JP4520529B2 - Discharge lamp, lighting device, and liquid crystal display device - Google Patents

Description

  The present invention relates to a discharge lamp, an illumination device using the discharge lamp as a main light source, and a liquid crystal display device, and more particularly to a discharge lamp in which a metal conductor is provided on the outer periphery of a glass bulb end portion on which an electrode is disposed.

  As a conventional technique, Patent Document 1 discloses a cold cathode discharge lamp 2000 in which a cap-shaped metal sleeve 2002 is provided at an end of a glass bulb 2001 as shown in FIG. The metal sleeve 2002 is electrically connected to an electrode 2004 disposed in the end portion of the glass bulb 2001 via a lead wire 2003. If the metal sleeve 2002 is fitted into a lamp holder of a lighting device, a cold cathode The discharge lamp 2000 can be fixed to the lighting device and further connected to the lighting circuit of the lighting device. Therefore, soldering or the like is unnecessary when attaching to the lighting device, and attachment is easier than a type without the metal sleeve 2002.

JP-A-7-220622

By the way, in the cold cathode discharge lamp 2000, when a negative voltage is applied to the electrode 2004 at the time of starting, ions in the glass bulb 2001 are generated by an electric field between the electrode 2004 and the proximity conductor 2005 (for example, a bottom plate of a lighting device). Is accelerated, collides with the electrode 2004, and secondary electrons are generated. Then, discharge starts from the secondary electrons.
However, in the cold cathode discharge lamp 2000, the distance L4 between the metal sleeve 2002 and the proximity conductor 2005 is shorter than the distance L3 between the electrode 2004 and the proximity conductor 2005, and the electrode 2004 and the metal sleeve 2002 have the same potential. Therefore, an electric field with high strength is generated between the metal sleeve 2002 and the adjacent conductor 2005, and the electric field strength between the electrode 2004 and the adjacent conductor 2005 is lowered. In this case, since the acceleration action of electrons inside the glass bulb 2001 is weakened, the discharge hardly occurs and the dark startability is deteriorated.

In particular, as shown by a two-dot chain line 2006, when the metal sleeve 2002 extends in the tube axis direction of the glass bulb 2001 and covers the entire electrode 2004, the metal sleeve 2002 becomes an obstacle, and the electrode 2004 and the adjacent conductor The darker start-up characteristic is worsened as the electric field strength during the period becomes even lower and the lighting becomes more difficult.
In view of the above problems, an object of the present invention is to provide a discharge lamp with good dark startability despite the fact that a metal conductor is provided on the outer periphery of the end portion where the electrode is disposed. Another object of the present invention is to provide an illuminating device and a liquid crystal display device with good dark startability.

In order to solve the above-described problem, a cold cathode discharge lamp according to the present invention is a tube in which an electrode is disposed inside at least one end of a glass bulb and is electrically connected to the electrode on the outer periphery of the end. A cold cathode discharge lamp provided with a metal metal conductor, wherein the cylindrical metal conductor is coiled and has a position where the electric field strength is high enough to induce ion bombardment at the start in the glass bulb. Thus, an emitter is provided between the proximity conductor and the electrode in a state of being attached to the lighting device provided with the proximity conductor electrically insulated from the lamp current path.

Further, in one aspect of the cold cathode discharge lamp according to the present invention, the emitter is on an orbit between the adjacent conductor and the electrode so as to avoid the metal conductor and reach the electrode from the adjacent conductor with the shortest distance. It is provided in.
In one aspect of the cold cathode discharge lamp according to the present invention, the emitter is provided on an inner surface of a portion of the glass bulb where the metal conductor is not provided.

In one aspect of the cold cathode discharge lamp according to the present invention, the emitter is provided on an outer surface of a portion of the electrode where the metal conductor is not provided.
Moreover, one aspect of the cold cathode discharge lamp according to the present invention is characterized in that the electrode is a bottomed cylindrical hollow electrode, and the emitter is provided on the inner surface of the electrode.
Moreover, one aspect of the cold cathode discharge lamp according to the present invention is characterized in that an auxiliary emitter different from the emitter is provided on the electrode .

  Also, in one aspect of the cold cathode discharge lamp according to the present invention, the edge of the metal conductor on the center side of the glass bulb is positioned closer to the center of the glass bulb than the end of the electrode on the center side of the glass bulb. It is characterized by that.

In one aspect of the cold cathode discharge lamp according to the present invention, the emitter is made of a cesium compound.
In one aspect of the cold cathode discharge lamp according to the present invention, the metal conductor is connected to a main body wound around an end of the glass bulb and a lead wire led out from the end of the glass bulb. And a connecting portion.
The illumination device according to the present invention includes the cold cathode discharge lamp.
A liquid crystal display device according to the present invention includes the above-described illumination device.

  According to the above configuration, since the emitter is provided at a position where the electric field strength is high enough to induce ion bombardment at the start in the glass bulb, the ions in the glass bulb are accelerated by the electric field and easily collide with the emitter and the electrode. , Secondary electrons generated upon collision are easily obtained. Therefore, even when the electric field generated between the electrode and the adjacent conductor is low because the discharge starting from the secondary electrons is easily started and the metal conductor becomes an obstacle, the dark startability is good.

Sectional drawing which shows the one end part of the cold cathode discharge lamp which concerns on a prior art example Sectional drawing which shows the discharge lamp which concerns on this Embodiment Perspective view showing sleeve The figure explaining the attachment state of a cold cathode discharge lamp The figure for explaining the electric field strength between an electrode and a metal conductor Sectional view showing the discharge lamp used in the experiment Diagram showing the effect of sleeve on dark starting characteristics The expanded sectional view which shows the one end part of the cold cathode discharge lamp of the modification 1 The expanded sectional view which shows the one end part of the cold cathode discharge lamp of the modification 2 The expanded sectional view which shows the one end part of the cold cathode discharge lamp of the modification 3 (A) is an enlarged plan view showing one end portion of the cold cathode discharge lamp of Modification 5, (b) is a cross-sectional view taken along line aa shown in (a), and (c) is a sleeve of Modification 5. Perspective view (A) is an enlarged plan view showing one end of the cold cathode discharge lamp of Modification 5, (b) is a cross-sectional view taken along the line bb shown in (a), and (c) is a sleeve of Modification 5. Perspective view The perspective view which shows the modification of a sleeve The expanded sectional view which shows the one end part of the cold cathode discharge lamp of the modification 6 The expanded sectional view which shows the one end part of the cold cathode discharge lamp of the modification 7 (A) is the front view which shows the one end part of the cold cathode discharge lamp of the modification 8, (b) is a side view of the modification 8, (c) is an expanded sectional view of the part surrounded by the circle shown in (a) Front view showing one end of a cold cathode discharge lamp of Modification 9 (A) is a front view which shows the one end part of the cold cathode discharge lamp of the modification 10, (b) is a perspective view which shows the sleeve of the modification 10. The expanded sectional view which shows the one end part of the cold cathode discharge lamp of the modification 11 The expanded sectional view which shows the one end part of the cold cathode discharge lamp of the modification 12 The expanded sectional view which shows the one end part of the cold cathode discharge lamp of the modification 13 The disassembled perspective view which shows the illuminating device which concerns on 1st Embodiment. The partially broken perspective view which shows the illuminating device which concerns on 2nd Embodiment. Schematic showing a liquid crystal display device according to the present embodiment

[Discharge lamp]
<Lamp configuration>
Hereinafter, a discharge lamp according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 2 is a cross-sectional view including the tube axis X of the discharge lamp according to the present embodiment. As shown in FIG. 2, the discharge lamp according to the present embodiment is a cold cathode discharge lamp 1 used as a light source of a backlight unit, and includes a glass bulb 10, a pair of electrodes 20, 21, and a pair of metal conductors. Sleeves 30 and 31 and an emitter 40.

The glass bulb 10 is formed by sealing both ends of a glass tube made of, for example, borosilicate glass (for example, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —K ₂ O—TiO ₂ ). The glass tube is not limited to borosilicate glass but may be made of lead glass, lead-free glass, soda glass, or the like. Lead glass, lead-free glass, soda glass, etc. contain many alkali metal oxides such as sodium oxide (Na ₂ O), and these alkali metals are likely to elute on the inner surface of the glass bulb over time. The dark startability of the cold cathode discharge lamp 1 can be improved.

  In particular, the glass of the glass bulb 10 preferably has an alkali metal oxide content of 3 [mol%] or more and 20 [mol%] or less. For example, when the alkali metal oxide is sodium oxide, the content is preferably 5 [mol%] or more and 20 [mol%] or less. If it is 5 [mol%] or more, the dark startability is improved, and if it exceeds 20 [mol%], the glass bulb 10 is blackened (browned) or whitened due to long-term use, leading to a decrease in brightness. There arises a problem that the strength of the glass bulb 10 is lowered.

  In consideration of protection of the natural environment, it is preferable to use lead-free glass for the glass bulb 10. In the present application, the lead-free glass means a glass having a lead content of less than 0.1 [wt%]. In the case of lead-free glass, lead is not positively added, but since some lead may be included as an impurity in the manufacturing process, it is defined as less than 0.1 [wt%].

The glass bulb 10 has a total length of 730 [mm], and includes a glass bulb body 11 and a pair of end portions 12 and 13 located on both sides in the longitudinal direction of the glass bulb body 11.
The glass bulb main body 11 has a circular cross section and has an outer diameter of 4 [mm], an inner diameter of 3 [mm], and a thickness of 0.5 [mm]. The pair of end portions 12 and 13 are sealed with sealing portions 14 and 15, respectively, and electrodes 20 and 21 are disposed inside. The maximum width A in the tube axis X direction of the glass bulb 10 of the sealing portions 14 and 15 is 2 [mm]. In addition, sleeves 30 and 31 are provided on the outer circumferences of the end portions 12 and 13.

The dimensions of the glass bulb 10 are not limited to the above. However, in order to obtain the elongated cold cathode discharge lamp 1, it is desirable that the glass bulb 10 has a small diameter and a thin wall, so that the glass bulb main body 11 has an inner diameter of 1.4 [mm] to 7.0 [mm], The wall thickness is preferably 0.2 [mm] to 0.6 [mm].
A phosphor layer 16 is formed on the inner surface of the glass bulb 10. The phosphor layer 16 includes, for example, a blue phosphor with europium-activated barium magnesium aluminate [BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ] (abbreviation: BAM-B), and a green phosphor with cerium / terbium co-activated phosphorus. A lanthanum acid [LaPO ₄ : Ce ³⁺ , Tb ³⁺ ] (abbreviation: LAP) and a red phosphor are formed of a rare earth phosphor composed of europium activated yttrium oxide [Y ₂ O ₃ : Eu ³⁺ ] (abbreviation: YOX). Yes.

  Further, inside the glass bulb 10, for example, about 1200 [μg] mercury and a neon / argon mixed gas (Ne95 [%] + Ar5 [%] of about 8 [kPa] (20 [° C.]) as a rare gas. ]) Is enclosed. Mercury and rare gas are not limited to the above. For example, a neon / krypton mixed gas (Ne95 [%] + Kr5 [%]) may be enclosed as a rare gas. When neon / krypton mixed gas is used as the rare gas, lamp startability is improved, and the cold cathode discharge lamp 1 can be lit at a low voltage.

