WO1999034402A1 - Electrode structure for electron emission, discharge lamp, and discharge lamp apparatus - Google Patents

Abstract

An electrode structure for electron emission capable of reducing the transition time from glow discharge to arc discharge, which can elongate the service life of electrodes and prevent blackening of inner walls of bulbs when used in discharge lamps and discharge lamp apparatus. The electrode structure (3A) for electron emission comprises an electron emitter (5) composed of an aggregate of granules (51), which emits electrons from its exposed surface heated by discharge, and convergence means arranged in contact at least partly with, or close at least partly to, the exposed surface of the electron emitter (5) so that discharges can be converged to the exposed surface. The electrode structure (3A) can be used in a discharge lamp (1) and a discharge lamp apparatus (9) that uses the discharge lamp (1).

Description

 TECHNICAL FIELD The present invention relates to an electron-emitting electrode assembly, a discharge lamp, and a discharge lamp device that have a long life. BACKGROUND ART Electron emission electrodes for discharge lamps are roughly classified into hot cathodes and cold cathodes. Of these, as the hot cathode, for example, a coil obtained by winding a transition wire and an alkaline earth metal oxide containing barium on a coil wound with a tungsten wire filament is often used.

 As another hot cathode, for example, a porous tungsten impregnated with an electron emitting material containing barium tungstate is well known.

 On the other hand, in recent years, discharge lamps for general lighting such as fluorescent lamps, as well as discharge lamps for backlights mounted on OA equipment such as facsimile machines and video equipment such as LCD televisions, have been developed to save resources and energy. Efficiency is being improved and valves are becoming smaller (smaller), and demand is increasing.

 However, among the above-mentioned hot cathodes, the former filament coil electrode cannot hold a large amount of electron emitting material because the filament coil length becomes shorter as the diameter of the bulb becomes smaller, so that a satisfactory life cannot be obtained and a thin wire is used. Therefore, the vibration resistance was weak. The latter porous tungsten electrode is used in high-current high-pressure discharge lamps, but it is difficult to manufacture this electrode. In addition, in the low current region of a low-pressure discharge lamp such as a fluorescent lamp, there was a problem that the cathode did not operate stably as a hot cathode.

As described above, in the above-described hot cathode, it is not possible to reduce the size of the bulb of the discharge lamp. Therefore, the hot cathode is made of a metal such as nickel or an aluminum-zirconium alloy. A cold cathode is used, but this cold cathode has a large cathode drop loss, and a large lamp current cannot be obtained.

 Therefore, as a means for reducing the size of the discharge lamp and increasing the lamp current, for example, an electrode assembly described in Japanese Patent Application Laid-Open No. Hei 16-65764 has been developed. Japanese Patent Application Laid-Open No. 1-65764 describes a hot cathode in which thermionic emission portions are formed by particles of semiconductor porcelain in a bottomed cylindrical container having an open front side.

 And, according to the description of this publication, the thermal capacity of the thermionic emitting portion is made lower than that of the container by making the thermionic emitting portion into a particle shape, and the temperature of the thermionic emitting portion rises faster during glow discharge, The transition to arc discharge is facilitated by facilitating thermionic emission. In this case, since the current density can be increased, the outer diameter of the electrode can be reduced and the discharge lamp bulb can be made narrower.

 However, the semiconductor porcelain of the thermionic emission portion described in Japanese Patent Application Laid-Open No. 1-65764 has a problem that the thermionic emission portion has a predetermined temperature during glow discharge due to insufficient activation of the surface. , The arc spot is not formed in the thermionic emission area, and the discharge may reach the periphery of the container. Then, when the discharge circulates into the container, the cathode fall voltage becomes large, so that the inner wall of the discharge lamp becomes black or the electrode has a short life. In particular, when the thermionic emission capability of the thermionic emitting portion is reduced, the discharge is likely to wrap around before the end of the life of the electrode, which promotes shortening of the lifetime.

 Also, for example, as described in Japanese Patent Application Laid-Open No. Hei 6-3202297 or Japanese Patent Application Laid-Open No. Hei 9-5097956, the hot cathode is held by a holder, and the holder It is connected to a lead wire for supply and is led out of the discharge lamp.

 At the time of a single discharge, the holder serves as a cold cathode and serves as a supply source of electrons. When the temperature rises at the time of a glow discharge, the electron emission from the semiconductor porcelain is activated and a transition to an arc discharge is made.

However, in the configuration described in Japanese Patent Application Laid-Open No. Hei 6-320297 or Japanese Patent Application Laid-Open No. Hei 9-5107956, the temperature of the thermionic emission portion during glow discharge is unlikely to rise, resulting in an arc. It takes time to shift to discharge. If the glow discharge time is long, the hot cathode is greatly affected by ion sputtering, which causes inconvenience to the hot cathode. That is, the active material on the surface of the semiconductor porcelain is sputtered, Inner lead spatter accumulates on the surface of the semiconductor porcelain, increasing the work function, resulting in a reduction in the ability to emit thermionic electrons, reducing the life of the electrodes, and reducing the inner wall of the bulb of the discharge lamp. Or blackening.

 As described above, in the semiconductor porcelain of the thermionic emission portion described in Japanese Patent Application Laid-Open No. 1-65764, the thermionic emission portion is specified at the time of glow discharge due to insufficient activation of the surface. If the temperature does not reach this temperature, arc spots will not be formed in the thermionic emission area, and discharge will easily flow around the outer periphery of the container. When the discharge circulates into the container, the cathode drop voltage increases, so that the inner wall of the bulb of the discharge lamp is blackened and the life of the electrode is shortened.

 In addition, in the configuration described in Japanese Patent Application Laid-Open No. Hei 6-302,977 or Japanese Patent Application Laid-Open No. Hei 9-5,079,596, the temperature of the thermionic emission portion during glow discharge is unlikely to rise, and arc discharge It takes time to switch to electricity. If the glow discharge time is long, the hot cathode is greatly affected by the ion knocking ring, so that the hot cathode is disadvantageously generated. In other words, the active material on the surface of the semiconductor porcelain is sputtered or sputtered on the container or inner lead and deposited on the surface of the semiconductor porcelain. There are problems that the electrode life is shortened and that the inner wall of the discharge lamp bulb is blackened.

 SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has an advantage in that electron emission that shortens the transition time from a glow discharge to an arc discharge, stabilizes the arc discharge, and prevents a reduction in electrode life and blackening of the inner wall of the bulb. An object of the present invention is to provide an electrode assembly, a discharge lamp using the electrode assembly, and a lamp device equipped with the discharge lamp. DISCLOSURE OF THE INVENTION The present invention provides the following inventions.

 (1) an electron emitter made of an aggregate of granules that are heated by electric discharge and emit thermoelectrons from an exposed surface;

Discharge concentrating means for concentrating discharge on the exposed surface by approaching or contacting at least a part of the exposed surface of the electron emitter; An electron-emitting electrode assembly comprising:

 The thermoelectron emission electrode is composed of an aggregate of granules, and when the exposed surface of the aggregate surface starts, a glow discharge occurs as a cold cathode, and ions accelerated by a high cathode drop voltage heat the entire electrode. However, the particles of the electron emitter have a small heat capacity L and a high thermal resistance to the particles adjacent to them, so it is easy to raise the temperature.After that, the particles are intensively heated and the thermoelectron force is sufficient. When it reaches the temperature at which it can be released, it shifts from glow discharge to arc discharge.

 That is, by providing the discharge concentrating portion, the electric field can be concentrated on the exposed surface of the electron emitter composed of aggregates of granules during the glow discharge, and the temperature of the electron emitter can be increased in a short time.

