing a configuration of an electrode pin 22. FIG. It is a drawing substitute photograph which shows the structure of an experiment sample. It is sectional drawing for demonstrating the structure of an experimental sample. It is a drawing substitute photograph which shows the result of an intensity | strength experiment. It is a drawing substitute photograph which shows the result of an intensity | strength experiment. (A) to (d) are process cross-sectional views for explaining a manufacturing method of the cold cathode fluorescent lamp 100 according to the first embodiment. (A) to (c) are process cross-sectional views for explaining a manufacturing method of the cold cathode fluorescent lamp 100 according to the first embodiment. (A) to (c) are process cross-sectional views for explaining a manufacturing method of the cold cathode fluorescent lamp 100 according to the first embodiment. It is a disassembled perspective view which shows the structure of the illuminating device 400 which concerns on Embodiment 2. FIG. It is a perspective view (partially cutaway sectional view) showing a configuration of lighting apparatus 500 according to Embodiment 3. 10 is a perspective view (partially cutaway cross-sectional view) showing a configuration of a liquid crystal display device 700 according to Embodiment 4. FIG.

In order to improve the adhesion between the electrode pin (encapsulation rod) of the electrode part and the end of the glass bulb in the cold cathode fluorescent lamp (that is, the strength at the part where the bead glass is applied), When a groove is formed on the peripheral surface of a discharge lamp electrode pin made of tungsten or the like by laser processing or the like, the bonding strength between the discharge lamp electrode pin and the glass bulb at the insertion portion is remarkably improved. The present inventors have found that this can be done, and have reached the present invention based on the knowledge.
[Embodiment 1]
Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. In the following drawings, components having substantially the same function are denoted by the same reference numerals for the sake of brevity. In addition, this invention is not limited to the following embodiment.

1. Cold cathode fluorescent lamp 100, electrode structure 20, and discharge lamp electrode pin 22
The cold cathode fluorescent lamp 100, the electrode structure 20, and the discharge lamp electrode pin 22 according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view schematically showing a configuration of a cold cathode fluorescent lamp 100 of the present embodiment (hereinafter simply referred to as “cold cathode fluorescent lamp 100”), and FIG. It is the figure which expanded and showed the edge part 10a sealed with the bead glass 15. FIG. FIG. 3 is a diagram schematically showing the configuration of a discharge lamp electrode pin 22 (hereinafter referred to as “electrode pin 22”) included in the cold cathode fluorescent lamp 100.

  The cold cathode fluorescent lamp 100 includes a glass bulb 10, a phosphor layer 12 formed on the inner surface of the glass bulb 10, and an electrode structure 20. The glass bulb 10 is made of a glass tube whose end 10 a is sealed with a bead glass 15, and mercury (Hg) is sealed inside the glass bulb 10. The phosphor layer 12 is composed of phosphor powder and a binder (binder), for example.

  The electrode structure 20 is a combination of a rod-shaped electrode pin main body 21, an electrode 24 connected to one end of the electrode pin main body 21, and an external lead wire 26 connected to the other end of the electrode pin main body 21. It is configured. In the cold cathode fluorescent lamp 100, the electrode 24 is located inside the glass bulb 100, and the external lead wire 26 is located outside the glass bulb 100. Further, the electrode pin and the external lead wire may be collectively referred to as a discharge lamp electrode pin.

  The electrode pin 22 is fixed to the end 10 a of the glass bulb 10 via the bead glass 15. Specifically, it is provided in a state of penetrating a portion sealed by the bead glass 15, and the end portion 10 a of the glass bulb 10 is formed by attaching the bead glass 15 to the peripheral surface at this portion. It is fixed to. The electrode pin 22 is made of, for example, tungsten (W) or molybdenum (Mo), and the electrode pin 22 included in the cold cathode fluorescent lamp 100 according to the present embodiment is made of tungsten (W) as an example. It is a pin.

  The electrode 24 is made of nickel (Ni), niobium (Nb), molybdenum (Mo), tungsten (W), etc., and the electrode 24 of the cold cathode fluorescent lamp 100 according to the present embodiment is, for example, present. It is a bottom cylindrical cup electrode and is made of nickel (Ni). The external lead wire 26 is made of, for example, nickel (Ni) or dumet, and the external lead wire 26 of the cold cathode fluorescent lamp 100 according to the present embodiment is, for example, a metal made of nickel (Ni). Is a line.

