JP2008117633A - Electrode for hot-cathode discharge lamp, hot-cathode discharge lamp, and lamp unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode for a hot-cathode discharge lamp that allows further service lifetime extension of a hot-cathode discharge lamp than the conventional one, to provide a hot-cathode discharge lamp having a longer service lifetime than the conventional one, and to provide a lamp unit. <P>SOLUTION: The electrode for a hot-cathode discharge lamp is provided with two lead wires 106, 107, a filament coil 105 connected between the two lead wires so as to hold an emitter 110, and a heat-resistant structure 109 which is fixed or whose moving range is regulated by a member other than the filament coil so as to suppress a change in filament coil shape. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrode used for a hot cathode discharge lamp, and more particularly to a technique for extending the life of a hot cathode discharge lamp.

  In recent years, the spread of liquid crystal display devices such as liquid crystal televisions and liquid crystal monitors is remarkable, and the demand for backlight units used in such liquid crystal display devices is increasing.

  Conventionally, as a light source for a backlight unit, a cold cathode discharge lamp has been widely used. However, with the recent increase in size of a liquid crystal television, a relatively large backlight unit is generally used for illumination. The use of hot cathode discharge lamps has been studied.

  Compared with cold cathode discharge lamps, hot cathode discharge lamps have high luminous efficiency and a large amount of light per lamp, so there is an advantage that the increase in the number of lamps used can be suppressed when used in a backlight unit. However, there is a drawback that the life is short, and the light source for the backlight unit cannot be easily replaced. Therefore, there is a strong demand for extending the life of the hot cathode discharge lamp.

  In addition, when a hot cathode discharge lamp is turned on, particularly when the emitter is scattered at the time of starting, the emitter held by the electrode disappears as the lighting time elapses, and there is no longer an emitter that contributes to lighting. In order to increase the lifetime, it is necessary to hold more emitters on the electrode than in the past or to suppress the disappearance of the emitters.

Therefore, in order to extend the life of the hot cathode discharge lamp, an electrode having a structure in which a filament holding an emitter is tightly wound around a refractory insulator is disclosed in Patent Document 1, which is disclosed in Patent Document 1. The refractory insulator becomes a thermal conductor and the temperature distribution of the filament is equalized, so that the thermionic emission distribution is equalized, the discharge heating is equalized, and the thermionic emission area is increased. It is described that the disappearance rate is suppressed and the life of the electrode is prolonged (paragraph 0004 and the like).
Japanese Patent Laid-Open No. 06-150880

  However, there is no clear description as to how long the life of the hot cathode discharge lamp is increased by the invention of Patent Document 1, and when the hot cathode discharge lamp is used in a backlight unit, a cold cathode which is often used is used. Since a lifetime equal to or longer than that of the lamp is desired, it is necessary to further extend the lifetime.

  It is an object of the present invention to provide a hot cathode discharge lamp electrode capable of extending the life of a hot cathode discharge lamp as compared to the prior art, a hot cathode discharge lamp having a longer life than that of the prior art, and a lamp unit.

  In order to achieve the above object, an electrode for a hot cathode discharge lamp according to the present invention comprises two lead wires, a filament coil connected between the two lead wires and holding an emitter, and heat resistance. And a structure in which a fixed or moving range is regulated by a member other than the filament coil and a shape change of the filament coil is suppressed.

  In order to achieve the above object, a hot cathode discharge lamp according to the present invention uses the above electrode.

  In order to achieve the above object, a lamp unit according to the present invention uses the hot cathode discharge lamp.

  The configuration described in the means for solving the problems makes it difficult for the shape of the filament coil to change, so that the filament coil can be made longer and larger than before, and more emitters can be held on the electrode than before. Can do.

  Therefore, the life of the hot cathode discharge lamp can be extended as compared with the conventional one.

  Here, in the hot-cathode discharge lamp electrode or the hot-cathode discharge lamp, the filament coil is a coil of double winding or more, and the structure further has an insulating property, and the outermost coil of the filament coil It can also be characterized by being inside the helix.

  Thereby, since the structure is not outside the filament coil, the filament coil can be enlarged by using the full space in the tube.

  Here, in the electrode used for the hot cathode discharge lamp or the hot cathode discharge lamp, the structure may be a cylindrical shape in which a position corresponding to a spiral axis in the outermost coil is hollow. it can.

  Here, in the hot cathode discharge lamp electrode or the hot cathode discharge lamp, the structure has a columnar shape located at a position corresponding to a helical axis in the outermost coil and is porous. You can also

  Thereby, the outer shape of the structure can be enlarged while being lightweight, and the filament coil can be made longer and larger.

  Here, in the hot cathode discharge lamp electrode or the hot cathode discharge lamp, the structure may be fixed or regulated by one or both of the two lead wires.

  Thereby, since the positional relationship between the filament coil and the lead wire is maintained via the structure, the filament coil can be made long and large.

  Here, in the hot-cathode discharge lamp electrode or the hot-cathode discharge lamp, the filament coil is a double-turn or more coil, and the spiral axis of the outermost coil of the filament coil is the tube axis of the hot-cathode discharge lamp. And substantially coincident or substantially parallel to each other.

  Thereby, since the filament coil can be extended in the longitudinal direction of the hot cathode discharge lamp, the filament coil can be lengthened.

  Here, in the hot cathode discharge lamp electrode or the hot cathode discharge lamp, the outermost coil of the filament coil has a single spiral structure, and the two lead wires are connected to the tube end side of the filament coil. It consists of a short lead wire and a long lead wire that is connected to the tube center side of the filament coil and goes to the tube end side in parallel with the filament coil. The long lead wire is insulated from the portion parallel to the filament coil. It can also be characterized by being surrounded by a member.