 (2) an electron emitter made of an aggregate of granules heated by discharge and emitting thermoelectrons from an exposed surface;

 Discharge concentrating means for concentrating discharge on the exposed surface by approaching or contacting at least a part of the exposed surface of the electron emitter;

 A container for accommodating the electron emitter;

An electron-emitting electrode assembly comprising:

 When the container is made of a conductive material, the container itself is used as a conductor portion. When the container is made of an insulating or semi-insulating material, a conductive member separate from the container is provided near the electron emitter in the container. By providing the body, the electric field can be concentrated on the conductor during glow discharge.

 Then, an arc discharge occurs on the exposed surface of the electron emitter facing the opening of the container.c Then, the temperature of the electron emitter can be raised in a short time to form an arc spot. When this electrode is used for a discharge lamp by promoting the transition to discharge, the inner wall of the bulb is not blackened and the life is not shortened.

 (3) an electron emitter made of an aggregate of granules that are heated by electric discharge and emit thermoelectrons from the exposed surface;

A container for accommodating the electron-emitting body, and using the portion of the electron-emitting body that is close to or in contact with at least a part of the exposed surface as a conductor to concentrate discharge on the exposed surface; An electron-emitting electrode assembly comprising:

 (4) The electron emission electrode structure (1) according to (3), wherein the container is made of metal.

 The material of the container is at least one or more of metals such as W, Mo, Re, Ta, Ti, Zr, Ni and Fe, which have a relatively low vapor pressure even at the temperature reached by the electrodes during discharge. It consists of alloys of metals or carbides C, nitrides N, silicides Si and borides B of these metals. These substances act as good conductors at the time of energization, so that they can sufficiently flow to the electron emitter contained inside, and arc spots are easily formed and good electron emission can be obtained.

 Further, a semiconductor material including an oxide such as Ba, Sr, Ca, or Th may be added to the above metal. These containers have a smaller heat capacity than those made entirely of metal, and are less susceptible to heat dissipation, so that arc spots are easily formed on the particles of the electron emitter.

 (5) The electron-emitting electrode assembly according to (4), wherein an outer surface of the metal container is coated with an insulating material.

 Discharge is less likely to occur in the insulative coated part, and the electric field is concentrated on the part where the metal is exposed, and a glow discharge can be generated intensively on a part of the exposed surface of the electron emitter. The insulating coating can be formed using at least one kind of metal oxide such as aluminum oxide, silicon oxide, zirconium oxide and tantalum oxide, or a mixture thereof.

(6) The electron emission electrode structure according to (2), wherein the container is insulative or semi-insulating.

 (7) The electron emission electrode assembly according to (6), wherein the container is made of a metal oxide.

(6), (7), the container, the mother crystal (B aT i 0 ₃ and B a Z RON etc.) additives (Ta ₂ 0 _3, etc.) a semi-insulating, for example obtained by such addition of Examples include semiconductor ceramics. This container does not have a good conductive action at normal temperature. When the temperature rises, the resistance value decreases and the container becomes a conductor. Once the conductor becomes a conductor, the temperature of the container becomes high, and the activation of the electron emitter contained in the container is promoted to maintain the discharge. Holding is continued.

 In the case of highly insulating containers, conductive metal plates, metal carbides, metal nitrides, etc. are placed on the surface of the container so that they can be electrically connected to the electron emitters contained in the container. What is necessary is just to provide the coating which consists of a coating.

 (8) The electron-emitting electrode assembly according to any one of (2) to (7), wherein the container is supported by a holder.

 (9) The electron-emitting electrode assembly according to (1), wherein the discharge concentrating means is a metal protrusion approaching or contacting at least a part of the exposed surface of the electron-emitting body.

 The electric field is more concentrated during glow discharge by making the tip of a metal projection made of a rod or a plate sharp. The pointed portion of the tip may have a sharp point, such as a needle-like, angular, conical or pyramidal shape, or a truncated fiber shape, a truncated pyramid shape, or an arc shape. desirable.

 When the container is conductive and a conductor portion is provided separately from the container, it is preferable that both are electrically connected to have the same potential.

 (10) The electron-emitting electrode structure according to (9), wherein the metal projection has a tongue shape.

 (11) The electron-emitting electrode assembly according to (1), wherein the discharge concentrating means is a conductive rod-shaped protrusion penetrating the electron-emitting body and protruding from the exposed surface.

(12) The bar-shaped projection force The electron emission electrode assembly according to (10), characterized in that the rod-shaped projection force protrudes from the center of the exposed surface.

 (13) The electron-emitting electrode assembly according to (11), wherein the rod-shaped projection projects eccentrically from the center of the exposed surface.

 Since the protruding rod-shaped protrusion protrudes from the position deviated from the center axis of the exposed surface of the electron emitter, the electron emission comes into contact with or in proximity to the protruding part where the arc spot is easily formed and the inner wall of the container. The body temperature easily rises, and the transition from glow discharge to arc discharge can be improved.

 (14) The electron emission electrode structure according to (2), wherein the discharge concentrating means is a metal mesh that covers an opening side of the container.

Conduction made of metal mesh facing the exposed surface of the electron emitter in the opening on the front side of the container By providing the body, the electric field concentrates on the mesh during the glow discharge, so that the temperature of the electron emitter can be raised to form an arc spot, and the transition to the arc discharge during the glow discharge is promoted, and this electrode When used in a discharge lamp, it does not blacken the inner wall of the bulb or shorten its life.

 The mesh may be a braided metal wire such as Ni, W, or stainless steel, or a metal plate having a large number of holes perforated.

 (15) The electron emission electrode structure according to any one of claims 9 to 13, wherein the discharge concentrating means is formed on the container or the holder.

(16) The particle of the electron emitter is formed from a material mainly composed of at least one oxide of an alkaline earth metal, a transition metal and a rare earth metal. (1) or (2) Electron emission electrode structure.

 It is desirable that the granule particles of the electron emitter be formed of a material mainly composed of at least one oxide of an alkaline earth metal, a transition metal and a rare earth metal.

As the material for example B a 0, S r 0, C a 0 and _{B a 4 T i 2 0 g} , B a Ta0 3, S rT i 0 3, S r Z R_〇 _alkaline earth metals such as metal + metal oxide alkaline earth metals such as objects or BaCe0 ₃ consisting mainly of metal + rare earth and (S c, Y, L, etc. a and Rantanoido) oxides of metals can be used those mainly. These have a low work function, have a small cathode drop loss, and have an effect that they do not easily react with atmospheric components, so that they are easy to manufacture.

 (17) A film of at least one of carbide, Z, or nitride of an alkaline earth metal, a transition metal, and a rare earth metal is formed on the surface of the granules of the electron emitter. The electron-emitting electrode structure according to (1) or (2),

As a coating formed on at least a part of the surface of the particle of the electron emitter, a coating made of carbide or Z or nitride of at least one of an alkaline earth metal, a transition metal and a rare earth metal, Ti, A thin film of a high melting point material made of a carbide or nitride such as Ta, Zr, Nb, Hf or W, for example, a carbide such as TaC or Tic or a nitride such as TIN or ZrN is formed. As a result, the alkaline earth metal, which contributes to the electrode material, especially emission (electron emission), is reduced by ion sputtering. Scattering and evaporation can be reduced.

 (18) a glass bulb for filling a gas to be discharged;

 An electron emitter provided in the bulb and made of an aggregate of granules that are heated by the discharge of the gas and emit thermoelectrons from the exposed surface; and at least a part of the exposed surface of the electron emitter is close to the electron emitter. Or a discharge concentrating means for contacting and concentrating discharge on the exposed surface;

A discharge lamp comprising:

 (19) a glass bulb for forming a discharge path by enclosing a gas to be discharged; and an aggregate of granules provided at an end of the glass bulb and heated by the discharge of the gas and emitting thermoelectrons from an exposed surface. And an electron emission electrode assembly comprising: an electron emitter made of the above; and discharge concentrating means for concentrating a discharge on the exposed surface by approaching or contacting at least a part of the exposed surface of the electron emitter.