  The electrodes 20 and 21 are made of, for example, rod-shaped nickel (Ni), and are joined to lead wires 22 and 23 sealed in the sealing portions 14 and 15. The electrodes 20 and 21 are not limited to nickel, and may be made of niobium (Nb), tantalum (Ta), tungsten (W), molybdenum (Mo), or the like. Moreover, the shape of the electrodes 20 and 21 is not limited to a rod shape, and may be a bottomed cylindrical shape, a flat plate shape, or the like.

  The lead wires 22 and 23 are tungsten (W) internal lead wires 22a and 23a having the same thermal expansion coefficient as that of the glass of the glass bulb 10, and nickel external lead wires 22b and 23b to which solder is easily attached. Is a connecting line formed by welding together. Each of the lead wires 22 and 23 extends linearly along the tube axis X direction of the glass bulb 10, and the joining surfaces of the internal lead wires 22 a and 23 a and the external lead wires 22 b and 23 b are formed on the glass bulb 10. It is almost flush with the outer surface. That is, the internal lead wires 22 a and 23 a are located inside the outer surface of the glass bulb 10, and the external lead wires 22 b and 23 b are located outside the outer surface of the glass bulb 10.

The internal lead wires 22a and 23a have a substantially circular cross section, a total length of 3 [mm], and a wire diameter of 0.8 [mm]. The internal lead wires 22a, 23a are sealed at the sealing portions 14, 15 of the glass bulb 10 at the end portions on the external lead wires 22b, 23b side, and the end portions on the opposite side to the external lead wires 22b, 23b side. Are joined to the electrodes 20 and 21.
The external lead wires 22b and 23b have a substantially circular cross section, a total length B of 1 [mm], a wire diameter of 0.6 [mm], and the axis of the external lead wires 22b and 23b substantially coincides with the tube axis X of the glass bulb 10. Has been placed. The external lead wires 22b and 23b are entirely buried in solder joint portions 32 and 33 in the sleeves 30 and 31, and are electrically connected to the sleeves 30 and 31 through the joint portions 32 and 33. Has been. The length C in the tube axis X direction of the joint portions 32 and 33 is 1.5 [mm].

  On the side of the internal lead wires 22a and 23a of the external lead wires 22b and 23b, bulged portions 24 and 25 having a larger outer diameter than the external lead wires 22b and 23b are provided so as to be in close contact with the edge of the glass bulb 10. It is preferable that That is, the bulging parts 24 and 25 are located outside the outer surface of the glass bulb 10. When the bulging portions 24 and 25 are thus provided, the dimensions from the bulging portions 24 and 25 to the electrodes 20 and 21 can be easily adjusted, and the gap D between the electrodes 20 and 21 and the inner surface of the glass bulb 10 is set to 0. 0. It can be kept as small as 5 [mm], and it is easy to adjust the effective light emission length E to be long.

The bulging portions 24 and 25 are made of the same nickel material as the external lead wires 22b and 23b. However, the bulging portions 24 and 25 are not limited to this, and may be made of a material such as iron / nickel alloy or copper / nickel alloy. Good.
The lead wires 22 and 23 are not limited to the connection between the internal lead wires 22a and 23a and the external lead wires 22b and 23b, but may be single wires. For example, when the glass bulb is made of lead-free glass, the lead wires 22 and 23 are preferably an alloy of iron and nickel.

  FIG. 3 is a perspective view showing a sleeve. As shown in FIG. 3, the sleeve 30 (31) is a cylindrical body having a substantially C-shaped cross section, has a slit 30a (31a), and is fitted on the end 12 (13) of the glass bulb 10. And attached to the outer periphery of the end 12 (13). As shown in FIG. 2, the sleeves 30 and 31 have, for example, a length F in the tube axis X direction of 11 [mm] and a thickness of 120 [μm], and are made of an alloy of iron and nickel. In addition to this, a copper alloy such as phosphor bronze, brass, or white can be used as the material of the sleeves 30 and 31. Further, the inner diameters of the sleeves 30 and 31 are designed to be slightly smaller than the outer diameter of the glass bulb 10, and some dimensional errors occur between the inner diameters of the sleeves 30 and 31 and the outer diameter of the glass bulb 10. Also, the dimensional error is absorbed by the slits 30 a and 31 a so that the inner surfaces of the sleeves 30 and 31 are in close contact with the outer surface of the glass bulb 10. The sleeves 30 and 31 are electrically connected to the external lead wires 22b and 23b of the electrodes 20 and 21 via solder joint portions 32 and 33, respectively.

  The sleeves 30 and 31 are not limited to cylinders having a substantially C-shaped cross section, and slits 30a and 31a are provided in a polygonal or elliptical cylinder having a substantially triangular or square cross section. Also good. Further, there may be a case where the slits 30a and 31a are not provided. Furthermore, the sleeves 30 and 31 are not limited to an alloy of iron and nickel, and may be made of at least a conductive material.

  FIG. 4 is a diagram for explaining a mounting state of the cold cathode discharge lamp. The cold cathode discharge lamp 1 is attached to the lighting device 50, for example, as shown in FIG. A plurality of pairs of lamp holders 52 and 53 are arranged on the bottom plate 51 of the lighting device 50 at positions corresponding to the mounting positions of the cold cathode discharge lamps 1. Each of the lamp holders 52 and 53 is formed by bending a plate made of copper alloy such as phosphor bronze or aluminum, and is a pair of clamping pieces 52a, 52b, 53a and 53b, and the clamping pieces 52a and 52b. , 53a, 53b are connected to each other at the lower end edge.

  The pair of sandwiching pieces 52a, 52b, 53a, 53b are provided with recesses that match the outer shape of the cold cathode discharge lamp 1, and if the cold cathode discharge lamp 1 is fitted in the recesses, the sandwiching pieces 52a, The cold cathode discharge lamp 1 is held by the lamp holders 52, 53 by the leaf spring action of 52b, 53a, 53b, and the lamp holders 52, 53 and the sleeves 30, 31 are electrically connected. The cold cathode discharge lamp 1 attached to the lighting device 50 is supplied with electric power from the lighting circuit (not shown) of the lighting device 50 via the lamp holders 52 and 53.

  Since the external lead wires 22b and 23b are accommodated in the sleeves 30 and 31 and are entirely buried in the joint portions 32 and 33, the external lead wires 22b and 23b are attached when the cold cathode discharge lamp 1 is attached to the lighting device 50. Is less likely to break the sealing portions 14 and 15 due to stress applied to the external lead wires 22b and 23b.

  The cold cathode discharge lamp 1 according to the present embodiment is designed so that the length F of the sleeves 30 and 31 in the tube axis X direction is longer than that of the conventional cold cathode discharge lamp. Therefore, as shown in FIG. 2, the glass bulb central side edges 30a, 31a of the sleeves 30, 31 are positioned closer to the glass bulb central side than the glass bulb central side edges 20a, 21a of the electrodes 20, 21. The distance G between the end edges 30a, 31a and the end edges 20a, 21a is 1.0 [mm] to 2.0 [mm].

  As shown in FIG. 4, the width H of the clamping pieces 52 a, 52 b, 53 a, 53 b of the lamp holders 52, 53 is also designed to be wide according to the length F of the sleeves 30, 31. By adopting such a configuration, the mounting properties of the sleeves 30 and 31 to the lamp holders 52 and 53 are improved, and the contact resistance between the sleeves 30 and 31 and the lamp holders 52 and 53 is reduced.

The emitter 40 is made of cesium sulfate having a relatively low work function. By providing such cesium sulfate on the inner surface of the glass bulb 10, thermal electrons can be released into the discharge space by applying a small amount of photoelectrons or thermal energy, and can quickly shift to lighting start.
The emitter 40 is not limited to one made of cesium sulfate, but a cesium compound having a relatively small work function and a low surface barrier necessary for electrons in the solid to leave the solid is suitable. Examples of cesium compounds other than cesium sulfate include cesium molybdate, cesium aluminate, cesium niobate, cesium tungstate, cesium oxide, and cesium hydroxide. Materials other than cesium compounds include alkaline earth metals (magnesium, calcium, strontium, barium), alkaline earth metal oxides, alkali metals (lithium, sodium, potassium, cesium), alkali metal oxides, electron emission Examples thereof include substances (lanthanum, yttrium, lanthanum barium, carbon) or substances mainly composed of at least one of oxides of the electron-emitting substances.

  The emitter 40 is provided in a cylindrical shape on the inner surface of one end 12 of the glass bulb 10. Specifically, the sleeve 30 is provided at a position closer to the glass bulb center than the edge 30a on the glass bulb center side, and the distance I between the edge 30a and the emitter 40 is, for example, 5 [mm]. It is. This position is a position where the electric field strength is high enough to induce ion bombardment at the start. Since the emitter 40 is provided at such a position, secondary electrons are easily generated in the glass bulb 10 at the time of starting. For this reason, even when the electric discharge generated in the glass bulb 10 is low because the micro discharge is likely to start in the glass bulb 10 and the sleeves 30 and 31 are obstructed, the dark startability is good.

The distance I between the edge 30a and the emitter 40 is not limited to the above. Since the electric field weakens as the distance from the edge 30a increases, it is preferable to arrange the emitter 40 at a position where the distance I where the electric field is strongest is 0 [mm].
More specifically, the emitter 40 is provided so that the emitter 40 is positioned between the adjacent conductor and the electrodes 20 and 21 when the cold cathode discharge lamp 1 is attached to the lighting device 50. Here, the proximity conductor is a conductor that is disposed in the vicinity of the cold cathode discharge lamp 1 and is electrically insulated from the lamp current path and that assists the starting. For example, the bottom plate 51 of the lighting device 50 corresponds to it.

The cold cathode discharge lamp 1 as described above is operated at a lighting frequency of 40 [kHz] to 120 [kHz] and a lamp current of 3.5 [mA] to 8.5 [mA].
<About electric field strength>
FIG. 5 is a diagram for explaining the electric field strength between the electrode and the metal conductor. When the cold cathode discharge lamp 1 is attached to the lighting device 50, as shown in FIG. 5, the distance L2 between the sleeve 30 and the bottom plate 51 is larger than the distance L1 between the electrode 20 and the bottom plate 51 as a proximity conductor. Shorter. Further, since the electrode 20 and the sleeve 30 are electrically connected, they have the same potential. Therefore, the electric field E ₁ generated between the electrode 20 and the bottom plate 51 has a lower electric field strength than the electric field E ₂ generated between the sleeve 30 and the bottom plate 51.

In particular, in the case of the cold cathode discharge lamp 1 according to the present embodiment, as described above, the glass bulb central side edge 30a of the sleeve 30 has the glass 20 central side edge 20a rather than the glass bulb central side edge 20a. It is located on the center side of the bulb, and the entire electrode 20 is accommodated in the sleeve 30. Therefore, the electric field E ₁ on the orbit that reaches the electrode 20 from the bottom plate 51 with the shortest distance while avoiding the sleeve 30 becomes longer to avoid the sleeve 30, and the electric field strength becomes lower.