  This eliminates the need to increase the distance between the filament coil and the long lead wire, thereby increasing the size of the filament coil.

  Here, in the electrode for a hot cathode discharge lamp, or the hot cathode discharge lamp, the filament coil has an outermost coil in the filament coil having a double spiral structure, and both ends are on the tube end side, Each end may be connected to the two lead wires, respectively.

  As a result, the filament coil can be enlarged without worrying about the contact or arc between the filament coil and the lead wire.

  Here, in the hot cathode discharge lamp electrode or the hot cathode discharge lamp, the outermost coil of the filament coil has a single spiral structure, and the two lead wires are connected to the tube end side of the filament coil. The short lead wire is composed of a long lead wire connected to the tube central portion side of the filament coil and parallel to the filament coil toward the tube end portion side, and the structure is provided on the tube central portion side of the long lead wire. It is also possible to suppress a change in the shape of the filament coil by suspending the filament coil in a direction from the tube central portion side toward the tube end portion side while fixing a part or restricting a moving range.

  Thereby, since the structure suspends the filament coil using the tension of the coil, the position of the filament coil is appropriately maintained, which is preferable.

  Here, in the hot cathode discharge lamp electrode or the hot cathode discharge lamp, the structure may be fixed by an inner wall of the tube.

  Thereby, the movement range of the position of the filament coil on the tube center side is preferably limited to a narrow range.

  Here, in the hot cathode discharge lamp electrode or the hot cathode discharge lamp, the structure may be fixed at a tube end portion of the hot cathode discharge lamp.

  As a result, the structure can be fixed simultaneously with the sealing of the electrodes, so that there are few additional manufacturing steps.

  Here, in the hot cathode discharge lamp electrode or the hot cathode discharge lamp, the structure further has conductivity, and is used for external connection connected to an external terminal having the same potential as the potential supplied to the long lead wire. Including the terminal, the long lead wire can be used for feeding the filament coil from the outside.

  Thereby, since a structure is utilized also as a lead wire, electric power feeding efficiency is good.

  Here, in the hot-cathode discharge lamp electrode or the hot-cathode discharge lamp, the structure includes a sleeve-shaped portion that covers the filament coil, and a tube-centered side of the sleeve-shaped portion that extends in the tube axis direction. It is also possible to include a hanging part that suspends a part of the long lead wire on the tube center side.

  Thereby, the structure can suppress loss of the emitter due to ion bombardment during lighting as a sleeve.

  Here, in the hot-cathode discharge lamp electrode or the hot-cathode discharge lamp, the filament coil is a single-turn or more coil, and the structure has a tube center portion in the longitudinal direction of the outermost coil of the filament coil. The shape change of the filament coil can be suppressed by pushing up in the direction from the side toward the tube center.

  Thereby, since the structure pushes up the filament coil using the tension of the coil, the position of the filament coil is appropriately maintained, which is preferable.

  Here, in the hot cathode discharge lamp electrode or the hot cathode discharge lamp, the structure further includes conductivity, and includes an external connection terminal connected to an external terminal, from the outside to a part of the filament coil. It can also be used when power is supplied.

  As a result, the structure can be used to supply power to only one side from the middle of the filament coil, so that only part of the filament coil can be used, or part of the filament coil and the rest of the part can be alternately used. Can be used.

  Here, in the electrode for a hot cathode discharge lamp or the hot cathode discharge lamp, the structure is made of a material having a decomposition temperature and a melting point of 1000 ° C. or higher and a specific resistance higher than that of the filament coil. Can also be characterized.

  Thereby, a structure can be provided with sufficient heat resistance and sufficient insulation.

  Here, in the lamp unit, the filament coil included in the hot-cathode discharge lamp is a single-turn or more coil, and the structure included in the hot-cathode discharge lamp is substantially in the center in the longitudinal direction of the outermost coil of the filament coil. The shape of the filament coil is suppressed by pushing up the portion in the direction from the tube end side toward the tube center side, includes a terminal for external connection that has conductivity and is connected to the external terminal, and the filament from the outside Used when power is supplied to a part of the coil. Further, at the time of starting, a voltage is applied between the external connection terminal and one of the lead wires to preheat for a certain period of time, and then between the two lead wires It is also possible to provide a lighting circuit for applying a voltage to the.

  Thereby, since only a part of the filament coil can be preheated at the time of starting, the loss of the emitter can be suppressed.

  Here, in the lamp unit, the lighting circuit further includes a first pattern that preheats for a predetermined time by applying a voltage between the external connection terminal and one of the lead wires at the time of starting, and the external connection The second pattern in which a voltage is applied between the terminal and the other of the lead wires to preheat for a certain period of time can be switched alternately or randomly each time the engine is started.

  As a result, the portion of the filament coil to be preheated can be switched each time the engine is started, so that the loss of the emitter is suppressed and at the same time, the loss of the emitter occurs almost uniformly, resulting in an extended life.

(Embodiment 1)
<Overview>
In Embodiment 1 of the present invention, in the electrode used in the hot cathode discharge lamp, the shape of the filament coil is changed by inserting a heat-resistant insulating structure fixed to the lead wire inside the helix in the outermost coil of the filament coil. It suppresses.

<Configuration>
FIG. 1 is a partially broken view showing an outline of a hot cathode discharge lamp according to Embodiment 1 of the present invention.