The electrode pin 22 according to the present embodiment has a longitudinal direction 35 of the electrode pin main body 21 in the electrode pin main body 21 and a portion 17 of the surface of the electrode pin main body 21 that is sealed to the end portion 10a of the glass bulb 10. And a groove 30 straddling a line extending along the line (virtual line 37 parallel to the longitudinal direction 35 in FIG. 3). In other words, in the configuration of the present embodiment, the groove 30 is formed in the portion of the surface of the electrode pin main body 21 that is welded by the bead glass.
More specifically, the electrode pin 22 has, for example, a direction 35 (virtual line in FIG. 3) along the central axis in a region of the peripheral surface where the bead glass 15 is attached (sealed portion 17). A groove 30 extending in a direction intersecting with (a direction along 37) is formed. For example, the groove 30 may be configured to extend in a state of substantially making a round of the central axis of the electrode pin main body 21.

  The bead glass 15 is a glass member for sealing the end portion 10a of the glass bulb 10 and for fixing the electrode pin 22 to the end portion 10a of the glass bulb 10, and is made of, for example, borosilicate glass. . In the cold cathode fluorescent lamp 100 according to the present embodiment, the glass bulb 10 is made of borosilicate glass as an example. Borosilicate glass is preferred because it is a glass with a reduced alkali component, and therefore adverse effects on the phosphor layer 12 can be reduced.

The groove 30 formed on the surface of the electrode pin main body 21 is, for example, a spiral groove. The groove 30 is formed by laser processing for irradiating the surface of the electrode pin main body 21 made of tungsten (W) with a laser (for example, YAG laser or CO ₂ laser).
In the example shown in FIGS. 1 to 3, the groove 30 is formed in a spiral shape with respect to the surface of the electrode pin main body 21, and in particular, 2 [winding] or more (for example, 2 [winding], 3 [winding]) 4 [winding], 6 [winding], or more), the surface of the electrode pin body 21 is formed.

In the case of the spiral groove 30, it is formed so as to straddle a line along the longitudinal direction 35 of the electrode pin main body 21. Specifically, for example, it is a direction that intersects with the longitudinal direction 35 of the electrode pin main body 21 and is swung in a state of substantially making a round around the axis.
In addition, as the groove | channel 30, it is also possible to form the cyclic | annular groove | channel which the other end of the groove | channel connected other than the spiral thing as shown in FIGS. 1-3, for example. The annular groove is formed of, for example, 2 [pieces] or more.

  The depth of the groove 30 is, for example, 0.5 [μm] or more. When the groove 30 is formed by laser processing, the depth of the groove 30 can be set to, for example, 3 [μm] to 50 [μm]. Further, the opening width of the groove 30 can be a width that allows the bead glass 15 to easily enter, for example, a width of 5 [μm] or more. In addition, Preferably, the opening width of the groove | channel 30 exists in the range of 5 [micrometers] or more and 70 [micrometers] or less.

  As shown in FIG. 3, the interval d (or pitch) between the spiral grooves 30 can be, for example, 10 [μm] to 500 [μm], and the spiral grooves 30 are formed. The length a (the length along the longitudinal direction 35) of the region can be set to, for example, 0.3 [mm] to 1.5 [mm]. Alternatively, the length a of the region in which the spiral groove 30 is formed may be a predetermined ratio (for example, 10 [%] to 50 [%]) with respect to the length L in the longitudinal direction 35 of the electrode pin main body 21. it can. However, the shape and size (depth, interval d, length a, spiral length, etc.) of the groove 30 are determined according to various conditions (material and shape (diameter, length, etc.) of the electrode pin main body 21 and the sealing portion 17. Any suitable material can be employed in accordance with the welding conditions.

2. Cross-sectional shape of groove 30 formed on the surface of electrode pin main body 21 The cross-sectional shape of groove 30 formed on the surface of electrode pin main body 21 will be described with reference to FIG.
As shown in FIG. 4, a groove 30 is formed on the surface of the electrode pin main body 21 so as to straddle a line 37 along the longitudinal direction 35 of the electrode pin main body 21. Then, a part of the bead glass 15 is inserted, whereby the sealing strength (sealability) between the electrode pin 22 (or the electrode pin main body 21) and the bead glass 14 can be improved.