  In the conventional cold cathode discharge lamp, since the emitter 40 is not provided at a position where the electric field strength is high enough to induce ion bombardment at the time of starting, secondary electrons are hardly generated in the glass bulb 10 at the time of starting, and the electric field strength is reduced. However, it was difficult to start a slight discharge under low conditions. However, in the cold cathode discharge lamp 1 according to the present embodiment, the emitter 40 is provided on the trajectory that reaches the electrode 20 from the bottom plate 51 with the shortest distance while avoiding the sleeve 30, and the position is subjected to ion bombardment at the start. Since the electric field strength is high enough to be attracted, secondary electrons are likely to be generated in the glass bulb 10 at the time of starting, and the startability in the dark is improved even under a low electric field strength.

<Dark start characteristics>
As described above, the conventional cold cathode discharge lamp 2000 as shown in FIG. 1 has poor dark startability, and is particularly lit when the metal sleeve 2002 covers the entire electrode 2004 as indicated by a two-dot chain line 2006. The more difficult it is, the worse the dark start characteristics. This is confirmed by experiments and will be described below.

FIG. 6 is a cross-sectional view showing a conventional discharge lamp used in an experiment of dark starting characteristics. FIG. 7 is a diagram illustrating the influence of the sleeve on the dark start characteristic.
As shown in FIG. 6, the lamp 2100 used in the experiment is such that the electrodes 2120 and 2121 are bottomed cylindrical hollow electrodes and the emitter 2140 is provided on the outer surface of the electrode 2120, and the sleeve 2130, Except for the fact that 2131 has different lengths in the tube axis X direction, it basically has the same configuration as the lamp 1 according to the present embodiment. Therefore, the same components as those in this embodiment are denoted by the same reference numerals as those of the present embodiment, and the description thereof is omitted.

  The lamp 2100 used in the experiment has a total length of 617 [mm]. The glass bulb 2110 has an inner diameter of 2.4 [mm], an outer diameter of 3.0 [mm], and a gas pressure of 60 Torr in the neon / argon mixed gas (Ne95 [%] + Ar5 [%]). Is enclosed. The electrodes 2120 and 2121 are made of nickel and have a length in the tube axis X direction of 5.5 [mm], an outer diameter of 2.1 [mm], and an inner diameter of 1.8 [mm]. The internal leads 2122a and 2123a have a length of 3 [mm] in the tube axis X direction. The emitter 2140 has a length K in the tube axis X direction of 1.6 [mm], and extends from the glass bulb central side edge to the glass bulb central side edge 2120a of the electrode 2120 in the tube axis X direction. The distance M is 0.5 [mm].

  As shown in FIG. 7, in the experiment, three types of lamps having different lengths in the tube axis X direction of the sleeves 2130 and 2131 were produced, and the influence of the sleeve on the dark starting characteristics was examined. The characteristics of each of the three types of lamps will be described. The lamp 2100 in which the length in the tube axis X direction of the sleeves 2130 and 2131 is 7.2 [mm] is the edge 2120a and 2121a on the glass bulb center side of the electrodes 2120 and 2121. Is positioned 2.0 mm from the edge of the sleeve 2130, 2131 on the glass bulb center side, and a part of the electrodes 2120, 2121 protrudes to the outside of the sleeve 2130, 2131. A lamp 2100 having a length of 9.2 [mm] in the tube axis X direction of the sleeves 2130 and 2131 is provided on the glass bulb central side edges 2120a and 2121a of the electrodes 2120 and 2121 and the glass bulb central side of the sleeves 2130 and 2131. The edge is substantially at the same position. In the lamp 2100 with the length of the sleeve 2130, 2131 in the tube axis X direction being 11.2 [mm], the edges 2120a, 2121a on the glass bulb center side of the sleeves 2130, 2131 are on the glass bulb center side of the electrodes 2120, 2121. The electrode 2120, 2121 is entirely housed in the sleeves 2130, 2131, being positioned on the center side of the glass bulb 2.0 mm from the end edge.

  Three lamps 2100 were produced for each type, and after starting for 48 [h] in a dark room, the start time t [ms] of each lamp 2100 was measured at a constant temperature of ambient temperature 25 [° C.], and the average of each type An attempt was made to calculate the start time t [ms]. However, the lamps 2100 in which the lengths of the sleeves 2130 and 2131 in the tube axis X direction are 11.2 [mm] were not lit because the dark start characteristics were extremely poor. As can be seen from this result, the lamp in which the entire electrode is housed in the sleeve needs to be provided with an emitter at a position where the electric field strength is high enough to induce ion bombardment at the time of starting.

In consideration of the problem that the emitter is scattered by ion bombardment at the start, the scattered material reacts with mercury to form amalgam, the inner surface of the glass bulb is blackened by the amalgam, and the luminous flux of the lamp is lost. The emitter is preferably provided near the sealing portion.
[Modification]
The configuration of the cold cathode discharge lamp 1 according to the present embodiment is not limited to the above configuration, and for example, the configurations shown in the first to seventh modifications may be considered. Note that the cold cathode discharge lamps according to the first to thirteenth modifications basically have the same configuration as the cold cathode discharge lamp 1 of the present embodiment. Therefore, the description of the common parts is simplified, and only different parts are described in detail.

<Modification 1>
FIG. 8 is an enlarged cross-sectional view showing one end portion of the cold cathode discharge lamp of the first modification. The cold cathode discharge lamp 100 shown in FIG. 8 is greatly different from the cold cathode discharge lamp 1 according to the present embodiment in that the sleeve 130 is made of a solder layer formed on the outer surface of the glass bulb 110. The configuration of this part is almost the same as that of the cold cathode discharge lamp 1.

  The cold cathode discharge lamp 100 includes a glass bulb 110 having a phosphor layer 116 formed on the inner surface, an electrode 120 disposed in an end portion 112 of the glass bulb 110, and a sleeve provided on the outer periphery of the end portion 112. 130 and an emitter 140. The electrode 120 is electrically connected to the sleeve 130 via a lead wire 122 composed of an internal lead wire 122a and an external lead wire 122b sealed in the sealing portion 114.

  The sleeve 130 has a cap shape including a joining portion 131 joined to the external lead wire 122b and a thin film portion 132 as a portion other than the joining portion 131, and is formed on the outer surface of the end 112 of the glass bulb 110. It is provided so as to cover the end portion 112. The sleeve 130 is electrically connected to a lamp holder (not shown) that holds the end 112 of the cold cathode discharge lamp 100 when the cold cathode discharge lamp 100 is attached to a lighting device (not shown). And electric power is supplied from the lighting circuit of a lighting device via a lamp holder (not shown).

  The joint portion 131 is a portion where the sleeve 130 is electrically connected to the lead wire 122. Since the joining portion 131 has a substantially conical shape in appearance, the area of the outer surface is small despite completely covering the entire outer surface of the external lead wire 122b. Therefore, since the area of the outer surface of the sleeve 130 is small and the heat dissipation action is also small, the temperature of the lead wire 122 is hardly lowered.

Further, since the external lead wire 122b is completely covered with the sleeve 130, there is little possibility that the external lead wire 122b is bent or the sealing portion 114 is damaged due to stress applied to the external lead wire 122b.
Note that the material forming the sleeve 130 is not limited to solder, and may be any material having at least conductivity. However, a material having a low thermal conductivity is preferable so that the heat dissipation action of the sleeve 130 does not increase. In general, solder is suitable as a material for the sleeve 130 because of its good conductivity, low thermal conductivity, and low price. In particular, a solder mainly composed of tin (Sn), tin-indium (In) alloy, tin-bismuth (Bi) alloy, or the like is more preferable because the sleeve 130 having high mechanical strength can be formed. . Among them, among antimony (Sb), zinc (Zn), aluminum (Al), gold (Au), silver (Ag), copper (Cu), iron (Fe), platinum (Pt) and palladium (Pd) The solder to which at least one kind is added is more suitable because it can form the sleeve 130 that is difficult to peel off from the glass bulb 110 because it is familiar with glass. In addition, solder that does not contain lead is preferable because the cold cathode discharge lamp 100 in consideration of the environment can be manufactured.

If the material forming the sleeve 130 is familiar with tungsten, the external lead 122b may be made of tungsten. That is, it can be considered that the entire lead wire 122 is formed of tungsten. By doing in this way, the disconnection defect of the lead wire 122 decreases and the cost of components can be reduced.
The sleeve 130 can be formed by a known dipping method (for example, Japanese Patent Application Laid-Open No. 2004-146351). A method for forming the sleeve 130 by the dipping method will be briefly described. For example, the end portion 112 of the glass bulb 110 in which the electrode 120 is sealed is immersed in molten solder in the melting tank. When the end 112 is immersed in the molten solder, ultrasonic waves may be applied. Since such a dipping method can form the sleeve 130 easily and inexpensively, the cold cathode discharge lamp 100 can be manufactured inexpensively.

The sleeve 130 may be formed by a method other than the dipping method. For example, you may form by methods, such as vapor deposition and plating.
It is conceivable that the outer surface of the sleeve 130 is covered with a material having conductivity and low thermal conductivity. For example, it is conceivable to cover the outer surface with a cylindrical member made of tantalum. Thereby, it is possible to make the sleeve difficult to peel off.

In addition, the electrode 120 has a rod shape, but is not limited thereto, and may have a bottomed cylindrical shape or a flat plate shape.
<Modification 2>
FIG. 9 is an enlarged cross-sectional view showing one end portion of the cold cathode discharge lamp of the second modification. The cold cathode discharge lamp 200 shown in FIG. 9 is greatly different from the cold cathode discharge lamp 1 according to the present embodiment in that the auxiliary emitter 241 is provided on the outer surface of the electrode 220. The configuration is almost the same as that of the cold cathode discharge lamp 1.

  The cold cathode discharge lamp 200 includes a glass bulb 210 having a phosphor layer 216 formed on the inner surface, an electrode 220 disposed in an end portion 212 of the glass bulb 210, and a sleeve provided on the outer periphery of the end portion 212. 230, an emitter 240 having substantially the same configuration as the emitter 40 according to the present embodiment, and an auxiliary emitter 241 different from the emitter 240. The electrode 220 is electrically connected to the sleeve 230 via a lead wire 222 composed of an internal electrode 222 a and an external electrode 222 b sealed in the sealing portion 214 and a joint portion 232.

  The auxiliary emitter 241 is provided on the outer periphery of the electrode 220 and is made of the same material as the emitter 240, for example. The edge 241 a on the glass bulb center side of the auxiliary emitter 241 is provided closer to the sealing portion 214. In the vicinity where the emitter 241 is provided, blackening occurs due to a large amount of cesium ions released by ion bombardment at the time of starting, so that the blackening does not affect the luminance of the cold cathode discharge lamp 200 as much as possible. It is preferable to provide the end edge 241a near the sealing portion 214 that is less likely to be affected.

In this modification, the electrode 220 has a rod shape, but is not limited thereto, and may have a bottomed cylindrical shape or a flat plate shape.
<Modification 3>
FIG. 10 is an enlarged cross-sectional view showing one end portion of the cold cathode discharge lamp of the third modification. The cold cathode discharge lamp 300 shown in FIG. 10 is a cold cathode according to the present embodiment in that the electrode 320 is a bottomed hollow electrode and an emitter 340 is provided on the inner surface of the electrode 320. This is largely different from the discharge lamp 1 and the other parts are almost the same as the cold cathode discharge lamp 1.