  As shown in FIG. 1, a hot cathode discharge lamp 100 according to Embodiment 1 of the present invention includes a glass tube 101 and hot cathode type electrodes 102 and 103 at both ends of the glass tube 101, respectively.

  The glass tube 101 is, for example, mercury (for example, about 4 to 10 mg) that contributes to light emission as a luminescent substance inside a substantially cylindrical envelope having an outer diameter of 18 mm, a wall thickness of 0.8 mm, and a length of 1010 mm. As a buffer gas, for example, a mixed gas of 50% argon-50% krypton (for example, a gas pressure of about 600 Pa) is sealed.

On the inner surface of the glass tube 101, a phosphor layer 104 that converts ultraviolet rays emitted from mercury into visible light is formed. For example, the phosphor layer 104 is a mixture of a red phosphor (Y ₂ O ₃ : Eu), a green phosphor (LaPO ₄ : Ce, Tb), and a blue phosphor (BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn). The rare earth phosphor is formed.

  Since the structure of the main part of the electrode 102 and the electrode 103 is the same, only the electrode 102 will be described here.

  The electrode 102 includes a filament coil 105, two lead wires 106 and 107, a bead glass 108, and a heat-resistant insulating structure 109. Two electrodes are formed on one end of a glass cylindrical tube material by, for example, a pinch seal method. A part of the lead wires 106 and 107 around the center is sealed.

  The filament coil 105 is a tungsten multi-winding coil (a coil of double winding or more) connected between two lead wires 106 and 107, and is an outermost coil having a single spiral structure (whether it is a double winding). In the hollow portion of each inner coil except for the double coil with a large winding width to be wound later and the triple coil with the largest winding width to be wound last in the case of triple winding) An electron emitting material 110 (commonly called “emitter”) such as SrO is filled. For example, in the case of a triple-winding coil, a single coil is wound by winding a filament, a secondary coil is wound by a secondary coil, and a double coil is wound by a tertiary coil. The main wire is arranged so as to pass through the primary winding hollow portion, and the electron emitting material 110 is filled in the single coil and the double coil.

  The lead wires 106 and 107 are metallic conductive wires to which both ends of the filament coil 105 are connected. The lead wires 106 and 107 have sufficient rigidity not to be deformed in normal use. The supplied electric power is guided to the filament coil 105, the filament coil 105 is directly supported by the connecting portion, and the heat-resistant insulating structure 109 is directly supported, thereby indirectly supporting the filament coil 105.

  The bead glass 108 is a lump of crow that fixes the two lead wires 106 and 107.

  The heat-resistant insulating structure 109 is a ceramic present inside the helix in the outermost coil of the filament coil 105 and is directly supported by the lead wires 106 and 107, thereby suppressing the shape change of the filament coil 105. ing.

  Here, the heat-resistant insulating structure 109 has a cylindrical shape, and is desirably porous for improving structural strength and light weight, and is located at a position corresponding to the helical axis of the outermost coil of the filament coil 105.

  FIG. 2 is a view of the electrode 102 shown in FIG. 1 as viewed from the left lateral direction.

  As shown in FIG. 2, a through hole 112 for passing the lead wire 106 is formed at one end of the cylindrical heat-resistant insulating structure 109, and similarly, a lead wire 107 is provided at the other end. A through-hole 113 (through the through-hole 112 in FIG. 2, see FIG. 1) is opened, and the heat-resistant insulating structure 109 is passed inside the spiral in the outermost coil of the filament coil 105. The lead wire 106 and 107 are fixed to the through holes 112 and 113 through the lead wires 106 and 107, respectively, and the lead wire 106 and one end of the filament coil 105 are welded at the welding point 114. Similarly, the welding point 115 (the welding point in FIG. It is formed by welding the lead wire 107 and the other end of the filament coil 105 at the back side of the point 114 (see FIG. 1).

  The shape of the heat-resistant insulating structure 109 is not limited to a cylindrical shape, and can be fixed or regulated by one or both of the lead wires 106 and 107, and the filament coil 105 can be fixed or the moving range can be regulated. Any shape may be used, and for example, it may be a polygonal column such as a triangular column or a quadrangular column, or may be a cylindrical shape such as a cylinder whose position corresponding to the spiral axis is hollow. .

  FIG. 3 is a diagram showing a modification of the electrode 102 in the first embodiment.

  As shown in FIG. 3, an electrode 150 which is a modification of the electrode 102 includes a heat-resistant insulating structure 159 having a cylindrical shape instead of the heat-resistant insulating structure 109 having a cylindrical shape. The elements are similar to the electrode 102.

The material of the heat-resistant insulating structure 109 may be any material as long as it is a structure having heat resistance and insulating properties. For example, a metal oxide such as aluminum oxide or an oxide such as silicon oxide, The filament coil 105 can withstand the high temperature of the filament coil 105 like a nitride (compound of nitrogen and a positive element) such as boron nitride or silicon nitride, a carbide such as silicon carbide, or a composite thereof. It is necessary to form with a material having a higher resistance. Here, since the operating temperature of the filament coil 105 is generally about 600 to 900 ° C., it is desirable that the decomposition temperature and melting point of this material be 1000 ° C. or more, and the specific resistance of tungsten which is the material of the filament coil 105 is about 6 Since it is × 10 ^-6 Ωcm (from RIKEN Dictionary), the resistivity of this material must be at least higher.

  Further, an exhaust pipe 111 is sealed together with the electrode 102 at one end portion (here, the electrode 102 side) of the glass tube 101. The exhaust pipe 111 is used for exhausting the inside of the pipe before sealing the buffer gas and the like after sealing the lead wires 106 and 107 and the like, and sealing the buffer gas and the like. Immediately, at a predetermined position protruding outward, it is closed by chip-off sealing or the like.