  More specifically, since the electrode pin main body 21 (for example, a pin made of tungsten (W)) and the bead glass 15 have different coefficients of thermal expansion, they are invisible levels between them. However, a slight gap can occur. Due to the influence of the gap, there is an increased possibility that a leak (that is, communication between the inside of the glass bulb 10 and the atmosphere) 50 of the sealing portion 17 occurs. However, if the groove 30 is formed on the surface of the electrode pin main body 21, the groove Since the bead glass 15 is inserted into the 30 recesses, the occurrence of the leak 50 can be prevented or reduced.

  In particular, when the groove 30 is formed by laser processing, the groove 30 is formed by melting a metal (for example, tungsten (W)). Therefore, as shown in FIG. It can be provided. That is, the groove 30 has a shape including a concave portion that is recessed from the surface of the electrode pin main body 21 and a convex portion that is connected to the concave portion and protrudes from the surface of the electrode pin main body 21 with respect to the center of the cross section. be able to. By adopting such a configuration, the effect of suppressing the occurrence of leak 50 between the electrode pin main body 21 and the bead glass 15 can be improved.

3. Discharge lamp electrode pins 22 and grooves 30
Next, the discharge lamp electrode pin 22 and the groove 30 of the cold cathode fluorescent lamp 100 according to the first embodiment will be further described with reference to FIGS. 6 to 10 are perspective views schematically showing the configuration of the electrode pin 22.
As described above, when the electrode pin 22 (or the electrode pin body 21) is made of tungsten (W) or molybdenum (Mo), the electrode pin 22 (or the electrode pin body 21) is made of tungsten (W). Alternatively, it is produced by extending molybdenum (Mo) by rolling or drawing. In this case, as shown in FIG. 6, a defect 55 (for example, a micro crack parallel to the drawing direction) 55 extending along the longitudinal direction 35 of the electrode pin main body 21 may exist on the surface 21 a of the electrode pin main body 21. . When this defect 55 exists, there is a high possibility that a leak due to a gap due to this defect 55 occurs.

  In the cold cathode fluorescent lamp 100 according to the present embodiment, as shown in FIG. 7, a spiral groove 30 (that is, a line 37 along the longitudinal direction 35 of the electrode pin main body 21 is formed on the surface 21 a of the electrode pin main body 21. Since the straddling groove 30) is formed, the defect 55 extending along the longitudinal direction 35 of the electrode pin main body 21 can be cut off by the groove 30. As described with reference to FIGS. 4 and 5, the bead glass 15 as a part of the glass bulb 10 enters the inside of the groove 30.

Therefore, in the cold cathode fluorescent lamp 100 according to the present embodiment, by forming the groove 30 on the surface of the electrode pin main body 21, a leak 50 (for example, a leak over time after completion of the product) caused by the defect 55 is generated. Can solve the problem of slow leak).
In view of the role of the groove 30 for cutting the defect 55 extending along the longitudinal direction 35 of the electrode pin main body 21, as shown in FIG. 8, the effect of preventing or suppressing the leak 50 can also be obtained by the annular groove 30. it can.

If the defect 55 can be cut effectively, the effect of the present embodiment can be obtained even if the discontinuous groove 30 is formed as shown in FIG.
On the other hand, as shown in FIG. 10, even a groove having a recess on the surface 21 a of the electrode pin main body 21 is a groove 32 parallel to the longitudinal direction 35 of the electrode pin main body 21 (that is, along the longitudinal direction 35. In the case of the groove 32) not intersecting with the line 37, the defect 55 extending along the longitudinal direction 35 of the electrode pin main body 21 cannot be cut off, so that the effect of preventing the leak 50 of the present embodiment cannot be obtained.

4). Sealing Strength Next, with reference to FIG. 11 to FIG. 14, the improvement of the sealing strength according to the configuration of the present embodiment will be described.
The inventors of the present application formed an experimental sample shown in FIG. 11 for the experiment on the sealing strength, and measured the strength. As shown in FIG. 11, the experimental sample has a configuration in which the bead glass 15 is attached to the region where the groove 30 is formed on the surface of the electrode pin main body 21. The electrode pin 22 includes an electrode pin main body 21 in which a groove 30 is formed, and a lead wire (external lead wire) 26 connected to one end of the electrode pin main body 21. The diameters of the electrode pin main body 21 and the external lead wire 26 are each 0.8 [mm].