  The cold cathode discharge lamp 300 includes a glass bulb 310 having a phosphor layer 316 formed on its inner surface, a bottomed cylindrical electrode 320 disposed in the end 312 of the glass bulb 310, and an outer periphery of the end 312. And an emitter 340 provided on the inner surface of the cylinder of the electrode 320. The electrode 320 is electrically connected to the sleeve 330 via a lead wire 322 composed of an internal electrode 322 a and an external electrode 322 b sealed in the sealing portion 314 and a joint portion 332.

The electrode 320 is made of nickel (Ni), and the overall length of the cylindrical portion is 5.2 [mm], the outer diameter is 2.7 [mm], the inner diameter is 2.3 [mm], and the wall thickness is 0.2. [Mm]. Note that the electrode 320 is not limited to nickel, and for example, it is conceivable that the electrode 320 is made of niobium (Nb), tantalum (Ta), molybdenum (Mo), or tungsten (W).
The electrode 320 is disposed so that the tube axis of the tube portion and the tube shaft of the glass bulb 310 are substantially coincident with each other, and the interval between the outer peripheral surface of the tube portion and the inner surface of the glass bulb 310 is the outer periphery of the tube portion. It is almost uniform over the entire area. Specifically, the distance between the outer peripheral surface of the cylindrical portion and the inner surface of the glass bulb 310 is 0.15 [mm]. Since the interval is narrowed in this way, discharge does not enter the interval, and discharge occurs only inside the electrode 320. Therefore, the sputtered material scattered by the discharge is less likely to adhere to the inner surface of the glass bulb 310, and the cold cathode discharge lamp 300 has a long life. As described above, since the electrode 320 is a hollow electrode, sputtering from the electrode to the inner surface of the glass bulb can be reduced, and mercury consumption can be reduced.

Furthermore, since it is difficult for the discharge to go around to the lead wire 322 side, the lead wire 322 is hardly heated by the discharge, and the cold cathode discharge lamp 300 can have a long life.
Note that the distance between the outer peripheral surface of the cylindrical portion of the electrode 320 and the inner surface of the glass bulb 310 is not necessarily 0.15 [mm]. However, in order to prevent discharge from entering, the distance is 0. It is preferable that it is 2 [mm] or less.

  Emitter 340 is provided over the entire area of the inner surface of electrode 320 using the same material as emitter 40 according to the present embodiment. The emitter 340 is not necessarily provided over the entire inner surface of the cylinder, and may be provided on a part of the inner surface. Since the emitter 340 is provided on the inner surface of the electrode 320, the inner surface of the glass bulb 310 is not easily blackened by cesium ions.

<Modification 4>
FIG. 11A is an enlarged plan view showing one end portion of the cold cathode discharge lamp of Modification 4, FIG. 11B is a cross-sectional view taken along line aa shown in FIG. 11A, and FIG. It is a perspective view which shows the sleeve of the modification 4.
The cold cathode discharge lamp 400 shown in FIGS. 11A and 11B is that a slit 431 for improving the electric field strength between the electrode 420 and a neighboring conductor (not shown) is formed in the sleeve 430. This is largely different from the cold cathode discharge lamp 1 according to the present embodiment, and the configuration of the other parts is substantially the same as that of the cold cathode discharge lamp 1.

  The cold cathode discharge lamp 400 includes a glass bulb 410 having a phosphor layer 416 formed on its inner surface, an electrode 420 disposed in the end portion 412 of the glass bulb 410, and a sleeve provided on the outer periphery of the end portion 412. 430 and an emitter 440 provided on the inner surface of the glass bulb 410. The electrode 420 is electrically connected to the sleeve 430 via a lead wire 422 including the internal electrode 422a and the external electrode 422b, and a joint portion 432.

  As shown in FIGS. 11A and 11B, the emitter 440 is slightly wider than the slit 431 in the radial direction of the glass bulb 410 and is provided at a position facing the slit 431. Thus, by providing the emitter 440 only in the region where the electric field strength is high, wasteful consumption of the material of the emitter 440 can be suppressed. In order to facilitate manufacture of the cold cathode discharge lamp 400, the emitter 440 may be provided in a cylindrical shape over the entire circumference of the glass bulb 410 in the radial direction. The emitter 440 may be provided on the outer surface of the electrode 420, for example, in a cylindrical shape in accordance with the position of the slit 431.

In this modification as well, the shape of the electrode 420 is not limited to a rod shape, but may be a bottomed cylindrical shape or a flat plate shape. However, the outer surface in the case of a bottomed cylindrical shape is the outer surface of the electrode 420. That means.
The sleeve 430 is a cylindrical body having a substantially C-shaped cross section, has a slit 431, and is attached to the outer periphery of the end portion 412 so as to be fitted to the end portion 412 of the glass bulb 410. Unlike the slit 30a according to the present embodiment, the slit 431 also has a function for improving the electric field strength between the electrode 420 and a nearby conductor (not shown). That is, in the slit 431 according to the modification example 4, first, even if a slight dimensional error occurs between the inner diameter of the sleeve 430 and the outer diameter of the glass bulb 410, similarly to the slit 30a according to the present embodiment. The inner surface of the sleeve 430 has a function for closely contacting the outer surface of the glass bulb 410. Secondly, by forming a portion where the sleeve 430 is not provided on the outer periphery of the glass bulb 410, that is, a portion where the sleeve 430 is not interposed between the electrode 420 and the adjacent conductor, It has a function of increasing the electric field strength between adjacent conductors.

  The slit 431 is wider than the slit 30a according to this embodiment, and the slit width J shown in FIG. 11C is about 1/6 of the outer circumference of the glass bulb 410, for example, an outer diameter of 4 [mm]. In the case of the glass bulb 410 (inner diameter 3 [mm]), it is about 2 [mm]. The slit width J is not limited to the above. However, in order to sufficiently increase the electric field strength, the slit width J should not be wide to some extent, and is 1/3 or more of the outer circumference of the glass bulb 410, for example, an outer diameter of 4 [mm] ( In the case of the glass bulb 410 having an inner diameter of 3 [mm], it is preferably 4 [mm] or more.

The emitter 440 is provided on the inner surface of the glass bulb 410 where the sleeve 430 is not provided on the outer periphery, that is, on the inner surface of the portion where the slit 431 is located on the outer periphery. When the emitter 440 is provided at a position where the electric field strength is high in this way, secondary electrons are likely to be generated in the glass bulb 410 at the time of starting.
As shown in FIGS. 11A and 11B, the emitter 440 is not limited to the case where it is provided on the inner surface of a part of the region where the slit 431 is located on the outer periphery, and the slit 431 on the outer periphery. It may be provided on the inner surface of all the regions in the portion where is located. Further, a part of the emitter 440 may be provided on the inner surface of a portion other than the portion where the slit 431 is located on the outer periphery.

The sleeve 430 is not limited to a cylinder having a substantially C-shaped cross section, and may be a cylinder having a cross section of a polygonal shape such as a substantially triangular shape or a substantially square shape, or a cylindrical body having an elliptical shape, provided with a slit 431. Further, the shape of the slit 431 is not limited to a linear shape as shown in FIG. 11, and may be a curved shape or a bent shape.
<Modification 5>
12A is an enlarged plan view showing one end portion of the cold cathode discharge lamp of Modification 5, FIG. 12B is a cross-sectional view taken along the line bb shown in FIG. 12A, and FIG. It is a perspective view which shows the sleeve of the modification 5. FIG.

12 (a) and 12 (b), the cold cathode discharge lamp 500 has a notch 531 formed in the sleeve 530 for improving the electric field strength between the electrode 520 and the adjacent conductor (not shown). This is largely different from the cold cathode discharge lamp 1 according to the present embodiment, and the configuration of other parts is almost the same as that of the cold cathode discharge lamp 1.
The cold cathode discharge lamp 500 includes a glass bulb 510 having a phosphor layer 516 formed on its inner surface, an electrode 520 disposed in an end portion 512 of the glass bulb 510, and a sleeve provided on the outer periphery of the end portion 512. 530 and an emitter 540 provided on the inner surface of the glass bulb 510. The electrode 520 is electrically connected to the sleeve 530 via a lead wire 522 and a joint portion (not shown).

The sleeve 530 is a cylindrical body having a circular cross section, has a notch portion 531, and is attached to the outer periphery of the end portion 512 so as to be fitted to the end portion 512 of the glass bulb 510.
The notch 531 has a function for improving the electric field strength between the electrode 520 and the adjacent conductor (not shown). The notch 531 has a length in the tube axis direction of the glass bulb 510 of 5 [mm] and a length in the radial direction of 2 [mm], for example.

By providing the notch 531, a portion where the sleeve 530 is not provided on the outer periphery of the glass bulb 510, that is, a portion where the sleeve 530 is not interposed between the electrode 520 and the adjacent conductor is formed, and the electrode inside the glass bulb 510 is formed. The distance between the 520 and the adjacent conductor is shortened to increase the electric field strength between the electrode 520 sandwiching the portion and the adjacent conductor. In order to sufficiently increase the electric field strength, the opening area of the notch 531 is preferably 10 [mm ² ] or more.

FIG. 13 is a perspective view showing a modification of the sleeve. As shown in FIG. 13, the opening area of the notch 551 of the sleeve 550 can be increased by increasing the radial width of the glass bulb 510. Further, by providing the slit 552 separately from the notch 551, it can be easily attached to the glass bulb 510.
The emitter 540 is provided on the inner surface of the glass bulb 510 where the sleeve 530 is not provided on the outer periphery, that is, on the inner surface of the portion where the notch 531 is located on the outer periphery. When the emitter 540 is provided at a position where the electric field strength is high in this way, secondary electrons are likely to be generated in the glass bulb 510 at the time of starting.

  As shown in FIGS. 12A and 12B, the emitter 540 is not limited to the case where it is provided on the inner surface of a part of the region where the notch 531 is located on the outer periphery. You may provide in the inner surface of all the areas | regions in the part in which the part 531 is located. Further, a part of the emitter 540 may be provided on the inner surface of a portion other than the portion where the notch portion 531 is located on the outer periphery. For example, the emitter 540 may be provided in a cylindrical shape over the entire circumference of the glass bulb 510 in the radial direction. Good. Further, the emitter 540 may be provided on the outer surface of the electrode 520, for example, in a cylindrical shape in accordance with the position of the notch 531.

In this modification as well, the shape of the electrode 520 is not limited to a rod shape, but may be a bottomed cylindrical shape or a flat plate shape. However, the outer surface in the case of a bottomed cylindrical shape is the outer surface of the electrode 520. That means.
Note that the sleeve 530 is not limited to a cylindrical body having a circular cross section, and may be a cylindrical body having a cross section of a polygon such as a substantially triangular shape or a substantially square shape, or an elliptical cylindrical body provided with a notch portion 531. Further, the shape of the notch 531 is not limited to a square as shown in FIG. 12, and may be a polygon other than a square, a circle, an ellipse, or the like.