<Summary>
As described above, according to the hot cathode discharge lamp of the first embodiment, since the shape change of the filament coil is suppressed by the heat-resistant insulating structure inserted inside the filament coil, the filament coil is made larger than before. can do.

Therefore, more electron-emitting materials can be held in the electrode than in the past, and the hot cathode discharge lamp can have a longer life than in the past.
(Embodiment 2)
<Overview>
In the second embodiment of the present invention, in an electrode used for a hot cathode discharge lamp, the filament coil is extended in the tube axis direction for extending the life and the outermost coil of the filament coil is wound in the tube axis direction of the lamp. When placed vertically, the heat resistance insulation structure fixed to the lead wire is inserted inside the spiral of the outermost coil of the filament coil in the same manner as in the first embodiment, thereby suppressing the shape change of the filament coil It is.

<Configuration>
FIG. 4 is a partially cutaway view showing an outline of a hot cathode discharge lamp according to Embodiment 2 of the present invention.

  As shown in FIG. 4, a hot cathode discharge lamp 200 according to the second embodiment of the present invention includes a glass tube 101 and hot cathode type electrodes 202 and 203 at both ends of the glass tube 101, respectively.

  Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The electrode 202 includes a filament coil 205, a short lead wire 206, a long lead wire 207, a bead glass 108, and a heat-resistant insulating structure 209, and is short at one end of a glass cylindrical tube material by, for example, a pinch seal method. A part around the center of the lead wire 206 and the long lead wire 207 is sealed.

  The filament coil 205 is a tungsten multi-turn coil in which the tube end side is connected to the short lead wire 206 and the tube center side is connected to the long lead wire 207, and the outermost coil has a single spiral structure. The spiral axis of the coil is substantially coincident with or substantially parallel to the tube axis of the lamp, and similarly to the first embodiment, the hollow portion of each inner coil excluding the outermost coil is filled with the electron emitting material 110.

  The short lead wire 206 and the long lead wire 207 are metallic conductive wires to which both ends of the filament coil 205 are connected. Like the lead wires 106 and 107 of the first embodiment, the short lead wire 206 and the long lead wire 207 are deformed in normal use. The electric power supplied from the outside of the hot-cathode discharge lamp 200 is guided to the filament coil 205, and the filament coil 205 is directly supported by the connecting portion, so that the heat-resistant insulating structure 209 is directly By supporting the filament coil 205 indirectly.

  The heat-resistant insulating structure 209 is a ceramic inside the helix in the outermost coil of the filament coil 205, and is directly supported by the short lead wire 206 and the long lead wire 207. The shape change is suppressed.

  Here, the heat-resistant insulating structure 209 has a cylindrical shape in which the position corresponding to the spiral axis in the outermost coil of the filament coil 205 is hollow.

  Note that the shape of the heat-resistant insulating structure 209 can be any shape as long as the filament coil 205 can be fixed or the movement range can be regulated, similarly to the heat-resistant insulating structure 109 of the first embodiment. Good.

  Further, the material of the heat-resistant insulating structure 209 may be any material as long as it is a structure having heat resistance and insulating properties, like the heat-resistant insulating structure 109 of the first embodiment.

  FIG. 5 is a diagram illustrating a modification of the electrode 202 in the second embodiment.

  As shown in FIG. 5, an electrode 250, which is a modification of the electrode 202, is a part of the long lead wire 207 that is parallel to the filament coil 205, surrounded by an insulating member 251 and fixed by a heat resistant adhesive 252. Other configurations are the same as those of the second embodiment.

<Summary>
As described above, according to the hot cathode discharge lamp of the second embodiment, as in the first embodiment, the shape change of the filament coil is suppressed by the heat-resistant insulating structure inserted inside the filament coil. The filament coil can be made larger than the conventional one, and further, the filament coil can be extended in the tube axis direction, so that the filament coil can be made longer than the conventional one.

  Therefore, more electron-emitting materials can be held in the electrode than in the past, and the hot cathode discharge lamp can have a longer life than in the past.

In particular, according to the modification of the second embodiment, it is not necessary to increase the distance between the filament coil and the long lead wire, so that the filament coil can be further enlarged.
(Embodiment 3)
<Overview>
In Embodiment 3 of the present invention, in an electrode used for a hot cathode discharge lamp, the filament coil is extended in the tube axis direction for the purpose of extending the life, the outermost coil of the filament coil has a double helical structure, When both are placed vertically on the tube axis direction of the lamp, the heat-resistant insulating structure is fixed to the lead wire or the like inside the helix of the outermost coil of the filament coil as in the first embodiment. By inserting the body, the shape change of the filament coil is suppressed.

<Configuration>
FIG. 6 is a partially broken view showing an outline of a hot cathode discharge lamp according to Embodiment 3 of the present invention.

  As shown in FIG. 6, the hot cathode discharge lamp 300 according to the third embodiment of the present invention includes a glass tube 101 and hot cathode type electrodes 302 and 303 at both ends of the glass tube 101, respectively.

  Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The electrode 302 includes a filament coil 305, lead wires 106 and 107, a bead glass 108, and a heat-resistant insulating structure 309. One end of a glass cylindrical tube material is connected to one end of the lead wires 106 and 107 by, for example, a pinch seal method. A part around the center is sealed and formed.