  Specifically, as shown in FIG. 12, after the electrode pin main body 21 and the external lead wire 26 are connected to each other by welding, the bead glass 15 is inserted so as to be supported by the welding hump 25 (arrow 60). Subsequently, the bead glass 15 is fused (attached) to the electrode pin main body 21. In this way, the experimental sample shown in FIG. 11 is produced. The electrode pin body 21 used in this experiment is made of tungsten (W), and the external lead wire 26 is made of nickel (Ni).

The results of the sealing strength experiment are shown in FIG. 13 and FIG. In order to measure the sealing strength (adhesion strength) of the experimental sample shown in FIG. 11, when the external lead wire 26 is pulled to remove the bead glass 15 from the electrode pin main body 21, the bead glass 15 is detached. Previously, it was found that the nickel (Ni) external lead wire 26 was cut.
A sample A shown in FIG. 13 has a spiral groove 30 (groove depth 10 [μm]) having 6 turns. Sample B has a spiral groove 30 with a turn number 3 (groove depth 10 [μm]), and sample C has a spiral groove 30 with a turn number 3 (groove depth 5). [Μm]) is formed.

  As a comparative example, the adhesion strength of an experimental sample in which no groove was formed on the surface of the electrode pin main body was examined. As shown in FIG. 14, when the external lead wire 26 was pulled, the bead glass 15 was removed from the discharge lamp electrode pin. The external lead wire 26 was not cut. The breaking strength at this time (breaking strength of the comparative example) was an average strength of 192.7 [N] (Weibull coefficient 22.9). Therefore, the breaking strength when the groove 30 is formed is much higher than that (actually, the adhesive strength was excellent enough to cause the external lead wire 26 to be cut, so the breaking strength could not be measured. ).

Next, the inventors of the present application produced a cold cathode fluorescent lamp 100 having electrode pins 22 and performed an evaluation experiment in which thermal stress was applied to the cold cathode fluorescent lamp 100. This experiment was performed as follows.
First, the external lead wire 26 portion of the cold cathode fluorescent lamp 100 is immersed in solder held at 350 [° C.] for 30 [seconds] and then cooled to room temperature by natural cooling 10 [times] repeatedly. It was. After repeatedly applying thermal stress to the sealing part 17 in this way, the lamp 100 was held in the atmosphere of 10 [atmospheric pressure] for 48 [hours]. Then, the lighting experiment of the cold cathode fluorescent lamp 100 was conducted. As a result, it was found that in the cold cathode fluorescent lamp 100 provided with the electrode pin 20 of the present embodiment, all the samples are turned on and show the designed brightness and emission spectrum. On the other hand, in the cold cathode fluorescent lamp according to the prior art in which no groove is formed on the surface of the electrode pin main body (comparative example), the lighting does not occur at a rate of 1 [lines] to 3 [lines] in 100 [lines]. A sample was seen.

  Furthermore, the present inventors conducted an evaluation experiment in which bending stress is applied to the external lead wire 26 of the cold cathode fluorescent lamp 100 according to the present embodiment. This experiment was performed as follows. First, bending stress was applied to the sealing portion 17 by bending the external lead wire 26 of the cold cathode fluorescent lamp 100 at a right angle to the longitudinal direction 35 of the electrode pin body. Thereafter, the lamp 100 was kept in the atmosphere of 10 [atmospheric pressure] for 48 [hours], and a lighting experiment of the cold cathode fluorescent lamp 100 was performed in the same manner as described above. As a result, it was found that the cold cathode fluorescent lamp 100 provided with the electrode pins 22 of the present embodiment turned on all the samples and exhibited the designed brightness and emission spectrum. On the other hand, in the cold cathode fluorescent lamp according to the prior art in which no groove is formed on the surface of the electrode pin main body (comparative example), the lighting is not performed at a rate of 1 [lines] to 4 [lines] in 100 [lines]. A sample was seen.

5). Manufacturing Method of Cold Cathode Fluorescent Lamp 100 and Electrode Structure 20 Next, a manufacturing method of the cold cathode fluorescent lamp 100 and the electrode structure 20 according to the present embodiment will be described with reference to FIGS. 15 and 16. 15 and 16 are process cross-sectional views for explaining the manufacturing method according to the present embodiment.
First, as shown in FIG. 15A, the electrode pin 22 having the groove 30 formed on the surface of the electrode pin main body 21 is produced. The electrode pin 22 in which the groove 30 is formed is prepared by preparing the electrode pin main body 21 and then forming the groove 30 across the line along the longitudinal direction 35 of the electrode pin main body 21 on the surface of the electrode pin main body 21. The The groove 30 is formed by laser processing (for example, using a YAG laser or a CO2 laser). However, as long as the groove 30 straddling the line along the longitudinal direction 35 of the electrode pin main body 21 can be formed, the method may be chemical etching or machining.