<Modification 6>
FIG. 14 is an enlarged cross-sectional view showing one end portion of the cold cathode discharge lamp of Modification 6. In the cold cathode discharge lamp 600 shown in FIG. 14, the edge 620a of the electrode 620 on the center side of the glass bulb is positioned closer to the center of the glass bulb than the edge 630a of the sleeve 630 on the center side of the glass bulb. It is greatly different from the cold cathode discharge lamp 1 according to the present embodiment in that it is provided at a position in consideration of the positional relationship, and the configuration of other parts is almost the same as the cold cathode discharge lamp 1. .

  The cold cathode discharge lamp 600 includes a glass bulb 610 having a phosphor layer 616 formed on its inner surface, an electrode 620 disposed in the end 612 of the glass bulb 610, and a sleeve provided on the outer periphery of the end 612. 630 and an emitter 640 provided on the inner surface of the glass bulb 610. The electrode 620 is electrically connected to the sleeve 630 via a lead wire 622 composed of an internal lead wire 622 a and an external lead wire 622 b sealed in the sealing portion 614 and a joint portion 632.

The emitter 640 is closer to the sealing portion 614 than the edge 620a on the glass bulb center side of the electrode 620 on the inner surface of the glass bulb 610, and closer to the glass bulb center side than the edge 630a on the glass bulb center side of the sleeve 630. It is provided in the position.
The sealing portion 614 side of the electrode 620 from the edge 620a on the glass bulb center side is out of the main light emitting region of the lamp. Therefore, even if the emitter 640 is provided there, the emitter 640 is scattered by ion bombardment at the time of starting, and the scattered matter and mercury react to form an amalgam, and the inner surface of the glass bulb 610 is blackened by the amalgam. The problem of loss of luminous flux is unlikely to occur.

On the other hand, since the electric field strength between the electrode 620 and the adjacent conductor (not shown) is higher on the glass bulb center side than the edge 630a on the glass bulb center side of the sleeve 630, if an emitter 640 is provided there, an emitter 640 can be provided at startup. Secondary electrons are easily generated in the glass bulb 610.
The length of the sleeve 630 in the tube axis direction of the glass bulb 610 is preferably 19 [mm] or less depending on the thickness of the sleeve 630. Further, since the glass bulb central portion side of the electrode 620 is closer to the glass bulb central portion than the edge 620a of the glass bulb central portion side, it becomes the main light emitting region of the lamp. The thickness is more preferably 10 [mm] or less. In addition, in order to suppress the heat radiation from the sleeve 630, it is preferable to make the sleeve 630 as small as possible, and the length of the sleeve 630 is preferably 19 [mm] or less.

In this modification, the electrode 620 has a rod shape, but is not limited thereto, and may have a bottomed cylindrical shape or a flat plate shape.
<Modification 7>
FIG. 15 is an enlarged cross-sectional view showing one end of the cold cathode discharge lamp of Modification 7. In the cold cathode discharge lamp 700 shown in FIG. 15, the edge 720a of the electrode 720 on the center side of the glass bulb is positioned closer to the center of the glass bulb than the end 730a of the sleeve 730 on the center side of the glass bulb. It is greatly different from the cold cathode discharge lamp 1 according to the present embodiment in that it is provided at a position in consideration of the positional relationship, and the configuration of other parts is almost the same as the cold cathode discharge lamp 1. .

  The cold cathode discharge lamp 700 includes a glass bulb 710 having a phosphor layer 716 formed on its inner surface, an electrode 720 disposed in an end 712 of the glass bulb 710, and a sleeve provided on the outer periphery of the end 712. 730 and an emitter 740 provided on the outer periphery of the electrode 720. The electrode 720 is electrically connected to the sleeve 730 via a lead wire 722 composed of an internal electrode 722 a and an external electrode 722 b sealed in the sealing portion 714 and a joint portion 732.

  The emitter 740 is provided on the outer surface of the electrode 720 at a position closer to the glass bulb center side than the edge 730a of the sleeve 730 on the glass bulb center side. Since the electric field strength between the electrode 720 and the adjacent conductor (not shown) is higher on the glass bulb central side than the edge 730a on the glass bulb central side of the sleeve 730, if the emitter 740 is provided there, the glass bulb is started at the start. Secondary electrons are likely to be generated in 710.

In addition, the emitter 740 is scattered by ion bombardment at the time of starting, and the scattered matter and mercury react to form amalgam, and the amalgam causes the inner surface of the glass bulb 710 to blacken, resulting in a loss of the luminous flux of the lamp. In order to make it difficult, it is preferable to provide the emitter 740 on the sealing portion 714 side.
The length of the sleeve 730 in the tube axis direction of the glass bulb 710 is, for example, 7.5 [mm]. The length of the sleeve 730 is preferably 19 [mm] or less depending on the thickness of the sleeve 730. Furthermore, since the glass bulb central portion side of the electrode 720 is closer to the glass bulb central portion than the edge 720a of the glass bulb central portion side, it becomes the main light emitting region of the lamp. The thickness is more preferably 10 [mm] or less. In addition, in order to suppress heat radiation from the sleeve 730, it is preferable to make the sleeve 730 as small as possible, and the length of the sleeve 730 is preferably 19 mm or less.

In this modification, the electrode 720 has a rod shape, but is not limited thereto, and may have a bottomed cylindrical shape or a flat plate shape.
<Modification 8>
16 (a) is a front view showing one end of the cold cathode discharge lamp of the modification 8, FIG. 16 (b) is a side view of the modification 8, and FIG. 16 (c) is surrounded by a circle shown in FIG. It is an expanded sectional view of a part.

  A cold cathode discharge lamp 800 shown in FIGS. 16A and 16B is greatly different from the cold cathode discharge lamp 1 according to the present embodiment in that a metal mesh is used for the sleeve 830. However, the configuration of the other parts is almost the same as that of the cold cathode discharge lamp 1. Therefore, only the above differences will be described, and descriptions of other configurations will be omitted.

The cold cathode discharge lamp 800 includes a glass bulb 810, an electrode (not shown) disposed inside at least one end 812 of the glass bulb 810, and the electrode and lead wire 822 on the outer periphery of the end 812. And a sleeve 830 as a metal conductor electrically connected to each other.
The sleeve 830 includes a main body portion 831, a clamping portion 832, and a conductive portion 833, and a lamp holder that holds the end portion 812 of the cold cathode discharge lamp 800 when the cold cathode discharge lamp 800 is attached to a lighting device (not shown). (Not shown) and electrically connected.

The main body 831 is a cap-shaped member that covers the outer periphery of the end 812, and is made of a metal mesh. The mesh of the main body portion 831 preferably has a wire diameter of 5 [μm] to 120 [μm] and an opening of 0.1 [mm] to 3 [mm]. The main body 831 is preferably made of a metal such as an iron / nickel alloy in order to obtain good conductivity.
The sandwiching portion 832 is a cylindrical body having a C-shaped cross section that is fixed to the inside of the opening of the main body portion 831 by welding or the like. The sandwiching portion 832 plays a role of sandwiching the glass bulb 810 and fixing the main body portion 831 to the glass bulb 810. Fulfill. The inner diameter of the holding portion 832 is designed to be slightly smaller than the outer diameter of the end portion 812. When the sleeve 830 is attached to the end portion 812, the end portion 812 pushes the holding portion 832 from the inside. Then, the end 812 is pushed into the main body 831. The sandwiching portion 832 fastens the end portion 812 from the outside with a force for returning to the original shape, so that the main body portion 831 is fixed to the glass bulb 810 by the force.

The conductive portion 833 is provided on the side opposite to the opening side of the main body portion 831 so as to be in contact with both the main body portion 831 and the lead wire 822, and electrically connects the main body portion 831 and the lead wire 822. It plays a role to connect. Also, it serves as a stopper for preventing the main body portion 831 from coming off the end portion 812.
As shown in FIG. 16C, the conductive portion 833 has a disc shape having a hole portion 833a for inserting the external lead wire 822b of the lead wire 822 in the center. The hole portion 833a has a mortar shape in which the main body portion side increases in diameter toward the main body portion side, and a welded portion between the external lead wire 822b and the internal lead wire 822a is formed in the mortar-shaped portion. 822c is stored.

  The conductive portion 833 is formed of conductive rubber, and when the temperature of the sleeve reaches about 140 [° C.], the conductive portion 833 is melted and the main body portion 831 and the lead wire 822 are insulated. Therefore, even when the sleeve 830 becomes high temperature due to overcurrent, it is possible to prevent the resin member such as an optical sheet from being deformed by the heat when mounted on an illumination device such as a backlight unit. Further, by forming a portion where the sleeve 830 is not provided on the outer periphery of the glass bulb 810, that is, a portion where the sleeve 830 is not interposed between the electrode and the proximity conductor, the electrode and the proximity conductor between which the portion is sandwiched are formed. It has a function of increasing the electric field strength between them.

<Modification 9>
FIG. 17 is a front view showing one end portion of the cold cathode discharge lamp of Modification 9. The cold cathode discharge lamp 850 shown in FIG. 17 is greatly different from the cold cathode discharge lamp 1 according to the present embodiment in that the sleeve 880 is coiled. This is almost the same as the discharge lamp 1. Therefore, only the above differences will be described, and descriptions of other configurations will be omitted.

The cold cathode discharge lamp 850 includes a glass bulb 860, an electrode (not shown) disposed inside at least one end 862 of the glass bulb 860, and the electrode and lead wire 872 on the outer periphery of the end 862. And a sleeve 880 as a metal conductor electrically connected to each other.
The sleeve 880 is obtained by bending a single metal wire into a coil shape, and includes a main body portion 881 wound around the outer periphery of the end portion 862 of the glass bulb 860 and a connection portion wound around the lead wire 872. 882. Before the metal wire is attached to the end 862 of the glass bulb 860, the diameter is 5 [μm] to 120 [μm], and the main body 881 has a mandrel diameter of 0.8 [mm] to 3.8 [mm]. ], The pitch length is 0.1 [mm] to 3 [mm], the connecting portion 882 has a mandrel diameter of 0.3 [mm] to 0.7 [mm], and the pitch length is 0 [mm]. .

  The sleeve 880 has a coil shape, and a portion where the sleeve 880 is not provided on the outer periphery of the glass bulb 860, that is, a portion where the sleeve 880 is not interposed between the electrode and the adjacent conductor is formed to sandwich the portion. It has a function of increasing the electric field strength between the electrode and the adjacent conductor. In order to obtain good dark start characteristics, the pitch length of the coil of the main body portion 881 is preferably within the above range. Further, in order to obtain good conductivity, the main body portion 881 is preferably made of a metal wire made of iron or nickel alloy.

  Since the mandrel diameter of the main body portion 881 is designed to be slightly smaller than the outer diameter of the glass bulb 860 and the mandrel diameter of the connection portion 882 is designed to be slightly smaller than the outer diameter of the lead wire 872, the main body portion 881 is made of the glass. The sleeve 880 is fixed to the glass bulb 860 by a force for fastening the bulb 860 and a force for fastening the lead wire 872 by the connecting portion 882. In order to more firmly fix the sleeve 880 to the glass bulb 860, the lead wire 872 and the connection portion 882 may be welded or bonded with a conductive adhesive.