  The filament coil 305 is a tungsten multi-winding coil connected between two lead wires 106 and 107, the outermost coil having a double helix structure, and both ends are on the tube end side. In addition, the spiral axis of the outermost coil is substantially coincident with or substantially parallel to the tube axis of the lamp, and the hollow portion of each inner coil except for the outermost coil is filled with the electron emitting material 110 as in the first embodiment. is doing.

  The lead wires 106 and 107 are connected to the filament coil 305 instead of the filament coil 105, guide the electric power supplied from the outside of the hot cathode discharge lamp 300 to the filament coil 305, and support the filament coil 305 directly at the connecting portion. Then, the filament coil 305 is indirectly supported by directly supporting the heat-resistant insulating structure 309.

  The heat-resistant insulating structure 309 is a ceramic having a portion located inside the helix in the outermost coil of the filament coil 305 and is directly supported by the lead wires 106 and 107, so that the shape of the filament coil 305 changes. Is suppressed.

  Here, the heat-resistant insulating structure 309 includes a main body portion that supports the columnar filament coil 305 and an auxiliary portion that is supported by the lead wires 106 and 107, because the structural strength is improved and the weight is reduced. The main body portion is located at a position corresponding to the rotation axis of the outermost coil of the filament coil 305.

  Note that the shape of the heat-resistant insulating structure 309 can be any shape as long as the filament coil 305 can be fixed or the movement range can be regulated, similarly to the heat-resistant insulating structure 109 of the first embodiment. Good.

  Further, the material of the heat resistant insulating structure 309 may be any material as long as it is a structure having heat resistance and insulating properties, like the heat resistant insulating structure 109 of the first embodiment.

<Summary>
As described above, according to the hot cathode discharge lamp of the third embodiment, as in the first embodiment, the shape change of the filament coil is suppressed by the heat-resistant insulating structure inserted inside the filament coil. Since the filament coil can be made larger than in the prior art, and the filament coil can be extended in the tube axis direction as in the second embodiment, the filament coil can be made longer than in the prior art.

  In addition, since the outermost coil of the filament coil has a double spiral structure and both ends are on the tube end side, it is not necessary to separate the distance from the long lead wire as in the second embodiment. The filament coil can be enlarged.

Therefore, more electron-emitting materials can be held in the electrode than in the past, and the hot cathode discharge lamp can have a longer life than in the past.
(Embodiment 4)
<Overview>
In Embodiment 4 of the present invention, in an electrode used for a hot cathode discharge lamp, the filament coil is extended in the tube axis direction for extending the life and the outermost coil of the filament coil is wound in the tube axis direction of the lamp. When placed vertically, a part of the lead wire or filament coil on the tube center side is fixed or the range of movement is restricted, and the filament coil is suspended in the direction from the tube center to the tube end side. Thus, the shape change of the filament coil is suppressed.

<Configuration>
FIG. 7 is a partially broken view showing an outline of a hot cathode discharge lamp according to Embodiment 4 of the present invention.

  As shown in FIG. 7, a hot cathode discharge lamp 400 according to the fourth embodiment of the present invention includes a glass tube 101 and hot cathode type electrodes 402 and 403 at both ends of the glass tube 101, respectively.

  Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The electrode 402 includes a filament coil 405, a short lead wire 406, a long lead wire 407, a bead glass 108, and a heat-resistant structure 409. A short lead is formed on one end of a glass cylindrical tube material by, for example, a pinch seal method. A part around the center of the wire 406 and the long lead wire 407 is sealed.

  The filament coil 405 is a tungsten multi-turn coil in which the tube end side is connected to the short lead wire 406 and the tube center side is connected to the long lead wire 407, and the outermost coil has a single spiral structure, The spiral axis of the coil is substantially coincident with or substantially parallel to the tube axis of the lamp, and similarly to the first embodiment, the hollow portion of each inner coil excluding the outermost coil is filled with the electron emitting material 110.

  The short lead wire 406 and the long lead wire 407 are metallic conductive wires to which both ends of the filament coil 405 are connected, and are deformed in normal use as in the case of the lead wires 106 and 107 of the first embodiment. The electric power supplied from the outside of the hot cathode discharge lamp 400 is guided to the filament coil 405, and the filament coil 405 is directly supported by the connecting portion.

  The heat-resistant structure 409 is a metal having heat resistance that directly supports the tube center portion side of the long lead wire 407 and is directly supported by the tube wall of the glass tube 101, and therefore, the filament coil 405. The shape change is suppressed.

  The shape of the heat-resistant structure 409 may be any shape as long as the filament coil 405 can be fixed or the movement range can be regulated.

  The material of the heat resistant structure 409 may be any material as long as it is a structure having heat resistance.

  FIGS. 8-14 is a figure which shows the modification of the electrode 402 in Embodiment 4, and the electrode 402a-electrode 402g.

  An electrode 402a shown in FIG. 8 includes a long lead wire 421 and a heat resistant structure 429 protruding from the tube wall of the glass tube 101 instead of the long lead wire 407 and the heat resistant structure 409. The filament coil 405 is suspended in a direction from the tube center side toward the tube end side by hooking the tip portion or the center portion of the wire 421 on the tube center side.

  An electrode 402b shown in FIG. 9 includes a heat-resistant structure 439 instead of the heat-resistant structure 409, and the heat-resistant structure 439 is a metal having a substantially L-shaped heat resistance, and is short at the tube end portion of the glass tube 101. It is sealed and fixed in the same manner as the lead wire 406 and the long lead wire 407, directly supports the tube center portion side of the long lead wire 407, and the filament coil 405 is connected to the tube end portion from the tube center portion side. Hanging in the direction toward the side.