  The groove 30 can be obtained, for example, by forming a concave portion on the surface of the electrode pin main body 21 while rotating the electrode pin main body 21 around the central axis in the longitudinal direction. As described above, the groove 30 may be a spiral groove, an annular groove, or another shape. The electrode pin body 21 can be obtained by extending a constituent metal material (for example, tungsten (W)) by drawing or the like and cutting it to a predetermined length. Since the defect 55 along the longitudinal direction 35 of the electrode pin main body 21 may occur during the drawing process, it is preferable to execute the configuration of the present embodiment (formation of the groove 30).

For example, in the electrode pin main body 21 made of an alloy of Fe and Ni, a defect 55 along the longitudinal direction 35 of the electrode pin main body 21 may be generated, so that the technique of adopting the configuration of the present embodiment is employed. There is a significant significance.
Next, as shown in FIG. 15B, the external lead wire 26 is disposed at one end (for example, one end face) of the electrode pin main body 21 in which the groove 30 is formed. Next, as shown in FIG. 15C, the electrode pin main body 21 and the external lead wire 26 are connected by welding. Note that a welding hump 25 may be formed on one end side of the external lead wire 26 (on the electrode pin main body 21 side) by welding. Further, if the groove 30 is formed at a central portion in the longitudinal direction of the electrode pin main body 21, the connection direction between the electrode pin main body 21 and the external lead wire 26 is set to one end side and the other end side of the electrode pin main body 21. It is possible to obtain a merit in the manufacturing process that any of the above can be performed.

Thereafter, as shown in FIG. 15D, the bead glass 15 is inserted into the electrode pin main body 21 in which the groove 30 is formed. At this time, the bead glass 15 is inserted so as to cover the groove 30. In the manufacturing method according to the present embodiment, the welding hump 25 is caused to function as a positioning member for the bead glass 15.
Next, as shown in FIG. 16A, the bead glass 15 and the electrode pin main body 21 are welded. This welding is performed by heating the bead glass 15. Next, as illustrated in FIG. 16B, the electrode 24 is connected to the other end (for example, the other end surface) of the electrode pin main body 21 by welding to obtain the electrode structure 20.

  Although the degree of adhesion between the bead glass 15 and the electrode pin main body 21 may be reduced due to heat during welding of the electrode 24, the groove 30 is formed on the surface of the electrode pin main body 21 in the configuration according to the present embodiment. Therefore, the degree of adhesion is improved, and even when heat is generated during such welding, a decrease in the degree of adhesion between the bead glass 15 and the electrode pin main body 21 can be effectively suppressed.

Next, as shown in FIG. 16C, the electrode structure 20 is inserted into the glass bulb 10 with the electrode 24 at the tip. Thereafter, the bead glass 15 and the glass bulb 10 provided in the electrode structure 20 are melted by heating, and both are brought into close contact and welded at the sealing portion 17, whereby the cold cathode fluorescent lamp according to the present embodiment. 100 is obtained.
Before and after the step of inserting the electrode structure 20 into the glass bulb 10, the step of forming the phosphor layer 12 on the inner surface of the glass bulb 10, the step of introducing mercury into the glass bulb 10, the step of introducing enclosed gas, etc. Is executed.

6). Variation on Manufacturing Method of Cold Cathode Fluorescent Lamp 100 The cold cathode fluorescent lamp 100 according to the present embodiment can also be manufactured as shown in FIG.
First, after performing the process shown in FIG. 15C, the cup electrode 24 is connected to the other end portion (for example, the other end surface) of the electrode pin main body 21 by welding as shown in FIG. 17A.

Next, as shown in FIG. 17B, the bead glass 15 is welded to the electrode pin main body 21. Thereafter, as shown in FIG. 17C, the electrode structure 20 is inserted into the glass bulb 10 and welded to each other by the sealing portion 17, whereby the cold cathode fluorescent lamp 100 according to the present embodiment. Is obtained.
Further, during the process of assembling the backlight from the cold cathode fluorescent lamp, a stress is applied to the external lead wire 26 of the cold cathode fluorescent lamp, and thereby, between the surface of the electrode pin main body 21 in the sealing portion 17 and the bead glass 15. Leakage may occur, but in the configuration according to the present embodiment, the groove 30 is formed on the surface of the electrode pin main body 21, thereby improving the adhesion strength at the sealing portion 17. The problem can be solved.