 A power supply circuit device connected to the electron emission electrode structure and applying a voltage between the electrode structures;

A discharge lamp device comprising:

 (20) An electron emitter made of an aggregate of granules which are provided in a glass bulb for enclosing a gas to be discharged and which are heated by the discharge of the gas and emit thermoelectrons from the exposed surface; A discharge concentrating means and a power dispersing means for concentrating a discharge on the exposed surface by approaching or contacting at least a part of the exposed surface;

 A housing for housing the discharge lamp;

 A discharge lamp device comprising:

Illumination equipment using this discharge lamp device can be used for backlight devices such as liquid crystal display devices, liquid crystal televisions and decorative devices, for reading documents such as facsimile machines, for exposing and removing static electricity in copiers, and for ordinary AA devices. It can be widely used as lighting equipment and lamps. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a partially cutaway plan view showing a discharge lamp (fluorescent lamp) device according to an embodiment of the present invention.

 FIG. 2 is a longitudinal sectional view showing a hot cathode, which is an electron emission electrode structure according to one embodiment of the present invention, which is sealed in the discharge lamp (fluorescent lamp) of FIG.

 FIG. 3 is a graph showing a relationship between a discharge current (A) of a hot cathode having an insulator and a cathode drop voltage (V).

 FIG. 4 is a graph showing the relationship between the discharge current (A) of the hot cathode having no insulator and the cathode drop voltage (V).

 FIG. 5 is a perspective view showing a hot cathode which is an electrode of another embodiment of the present invention.

FIG. 6 is a graph showing the relationship between the input power (W) of the fluorescent lamp using the hot cathode shown in FIG. 5 and the reciprocal of the g-arc transition time g (sec− ¹ ).

 FIG. 7 is a plan view showing a hot cathode according to another embodiment of the present invention.

 FIG. 8 is a side view of the hot cathode shown in FIG.

 FIG. 9 is a plan view showing a hot cathode according to another embodiment of the present invention.

 FIG. 10 is a side view of the hot cathode shown in FIG.

 FIG. 11 is a plan view showing a hot cathode according to another embodiment of the present invention.

 FIG. 12 is a side view of the hot cathode shown in FIG.

 FIG. 13 is a perspective view showing a hot cathode according to another embodiment of the present invention.

 FIG. 14 is a perspective view showing a hot cathode according to another embodiment of the present invention.

 FIG. 15 is a partial cross-sectional plan view of the fluorescent lamp using the hot cathode shown in FIG.

 FIG. 16 is a perspective view showing a hot cathode according to another embodiment of the present invention.

 FIG. 17 is a top view showing a hot cathode according to another embodiment of the present invention.

 FIG. 18 shows a hot cathode according to another embodiment of the present invention, in which (a) is a top view and (b) is a longitudinal sectional view.

 FIG. 19 is a partially cutaway sectional view showing a hot cathode according to another embodiment of the present invention.

FIG. 20 is a perspective view showing the discharge lamp device of the embodiment. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of an electron-emitting electrode structure and a discharge lamp according to the present invention will be described with reference to the drawings.

 FIG. 1 is a partially cutaway plan view showing a discharge lamp device, and FIG. 2 is a longitudinal sectional view showing an electron emission electrode assembly.

 In the figure, reference numeral 1 denotes a discharge lamp, for example, a fluorescent lamp, and this lamp 1 is a translucent container having a straight tubular outer diameter of, for example, 3 to 15 mm, here, about 4 mm, and a total length of about 300 mm. The hot cathode 3 A, 3 A force as an electrode assembly is provided inside the both ends of the glass bulb 2 <The lead wires 4, 4 that are arranged facing each other and connected to the hot cathode 3 A, 3 A at the end are airtight, respectively. Sealed to.

 A rare gas, for example, an argon gas (A r), which is a discharge medium, is sealed in the glass bulb 2 with a mercury force of 20 Torr. The distance between the hot cathodes 3 A, 3 A is set to about 260 mm. Further, a phosphor film (not shown) is formed on the inner or outer wall surface of the glass bulb 2 by coating.

 In addition, the hot cathode 3A includes a container 6 filled with the electron emitter 5, a holder 7A for holding the container 6, and a lead wire 4 supporting the holder 7A and making an electrical connection. It is composed of (Note that the hot cathode does not include lead wires. ©.)

 The container 6 is made of a conductive material such as tantalum Ta and zirconium Zr as a main component, and has a shape of a bottomed cylinder (cup) having a circular bottom surface 61 and an opening 62 at the end. In addition, a circumferential concave portion 63 is formed on the outer peripheral side surface. The holder 7A is made of nickel and has a shape of a bottomed cylinder (cup) having a circular bottom surface 7 1 for receiving the container 6 and an opening 72, and the inside of the concave portion 63 of the container 6 is formed. The periphery of the opening 72 of the holder 7A was inserted into the holder 7A, and the two were mechanically and electrically connected by crimping, and the container 6 was coaxially attached to the holder 7A. It has a configuration.

The container 6 contains mainly oxides of barium Ba and tantalum Ta having a diameter of 10 / m to 500 / zm, preferably a diameter of 20 to 100 μm. a small amount of zirconium oxide Z r 0 ₂ granules 5 1 of a semiconductor ceramic obtained by adding, Are filled and housed. Reference numeral 8 denotes an insulator made of aluminum oxide, which is coated on the lower surface side of the recess 63 on the outer surface of the container 6 and on the inner surface of the holder 7A.

 The lead wire 4 is welded almost at the center of the bottom surface 71 of the holder 7A, and as described above, the container 6, the holder 7A, the electron emitter 5, and the lead wire 4 constitute the hot cathode 3A. ing.

 In addition, the conductive material forming the above-mentioned container 6 is, in addition to the above, tungsten W, molybdenum Mo, rhenium Re, titanium T i ヽ tantalum Ta, zirconium Zr, niobium Nb, hafnium Hf, nickel Ni or iron It can be formed from at least one kind of Fe or an alloy of these metals, or a carbide C, a nitride N, a silicide Si, or a boride B of these metals. Further, a semiconductor material composed of an oxide such as barium Ba, strontium Sr, or calcium Ca thrium Th may be added to the above-described metals.

As another material for forming the container 6, for example, host crystals (B aT i 0 ₃ and Ba Z R_〇 _3, etc.) to additive (Ta ₂ 0 _3, etc.) a semi-insulating obtained by such addition of For example, even in the case of semiconductor ceramics, or BaO, SrO,. & 0 Ya _{8 a 4 T i 2 0 9} , B aTa0 3, S rT I_〇 _3, S r Z r Og those mainly composed of Al force Li earth metals + metal oxides, such as and B a CeO _3, such Al earth metal + rare earth (Sc, Y, La, lanthanide, etc.) Metal oxides mainly used can be used.

 Further, in the case of the container 6 made of the above-mentioned material of the alkaline earth metal, the transition metal and the rare earth metal, the surface or the surface of the container 6 is made of at least one of a carbide and a nitride of the alkaline earth metal, the transition metal and the rare earth metal. For example, by forming a coating of a high melting point material such as a carbide such as TaC or TiC or a nitride such as TiN or ZrN, the electrode container 6 is prevented from being scattered or evaporated by ion sputtering. Can be reduced.

When the container 6 is made of an insulating material, a conductive metal plate or rod may be brought close to the surface of the container 6, or a coating made of metal carbide or metal nitride may be formed. The electron emitter 5, in addition to barium B a of the above-mentioned materials, strontium S r, oxides of calcium C a and _{B a 4 T i 9 O g} , B a T A_〇 _3, S r T i O _3, S r Z r 0 have with those of the alkaline earth metal tens metal oxide as a main component, such as ₃ B a C e 0 ₃ alkaline earth metals such as metal + rare earth (scandium S c, Germany tri © arm Y , Lanthanum La, lanthanide, etc.) Those mainly composed of metal oxides can be used.