  The heat-resistant structure 439 has conductivity and includes an external connection terminal connected to an external terminal having the same potential as the potential supplied to the long lead wire 407. Together with the long lead wire 407, the filament coil 405 is externally provided. You may use for the electric power feeding to.

  An electrode 402c illustrated in FIG. 10 includes a heat resistant structure 449 instead of the heat resistant structure 409, and the heat resistant structure 449 is a metal having a substantially U-shaped heat resistance, and is the same as the heat resistant structure 439 except for the shape. It is.

  An electrode 402d shown in FIG. 11 includes a heat-resistant structure 459 instead of the heat-resistant structure 409, and the heat-resistant structure 459 is a metal having a substantially V-shaped heat resistance, and is the same as the heat-resistant structure 439 except for the shape. It is.

  An electrode 402e shown in FIGS. 12A and 12B includes a heat-resistant structure body 460, suspension fittings 461 and 462, and a fixing fitting 463 instead of the heat-resistant structure 409, and includes a short lead wire 406 and a long lead wire. Instead of 407, lead wires 464 and 465, connection reinforcing members 466 and 467, and lead-in wires 468 and 469 are provided.

  The heat-resistant structure body 460 is a sleeve-shaped metal having heat resistance covering the filament coil 405, and is welded and fixed to the connection reinforcing member 466 through a metal fixing metal fitting 463 also having heat resistance. And supporting a part of the lead wire 465 on the tube center side directly by the hanging metal fittings 461 and 462 having insulation and heat resistance and extending in the tube axis direction from the tube center side of the sleeve-shaped portion, The filament coil 405 is suspended in a direction from the tube center side toward the tube end side.

  An electrode 402f shown in FIGS. 13A and 13B includes a filament coil 475 whose outermost coil has a double helix structure instead of the filament coil 405, the short lead wire 406, and the long lead wire 407 of the electrode 402e. The suspension metal fittings 461 and 462 directly support a part of the filament coil 475 on the tube center side, and are suspended in a direction from the tube center side toward the tube end side. Other components are the same as those of the electrode 402e.

  Electrodes 402g shown in FIGS. 14 (a) and 14 (b) are provided with a hanging fitting 481 instead of the hanging fittings 461 and 462 of the electrode 402f, and only the hanging fitting 481 is provided on the tube center side of the filament coil 475. A part is directly supported and hung in the direction from the tube center side toward the tube end side.

<Summary>
As described above, according to the hot cathode discharge lamp of the fourth embodiment, when the filament coil is extended in the tube axis direction, the filament coil can be suspended, so that the filament coil is made longer than the conventional one. In addition, more electron-emitting materials can be held on the electrodes than in the past.

Therefore, the life of the hot cathode discharge lamp can be extended as compared with the conventional one.
(Embodiment 5)
<Overview>
In Embodiment 5 of the present invention, in the electrode used for the hot cathode discharge lamp, in the electrode used for the hot cathode discharge lamp, the substantially central portion in the longitudinal direction of the outermost coil of the filament coil is changed from the tube end side to the tube center side. By pushing up in the direction of heading, the shape change of the filament coil is suppressed.

<Configuration>
FIG. 15 is a partially broken view showing an outline of a hot cathode discharge lamp according to Embodiment 5 of the present invention.

  As shown in FIG. 15, a hot cathode discharge lamp 500 according to the fifth embodiment of the present invention includes a glass tube 101 and hot cathode type electrodes 502 and 503 at both ends of the glass tube 101, respectively.

  Here, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The electrode 502 includes a filament coil 505, lead wires 506 and 507, a bead glass 108, and a heat-resistant structure 509. One end of a glass cylindrical tube material is formed at the center of the lead wires 506 and 507 by, for example, a pinch seal method. A part of the area is sealed and formed.

  The filament coil 505 is a single-turn or more coil made of tungsten connected between two lead wires 506 and 507, both end portions are on the tube end side, and the substantially central portion is a heat-resistant structure. It is supported by 509 and pushed up toward the center of the tube, and the hollow portion of the coil is filled with the electron emitting material 110.

  The lead wires 506 and 507 are connected to the filament coil 505 and have sufficient rigidity so as not to be deformed in normal use, like the lead wires 106 and 107 of the first embodiment. Electric power supplied from the outside is guided to the filament coil 505, and the filament coil 505 is directly supported by the connecting portion.

  The heat-resistant structure 509 is a heat-resistant metal rod having a substantially Y-shaped tip, and is sealed and fixed in the same manner as the lead wires 506 and 507 at the tube end of the glass tube 101. The substantially central portion of the filament coil 505 is directly supported to suppress the shape change of the filament coil 505.

  The shape of the heat-resistant structure 509 may be any shape as long as the filament coil 505 can be fixed or the movement range can be regulated.

  16A to 16C are diagrams illustrating examples of the shape of the tip of the heat-resistant structure 509. FIG.

  As shown in FIGS. 16A to 16C, the tip of the heat-resistant structure 509 has a substantially Y shape, a substantially U shape, or a substantially semicircular shape. Assembling becomes easy and the filament coil does not easily come off from the structure. Note that the tip of the heat-resistant structure 509 may have any shape as long as the filament coil 505 can be supported.

  The heat-resistant structure 509 includes an external connection terminal connected to an external terminal, and may be used when power is supplied to a part of the filament coil 505 from the outside. In this way, since heat can be supplied to only one side from the middle of the filament coil 505 using the heat resistant structure 509, only a part of the filament coil 505 can be used, or a part of the filament coil 505 and the remainder thereof. Can be used alternately.