In addition, in the configuration in which the lifetime of the backlight, and hence the life of the liquid crystal display device, is determined by the leakage of the cold cathode fluorescent lamp, in the configuration according to this embodiment, the life of the backlight and the life of the liquid crystal display device are determined. Can be improved.
Furthermore, in the configuration according to the present embodiment, since the strength of the sealing portion 17 is improved by forming the groove 30, long life and high reliability can be achieved without using a complicated configuration or an expensive member. As a result, the technical value including the cost is very large.

Although the present invention has been described with reference to the preferred embodiment, such description is not a limitation, and various modifications can of course be made.
[Embodiment 2]
Illumination apparatus 400 according to Embodiment 2 of the present invention will be described with reference to FIG.
As shown in FIG. 18, an illumination device 400 according to Embodiment 2 of the present invention is a direct-type backlight unit, and has a rectangular parallelepiped housing 401 having one surface opened, and the interior of the housing 401. A plurality of lamps 100, a socket 402 for electrical connection to a lighting circuit (not shown) for lighting the lamp 100, and an optical sheet 403 covering the opening of the housing 401. I have.

Note that the cold cathode fluorescent lamp 100 according to the first embodiment is employed as the lamp 100 of the illumination device 400 according to the present embodiment.
The casing 401 is made of, for example, polyethylene terephthalate (PET) resin, and a reflection surface 404 is formed on the inner surface thereof by vapor deposition of a metal such as silver (Ag).
Note that as the material of the housing 401, a material other than a resin material, for example, a metal material such as aluminum (Al) or a cold-rolled material (for example, SPCC) can be used. Further, as the reflective surface 404 on the inner surface, in addition to the metal vapor-deposited film, for example, a reflective sheet whose reflectance is increased by adding calcium carbonate, titanium dioxide or the like to polyethylene terephthalate (PET) resin is attached to the casing 401. Things can also be used.

  Inside the casing 401, a socket 402, an insulator 405, and a cover 406 are disposed. The sockets 402 are provided at predetermined intervals in the lateral direction (vertical direction) of the housing 401 corresponding to the arrangement of the lamps 100. The socket 402 is formed by processing a plate material made of stainless steel or phosphor bronze, for example, and has a fitting portion 402a into which the external lead wire 104b is fitted. And the lead wire 103 is elastically deformed and fitted so as to push the fitting portion 402a. As a result, the external lead wire 103a fitted in the fitting part 402a is pressed by the restoring force of the fitting part 402a and is difficult to come off. As a result, the external lead wire 103a can be easily fitted into the fitting portion 402a, and can be made difficult to come off after being fitted at one end.

The socket 402 is covered with an insulator 405 so as not to short-circuit between adjacent sockets 402. The insulator 405 is formed using, for example, polyethylene terephthalate (PET) resin.
Note that the insulator 405 is not limited to the above structure.
Since the socket 402 is disposed in the vicinity of the electrode 102 that is relatively hot during the operation of the lamp 100, the insulator 405 is preferably formed using a heat-resistant material. For example, a polycarbonate (PC) resin, silicone rubber, or the like can be used as a material for the heat-resistant insulator 405.

Inside the housing 401, a lamp holder 407 may be provided at a place where necessary. The lamp holder 407 that fixes the position of the lamp 100 inside the housing 401 uses, for example, polycarbonate (PC) resin and has a shape that conforms to the outer surface shape of the lamp 100.
Here, the “location as necessary” in the above is a case where the lamp 100 is long, for example, exceeding the total length of 600 [mm], such as near the center in the longitudinal direction of the lamp 100. In addition, this is a place necessary for eliminating the bending of the lamp 100.

The cover 406 divides the socket 402 from the space inside the housing 401, and is made of, for example, polycarbonate (PC) resin. The cover 406 keeps the periphery of the socket 402 warm, and at least the housing 401 side. By making the surface highly reflective, a decrease in luminance at the end of the lamp 100 can be reduced.
The opening of the housing 401 is covered with a translucent optical sheet 403 and is sealed so that foreign matter such as dust and dirt does not enter inside. The optical sheets 403 are configured by laminating a diffusion plate 408, a diffusion sheet 409, and a lens sheet 410.