<Modification 10>
FIG. 18A is a front view showing one end portion of the cold cathode discharge lamp of Modification Example 10, and FIG. 18B is a perspective view showing the sleeve of Modification Example 10. FIG. The cold cathode discharge lamp 900 shown in FIGS. 18 (a) and 18 (b) is largely different from the cold cathode discharge lamp 1 according to the present embodiment in the configuration of the sleeve 930. This is substantially the same as the cold cathode discharge lamp 1. Therefore, only the above differences will be described, and descriptions of other configurations will be omitted.

The cold cathode discharge lamp 900 includes a glass bulb 910, an electrode (not shown) disposed inside at least one end 912 of the glass bulb 910, and the electrode and lead wire 922 on the outer periphery of the end 912. And a cylindrical sleeve 930 as a metal conductor electrically connected to each other.
The sleeve 930 is punched into a substantially U shape at one location on the outer peripheral surface, and the punched portion is a slit portion 931 for taking light into the end portion 912 of the glass bulb 910. The remaining three sides surrounded by the slit portion 931 form a clip portion 932 for fixing the sleeve 930 to the glass bulb 910. In the cold cathode discharge lamp 900, since the sleeve 930 is formed with the slit portion 931, that is, a portion where the sleeve 930 is not interposed between the electrode and the adjacent conductor, the gap between the electrode sandwiching the portion and the adjacent conductor is formed. It has a function of increasing the electric field strength. The substantially U-shaped punched portion is not limited to one place, and may be provided at a plurality of places.

Restriction pieces 933a to 933e are provided on the edge of the lead wire side of the sleeve 930. When the sleeve 930 is attached to the glass bulb 910, the end 912 of the glass bulb 930 is brought into contact with the restriction pieces 933a to 933e. Thus, the sleeve 930 is positioned.
Further, the sleeve 930 has a conductive portion 934 for electrically connecting the sleeve 930 and the lead wire 922 at the end edge on the lead wire 922 side. The conductive portion 934 is a long plate made of bimetal, and has a narrow bent portion 934a extending at the end edge on the lead wire 922 side, and a width provided at the tip of the bent portion 934a. The contact portion 934b is formed in a substantially V shape so as to sandwich the lead wire 922.

  The conductive portion 934 is bent at the bent portion 934a so that the contact portion 934b and the lead wire 922 are in contact with each other. When the temperature of the sleeve 930 reaches about 140 [° C.], the bent angle of the bent portion 934a is The contact portion 934b is separated from the lead wire 922, and the sleeve 930 and the lead wire 922 are insulated. Therefore, even when the overcurrent flows and the sleeve 930 becomes high temperature, it is possible to prevent the resin member such as the optical sheet from being deformed by the heat when the sleeve 930 is mounted on an illumination device such as a backlight unit.

Note that the conductive portion 934 does not necessarily need to be made of a bimetal and may have a configuration that does not deform. In that case, the contact portion 934b and the lead wire 922 may be welded.
<Modification 11>
FIG. 19 is an enlarged cross-sectional view showing one end portion of the cold cathode discharge lamp of Modification 11. A cold cathode discharge lamp 1000 shown in FIG. 19 is substantially the same as the cold cathode discharge lamp 1 according to the present embodiment except that the configuration of the sleeve 1030 is different. Therefore, only the configuration of the sleeve 1030 will be described in detail, and the description of the other configurations will be simplified.

  The cold cathode discharge lamp 1000 includes a glass bulb 1010 having a phosphor layer 1016 formed on the inner surface, an electrode 1020 disposed in an end portion 1012 of the glass bulb 1010, a sleeve 1030 provided at the end portion, And an emitter 1040 provided on the inner surface of the glass bulb 1010. The electrode 1020 is electrically connected to the sleeve 1030 via a lead wire 1022 including an internal lead wire 1022a and an external lead wire 1022b sealed in a sealing portion 1014.

The sleeve 1030 is made of an alloy of iron and nickel, and includes a cap portion 1031 that is a main body and a narrow tube portion 1032 that extends from an end portion of the cap portion 1031 on the closing side. In addition to this, the material of the sleeve 1030 may be a copper alloy such as phosphor bronze, brass, or white.
The cap portion 1031 is externally fitted to the end portion 1012 of the glass bulb 1010 so as to cover the outer surface thereof. In the drawing, no gap is provided between the cap portion 1031 and the glass bulb 1010, but a gap may be provided.

  An opening 1033 for inserting the external lead wire 1022b is provided at the end of the cap portion 1031 on the closing side, and the opening 1033 communicates with the inside of the thin tube portion 1032. The external lead wire 1022b is welded to the narrow tube portion 1032 by resistance welding, laser welding, or the like while being inserted into the narrow tube portion 1032 from the inside of the cap portion 1031 through the opening 1033. 1020 and the sleeve 1030 are electrically connected. Note that the external lead wire 1022b and the thin tube portion 1032 may be connected by caulking.

The sleeve 1030 is electrically connected to a lamp holder (not shown) that holds the end 1012 of the cold cathode discharge lamp 1000 when the cold cathode discharge lamp 1000 is attached to a lighting device (not shown).
The sleeve 1030 may be provided with a slit. The shape of the end portion 1012 of the glass bulb 1010 is likely to vary, and a dimensional error is likely to occur between the outer diameter of the glass bulb 1010 and the inner diameter of the sleeve 1030. However, if the sleeve 1030 is provided with a slit, even if such a dimensional error occurs, the slit absorbs the dimensional error, and the inner surface of the sleeve 1030 and the outer surface of the glass bulb 1010 are brought into close contact with each other. The sleeve 1030 can be stably fixed to the end portion 1012 of the glass bulb 1010.

<Modification 12>
FIG. 20 is an enlarged cross-sectional view showing one end of the cold cathode discharge lamp of Modification 12. A cold cathode discharge lamp 1100 shown in FIG. 20 is substantially the same as the cold cathode discharge lamp 1 according to the modification 11 except for the shape of the sleeve 1130. Therefore, only the configuration of the sleeve 1130 will be described in detail, and the description of the other configurations will be simplified.

  The cold cathode discharge lamp 1100 includes a glass bulb 1110 having a phosphor layer 1116 formed on the inner surface, an electrode 1120 disposed in an end portion 1112 of the glass bulb 1110, a sleeve 1130 provided at the end portion, And an emitter 1140 provided on the inner surface of the glass bulb 1110. The electrode 1120 is electrically connected to the sleeve 1130 via a lead wire 1122 including an internal lead wire 1122a and an external lead wire 1122b sealed with a sealing portion 1114.

  The sleeve 1130 is externally fitted to the end portion 1112 of the glass bulb 1110 so as to cover the outer surface thereof. The end of the sleeve 1130 on the closing side has a mortar shape that decreases in diameter toward the end edge, and an opening 1131 is provided in the end edge that has the smallest diameter. The external lead wire 1122b is welded to the sleeve 1130 by resistance welding, laser welding, or the like with the tip inserted into the opening 1131, and the electrode 1120 and the sleeve 1130 are electrically connected by the welded portion. Yes.

The sleeve 1130 has a configuration in which the end on the closing side has a mortar shape as described above, so that the external lead wire 1122b can be easily inserted into the opening 1131.
The sleeve 1130 may be provided with a slit. The shape of the end portion 1112 of the glass bulb 1110 is likely to vary, and a dimensional error is likely to occur between the outer diameter of the glass bulb 1110 and the inner diameter of the sleeve 1130. However, if the sleeve 1130 is provided with a slit, even if such a dimensional error occurs, the slit absorbs the dimensional error and the inner surface of the sleeve 1130 and the outer surface of the glass bulb 1110 are brought into close contact with each other. The sleeve 1130 can be stably fixed to the end 1112 of the glass bulb 1110.

<Modification 13>
FIG. 21 is an enlarged cross-sectional view showing one end portion of the cold cathode discharge lamp of Modification 13. A cold cathode discharge lamp 1200 shown in FIG. 21 is substantially the same as the cold cathode discharge lamp 1 according to the modification 12 except for the shape of the sleeve 1230. Therefore, only the configuration of the sleeve 1230 will be described in detail, and the description of the other configurations will be simplified.

  The cold cathode discharge lamp 1200 includes a glass bulb 1210 having a phosphor layer 1216 formed on the inner surface, an electrode 1220 disposed in an end portion 1212 of the glass bulb 1210, a sleeve 1230 provided at the end portion, And an emitter 1240 provided on the inner surface of the glass bulb 1210. The electrode 1220 is electrically connected to the sleeve 1230 via a lead wire 1222 including an internal lead wire 1222a and an external lead wire 1222b sealed with a sealing portion 1214.

  The sleeve 1230 includes a cap portion 1231 that is a main body and a narrow tube portion 1232 that extends from an end portion of the cap portion 1231 on the closing side. The cap portion 1231 is externally fitted to the end portion 1212 of the glass bulb 1210 so as to cover the outer surface thereof. The end of the cap portion 1231 on the closing side has a mortar shape that decreases in diameter toward the end edge, and an opening 1233 through which the external lead wire 1222b is inserted is formed in the end edge having the smallest diameter. The opening 1233 communicates with the inside of the narrow tube portion 1232.

  The external lead wire 1222b is welded to the narrow tube portion 1232 by resistance welding, laser welding, or the like while being inserted into the narrow tube portion 1232 from the inside of the cap portion 1231 through the opening 1233, and the electrode 1220 is welded by the welded portion. And the sleeve 1230 are electrically connected. Note that the external lead wire 1222b and the narrow tube portion 1232 may be connected by caulking.

The sleeve 1230 has a configuration in which the end on the closing side has a mortar shape as described above, so that the external lead wire 1222 b can be easily inserted into the opening 1231. In addition, since the thin tube portion 1232 is provided, the external lead wire 1222b is easily connected by welding or caulking.
The sleeve 1230 may be provided with a slit. The shape of the end portion 1212 of the glass bulb 1210 is likely to vary, and a dimensional error is likely to occur between the outer diameter of the glass bulb 1210 and the inner diameter of the sleeve 1230. However, if the sleeve 1230 is provided with a slit, even if such a dimensional error occurs, the slit absorbs the dimensional error, and the inner surface of the sleeve 1230 and the outer surface of the glass bulb 1210 are brought into close contact with each other. The sleeve 1230 can be stably fixed to the end portion 1212 of the glass bulb 1210.

<Other variations>
Although the cold cathode discharge lamp according to the present embodiment has been described based on the embodiment, the discharge lamp according to the present invention is not limited to the above. For example, the discharge lamp according to the present invention may be a discharge lamp in which the configurations of the present embodiment and the first to thirteenth modifications are appropriately combined. The discharge lamp according to the present invention is not limited to a cold cathode discharge lamp. The emitter may be provided not only on one end side of the glass bulb but also on both end sides. Furthermore, the following modifications are also conceivable.