  FIGS. 17A and 17B are diagrams illustrating an example of a power feeding method using the heat-resistant structure 509. FIG.

  The lamp unit shown in FIGS. 17A and 17B includes a lighting circuit composed of a power supply circuit 550 and a changeover switch 551, and a hot cathode discharge lamp 500, and in the state shown in FIG. A voltage is applied between the external connection terminal of the structure 509 and the lead wire 507 to preheat for a certain time, and then a voltage is applied between the two lead wires 506 and 507 in the state shown in FIG. Since only a part of the filament coil can be preheated at the time of starting, the loss of the emitter can be suppressed.

  18A and 18B are diagrams illustrating another example of a power feeding method using the heat-resistant structure 509. FIG.

  The lamp unit shown in FIGS. 18A and 18B includes a lighting circuit composed of a power supply circuit 550 and changeover switches 551 and 552, and a hot cathode discharge lamp 500, and is in the state shown in FIG. Then, a voltage is applied between the external connection terminal of the heat-resistant structure 509 and the lead wire 507 to preheat for a certain time, and then the voltage between the two lead wires 506 and 507 in the state shown in FIG. In the state shown in (c), at the time of start-up, a voltage is applied between the lead wire 506 and the external connection terminal of the heat-resistant structure 509 to preheat for a certain period of time. In the state shown in b), the second pattern in which a voltage is applied between the two lead wires 506 and 507 can be switched alternately or randomly each time starting, and preheating is performed each time starting. Filament coil It is possible to switch the frequency at the same time to suppress the loss of the emitter occurs loss of emitter substantially uniformly, so that the result in life is extended.

  FIGS. 19, 20A, and 20B are diagrams showing a modification of the electrode 502, the electrode 502a, and the electrode 502b in the fifth embodiment.

  An electrode 502a illustrated in FIG. 19 includes a filament coil 555 instead of the filament coil 505, and the filament coil 555 rotates around the heat-resistant structure 509 to form a double spiral structure.

  An electrode 502b illustrated in FIG. 20A includes a heat resistant structure 569 in place of the heat resistant structure 509 in the electrode 502a, and the heat resistant structure 569 is provided at four substantially equal intervals in the longitudinal direction of the heat resistant structure 509. Auxiliary plates as shown in FIG. 20B are attached.

<Summary>
As described above, according to the hot cathode discharge lamp of the fifth embodiment, since the substantially central portion of the filament coil can be pushed up, the filament coil can be made longer than the conventional one, or more electron emitting materials than the conventional one. Can be held on the electrode.

  Therefore, the life of the hot cathode discharge lamp can be extended as compared with the conventional one.

  The present invention can be widely applied to various devices such as a hot cathode discharge lamp and a backlight unit using the hot cathode discharge lamp. Since the present invention can provide a hot-cathode discharge lamp having a long life, the application range of the hot-cathode discharge lamp is widened and its industrial utility value is extremely high.

It is a partially broken figure which shows the outline | summary of the hot cathode discharge lamp in Embodiment 1 of this invention. It is the figure which looked at the electrode 102 shown in FIG. 1 from the left horizontal direction. 6 is a diagram illustrating a modification of the electrode 102 in Embodiment 1. FIG. It is a partially broken figure which shows the outline | summary of the hot cathode discharge lamp in Embodiment 2 of this invention. 10 is a diagram illustrating a modification of the electrode 202 in Embodiment 2. FIG. It is a partially broken figure which shows the outline | summary of the hot cathode discharge lamp in Embodiment 3 of this invention. It is a partially broken figure which shows the outline | summary of the hot cathode discharge lamp in Embodiment 4 of this invention. It is a figure which shows the modification of the electrode 402 in Embodiment 4, and the electrode 402a. It is a figure which shows the modification of the electrode 402 in Embodiment 4, and the electrode 402b. It is a figure which shows the modification of the electrode 402 in Embodiment 4, and the electrode 402c. It is a figure which shows the modification of the electrode 402 in Embodiment 4, and electrode 402d. It is a figure which shows the modification of the electrode 402 in Embodiment 4, and the electrode 402e. It is a figure which shows the modification of the electrode 402 in Embodiment 4, and the electrode 402f. It is a figure which shows the modification of the electrode 402 in Embodiment 4, and the electrode 402g. It is a partially broken figure which shows the outline | summary of the hot cathode discharge lamp in Embodiment 5 of this invention. It is a figure which shows the example of the shape of the front-end | tip of the heat-resistant structure 509. FIG. It is a figure which shows an example of the electric power feeding method using the heat-resistant structure 509. FIG. It is a figure which shows another example of the electric power feeding method using the heat-resistant structure 509. FIG. It is a figure which shows the modification of the electrode 502 in Embodiment 5, and the electrode 502a. It is a figure which shows the modification of the electrode 502 in Embodiment 5, and the electrode 502b.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Hot cathode discharge lamp 101 Glass tube 102 Electrode 103 Electrode 104 Phosphor layer 105 Filament coil 106 Lead wire 107 Lead wire 108 Bead glass 109 Heat-resistant insulating structure 110 Electron emission substance 111 Exhaust pipe 112 Through-hole 113 Through-hole 114 Welding point 115 Welding point 150 Electrode 159 Heat-resistant insulating structure 200 Hot cathode discharge lamp 202 Electrode 205 Filament coil 206 Short lead wire 207 Long lead wire 209 Heat-resistant insulating structure 250 Electrode 251 Insulating member 252 Heat-resistant adhesive 300 Hot cathode discharge lamp 302 Electrode 305 Filament coil 309 Heat-resistant insulating structure 400 Hot cathode discharge lamp 402 Electrode 402a Electrode 402b Electrode 402c Electrode 402d Electrode 402e Electrode 402f Electrode 402g Electrode 4 5 Filament Coil 406 Short Lead Wire 407 Long Lead Wire 409 Heat Resistant Structure 421 Long Lead Wire 429 Heat Resistant Structure 439 Heat Resistant Structure 449 Heat Resistant Structure 459 Heat Resistant Structure 460 Heat Resistant Structure Body 461 Hanging Bracket 462 Suspension Bracket 463 Fixed Metal fitting 464 Lead wire 465 Lead wire 466 Connection reinforcing member 468 Lead wire 475 Filament coil 481 Hanging metal fitting 500 Hot cathode discharge lamp 502 Electrode 502a Electrode 502b Electrode 505 Filament coil 506 Lead wire 507 Lead wire 509 Heat-resistant structure 550 Power supply circuit 551 Switch 555 Filament coil 569 Heat-resistant structure