  The diffusion plate 408 is, for example, a plate-like body configured using polymethyl methacrylate (PMMA) resin, and is disposed so as to close the opening of the housing 401. The diffusion sheet 409 is configured using, for example, a polyester resin. The lens sheet 410 is configured by, for example, pasting an acrylic resin and a polyester resin. These optical sheets 403 are disposed so as to be sequentially superimposed on the diffusion plate 408.

As described above, the illumination device 400 according to Embodiment 2 of the present invention is excellent in reliability.
[Embodiment 3]
An illumination device 500 according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 19 is a perspective view (partially cutaway view) of lighting apparatus 500 according to Embodiment 3 of the present invention.
As shown in FIG. 19, an illumination device 500 according to Embodiment 3 of the present invention is an edge light type backlight unit, which includes a reflector 501, a lamp 100, a socket (not shown), a light guide plate 502, A diffusion sheet 503, a prism sheet 504, and the like are included.

  The reflection plate 501 is disposed so as to surround the periphery of the light guide plate 502 excluding the liquid crystal panel side (arrow Q), and includes a bottom surface portion 501 a that covers the bottom surface, and a curved lamp side surface portion 501 c that covers the periphery of the lamp 100. The light irradiated from the lamp 100 is reflected from the light guide plate 502 to the liquid crystal panel (not shown) side (arrow Q). The reflector 501 is made of, for example, a film-like polyethylene terephthalate (PET) vapor-deposited with silver (Ag) or a laminate of metal foil such as aluminum.

The socket (not shown) has substantially the same configuration as the socket 402 used in the lighting device 400 according to the second embodiment.
The light guide plate 502 guides the light reflected by the reflection plate 501 to the liquid crystal panel side. The light guide plate 502 is made of, for example, translucent plastic, and is laminated on the reflection plate 501 a provided on the bottom surface of the lighting device 500. ing. As a constituent material, polycarbonate (PC) resin, cycloolefin-based resin (COP), or the like can be used.

The diffusion sheet 503 is for expanding the visual field, and is made of, for example, a film having a diffusion transmission function made of polyethylene terephthalate resin or polyester resin, and is laminated on the light guide plate 502.
The prism sheet 504 is for improving luminance, and is made of, for example, a sheet obtained by bonding an acrylic resin and a polyester resin, and is laminated on the diffusion sheet 503. Note that a diffusion sheet 503 may be further stacked on the prism sheet 504.

In the illumination device 500 according to Embodiment 3 of the present invention, a reflection sheet (not shown) is provided on the outer surface of the glass bulb 10 except for a part in the circumferential direction of the lamp 100 (the light guide plate 502 side when inserted into the illumination device 500). Aperture-type lamps provided with).
As described above, the illumination device 500 according to Embodiment 3 of the present invention is excellent in reliability.
[Embodiment 4]
A configuration of a liquid crystal display device 700 according to Embodiment 4 of the present invention will be described with reference to FIG.

As shown in FIG. 20, a liquid crystal display device 700 according to the fourth embodiment of the present invention is, for example, a 32 [inch] liquid crystal television, and includes a liquid crystal screen unit 701 including a liquid crystal panel and the second embodiment. The lighting device 400 according to the above and a lighting circuit 702 are configured.
The liquid crystal screen unit 701 is a known one and includes a liquid crystal panel (color filter substrate, liquid crystal, TFT substrate, etc .; not shown), and forms an image based on an image signal input from the outside.

The lighting circuit 702 is a circuit for driving and driving the lamp 100 in the lighting device 400. The lamp 100 operates at a lighting frequency of 40 [kHz] to 100 [kHz] and a lamp current of 3.0 [mA] to 25 [mA].
In the fourth embodiment of the present invention, the illumination device 400 is applied as an example of the illumination device of the liquid crystal display device 700. However, for example, the illumination device 500 can also be applied.

  As described above, in the liquid crystal display device 700 according to Embodiment 4 of the present invention, high display quality can be ensured.

  INDUSTRIAL APPLICABILITY The present invention is useful for realizing a discharge lamp (cold cathode fluorescent lamp), an illuminating device, and a liquid crystal display device having a simple configuration and excellent reliability.