 In the case of the electron emitter 5 made of a material of the alkaline earth metal, the transition metal and the rare earth metal, at least one of the alkaline earth metal, the transition metal and the rare earth metal By forming a coating of one carbide or nitride, for example, a carbide such as TaC or TiC, or a nitride having a high melting point such as TiN or ZrN, the electron emitter 5 is formed. Scattering and evaporation by ion sputtering can be reduced.

 In producing the container 6 and the electron emitter 5, both may be sintered together.

 The holder 7A is also formed of a material containing at least one of conductive metals such as nickel Ni, tantalum Ta, titanium Ti, zirconium Zr, aluminum A1 and tungsten W. Can be.

 In addition, the holder 7A is not limited to a cover structure that covers and holds substantially the entire outer surface and the bottom surface 61 of the container 6, and may have a column structure such as a frame. Further, when the lead wire 4 can be directly connected to the container 6 to support and electrically connect the container 6, the holder 7A is not particularly required.

The insulator 8 was formed by applying a solution in which fine particles of aluminum oxide having a particle diameter of 0.1 μm or less were dispersed in an alcohol-based solvent using a brush, and applying the solution at about 200 ° C. after the application. It may be formed by heating in the air for about 5 minutes to remove the solvent and moisture, or it may be applied by immersing the necessary part in the solution or by adding the solution. Further, the insulator 9 may be made of aluminum oxide A i ₂ 〇 ₃ヽsilicon oxide S i 0 ₂ヽSani匕zirconium Z r 0 ₂ and at least one or a mixture of tantalum oxide T a than zero ₅ metal oxides such as May be used.

The hot cathodes 3 A and 3 A having the above structure as an electrode assembly are When the lead wires 4 and 4 (the base is provided) are connected to the power supply circuit device C having a high-frequency lighting circuit and the like, and the fluorescent lamp 1 is completed, the holders 7 A made of a conductive material are connected. Through this, an electric current flows through the container 6 made of the same conductive material, which is supported and electrically connected to the holder 7A.

Then, a discharge is generated between the hot cathodes 3 A, 3 A, which use the container 6, which is disposed opposite to both ends of the glass bulb 2 serving as a discharge path, as a conductor, and this discharge causes the rare gas in the bulb 2 to flow. Is ionized and excited to generate ultraviolet light, which is converted into visible light by the phosphor coating, and this visible light is emitted to the outside through the bulb 2 wall. The discharge from the hot cathodes 3 A and 3 A facing this discharge path causes a glow discharge as a cold cathode at the time of starting, and heats the entire ion force electrode accelerated by a high cathode drop voltage to raise the temperature. The granules 51 of the electron emitter 5 have a small heat capacity and a high thermal resistance with the adjacent granules 51, so that the temperature is easy to rise, and then the granules 51 are heated intensively When the electron force reaches a temperature at which sufficient discharge is possible, the transition from glow discharge to arc discharge occurs, and an arc spot is formed on the granules 51 to operate as a hot cathode. The glow discharge occurs from almost the entire surface of the conductive container 6 except for the outer surface thereof, and then moves to an arc discharge. This arc discharge is caused by the exposed surface of the surface of the electron-emitting body 5 filled and stored in the container 6. 5 5 Forces, etc., more specifically, openings 6 2 Granules 5 in contact with the inner wall surface. This is a five-element semiconductor porcelain (ceramic) that has a large electric resistance and is hard to allow current to flow, and is in contact with or close to the inner wall of the container 6 that is the conductor. An arc spot is formed from granules 51, .... When the electron-emitting material is scattered and consumed from the granules 51 forming the electron-emitting body 5, the arc spot moves to the adjacent granules 51 to sustain the discharge _c. A gap is formed between the outer surface of the holder and the inner surface of the holder 7A, and the gap acts as a hollow one-sided sword to cause discharge to flow into this portion. In the present invention, the insulator 8 formed on the outer surface of the container 6 and the inner surface of the holder 7A prevents the discharge from flowing to the bottom side of the container 6, thereby stabilizing the discharge. As a result, as a means for concentrating the discharge of the hot cathode 3 A, the conductive container 6 performs its function, the temperature of the electron emitter 5 appropriately rises, and the arc spot moves greatly during lighting. The arc spot is properly formed without any fluctuations in the discharge and stable discharge can be maintained.

 In addition, the fluorescent lamp 1 has a short transition time from a spark discharge to an arc discharge, can reduce the cathode drop voltage, can improve luminous efficiency, and can reduce spatter due to ion bombardment. (2) Longer life can be achieved by preventing blackening of the inner wall.

 Figs. 3 and 4 show the measurement results of the cathode drop voltage (V) when the insulator 8 was coated on the outer surface of the container 6 and the inner surface of the holder 7A and when the insulator 8 was not formed. Show.

 Compared to the case where the insulator 8 shown in FIG. 4 is not formed, the cathode drop voltage (V) is almost the same as the discharge current (A) when the insulator 8 is formed as shown in FIG. It does not fluctuate stably, and the cathode drop voltage (V) for the same discharge current (A) can be reduced, thereby preventing the electrode life from being shortened.

 Next, another embodiment of the hot cathode as the electrode assembly of the present invention will be described with reference to FIG. FIG. 5 is a perspective view showing the hot cathode 3B, and is the same as that shown in FIG. 1 except for the holder, and the same portions are denoted by the same reference numerals and description thereof will be omitted.

 The holder 7B shown in FIG. 5 has a bottomed cylindrical shape similar to that of the above embodiment, and has a pair of projections 7 3, 7 3 protruding from the opening 72 of the holder 7B. Has been established upright. The projections 73, 73 have a claw-shaped tongue piece 74 bent inward at a substantially right angle inward facing the electron emitter 5 above the opening 62 of the container 6. The tips of both tongue pieces 74, 74 are formed in a triangular shape with an acute angle, and the sharp tips 75, 75 of the mutual emitters 5 face the exposed surface 55 of the surface layer. It is arranged.

Therefore, by bending the tip 75 of the tongue piece 74 at the corner of the container 6, the container 6 can be easily attached to the holder 7B and held without damaging the container 6. 6 can be prevented from moving in the axial direction. Further, even if thermal expansion occurs in the holder 7B during discharging or the like, the container 6 can be held and the container 6 can be prevented from falling off. The projections 73, 73 were formed integrally from the holder 7B. As long as 3 is electrically connected to the holder 7B, it may be formed separately from the holder 7B and integrated later, and the projections 7 3 are not limited to two pairs. One or three or more may be formed.

 The hot cathode 3 B is mounted on the opening 6 2 of the container 6 with the tongue piece 7 4 facing the electron emitter 5, with the tip 7 5 The glow discharge force is generated. This glow discharge causes a concentration of an electric field at the tip part 75, and promotes a temperature rise of the granules 51,... Of the electron emitters 5 located in the vicinity thereof. An arc spot can be easily formed on the surface. As described above, the transition from a single-port discharge to an arc discharge in a short period of time makes it difficult for ion sputtering to occur, and blackening of the inner wall of the glass bulb 2 and reduction of the electrode life can be prevented. The tip 75 of the tongue piece 74 is desirably formed at an acute angle because the sharper the electric field concentration tends to occur.

FIG. 6 shows a discharge lamp (characteristics of which are indicated by Okina) of the discharge lamp of the present invention using an electrode 3 B having a conductor portion formed of a tongue piece 74 of the embodiment shown in FIG. 5 is a graph comparing the input power [W] of a discharge lamp without a conductor portion (characteristics are indicated by an X mark) with the reciprocal of the glow arc time [g (sec− ¹ )].