1. About Glass Bulb (1) About UV Absorption 254 [nm] and 313 [nm] UV can be absorbed by doping glass, which is a material of glass bulb, with a predetermined amount of transition metal oxide depending on its type. . Specifically, for example, in the case of titanium oxide (TiO ₂ ), by doping at a composition ratio of 0.05 [mol%] or more, ultraviolet rays of 254 [nm] are absorbed and the composition ratio is doped at 2 [mol%] or more. Thus, it is possible to absorb ultraviolet rays of 313 [nm]. However, when titanium oxide is doped more than the composition ratio of 5.0 [mol%], the glass is devitrified, so the composition ratio is 0.05 [mol%] or more and 5.0 [mol%] or less. It is preferable to dope in the range.

In the case of cerium oxide (CeO ₂ ), 254 [nm] ultraviolet rays can be absorbed by doping with a composition ratio of 0.05 [mol%] or more. However, when cerium oxide is doped more than 0.5 [mol%], the glass is colored, so cerium oxide has a composition ratio of 0.05 [mol%] to 0.5 [mol%]. It is preferable to dope in the following range. In addition, since coloring of glass by cerium oxide can be suppressed by doping tin oxide (SnO) in addition to cerium oxide, cerium oxide can be doped to a composition ratio of 5.0 [mol%] or less. . In this case, if cerium oxide is doped with a composition ratio of 0.5 [mol%] or more, ultraviolet rays of 313 [nm] can be absorbed. However, even in this case, when the composition ratio of cerium oxide is more than 5.0 [mol%], the glass is devitrified.

  In the case of zinc oxide (ZnO), ultraviolet rays of 254 [nm] can be absorbed by doping at a composition ratio of 2.0 [mol%] or more. However, when zinc oxide is doped more than 20 [mol%], the glass may be devitrified, so zinc oxide is in the range of 2.0 [mol%] to 20 [mol%]. It is preferable to dope.

Further, in the case of iron oxide (Fe ₂ O ₃ ), 254 [nm] ultraviolet rays can be absorbed by doping at a composition ratio of 0.01 [mol%] or more. However, when iron oxide is doped more than the composition ratio of 2.0 [mol%], the glass is colored, so the iron oxide is contained in the composition ratio of 0.01 [mol%] to 2.0 [mol%]. It is preferable to dope in the following range.

(2) Infrared transmission coefficient The infrared transmission coefficient indicating the water content in the glass is adjusted to be in the range of 0.3 to 1.2, particularly 0.4 to 0.8. Is preferred. When the infrared transmittance coefficient is 1.2 or less, it becomes easy to obtain a low dielectric loss tangent applicable to a high voltage application lamp such as an external electrode fluorescent lamp (EEFL) or a long cold cathode fluorescent lamp, and 0.8 or less. If so, the dielectric loss tangent becomes sufficiently small and can be applied to a high voltage application lamp.

The infrared transmittance coefficient (X) can be expressed by the following formula.
[Expression 1] X = (log (a / b)) / t
a: Transmittance [%] of a minimum point in the vicinity of 3840 [cm ⁻¹ ]
b: Transmittance [%] of a minimum point in the vicinity of 3560 [cm ⁻¹ ].
t: Glass thickness (3) Glass bulb shape The shape of the glass bulb is not limited to a straight tube shape, and may be, for example, an L shape, a U shape, a U shape, a spiral shape, or the like. . Further, the cross section cut perpendicularly to the tube axis is not limited to a substantially circular shape, and may be a flat shape such as a track shape or a rounded round shape, an elliptical shape, or the like.

2. Regarding the phosphor The phosphor constituting the phosphor layer is not limited to the above. As described below, it can be appropriately selected from various viewpoints.
For example, a blue phosphor is in the range of 430 [nm] to 460 [nm], a green phosphor is in the range of 510 [nm] to 550 [nm], and a red phosphor is 600 [nm] to 780 [nm]. In the following ranges, those having an emission peak can be used.

(1) UV absorption For example, in recent years, with the increase in size of liquid crystal color televisions, polycarbonate having good dimensional stability has been used for the diffusion plate that closes the opening of the backlight unit. This polycarbonate is easily deteriorated by ultraviolet rays having a wavelength of 313 [nm] emitted from mercury. In such a case, a phosphor that absorbs ultraviolet rays having a wavelength of 313 [nm] may be used. The following phosphors absorb 313 [nm] ultraviolet rays.

(A) Blue europium / manganese co-activated barium aluminate / strontium / magnesium [Ba _1-xy Sr _x Eu _y Mg _1-z Mn _z Al ₁₀ O ₁₇ ] or [Ba _1-xy Sr _x Eu _{y Mg 2-z Mn z Al} 16 O 27]
Here, x, y, and z are preferably numbers satisfying the conditions of 0 ≦ x ≦ 0.4, 0.07 ≦ y ≦ 0.25, and 0 ≦ z <0.1, respectively.

Examples of such a phosphor include europium activated barium magnesium aluminate [BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ], [BaMgAl ₁₀ O ₁₇ : Eu ²⁺ ] (abbreviation: BAM-B), and europium attached. There are active barium aluminate / strontium / magnesium [(Ba, Sr) Mg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ], [(Ba, Sr) MgAl ₁₀ O ₁₇ : Eu ²⁺ ] (abbreviation: SBAM-B), and the like.

(B) Green • Manganese inactive magnesium gallate [MgGa ₂ O ₄ : Mn ²⁺ ] (abbreviation: MGM)
Manganese activated cerium aluminate, magnesium, zinc [Ce (Mg, Zn) Al ₁₁ O ₁₉ : Mn ²⁺ ] (abbreviation: CMZ)
Terbium-activated cerium aluminate / magnesium [CeMgAl ₁₁ O ₁₉ : Tb ³⁺ ] (abbreviation: CAT)
Europium / manganese co-activated barium aluminate / strontium / magnesium [Ba _1-xy Sr _x Eu _y Mg _1-z Mn _z Al ₁₀ O ₁₇ ] or [Ba _1-xy Sr _x Eu _y Mg _{2 -z} Mn _z Al ₁₆ O _27]
Here, x, y and z are numbers satisfying the conditions of 0 ≦ x ≦ 0.4, 0.07 ≦ y ≦ 0.25, and 0.1 ≦ z ≦ 0.6, respectively, and z is 0.4 It is preferable that ≦ x ≦ 0.5.

Examples of such phosphors include europium / manganese co-activated barium aluminate / magnesium [BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺ ], [BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ ] (abbreviation). : BAM-G), europium / manganese co-activated barium aluminate / strontium / magnesium [(Ba, Sr) Mg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺ ], [(Ba, Sr) MgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ ] (abbreviation: SBAM-G).

(C) Red • Europium activated phosphorus • Yttrium vanadate [Y (P, V) O ₄ : Eu ³⁺ ] (abbreviation: YPV)
Europium activated yttrium vanadate [YVO ₄ : Eu ³⁺ ] (abbreviation: YVO)
Europium-activated yttrium oxysulfide [Y ₂ O ₂ S: Eu ³⁺ ] (abbreviation: YOS)
Manganese-activated magnesium fluoride germanate [3.5MgO.0.5MgF ₂ .GeO ₂ : Mn ⁴⁺ ] (abbreviation: MFG)
Dysprosium-activated yttrium vanadate [YVO ₄ : Dy ³⁺ ] (red and green two-component phosphor, abbreviation: YDS)
Note that phosphors of different compounds may be mixed and used for one kind of emission color. For example, only BAM-B (absorbs 313 [nm]) in blue, LAP (does not absorb 313 [nm]) in green, BAM-G (absorbs 313 [nm]) in green, and YOX in red A phosphor of (does not absorb 313 [nm]) and YVO (absorbs 313 [nm]) may be used. In such a case, as described above, the phosphor that absorbs the wavelength 313 [nm] is adjusted so that the total weight composition ratio is larger than 50 [%], so that the ultraviolet rays leak out of the glass tube. Can be almost prevented. Therefore, when the phosphor layer 105 includes a phosphor that absorbs ultraviolet rays of 313 [nm], deterioration due to ultraviolet rays such as a diffusion plate made of polycarbonate (PC) that closes the opening of the backlight unit is suppressed, The characteristics as a backlight unit can be maintained for a long time.

  Here, “absorbing ultraviolet rays of 313 [nm]” means an excitation wavelength spectrum near 254 [nm] (excitation wavelength spectrum means excitation light emission while changing the wavelength of the phosphor, and the excitation wavelength and emission intensity are changed. The intensity of the excitation wavelength spectrum at 313 [nm] is defined as 80 [%] or more. That is, the phosphor that absorbs ultraviolet rays of 313 [nm] is a phosphor that can absorb ultraviolet rays of 313 [nm] and convert it into visible light.

(2) High color reproduction Liquid crystal display devices typified by liquid crystal color televisions have been used as a light source for a backlight unit of the liquid crystal display device in accordance with the recent high color reproduction that has been made as part of higher image quality. There is a need to expand the reproducible chromaticity range in cathode fluorescent lamps and external electrode fluorescent lamps.

  In response to such a request, for example, by using the following phosphor, the chromaticity range can be expanded as compared with the case of using the phosphor in the embodiment. Specifically, in the CIE1931 chromaticity diagram, the chromaticity coordinate value of the phosphor for high color reproduction includes a triangle formed by connecting the chromaticity coordinate values of the three phosphors used in the embodiment. Located at the coordinates that expand the reproduction range.

In addition, the chromaticity coordinate value of the phosphor (powder) described below is rounded off to the fourth decimal place after the value measured with a spectroscopic analysis device (MCPD-7000) manufactured by Otsuka Electronics Co., Ltd. It is a thing. Moreover, this chromaticity coordinate value is a representative value in each phosphor material, and may show a slightly different value due to a measurement method (measurement principle) or the like.
(A) Blue • Europium activated strontium chloroapatite [Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ ] (abbreviation: SCA), chromaticity coordinates: x = 0.153, y = 0.030
In addition to the above, europium-activated strontium, calcium, barium, chloroapatite [(Sr, Ca, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ ] (abbreviation: SBCA) can also be used, and the wavelength 313 [nm] SBAM-B, which can absorb the ultraviolet rays, can also be used for high color reproduction.

(B) Green BAM-G, chromaticity coordinates: x = 0.136, y = 0.572
CMZ, chromaticity coordinates: x = 0.164, y = 0.722
CAT, chromaticity coordinates: x = 0.284, y = 0.635
Terbium / manganese co-activated cerium aluminate / magnesium [CeMgAl ₁₁ O ₁₉ : Tb ³⁺ , Mn ²⁺ ] (abbreviation: CAM), chromaticity coordinates: x = 0.256, y = 0.657
Manganese-activated zinc silicate [Zn ₂ SiO ₄ : Mn ²⁺ ] (abbreviation: ZSM), chromaticity coordinates: x = 0.248, y = 0.700
As described above, these can also absorb ultraviolet rays having a wavelength of 313 [nm], and in addition to the three phosphor particles described here, MGM can also be used for high color reproduction.

(C) Red • YOS, chromaticity coordinates: x = 0.658, y = 0.330
YVO, chromaticity coordinates: x = 0.661, y = 0.328
MFG, chromaticity coordinates: x = 0.708, y = 0.288
As described above, these can also absorb ultraviolet rays having a wavelength of 313 [nm], and besides the three phosphor particles described here, YPV and YDS can also be used for high color reproduction.