10. Glass bulb 10a. End of glass bulb 12. Phosphor layer 15. Bead glass 17. Insertion part 20. Electrode structure 21. Electrode pin body 22. Electrode pin for discharge lamp 24. Cup electrode 26. External lead wire 30. Groove 30. Longitudinal direction 55. Defect 100. Cold cathode fluorescent lamp 400,500. Lighting device 700. Liquid crystal display

Claims (26)

A discharge lamp electrode pin sealed to the end of a glass bulb,
An electrode pin body;
A discharge lamp characterized by comprising a groove across a line along the longitudinal direction of the electrode pin main body at a location sealed to the end of the glass bulb in the surface of the electrode pin main body. Electrode pin. The electrode pin for a discharge lamp according to claim 1, wherein the groove is formed in a spiral shape on a surface of the electrode pin main body. 3. The electrode pin for a discharge lamp according to claim 2, wherein the spiral groove is formed 2 or more turns on the surface of the electrode pin main body. 2. The electrode pin for a discharge lamp according to claim 1, wherein the groove is formed in an annular shape in which one end and the other end are connected on the surface of the electrode pin main body. 5. The electrode pin for a discharge lamp according to claim 4, wherein the annular groove is formed at least 2 [pieces] on the surface of the electrode pin main body. The depth of the said groove | channel is 0.5 [micrometer] or more. The electrode pin for discharge lamps of Claim 1 characterized by the above-mentioned. The groove is
A recess recessed from the surface of the electrode pin body;
The discharge lamp electrode pin according to claim 1, further comprising: a convex portion connected to the concave portion and projecting from a surface of the electrode pin main body. The electrode pin for a discharge lamp according to claim 1, wherein the electrode pin body is produced by being rolled or drawn. The electrode pin for a discharge lamp according to claim 1, wherein the electrode pin body is made of tungsten or molybdenum. The electrode pin for a discharge lamp according to claim 1, wherein the electrode pin main body is made of an alloy of iron and nickel. The discharge pin electrode pin according to claim 1, wherein the groove is formed by laser processing. The electrode pin for a discharge lamp according to claim 1, wherein a lead wire is connected to one end of the electrode pin main body. The electrode pin for a discharge lamp according to claim 12, wherein the lead wire is made of nickel. It has a discharge lamp electrode pin sealed to the end of the glass bulb,
The discharge lamp electrode pins are:
An electrode pin body;
Of the surface of the electrode pin main body, in a place sealed to the end of the glass bulb, it comprises a groove across a line along the longitudinal direction of the electrode pin main body,
A lead wire is connected to one end of the electrode pin body,
A cup electrode is connected to the other end of the electrode pin main body. The electrode structure according to claim 14, wherein a glass bead is sealed on a surface of the electrode pin main body. A glass bulb,
A phosphor layer formed on the inner surface of the glass bulb;
Having an electrode pin for a discharge lamp sealed at an end of the glass bulb;
A cold cathode fluorescent lamp, wherein the discharge lamp electrode pin according to any one of claims 1 to 11 is applied as the discharge lamp electrode pin. The cold-cathode fluorescent lamp according to claim 16, wherein the glass bulb is made of borosilicate glass. A method of manufacturing an electrode pin for a discharge lamp,
Preparing an electrode pin body (a);
And (b) forming a groove extending over a line along the longitudinal direction of the electrode pin main body on the surface of the electrode pin main body. The method of manufacturing an electrode pin for a discharge lamp according to claim 18, wherein the step (b) is performed by laser processing. The method of manufacturing an electrode pin for a discharge lamp according to claim 18, wherein, in the step (b), the groove is formed in a spiral shape while rotating the electrode pin main body. The method of manufacturing an electrode pin for a discharge lamp according to claim 18, wherein, in the step (b), the groove is formed in an annular shape in which one end and the other end are connected while rotating the electrode pin main body. . The step (a)
The manufacturing method of the electrode pin for discharge lamps of Claim 18 including the sub process which extends the metal material which comprises an electrode pin main body by a rolling process or a drawing process. The method for producing an electrode pin for a discharge lamp according to claim 22, wherein the material constituting the electrode pin body is tungsten or molybdenum. Preparing an electrode pin body (a);
Forming a groove across the line along the longitudinal direction of the electrode pin main body on the surface of the electrode pin main body (b);
Connecting a lead wire to one end of the electrode pin body;
Connecting a cup electrode to the other end of the electrode pin body;
A method of manufacturing a cold cathode fluorescent lamp, comprising: welding a glass member to a region of the electrode pin body in which the groove is formed. An illuminating device comprising the cold cathode fluorescent lamp according to claim 16. A liquid crystal display device comprising the illumination device according to claim 25.

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