 As shown in FIG. 6, the reciprocal of g in the glow-arc transition time with a small input power W can be obtained with the protrusion 73 (conductive portion). Therefore, by forming the protrusions 73 (conductive portions) 74, the glow-arc transition time can be shortened, and the time during which a gap or the like occurs can be shortened.

 Next, another embodiment of the hot cathode as the electrode assembly of the present invention will be described with reference to FIGS. 7 to 10. FIG. 7 and 8 show the same hot cathode 3C, FIG. 7 shows a plan view, FIG. 8 shows a side view of FIG. 7, and FIGS. 9 and 10 show the same hot cathode 3D, and FIG. 9 shows a flat view FIG. 10 is a side view of FIG. 9, and both hot cathodes 3C and 3D have the same configuration as that shown in FIG. 1 or FIG. And the description is omitted.

The hot cathode 3C shown in FIGS. 7 and 8 also has the container 6 housed in the holder 7C, and the holder 7C has a bottomed cylindrical shape similar to that of the hot cathode 3B shown in FIG. , Opening 7 2 A pair of projections 7 3, 7 3 projecting upward from the end face are formed upright on the body. Have been. The projections 7 3 and 7 3 are bent inward at a right angle to the exposed surface 55 of the surface of the electron emitter 5 slightly above the opening 62 of the vessel 6 as a discharge concentrating conductor. And a tongue piece 74 serving as a conductive portion. The arc-shaped distal ends 76, 76 of the tongue pieces 74, 74 are disposed facing the exposed surface 55 of the surface layer of the electron emitter 5 so as to be spaced apart therefrom.

 As shown in FIGS. 7 and 8, even if the tips 76 and 76 of the projections 73 and 73 are formed in an arc shape, electric field concentration may occur between the tips 76 and 76. it can.

 Here, in the embodiment shown in FIGS. 7 and 8, the hot cathode 3 shown in the embodiment having a projection 73 forming an electric conductor having a tip end 76 formed in an arc shape is used. For comparison, a start-up lighting voltage test and a blinking test were performed using a hot cathode having no protrusion 73.

 For the test, use a fluorescent lamp 1 with a tube diameter of glass bulb 2 of about 6 mm, a distance between hot cathodes 3 C and 3 C of about 150 mm, and argon gas sealed at about 10 OT orr. The part 73 was formed using a nickel metal plate having a width of about 1 mm.

 Then, in the starting lighting voltage test, if the voltage at which the temperature changes from a single discharge to an arc discharge is defined as the starting lighting voltage after leaving for 3 hours in a place where the ambient temperature is 25 ° C, as shown in Table 1, It can be seen that in the case of forming 3, the starting voltage is greatly reduced.

(table 1 )

また、 点滅試験では、 二次開放電圧約 2. 3 k V r m s、 ランプ電流約 2 0 m A、 ランプ電圧約 2 0 0 V r m sの特性を有する点灯回路を用い、 3 0秒間点灯、 3 0秒間消灯を 1サイクルとして点滅点灯を繰り返し、 不点となるまでの回数を 測定すると、 表 2に示すように突起部 （導電体部） 7 3を形成したものでは不点 となるまでの回数が大きく増加し、 点滅寿命が向上することがわかる。 (表 2 ) Lighting voltage (kV rms)

In the blinking test, a lighting circuit with the characteristics of a secondary open-circuit voltage of about 2.3 kV rms, a lamp current of about 20 mA, and a lamp voltage of about 200 V rms was used. Repeating blinking and lighting with one cycle of turning off for 2 seconds, and measuring the number of times until it becomes a point, as shown in Table 2, the number of times until it becomes a point with the projection (conductive part) 73 formed as shown in Table 2 It can be seen that there is a large increase and the blinking life is improved. (Table 2)

次に、 図 9および図 1 0に示す本発明の電極構体である熱陰極 3 Dの他の実施 の形態を説明する。 Number of flashes (10,000 times)

Next, another embodiment of the hot cathode 3D as the electrode assembly of the present invention shown in FIGS. 9 and 10 will be described.

 In the hot cathode 3C shown in FIG. 7 and FIG. 8, the force of forming the projection 73 having the tongue piece 74 integrally from the holder 7C. The hot cathode 3D is attached to the holder 7D by the holder 7D. D is formed by connecting a rod-shaped projection 77, which is a conductor part bent at a right angle and is separate from D. The tip of the rod-shaped projection 77 is connected to the electron-emitting body 5 in the container 6 It faces 5.

 Thus, even when the discharge concentrating means is the rod-shaped protrusion 77, the same operation and effect as those of the protrusion 73 shown in FIGS. 7 and 8 described above can be obtained. If the tip of the rod-like projection 77 is sharpened, the electric field is concentrated and the effect can be further improved.

 Further, another embodiment of the hot cathode as the electrode assembly of the present invention will be described with reference to FIGS. 11 and 12. FIG. FIGS. 11 and 12 show the same hot cathode 3E, FIG. 11 is a plan view, FIG. 12 is a side view of FIG. 11, and the same parts as those shown in FIGS. The same reference numerals are given and the description is omitted.

 In the hot cathode 3E shown in FIGS. 11 and 12, the conductor portion is replaced with the above-mentioned plate-shaped tongue piece 73 and the rod-shaped projection 77, and is knitted vertically and horizontally by a conductive metal wire, or A mesh-like metal mesh 78 having a large number of through holes formed in a metal plate is provided in an opening 62 on the front surface of the container 6 so as to cover and close the exposed surface 55 of the surface of the electron emitter 5. As described above, even when the discharge concentration means is a metal mesh 78 having conductivity, the same operation and effect as those of the hot cathode of the above embodiment can be obtained.

The mesh 78 may be formed by knitting a metal wire such as nickel Ni, tungsten W, or stainless steel, or a metal plate having a large number of holes perforated. Further, another embodiment of the hot cathode as the electrode assembly of the present invention will be described with reference to FIGS. Fig. 13, Fig. 14 and Fig. 16 are perspective views showing the hot cathodes 3F, 3G and 3H, and Fig. 15 is a cutaway view of a part of the fluorescent lamp 1 in which the hot cathode 3G of Fig. 14 is sealed. In the plan view, the same portions as those shown in FIGS. 1 to 12 are denoted by the same reference numerals, and description thereof will be omitted. The hot cathodes 3F, 3G, and 3H shown in FIGS. 13, 14, and 16 each use a conductive rod-like projection made of metal such as an electrode rod as a discharge concentrating means. is there.

 In the hot cathode 3F as an electrode assembly shown in FIG. 13, the container 6F has a through hole (not shown) formed at the center of the bottom surface 61, and the particles filled and stored in the through hole and the container 6F. A conductive material made of tungsten W, molybdenum Mo, titanium Ti, tantalum Ta, nickel Ni, or the like that penetrates between the granules 51 of the electron emitter 5 and projects from the center of the opening 6 2. The electrode rods that make up the body are 4 A. The electrode rod 4 A forming the rod-shaped projection may be one that also serves as the tip of the lead wire 4, or may be one that is formed separately from the lead wire 4 by welding or the like.

 Note that, for example, the lead wire 4 also serving as the electrode rod 4A is welded and fixed to a through hole of the container 6F. In addition, when the tip of the electrode rod 4A protruding from the opening 62 and forming the conductor portion is formed at an acute angle, discharge is more likely to occur.

 In this way, the tip of the electrode rod 4A, which also serves as the conductive lead wire 4 penetrating through the container 6F and the electron emitter 5, also serves as the conductor, and the tip of the electrode rod 4A protrudes above the opening 62. As a result, the electric field can be concentrated at the tip, the temperature of the electrode rod 4 A can be increased, and the granules 51 of the electron emitter 5 in contact with or in proximity to the electrode rod 4 A can be activated. You. Then, an arc spot is generated from the surface of the granules 51 in contact with the outer surface of the electrode rod 4A, and when the electron emission from the granules 51 ends, the adjacent granules 51 move to the hairspout force. The spot moves one after another to the adjacent granules 51,..., So that the discharge can be stably maintained.