  In addition, the chromaticity coordinate values shown above are representative values measured only with each phosphor powder, and due to the measurement method (measurement principle), etc., the chromaticity coordinates indicated by each phosphor powder The value may be slightly different from the value listed above. For reference, the chromaticity coordinate values of the phosphor powders of the first embodiment are YOX (x = 0.463, y = 0.348), LAP (x = 0.351, y = 0.585). , BAM-B (x = 0.148, y = 0,055).

Furthermore, the phosphor used for emitting each color of red, green, and blue is not limited to one type for each wavelength, and a plurality of types may be used in combination.
Here, the case where a phosphor layer is formed using the above-described phosphor particles for high color reproduction will be described. In this evaluation, there are three evaluations in the case of using a phosphor for high color reproduction based on the area of the NTSC triangle (NTSC triangle) connecting the chromaticity coordinate values of the three primary colors of the NTSC standard in the CIE1931 chromaticity diagram. This is performed by the ratio of the area of the triangle that can connect the chromaticity coordinate values (hereinafter referred to as NTSC ratio).

  For example, when BAM-B is used as blue, BAM-G as green, and YVO as red (Example 1), the NTSC ratio is 92%, and SCA is used as blue, BAM-G as green, and YVO as red. (Example 2) When NTSC ratio is 100%, SCA is used as blue, BAM-G is used as green, and YOX is used as red (Example 3), NTSC ratio is 95%. The luminance can be improved by 10 [%] as compared with the above.

The chromaticity coordinate values used for the evaluation here are measured in a state where a liquid crystal display device incorporating a lamp or the like is used.
[Lighting device]
<First Embodiment>
FIG. 22 is an exploded perspective view showing the lighting apparatus according to the first embodiment. As shown in FIG. 22, the lighting apparatus according to the first embodiment is a direct-type backlight unit 1300, and includes a flat rectangular parallelepiped casing 1302 having an opening on one surface, and an interior of the casing 1302. Are provided with a plurality of cold cathode discharge lamps 1 according to the present invention and optical sheets 1304 covering the opening of the housing 1302.

The housing 1302 is made of, for example, polyethylene terephthalate (PET) resin, and a reflective surface 1306 is formed on the inner surface thereof by depositing a metal such as silver or aluminum. Note that the housing 1302 may be made of a material other than resin, for example, a metal material such as aluminum or a cold-rolled material (for example, SPCC). In addition to the metal vapor deposition film as the reflection surface 1306 on the inner surface, for example, a reflection sheet whose reflectance is increased by adding calcium carbonate, titanium dioxide (TiO ₂ ), or the like to polyethylene terephthalate (PET) resin is added to the housing 1302. You may affix and comprise.

Inside the housing 1302, a cold cathode discharge lamp 1, a set of sockets 1308, and a set of covers 1310 are arranged.
The pair of sockets 1308 are arranged substantially in parallel with an interval in the longitudinal direction of the housing 1302. The socket 1308 is obtained by processing a plate material (band material) made of copper alloy such as phosphor bronze. The socket 1308 includes a pair of holding pieces 1308A into which the sleeves 30 and 31 of the cold cathode discharge lamp 1 are fitted, and adjacent holding pieces. The connecting piece 1308B that electrically connects the pieces 1308A with each other at the lower end edge is continuous with the short side of the housing 1302. When the sleeves 30 and 31 of the cold cathode discharge lamp 1 are fitted into the pair of sandwiching pieces 1308A, the cold cathode discharge lamp 1 is held by the pair of sandwiching pieces 1308A and the pair of sandwiching pieces 1308A and the sleeves 30 and 31 are connected. Electrically connected. The cold cathode discharge lamp 1 attached to the pair of sockets 1308 is supplied with power from the lighting circuit 1524 (see FIG. 24) of the backlight unit 1300 via the socket 1308.

The cover 1310 is for ensuring insulation between the pair of sandwiching pieces 1308A and the pair of sandwiching pieces 1308A adjacent thereto.
The optical sheet 1304 includes, for example, a diffusion plate 1312, a diffusion sheet 1314, and a lens sheet 1316. The diffusion plate 1312 is, for example, a plate-like body made of polymethyl methacrylate (PMMA) resin, and is disposed so as to close the opening of the housing 1302. The diffusion sheet 1314 is made of, for example, a polyester resin. The lens sheet 1316 is, for example, a laminate of an acrylic resin and a polyester resin. These optical sheets 1304 are arranged so as to be sequentially superimposed on the diffusion plate 1312.

Since the backlight unit 1300 as described above includes the cold cathode discharge lamp 1 according to the present invention as a main light source, the dark start-up characteristics are good.
<Second Embodiment>
FIG. 23 is a partially broken perspective view showing the lighting apparatus according to the second embodiment. As shown in FIG. 23, the illumination device according to the second embodiment is an edge light type backlight unit 1400, which includes a reflector 1410, a cold cathode discharge lamp 1 according to the present invention, a socket (not shown), The light guide plate 1420, the diffusion sheet 1430, and the prism sheet 1440 are included.

  The reflection plate 1410 is disposed so as to surround the periphery of the light guide plate 1420 except for the liquid crystal panel side (arrow Q), and the side surface excluding the side where the cold cathode discharge lamp 1 is disposed and the bottom surface portion 1411 covering the bottom surface. And a curved lamp side surface portion 1413 covering the periphery of the cold cathode discharge lamp 1, and light emitted from the cold cathode discharge lamp 1 is transmitted from the light guide plate 1420 to a liquid crystal panel (not shown). ) Side (arrow Q). The reflection plate 1410 is made of, for example, a film-like PET deposited with silver or a laminate of a metal foil such as aluminum.

The socket has substantially the same configuration as the backlight unit 1300 that is the lighting device according to the first embodiment. In FIG. 23, the end of the cold cathode discharge lamp 1 is omitted for convenience of illustration.
The light guide plate 1420 is for guiding the light reflected by the reflection plate 1410 to the liquid crystal panel side, and is made of, for example, translucent plastic, and is laminated on the bottom surface portion 1411 of the reflection plate 1410. As a material, polycarbonate (PC) resin or cycloolefin-based resin (COP) can be applied.

The diffusion sheet 1430 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 1420.
The prism sheet 1440 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 1430. Note that a diffusion plate may be further stacked on the prism sheet 1440.

In the case of the present embodiment, a reflective sheet (not shown) is provided on the outer surface of the glass bulb 101 except for a portion in the circumferential direction of the cold cathode discharge lamp 1 (on the light guide plate 1420 side when inserted into the lighting device 1400). It may be an aperture type lamp provided.
Since the backlight unit 1400 as described above includes the cold cathode discharge lamp 1 according to the present invention as a main light source, it has good dark start-up characteristics.

[Liquid Crystal Display]
FIG. 24 shows an outline of the liquid crystal display device according to the embodiment. As shown in FIG. 24, a liquid crystal display device 1500 is, for example, a 32 [inch] liquid crystal television, and includes a liquid crystal screen unit 1522 including a liquid crystal panel and the backlight unit according to the present invention disposed on the back of the liquid crystal screen unit 1522. 1300 and a lighting circuit 1524.

The liquid crystal screen unit 1522 is a well-known one, and includes a liquid crystal panel (color filter substrate, liquid crystal, TFT substrate, etc.) (not shown), a drive module, etc. (not shown), and color based on an image signal from the outside. Form an image.
The lighting circuit 1524 lights the cold cathode discharge lamp 1 (FIG. 22) inside the backlight unit 1300. The cold cathode discharge lamp 1 is operated at a lighting frequency of 40 [kHz] to 100 [kHz] and a lamp current of 3.0 [mA] to 25 [mA].

In FIG. 24, the backlight unit 1300 according to the first embodiment is used as the light source device of the liquid crystal display device 1500. However, the present invention is not limited to this. For example, the backlight unit 1400 according to the second embodiment is used. Also good.
Since the liquid crystal display device 1500 as described above includes the cold cathode discharge lamp 1 according to the present invention as a main light source, the dark start-up characteristic is good.

  The present invention can be widely applied to discharge lamps. In particular, it is possible to provide a discharge lamp with high accuracy in attaching the lighting device to the lamp holder.

1,100,200,300,400,500,600,700,800,850,900,1000,1100,1200 Discharge lamp 10,110,210,310,410,510,610,710,810,860,910 , 1010, 1110, 1210 Glass bulb 12, 13, 112, 212, 312, 412, 512, 612, 712, 812, 862, 912, 1012, 1112, 1212 End portion 20, 21, 120, 220, 320, 420 , 520, 620, 720, 1020, 1120, 1220 Electrode 30, 31, 130, 230, 330, 430, 530, 550, 630, 730, 830, 880, 930, 1030, 1130, 1230 Sleeve (metal conductor)
40, 140, 240, 340, 440, 540, 640, 740, 1040, 1140, 1240 Emitter 51 Bottom plate (proximity conductor)
DESCRIPTION OF SYMBOLS 50 Lighting device 241 Auxiliary emitter 431 Slit 531 Notch 1300, 1400 Illuminating device 1500 Liquid crystal display device

Claims (9)

A cold cathode discharge lamp in which an electrode is disposed inside at least one end of a glass bulb, and a cylindrical metal conductor electrically connected to the electrode is provided on the outer periphery of the end,
The cylindrical metal conductor is coiled,
The position where the electric field strength is high enough to induce ion bombardment at the start in the glass bulb,
A cold cathode discharge lamp, characterized in that an emitter is provided between the proximity conductor and the electrode in a state of being attached to a lighting device provided with a proximity conductor electrically insulated from the lamp current path. .   2. The emitter according to claim 1, wherein the emitter is provided on a trajectory that reaches the electrode from the proximity conductor at a shortest distance while avoiding the metal conductor between the proximity conductor and the electrode. Cold cathode discharge lamp.   3. The cold cathode discharge lamp according to claim 1, wherein the emitter is provided on an inner surface of a portion of the glass bulb where the metal conductor is not provided. 4.   The cold cathode discharge lamp according to claim 1 or 2, wherein the emitter is provided on an outer surface of a portion of the electrode where the metal conductor is not provided. A cold cathode discharge lamp in which an electrode is disposed inside at least one end of a glass bulb, and a cylindrical metal conductor electrically connected to the electrode is provided on the outer periphery of the end,
The cylindrical metal conductor is coiled,
The electrode is a bottomed cylindrical hollow electrode,
The cold cathode discharge lamp according to claim 1, wherein the emitter is provided at a position where the electric field strength is high enough to induce ion bombardment at the time of starting in the glass bulb, and provided on the inner surface of the cylinder of the electrode.   The cold cathode discharge lamp according to claim 1, wherein the emitter is made of a cesium compound.   The said metal conductor has a main-body part wound by the edge part of the said glass bulb | bulb, and the connection part connected to the lead wire derived | led-out from the edge part of the said glass bulb | bulb. The cold cathode discharge lamp according to any one of the above.   An illuminating device comprising the cold cathode discharge lamp according to claim 1.   A liquid crystal display device comprising the illumination device according to claim 8.

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