Claims (19)

Two lead wires,
A filament coil connected between the two lead wires and holding the emitter;
An electrode for a hot cathode discharge lamp, comprising: a structure having heat resistance, a fixed or moving range is restricted by a member other than the filament coil, and a shape change of the filament coil is suppressed. The filament coil is a coil of double winding or more,
The structure is
2. The electrode for a hot cathode discharge lamp according to claim 1, further comprising an insulating property and located inside a helix of the outermost coil of the filament coil. The structure is
The electrode for a hot cathode discharge lamp according to claim 2, wherein the outermost coil has a cylindrical shape in which a position corresponding to a spiral axis is hollow. The structure is
The electrode for a hot cathode discharge lamp according to claim 2, wherein the electrode is a columnar shape located at a position corresponding to a helical axis in the outermost coil and is porous. The structure is
The electrode for a hot cathode discharge lamp according to claim 2, wherein the electrode is fixed or regulated by one or both of the two lead wires. The filament coil is
The hot cathode according to claim 1, wherein the hot cathode is a coil of double winding or more, and a spiral axis of an outermost coil of the filament coil is substantially coincident with or substantially parallel to a tube axis of the hot cathode discharge lamp. Electrode for discharge lamp. In the filament coil, the outermost coil has a single spiral structure,
The two lead wires are connected to the short lead wire connected to the tube end portion side of the filament coil and to the tube center portion side of the filament coil and are directed to the tube end portion side in parallel with the filament coil. Consisting of long lead wires,
The electrode for a hot cathode discharge lamp according to claim 6, wherein a portion of the long lead wire parallel to the filament coil is surrounded by an insulating member. The filament coil is
The outermost coil in the filament coil has a double helix structure, both ends are on the tube end side, and each end is connected to the two lead wires, respectively. Item 7. The hot cathode discharge lamp electrode according to Item 6. In the filament coil, the outermost coil has a single spiral structure,
The two lead wires are connected to a short lead wire connected to the tube end portion side of the filament coil and to a tube center portion side of the filament coil and are directed to the tube end portion side in parallel with the filament coil. Consisting of long lead wires,
The structure is formed by suspending the filament coil in a direction from the tube central portion side to the tube end portion side while fixing or restricting a moving range of a part of the long lead wire on the tube central portion side. The shape change of the said filament coil is suppressed. The electrode for hot cathode discharge lamps of Claim 6 characterized by the above-mentioned. The electrode for a hot cathode discharge lamp according to claim 9, wherein the structure is fixed by an inner wall of the tube. The electrode for a hot cathode discharge lamp according to claim 9, wherein the structure is fixed at a tube end of the hot cathode discharge lamp. The structure is
Furthermore, it has conductivity and includes an external connection terminal connected to an external terminal having the same potential as the potential supplied to the long lead wire, and is used for feeding the filament coil from the outside together with the long lead wire. The hot-cathode discharge lamp electrode according to claim 11. The structure is
A sleeve-shaped portion that covers the filament coil; and a hanging portion that extends in the tube axis direction from the tube center side of the sleeve-shaped portion and suspends a part of the long lead wire on the tube center side. The electrode for a hot cathode discharge lamp according to claim 9. The filament coil is a coil of a single turn or more,
The structure suppresses a change in the shape of the filament coil by pushing up a substantially central portion in the longitudinal direction of the outermost coil of the filament coil in a direction from the tube end side toward the tube center side. The electrode for hot cathode discharge lamps according to claim 1. The structure is
The hot cathode discharge lamp according to claim 14, further comprising an external connection terminal that is electrically conductive and connected to an external terminal, and is used when power is supplied to a part of the filament coil from the outside. Electrode. The structure is
The electrode for a hot cathode discharge lamp according to claim 1, wherein the electrode is formed of a material having a decomposition temperature and a melting point of 1000 ° C or higher and a specific resistance higher than that of the filament coil.   The hot cathode discharge lamp using the electrode for hot cathode discharge lamps as described in any one of Claims 1-16. A hot cathode discharge lamp using the hot cathode discharge lamp electrode according to claim 15,
And a lighting circuit for applying a voltage between the external connection terminal and one of the lead wires to preheat for a certain period of time and then applying a voltage between the two lead wires. Characteristic lamp unit. The lighting circuit further includes:
At the time of starting, a voltage is applied between the external connection terminal and one of the lead wires, and a voltage is applied between the external connection terminal and the other of the lead wires. 19. The lamp unit according to claim 18, wherein the second pattern that is applied and preheated for a predetermined time is switched alternately or randomly each time the engine is started.

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