 The hot cathode 3G shown in FIG. 14 is the same as the hot cathode 3F shown in FIG. 13 except that the lead wire 4 serving also as the electrode rod 4A formed of a rod-like projection is coaxial with the container 6G axis, but is centered. It passes through a position deviated from the axis 69.

That is, the lead wire 4 which also serves as the electrode rod 4 A has a capacity on the base end side outside the container 6 G. Force on the central axis of container 6F Container 6G Bend 4 near the bottom 6 1 Of these, it is configured to be offset from the axis 69.

 Then, the hot cathodes 3G, 3G are sealed to the end of the glass bulb 2, as shown in FIG. 15, to complete the fluorescent lamp 1A. When the hot cathode 3G is energized, current flows through the conductive electrode rod 4A and the container 6G, and discharge occurs between the hot cathode 3G and the opposing hot cathode 3G. At this time, since the electrode rod 4A in the container 6G is closer to the inner wall of the container 6G than when it is on the central axis 69 of the container 6G, the electrode rod 4A and the The temperature rises as G becomes the hot cathode 3 G, and as a result, the temperature of the electron emitter 5 also rises and the activation of the particles 51,… can be enhanced, and the transition from glow discharge to arc discharge is favorable. Becomes

 Also, even when the electrode rod 4A is located at an offset position which is not located at the center of the container 6G, the occurrence of the arc spot moves along the particles 51 of the electron emitter 5 facing the opening 62. Therefore, an appropriate arc discharge can be performed, and slight deviation has little effect on the light emission characteristics. In addition, since the lamp 1A is sealed on the lead 4 at the sealing portion at the end of the bulb 2 and almost on the center axis of the screw 2, the sealing portion is caused by the bias of the lead wire 4. There are no cracks due to non-uniformity of glass meat deposits.

 If the granules 51 of the particle-shaped electron emitter 5 near the inner wall of the container 6 F have exhausted the electron-emitting substance and no longer emit thermionic electrons, the other granules 51 adjacent to the inner wall of the container 6 in the circumferential direction will be removed. It was confirmed that the particles emitted thermoelectrons and subsequently transferred to the granules 51 adjacent to the inner wall in the circumferential direction.

 The fluorescent lamp 1A using the hot cathodes 3G and 3G is almost the same as the one shown in Fig. 6 when comparing the relationship between the average input power W and the inverse g of the glow-arc transition time. As a result, the conductive rod 4 A protruding from the container 6 G can be formed to obtain a large reciprocal of the glow-arc transition time g with a small input power. Therefore, by forming the protruding conductive rod 4A, the glow-arc transition time can be shortened, and the time for generating ion packs can be shortened.

Further, a hot cathode 3H according to another embodiment will be described with reference to FIG. FIG. 16 is a perspective view showing a hot cathode. The hot cathode 3 H as an electrode shown in FIG. 16 is a container 6 H The electrode rod 4 A also serving as the lead wire 4 is erected along the central axis of the lead wire 4, and a branch part 42 is formed on the lead wire 4. Four electrode rods 4B are provided in a branched shape, and each of the tips protrudes from the opening 62 as a rod-shaped projection.

 The electrode rods 4 A, 4 B,... Formed of rod-shaped projections forming the conductors are arranged at irregular intervals even if the electrode rods 4 B,. And the number of branches may be one or more.

 By providing a plurality of the electrode rods 4A, 4B,... Forming the conductors, the temperature rise not only around the electrode rods 4A, 4B,. As a result, an emission region is formed in the entire area of the electron emitter 5, the glow-arc transition time can be shortened, and the time during which ion sputtering occurs can be shortened. Also, after the exhaustion of the granules 51,... Of the electron emitters 5 around one of the electrode rods 4A and 4B, an arc spot is formed around the other electrode rods 4A and 4B. , Longer life.

 FIGS. 17 to 19 show other embodiments of the hot cathodes 3 J to 3 L as an electrode assembly. In the drawings, the same parts as those in FIG. Is omitted. These hot cathodes 3 J to 3 L shown in FIGS. 17 to 19 differ from those shown in FIGS. 2 to 16 in the shape of the container.

 FIG. 17 is a top view of the hot cathode 3 J having conductivity.The container 6 J shown in the hot cathode 3 J has a granule 5 of the electron emitter 5 with respect to the outer peripheral shape which is circular when viewed from the top. 1, an opening portion 6 for accommodating the inner wall is formed as a wavy uneven peripheral edge 63. The discharge lamp in which the hot cathode 3 J is sealed has an irregular inner wall of the container 6 J, so that the circumference of the inner wall can be longer than when the inner wall is simply made the same concentric circle as the outer wall. 5 Granules 5 1, ... can take a large area in contact with. When the lamp is energized, the absolute number of contact or proximity between the irregular peripheral edge 6 3 of the irregular inner wall 6 2 of the conductive container 6 J and the granules 51 of the electron emitter 5 increases. .

When the discharge lamp is energized, the granules 51 of the electron-emitting body 5 that are in contact with or close to the uneven inner wall 62 of the container 6 J, which is a conductive part, also exert a force on the surface granules. An arc spot is generated from 51, and the arc spot emits electrons in granules 51. When the radioactive material is scattered and consumed, it moves to the adjacent particles 51 and the discharge is maintained. As a result, it is easy for discharge to occur, and the arc spot does not move significantly during lighting, so that stable discharge without fluctuation in discharge can be maintained. In addition, the above lamp has a short transition time from glow discharge to arc discharge, can reduce the cathode drop voltage, can improve the luminous efficiency, and can reduce the spatter caused by the ion impact. Prevents long life.

 FIG. 18 shows another hot cathode 3 K, wherein FIG. 18 (a) is a top view and FIG. 18 (b) is a longitudinal sectional view.

 The hot cathode 3K has a circular projecting portion 64 that is integrally erected from the bottom surface of the circular container 6K toward the center of the opening. The recesses 65 are filled with granules 51,... Of the electron emitters 5 in an annular shape. In this case, the central projecting portion 64 is also a conductor, and an arc spot serving as a starting point of the discharge can be generated on the entire extension of the inner wall 62 and the peripheral portion of the projecting portion 64. The same operation and effect as those of the above embodiment can be obtained.

 The hot cathodes 3 J and 3 K shown in FIGS. 17 and 18 have a longer total length of the inner wall of the containers 6 J and 6 K than the simple circular shape. There is no advantage in that thermionic emission is easily generated and the arc discharge can be maintained for a long period of time.

 In addition, the shape of the container is not limited to a perfect circle, but may be an oval, may be a polygon such as a regular square or a rectangle, and the peripheral shape of the inner wall may have wavy concaves and convexes on the perfect circular inner wall as shown. The inner wall is not limited to the one formed, and the inner wall may have a polygonal shape such as an ellipse, a square, a rectangle, or the like, and a corrugated or saw-toothed irregularity may be formed. In addition, the shape of the central protruding portion 64 is not limited to a perfect circle, but may be one or a plurality of oval or polygonal shapes, and may be separated or continuously formed. Irregularities may be formed around the periphery.

By formulating this, for example, in the case of a circular container, it is sufficient if the length around the inner wall of the concave portion of the container and the projected area S of the opening have a relationship of L> 2 (7ΓS) ^1/2 . In short, it is only necessary to increase the peripheral length of the inner wall of the container.

The hot cathode 3 L shown in FIG. 19 is different from the shape force of the container 6 L described above. That is, all of the above-mentioned ones have a cylindrical shape with the same diameter, but this container 6L has a larger diameter on the opening 62 side than on the bottom surface 61.

 In this way, the container 6L having the opening 62 side formed in the shape of a large horn is in contact with the outer periphery of the container 6L and the opening 72 of the holder 7L so that there is no apparent gap. Therefore, it is possible to prevent discharge from flowing into the space between the two through this gap.

 The container 6 L has a particulate electron emitter 5 composed of a large number of granules 52, 53,... On an exposed surface 55 on the front side where an arc spot serving as a discharge base is likely to be formed. By being able to arrange, the discharge lamp in which the hot cathode 3 L is sealed can stably arc discharge, does not cause flickering at the time of lighting, and can extend the life.

 Further, according to the inventors' consideration, in the discharge lamp described in the above embodiment, the charged pressure of the rare gas (Torr) and the average particle diameter D (μ m) and the discharge current IL (mA), the ability to promote the transition from glow discharge to arc discharge and stabilize the arc discharge for a long time was found.

That is, for example, the hot cathodes 3 B and 3 B shown in FIG. 5 are placed between the electrodes at both ends of a glass bulb 1 having an outer diameter of about 4 mm and a total length of about 300 mm as shown in FIG. 1. A fluorescent lamp with a phosphor film formed on the inner surface of the bulb 1 opposite to it by about 260 mm is filled with argon Ar as a rare gas along with the vapor of mercury Hg, and its filling pressure and granular It was manufactured by changing the average particle size of the granules 51 of the electron emitter 5. An electron emitter 5 composed of an aggregate of granules 51,... Having a particle diameter of 10 to 100 m is accommodated in a bottomed cylindrical container 6 constituting the hot cathode 3B. The granules 5 1 of the container 6 and electron emitter 5, ... are formed from those consisting mainly of small amounts of Sani匕zirconium Z r 0 ₂ in the oxide Roh "helium B a tantalum T a, The surface is coated with a thin film of carbonized TaC to improve spatter resistance.

The results shown in Tables 3 to 5 were obtained by changing the gas pressure in the bulb 1, the average particle size of the granules 51 of the electron emitter 5, and the discharge current. The average particle size mm was determined by the arithmetic mean of the particle size distribution. The charged gas pressure is the total pressure of the sealed gas.For example, argon Ar / neon Ne is about 70 Torr in total pressure and about room temperature at room temperature. When mercury vapor is included, the charged gas pressure is about 7 OTorr.

(Table 3)

(表 4)

(Table 4)

Granule diameter IIA _r pressure Gross arc point M i test P * I during life

(Am) (mA) (Torr) m 10sON Arc D • lOsOrr

31 75 10 10 X X X 1

32 20 X X X 3

33 30 X X X 4

34 50 〇 X X 7

35 70 〇 X X 9.

36 100 〇 〇 〇 13

37 20 10 X X X 3

38 20 X X X 5

39 30 〇 X X 8

40 50 〇 〇 〇 13

41 70 〇 〇 〇 19

42 100 〇 〇 〇 27

43 30 10 X X X 4

44 20 o X X 8

 30 X o o 12

50 o o o 20

47 70 〇 〇 〇 28

 100 o 〇 〇 40

49 50 10 X X 7

50 20 o 〇 〇 13

51 30 〇 〇 〇 20

52 50 〇 〇 〇 33

53 70 〇 〇 〇 47

u り O 154 100

u ri O 1

55 70 10 〇 X X 9

56 20 〇 〇 〇 19

57 30 〇 〇 〇 28

58 50 〇 〇 〇 47

59 70 〇 〇 〇 65

60 100 〇 〇 〇 93 (Table 5)

Difficult Diameter IIA _r Pressure Glow Arc Point P, I

Να Ma-tts

 (mA) (Torr) W DlOsOFF V 9 V V

 丄 1

Dl 丄 D en

 ο c O eight V V

 Δ o i n

 63 1U input v V

 0

64 20 〇 〇 〇 10

65 50 〇 〇 〇 24 o

66 100 Δ X X Λ Δ

, Y rr

67 5 X X X 0

68 10 U J

69 20 〇 〇 〇 19

70 50 〇 〇 〇 48

71 loU Δ v v v A. o

 cr

 72 0 U v 7

 ί

1

73 1U Lily 丄 4 A

74 20 〇 〇 〇 29

75 50 〇 〇 〇 71 v v v A

76

 77 0 l r 1 n

78 l inU r r

79 20 〇 〇 〇 38

80 50 ■ 〇 〇 〇 95

81 250 2 X X X 5

82 5 〇 〇 〇 12

83 10 〇 〇 〇 24

84 20 〇 〇 〇 48

85 50 〇 〇 〇 119 Here, for the transition from glow discharge to arc discharge, X (bad) if it exceeds 1 second, 〇 (good) if it is within 1 second, and the blinking test is on for 10 seconds. Repeated for 10 seconds, X when life is less than 100,000 times, X when life is more than 100,000 times, for arc discharge during life, barium B a on particle 51 surface X was used when discharging from granules other than granules 51 while remaining, and granule 51 power when barium Ba was left on granules 51, and Δ when discharging.

 Then, assuming that the noble gas filling pressure is PTor, the average particle size of the granules 51 of the particulate electron emitter 5 is Dzm, and the discharge current is ILmA,

 P X I L / Ό≥1 0

In this case, the transition from the glow discharge to the arc discharge is promoted, the arc discharge is stabilized, and the inner wall of the glass bulb 1 can be prevented from being blackened and the life force can be prevented from becoming shorter.

 In the above formula, the higher the charged gas pressure is, the better. However, if the charged gas pressure is increased depending on the specification conditions, the starting voltage will increase and the luminous efficiency will decrease, so the charged gas pressure is limited according to the specification conditions. It should be noted that the filled gas is a mixture of other gases, for example, a mixed gas of sodium Na, neon Ne and argon Ar, a mixed gas of plasma Ba and argon Ar, and a mixed gas of vacuum Ba and xenon Xe. Similar results were obtained in experiments with mixed gas.

Furthermore, when a mixture of granular electron emitters 5 having different particle size distributions is used as the electron emission electrode structure, a discharge lamp that can easily perform dimming can be obtained. That is, for example, the container 6 in L of the hot cathode 3 L shown in FIG. 1 9, the average particle size two peak values large and small cloth made of a semiconductor ceramic such as an oxide B a T a 0 ₃ of barium and Tali © arm A plurality of thermionic radiators 5 are filled and stored. The particle size distribution is relatively large-sized granules with a peak at an average particle size of about 100 m 52, and those with relatively small-sized granules with a peak at an average particle size of about 30 // m 5 3 The particle size distribution is in the range of 10 tzm to 150 m.

 When the fluorescent lamp containing the hot cathodes 3 L and 3 L is lit through a dimming circuit device (not shown), when the lamp current without dimming is about 30 mA, Comparison of the electron emitters 5 contained in a 6 L container with a particle size of about 100 μm

- twenty one - An arc spot occurs in one or two of the target granules 52,… to maintain stable discharge. In the case of relatively small-sized granules with a particle size of about 30 / zm 53,…, the arc storage occurs over several particles, causing the heat storage structure to collapse and other granules to fall. The spot moves easily. Therefore, as a result, a stable arc spot is generated in the relatively large-sized granules 52 having a particle size of about 100.

 When the fluorescent lamp is lit and the current is reduced to about 5 mA for dimming, one or two relatively small granules 53, ... It occurs and maintains stable discharge. However, the relatively large-sized granules 52,... Having a particle size of about 100 mm are larger than the relatively small-sized granules 53,... Having a heat capacity of about 30 / m. Therefore, if the current is as low as about 5 mA, sufficient heat cannot be obtained to emit thermoelectrons. Therefore, as a result, a stable arc spot is generated in the granules 53 having a relatively small diameter of about 30 m, from which electrons can be easily emitted.

 Therefore, a discharge lamp using such a mixture of electron emitters having different particle size distributions can increase the temperature of the electron emitters having a particle size at the peak corresponding to the lamp current to generate an arc spot. Can be. By applying this power to a discharge lamp that performs dimming by current control corresponding to the current value, stable arc discharge and dimming can be performed.

 The peak value of the particle size distribution is not limited to a mixture of two types, but may be three or more types. However, the effect is greater when the difference between adjacent average particle sizes is 1.5 times or more. No.

 FIG. 20 is a perspective view showing an embodiment of the discharge lamp device 9 according to the present invention. In FIG. 20, reference numeral 91 denotes a housing. Inside the housing 91, support members 93, 93 (e.g., not shown) such as a reflector 92, a socket for supporting the fluorescent lamp 1, and the like are shown. ) And power supply circuit device C are provided.

 The discharge lamp device 9 is used for reading a document of a backlight / facsimile of a liquid crystal display device. As described above, since the fluorescent lamp 1 has improved light emission characteristics and a long life, these devices also have light emission characteristics. The lamp 1 does not need to be replaced for a long period of time and maintenance is easy.

Note that the present invention is not limited to the above embodiment. For example, as mentioned above In the electrode structure according to the embodiment, the granular electron emitter is accommodated in the container, but the granular electron emitter is put in a sintering container, and is taken out from the container after sintering. A lead wire or the like may be connected to form an electrode assembly.The container functions as a means to support the electrode assembly in the valve or to electrically connect to the lead wire, but it is not essential. Absent.

 Further, the container constituting the hot cathode, which is an electrode structure, is made of a semi-insulating so-called conductive ceramic in which a conductive metal is mixed with a semiconductor ceramic material, even if the container is made of the above-mentioned conductive metal. Or a material made of a semiconductor porcelain material or an insulating material and having a surface provided with conductivity. In short, any material can be used as long as it acts as a good conductor at the time of energization and can sufficiently flow through the electron emitter contained inside.

 In addition, the discharge lamp is not limited to a fluorescent lamp, but can be applied to other discharge lamps such as an ultraviolet radiation lamp. Further, the discharge lamp may be a lamp that emits rare gas, and may not be filled with mercury as a discharge medium. Further, the shape of the glass bulb is not limited to a straight tube shape, and a lamp using a plate-shaped bulb may be used.

 Further, the number of electrodes provided on one discharge lamp is not limited to one pair (two), and may be three or more. Also, a lamp in which a part of the electrodes is provided on the outer surface of the bulb may be used. Of course you can.

Further, the discharge lamp device is not limited to the configuration of the embodiment, and various modifications can be made to the shape and configuration. Further, the housing described here is not limited to a box-shaped housing for housing a lamp or the like, but also includes a plate-shaped housing to which a lamp, a support member, and the like are exposed and attached. In the discharge lamp device, a power supply circuit device for lighting and a reflecting mirror may be provided as a single body and are not essential. INDUSTRIAL APPLICABILITY As described above, the electron-emitting electrode structure according to the present invention enables rapid emission of thermoelectrons at the time of starting a discharge lamp and promotes lighting of the lamp. Further inside the lamp bulb It is possible to provide a long-life electrode capable of preventing the wall from being blackened or shortening the life. Therefore, according to the lighting device using the lamp, the light emission characteristics and the life characteristics can be improved, and the maintenance work can be facilitated. It can be widely used for backlighting of liquid crystal display devices, liquid crystal televisions and decorative devices, reading originals such as facsimile machines, exposing and removing static electricity in copiers, etc. 0 A equipment or ordinary lighting equipment and lamps. Wear.

Claims

The scope of the claims 1. an electron emitter made of an aggregate of granules that are heated by the discharge and emit thermoelectrons from the exposed surface;  Discharge concentrating means for concentrating discharge on the exposed surface by approaching or contacting at least a part of the exposed surface of the electron emitter; An electron-emitting electrode assembly comprising:  2. an electron emitter made of aggregates of granules that are heated by the discharge and emit thermoelectrons from the exposed surface;  Discharge concentrating means for concentrating discharge on the exposed surface by approaching or contacting at least a part of the exposed surface of the electron emitter;  A container for accommodating the electron emitter; An electron-emitting electrode assembly comprising:  3. an electron emitter made of an aggregate of granules that are heated by the discharge and emit thermoelectrons from the exposed surface;  A container for accommodating the electron-emitting body, and using the portion in contact with or in contact with at least a part of the exposed surface of the electron-emitting body as a conductor to concentrate discharge on the exposed surface. Emission electrode assembly.  4. The electron emission electrode structure according to claim 3, wherein the container is made of metal.  5. The electron emission electrode structure according to claim 4, wherein an outer surface of the metal container is coated with an insulating material.  6. The electron-emitting electrode assembly according to claim 2, wherein the container is insulative or semi-insulating.  7. The electron emission electrode structure according to claim 6, wherein the container is made of a metal oxide.  8. The electron emission electrode assembly according to claim 2, wherein the container is supported by a holder. 9. The discharge concentrating means is positioned close to at least a part of the exposed surface of the electron emitter. 2. The electron emission electrode structure according to claim 1, wherein the electron emission electrode structure is a metal projection that is in contact with the electron emission electrode.  10. The electron-emitting electrode structure according to claim 9, wherein the metal projection has a tongue shape.  11. The electron emission electrode assembly according to claim 1, wherein the discharge concentrating means is a rod-like projection penetrating the electron emitter and protruding from the exposed surface.  12. The electron-emitting electrode structure according to claim 10, wherein the rod-shaped projection projects from a center of the exposed surface.  13. The electron-emitting electrode structure according to claim 11, wherein the rod-shaped projection projects eccentrically from the center of the exposed surface.  14. The electron emission electrode assembly according to claim 2, wherein the discharge concentrating means is a metal mesh that covers an opening side of the container.  15. The electron emission electrode assembly according to claim 9, wherein the discharge concentrating means is formed on the container or the holder. 1 6. The granules of the electron emitter are formed from a material mainly composed of at least one oxide selected from the group consisting of alkaline earth metal, transition metal and rare earth metal. Or the electron-emitting electrode assembly according to 2.  1 7. A film of at least one of an alkaline earth metal, a transition metal and a rare earth metal, formed of a carbide, Z or nitride on the surface of the granules of the electron emitter. 3. The electron-emitting electrode assembly according to 1 or 2. 1 8. Glass bulb for filling gas for discharge;  An electron emitter provided in the bulb and made of an aggregate of granules that are heated by the discharge of the gas and emit thermoelectrons from the exposed surface; and at least a part of the exposed surface of the electron emitter is close to the electron emitter. Or a discharge concentrating means for contacting and concentrating discharge on the exposed surface; A discharge lamp comprising:  1 9. a glass bulb that fills the gas to be discharged and forms a discharge path; An electron emitter provided at an end of the glass bulb and made of an aggregate of granules heated by the gas discharge and emitting thermoelectrons from the exposed surface; and at least a part of the exposed surface of the electron emitter Concentrates the discharge on the exposed surface by approaching or touching An electron emission electrode assembly comprising discharge concentrating means;  A power supply circuit device connected to the electron emission electrode structure and applying a voltage between the electrode structures; A discharge lamp device comprising:  20. An electron emitter made of an aggregate of granules provided in a glass bulb for enclosing a gas to be discharged and heated by the discharge of the gas and emitting thermoelectrons from an exposed surface; A discharge lamp including discharge concentrating means for concentrating a discharge on the exposed surface by approaching or contacting at least a part of the surface;  A housing for housing the discharge lamp; A discharge lamp device comprising: