WO2007023945A1

WO2007023945A1 - Discharge plasma generation auxiliary device

Info

Publication number: WO2007023945A1
Application number: PCT/JP2006/316729
Authority: WO
Inventors: Takashi Hatai; Koichi Aizawa; Tsutomu Ichihara
Original assignee: Matsushita Electric Works, Ltd.
Priority date: 2005-08-26
Filing date: 2006-08-25
Publication date: 2007-03-01

Abstract

A discharge plasma device includes a discharge tube (A). The discharge tube (A) has a hermetic vessel (1) filled with a discharge gas. The hermetic device (1) contains a pair of discharge electrodes (2a, 2b), an electron source (3) for supplying electrons into the discharge gas, and a grid electrode (4) opposing the electron emitting surface of the electron source (3). The discharge plasma device includes power source (5) for applying voltage across the discharge electrodes (2a, 2b), discharge detection means (6) for detecting a discharge state of the discharge tube (A), and control means (7) for controlling the potential of the electron source (3) so as to suppress collision of plus ions to the electron source (3) when discharge start of the discharge tube (A) is detected by the discharge detection means (6). The grid electrode (4) has an opening for passing electrons emitted from the electron source (3). The electron source (3) and the grid electrode (4) constitute a discharge plasma generation auxiliary device.

Description

Specification

Discharge plasma generation auxiliary device

Technical field

[0001] The present invention relates to a discharge plasma apparatus using a discharge plasma, such as a fluorescent lamp, an ultraviolet lamp, a plasma display panel, or the like, or a discharge plasma generation assisting apparatus used in a light emitting device.

Background art

Conventionally, an airtight container in which a gas as a discharge medium (hereinafter referred to as “discharge gas” t ヽぅ) is sealed, and a pair of discharge electrodes arranged in the airtight container and applying an electric field to the discharge gas (Hereinafter referred to as “discharge electrodes”) are widely used as fluorescent lamps, ultraviolet lamps, plasma display panels, and the like. The pair of discharge electrodes function as an energy supply unit that supplies energy for generating discharge plasma.

[0003] Specifically, in a fluorescent lamp, for example, a discharge medium containing mercury enclosed in a light-transmitting hermetic container is excited by discharge to generate ultraviolet rays, and is deposited on the inner surface of the hermetic container. The phosphor layer is excited to emit light. On the other hand, in recent years, as interest in global environmental issues has increased, rare gas fluorescent lamps (anhydrous silver fluorescent lamps) that use rare gases such as xenon gas as a discharge medium have been researched and developed in various places. ! / However, the rare gas fluorescent lamp has a problem that its efficiency is lower than that of a conventional fluorescent lamp using mercury, and in order to obtain a luminance equivalent to that of the conventional fluorescent lamp, it is higher between the discharge electrodes. There is another problem that voltage must be applied.

[0004] Therefore, a field emission electron source (hereinafter referred to as "electron source") that supplies electrons into the discharge gas in the hermetic container is used as a discharge plasma generation assist device (hereinafter referred to as "electron source"). Providing a discharge plasma device or light-emitting device that reduces the discharge starting voltage, reduces the sustaining voltage of the discharge plasma, and stabilizes the discharge plasma. (For example, see Patent Document 1). In other words, in an airtight container filled with xenon gas, a discharge plasm between a pair of discharge electrodes. Place the electron source outside the generator space and drive the electron source at the same time as applying the voltage between the discharge electrodes or before applying the voltage to reduce the discharge start voltage. Yes. In other words, the discharge start voltage is reduced by operating the electron source as an igniter. In this way, it is known that the discharge start voltage can be reduced to about half compared to the case where no electron source is provided.

Patent Document 1: Japanese Unexamined Patent Publication No. 2002-150944

Disclosure of the invention

Problems to be solved by the invention

[0005] By the way, in order to effectively supply high-engineering energy electrons to a discharge plasma generation space, a discharge plasma apparatus equipped with such an electron source or a light-emitting apparatus is supplied with a discharge plasma. It is preferable to arrange it as close as possible to the generation space. However, in this case, since the electron source is exposed to the discharge plasma, there is a problem when it deteriorates due to damage (damage) due to ion bombardment or the like. For example, if a larger current is applied to reduce the discharge start voltage, the discharge plasma may reach the electron emission surface of the electron source or a discharge may occur between the discharge electrode and the electron source. Ions collide with the electron emission surface of the electron source, and the electron source is damaged. For this reason, there is a problem that the lifetime of the electron source is shortened and, as a result, the lifetime of the discharge plasma device or the light emitting device is shortened and its reliability is lowered.

[0006] Further, for example, in the discharge plasma apparatus or the light emitting apparatus described in Patent Document 1, a sufficient amount in the discharge gas is required to ensure the start of the discharge plasma and the discharge stability. It is necessary to supply a quantity of electrons. On the other hand, in order to increase the amount of electrons supplied to the discharge gas, it is necessary to increase the amount of electrons emitted from the electron source, so that the driving voltage of the electron source is increased or the driving period is extended. There is a need to. For this reason, for example, a discharge plasma apparatus that needs to stabilize the discharge plasma over a long period of time, such as a straight tube type ultraviolet lamp or fluorescent lamp, which has a long hermetic container and a long discharge path. However, in the case of a light emitting device, it is necessary to drive the electron source under more severe conditions, and the lifetime and reliability of the electron source are particularly problematic.

[0007] As described in Patent Document 1, as an electron source, a ballistic electron surface emission type electron source (hereinafter referred to as “BSD (Ballistic electron Surface-emitting Device)”) MIM (Met When a planar electron source such as an aHnsulator-Metal type electron source is used, it can be affected by the impact of ion bombardment compared to a non-planar electron source such as a Spindt type electron source. However, a relatively large molecular weight V 比較的 gas such as argon gas or xenon gas is sealed in an airtight container, or is accelerated due to the structure of a discharge plasma device or light emitting device. When ions collide with the surface electrode of the planar electron source, the planar electron source is also damaged by ion bombardment.

[0008] The present invention has been made to solve the above-described conventional problems, and provides an electron source for reducing the discharge start voltage by supplying electrons into a discharge gas filled in an airtight container. It is an object of the present invention to provide means for enabling the discharge plasma apparatus or light emitting apparatus provided to extend the life of the electron source and thus the apparatus and improve the reliability. Means for solving the problem

[0009] A discharge plasma apparatus having a discharge plasma generation auxiliary device (hereinafter referred to as "auxiliary device" t ヽぅ) according to the present invention is a hermetic container in which a discharge gas as a discharge medium is enclosed. It has. Further, the discharge plasma apparatus or the light emitting apparatus includes an energy supply unit that is disposed in at least one of the inside and the outside of the hermetic container and supplies energy for generating discharge plasma by discharging the discharge gas. Speak. The auxiliary device according to the present invention can be used in a lighting device or the like, and assists the generation of discharge plasma. This auxiliary device includes an electron source that supplies electrons into the discharge gas (field emission type electron source), and protective means for protecting the electron source such as an ion source of discharge plasma generated in the hermetic container. Basic features.

[0010] In the present invention, the auxiliary device includes a discharge detector that detects discharge of the discharge gas, and positive ions in the discharge plasma collide with the electron source when the discharge start of the discharge gas is detected. And a control means for controlling the potential of the electron source so as to suppress this. Here, when the energy supply unit includes at least one pair of discharge electrodes, the discharge detector detects the start of discharge of the discharge gas based on a change in impedance, current, or voltage between the pair of discharge electrodes. Is preferred. Further, it is preferable that the control means controls the potential of the electron source to be higher than the potential before detecting the start of discharge after detecting the start of discharge of the discharge gas. In the present invention, it is preferable that the protection means includes a protection member that has an electron passage portion for allowing electrons to pass therethrough and also protects the surface electrode of the electron source by the ion force of the discharge plasma. In this case, it is preferable that at least a portion of the protective member facing the surface electrode is made of a conductive material and has an electron passage portion. The protective member may be formed in a net shape.

In the present invention, the protection member may be a secondary electron emission member. Further, at least one of the inner side and the outer side of the protective member may include a secondary electron emission member. The potential of the protective member may be controlled to be the same or higher than the potential of the electron emission portion of the electron source. The potential difference between the protective member and the electron emission portion of the electron source may be controlled to be smaller than the discharge start voltage.

[0013] In the present invention, when the energy supply unit includes a force sword electrode and an anode electrode, the potential of the protective member is higher than the potential of the force sword electrode, and the potential of the anode electrode You may control so that it may become lower. Further, the potential difference between the potential of the anode electrode and the potential of the protective member may be controlled to be smaller than the discharge start voltage.

[0014] In the present invention, the protective member may be formed of a material that satisfies the relationship represented by the following formula.

y≤l / (e ^ad -l)

Moreover, you may control the electric potential of a protection member so that the relationship shown by the following formula | equation may be satisfy | filled.

α≤1η {(1 / γ) + 1} / ά

In the above formula, d is the distance between the protective member and the cathode electrode, α is the electron multiplication factor in the space between the protective member and the cathode electrode, and y is the secondary electron emission coefficient due to the ions of the discharge plasma. It is.

[0015] In the present invention, the protective member may be composed of a first protective member close to the electron source and a second protective member remote from the electron source. In this case, the potential of the first protective member is controlled to be higher than that of the electron source, and the potential of the first protective member and the potential of the second protective member are different from each other. You may control so that it may become. Further, the potential of the second protective member may be controlled to be lower than the potential of the anode electrode and higher than the potential of the force sword electrode. The potential of the second protective member is lower than the potential of the first protective member. You may control so that it may become. The aperture ratio of the second protective member is preferably lower than the aperture ratio of the first protective member.

In the present invention, the electron source is disposed so as not to be directly exposed to the discharge plasma, while the secondary electron emission portion may be disposed obliquely in front of the electron emission surface of the electron source. The electron source may be a ballistic electron surface emission electron source.

The invention's effect

[0017] According to the present invention, an electron source and thus a light emitting device including an electron source for supplying electrons into a discharge gas filled in an airtight container to reduce a discharge start voltage is provided. The life of the device can be extended and the reliability can be improved.

Brief Description of Drawings

FIG. 1A is a schematic diagram showing a schematic configuration of a discharge device including an auxiliary device according to Embodiment 1.

FIG. 1B is a schematic diagram showing a schematic configuration of a discharge device including the auxiliary device according to Embodiment 1.

FIG. 1C is a diagram showing a relationship between current and voltage in the discharge device according to Embodiment 1.

2A is a cross-sectional view showing a schematic configuration of an electron source of the discharge device according to Embodiment 1. FIG.

2B is a cross-sectional view showing a schematic structure of a draft layer of the electron source shown in FIG. 2A.

FIG. 3A is a schematic diagram showing the operation of the discharge device according to Embodiment 1.

FIG. 3B is a schematic diagram showing the operation of the discharge device according to Embodiment 1.

FIG. 4A is a schematic diagram showing an operation of the discharge device including the auxiliary device according to the second embodiment.

FIG. 4B is a schematic diagram showing the operation of the discharge device including the auxiliary device according to Embodiment 2.

FIG. 4C is a schematic diagram showing an operation of the discharge device including the auxiliary device according to the second embodiment.

FIG. 5 is a schematic diagram showing a schematic configuration of a discharge device including an auxiliary device according to a third embodiment.

6A is a cross-sectional view showing a schematic configuration of an auxiliary device of the discharge device shown in FIG.

6B is a plan view of the auxiliary device shown in FIG. 6A.

FIG. 7 is a sectional view showing a schematic configuration of an auxiliary device according to a fourth embodiment.

FIG. 8A is a cross-sectional view showing a schematic configuration of the auxiliary device according to the fifth embodiment. FIG. 8B is a plan view of the auxiliary device shown in FIG. 8A.

FIG. 9 is a cross-sectional view showing a schematic configuration of an auxiliary device according to a sixth embodiment.

[10] FIG. 10 is a schematic diagram showing a schematic configuration of a discharge device including the auxiliary device according to the seventh embodiment.

[11] FIG. 11 is a schematic diagram showing a schematic configuration of a discharge device including the auxiliary device according to the eighth embodiment.

[12A] FIG. 12 is a schematic diagram showing the configuration of the base material of the secondary electron emission portion in the discharge device shown in FIG.

FIG. 12B is a schematic diagram showing the configuration of the base material of the secondary electron emission portion in the discharge device shown in FIG.

[12C] FIG. 12C is a schematic diagram showing the configuration of the base material of the secondary electron emission portion in the discharge device shown in FIG.

[13A] FIG. 13A is a schematic diagram showing a configuration of a base material of a secondary electron emission portion in the discharge device shown in FIG.

[13B] FIG. 13B is a schematic diagram showing the configuration of the base material of the secondary electron emission portion in the discharge device shown in FIG.

[13C] FIG. 13C is a schematic diagram showing the configuration of the base material of the secondary electron emission portion in the discharge device shown in FIG.

FIG. 14 is a schematic diagram showing a schematic configuration of a discharge device including the auxiliary device according to the ninth embodiment.

15] A schematic cross-sectional view showing a schematic configuration of the auxiliary device according to the tenth embodiment.

FIG. 16 is a schematic diagram showing a schematic configuration of a discharge device provided with an auxiliary device according to an eleventh embodiment.

圆 17] A schematic cross-sectional view showing a schematic configuration of the auxiliary device according to the twelfth embodiment. 18] A schematic cross-sectional view showing a schematic configuration of the auxiliary device according to the thirteenth embodiment. FIG. 19A is a schematic diagram showing the configuration of the energy supply means of the discharge device.

圆 19B] A schematic diagram showing the configuration of the energy supply means of the discharge device.

FIG. 19C is a schematic diagram showing the configuration of the energy supply means of the discharge device. FIG. 19D is a schematic diagram showing the configuration of the energy supply means of the discharge device.

圆 19E] A schematic diagram showing the configuration of the energy supply means of the discharge device.

FIG. 19F is a schematic diagram showing the configuration of the energy supply means of the discharge device.

FIG. 19G is a schematic diagram showing a configuration of energy supply means of the discharge device.

FIG. 19H is a schematic diagram showing the configuration of the energy supply means of the discharge device.

191] A schematic diagram showing the configuration of the energy supply means of the discharge device.

[19J] A schematic view showing the configuration of the energy supply means of the discharge device.

FIG. 20A is a schematic diagram showing the configuration of the energy supply means of the discharge device.

FIG. 20B is a graph showing changes in voltage over time.

FIG. 20C is a graph showing a change with time of voltage.

21A] A schematic diagram showing the configuration of the energy supply means of the discharge device.

FIG. 21B is a graph showing a change with time of voltage.

FIG. 21C is a graph showing a change with time of voltage.

[22] FIG. 22 is a schematic cross-sectional view showing a schematic configuration of a modified example of the discharge device.

圆 23] A schematic cross-sectional view showing a schematic configuration of a modified example of the discharge device.

FIG. 24 is a schematic cross-sectional view showing a schematic configuration of a modified example of the discharge device.

FIG. 25 is a schematic cross-sectional view showing a schematic configuration of a modified example of the discharge device.

[26] FIG. 26 is a schematic diagram showing a schematic configuration of a discharge device including the auxiliary device according to the fourteenth embodiment.

FIG. 27A is a schematic diagram showing a schematic configuration of a discharge device including the auxiliary device according to the fifteenth embodiment.

27B] A schematic cross-sectional view showing a schematic structure of the auxiliary device of the discharge device according to Embodiment 15.

[28] FIG. 28 is a schematic diagram showing a schematic configuration of a discharge device including the auxiliary device according to the sixteenth embodiment.

29 is a schematic cross-sectional view showing a schematic configuration of an auxiliary device of the discharge device shown in FIG. 28. 30] FIG. 30 is a schematic diagram showing a schematic configuration of another discharge device including the auxiliary device according to the sixteenth embodiment. Explanation of symbols

[0019] 1 airtight container, 2a discharge electrode, 2b discharge electrode, 2c discharge electrode, 3 field emission electron source, 3a electron source element, 4 grid electrode, 5 power supply, 6 discharge detection means, 7 control means, 8 discharge plasma Production space, 10 discharge plasma, 14 insulating substrate, 15 lower electrode, 16 strong electric field drift layer, 17 surface electrode, 20 protective member, 21 insulating protective member, 21a window hole, 22 conductive protective member, 22a opening, 25 Secondary electron emitter, 30 Extraction electrode, 31 First protective member, 31a opening, 32 Second protective member, 32a opening, 40 Secondary electron emitting member, 51 Grain, 52 Silicon oxide film , 63 Silicon microcrystal, 64 silicon oxide film.

BEST MODE FOR CARRYING OUT THE INVENTION

[0020] This application is based on Japanese Patent Application No. 2005-246800 and Japanese Patent Application No. 2005-246801 filed in Japan, the contents of which are fully incorporated herein. Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. In the accompanying drawings, common components are denoted by the same reference numerals.

[0021] (Embodiment 1)

As shown in FIG. 1A, a discharge plasma apparatus or a light emitting apparatus (hereinafter collectively referred to as “discharge apparatus”) provided with an auxiliary apparatus (discharge plasma generation auxiliary apparatus) according to Embodiment 1 is a discharge tube A. It has. The discharge tube A includes an airtight container 1 in which a gas (discharge gas) as a discharge medium is enclosed. In the airtight container 1, a pair of plasma discharge electrodes 2a and 2b, an electron source 3 (field emission electron source) for supplying electrons into the discharge gas, and an electron emission surface of the electron source 3 are provided. Opposing grid electrodes 4 are accommodated.

Further, the discharge device includes a power source 5 that applies a voltage between the discharge electrodes 2a and 2b, a discharge detection means 6 that detects a discharge state of the discharge tube A, and a discharge detection means 6 that discharges the discharge tube A. Control means 7 is provided for controlling the potential of the electron source 3 so as to suppress the collision of positive ions with the electron source 3 when the start is detected. The grid electrode 4 has an opening (not shown) for allowing electrons emitted from the electron source 3 to pass therethrough. In Embodiment 1, the electron source 3 and the grid electrode 4 constitute an auxiliary device (idanator)! / Speak.

[0023] In the discharge device according to Embodiment 1, the electron source 3 is driven to discharge from the electron source 3. The electron force that has passed through the opening of the grid electrode 4 is supplied to the space between the discharge electrodes 2a and 2b. The arrow in FIG. 1A indicates the flow of electrons e− emitted from the electron source 3 and passing through the opening of the grid electrode 4. As a result, the voltage required to start plasma discharge (hereinafter referred to as “discharge start voltage”) can be reduced, and power consumption can be reduced. If the electron source 3 is driven even after the start of discharge, the discharge plasma can be stabilized, the sustaining voltage can be reduced, and the power consumption can be further reduced.

The discharge tube A is a straight tube type rare gas fluorescent lamp. The hermetic container 1 is made of a translucent material such as quartz glass or translucent ceramics. In the airtight container 1, xenon gas is sealed as a discharge gas. A phosphor layer (not shown) that emits light by being excited by ultraviolet rays generated by the excitation of xenon gas is provided on the inner surface of the hermetic container 1.

[0025] The discharge device according to Embodiment 1 discharges discharge tube A by applying a DC voltage from power supply 5 to both discharge electrodes 2a and 2b when a power switch (not shown) is turned on. It has become to let you. That is, the discharge tube A is lit by direct current. Of the pair of discharge electrodes 2a and 2b, the discharge electrode 2a arranged at one end in the longitudinal direction of the hermetic container 1 (left side in FIG. 1A) is an anode electrode, and the other end (FIG. 1A). The discharge electrode 2b arranged on the right side is a force sword electrode (in the first and second embodiments, the “discharge electrode 2a” and the “discharge electrode 2b” are appropriately replaced with the “anode electrode 2a” and the “force electrode”, respectively. Sword electrode 2b ”). The electron source 3 is disposed in the vicinity of the anode electrode 2a on the side opposite to the force sword electrode 2b with respect to the anode electrode 2a. In the first embodiment, the power source 5 is a pulse power source that outputs a DC pulse voltage.

As shown in FIG. 2A, the electron source 3 includes a rectangular plate-like insulating substrate 14 having a force such as an insulating glass substrate or an insulating ceramic substrate. A lower electrode 15 made of a metal film such as a tungsten film is formed on one surface of the insulating substrate 14. On the lower electrode 15, a strong electric field drift layer 16 (hereinafter referred to as “drift layer 16” for short) is formed. On the drift layer 16, a surface electrode 17 made of a metal thin film such as a gold thin film is formed. In the electron source 3, the drift layer 16 constitutes an electron passage layer. The lower electrode 15, the drift layer 16, and the surface electrode 17 constitute an electron source element 3 a that emits electrons through the surface electrode 17. The surface of the surface electrode 17 constitutes an electron emission surface.

As shown in FIG. 2B, the drift layer 16 is formed at least on the surface of the grain 51 of columnar polycrystalline silicon grains (semiconductor crystals) 51 arranged on the surface side of the lower electrode 15. Thin silicon oxide film 52, a number of nanometer-order silicon microcrystals (semiconductor microcrystals) 63 located between grains 51, and crystal grains of silicon microcrystals 63 formed on the surface of each silicon microcrystal 63 It is composed of a large number of silicon oxide films (insulating films) 64 which are oxide films having a film thickness smaller than the diameter. Each grain 51 extends in the thickness direction of the lower electrode 15, that is, in the thickness direction of the insulating substrate 14.

[0029] When electrons are emitted from the electron source element 3a, a driving voltage is applied between the surface electrode 17 and the lower electrode 15 by a driving power source so that the surface electrode 17 is at a higher potential than the lower electrode 15. Apply. As a result, electrons injected from the lower electrode 15 into the drift layer 16 drift through the drift layer 16 and are emitted through the surface electrode 17.

[0030] In the electron source element 3a according to Embodiment 1, electrons can be emitted even when the drive voltage applied between the surface electrode 17 and the lower electrode 15 is a low voltage of about 10 to 20V. The electron source element 3a is less dependent on the degree of vacuum of the electron emission characteristics and does not generate a pobbing phenomenon during electron emission, and can stably emit electrons with high electron emission efficiency.

[0031] Although the basic configuration of the electron source element 3a is well known, it is considered that electron emission occurs in the following model. That is, when a voltage is applied between the surface electrode 17 and the lower electrode 15 such that the surface electrode 17 has a high potential, electrons e− are injected from the lower electrode 15 into the drift layer 16. Further, most of the electric field applied to the drift layer 16 is applied to the silicon oxide film 64. Therefore, the injected electron e− is accelerated by the strong electric field applied to the silicon oxide film 64. These electrons e− drift in the region 65 between the grains 51 in the drift layer 16 toward the surface in the direction indicated by the arrow in FIG. 2B, and are emitted by tunneling through the surface electrode 17.

In addition, in the drift layer 16, electrons injected from the lower electrode 15 are converted into silicon microcrystals 63. Drifted by the electric field applied to the silicon oxide film 64 that is hardly scattered by the. These electrons e− are emitted through the surface electrode 17 (ballistic electron emission phenomenon). Heat generated in the drift layer 16 is released through the grains 51. Therefore, no pobbing phenomenon occurs when electrons are emitted, and electrons can be stably emitted.

In the drift layer 16 of the electron source according to Embodiment 1, the silicon oxide film 64 that is an insulating film is formed by an acid process. However, a nitriding process or an oxynitriding process may be used instead of the acid process. When the nitridation process is used, all of the insulating films are silicon nitride films. When the oxynitridation process is used, the insulating film is a silicon oxynitride film.

As described above, the grid electrode 4 is disposed opposite to the electron emission surface of the electron source 3. Therefore, when a driving voltage is applied to the electron source 3 and a voltage of, for example, about 100 V is applied between the grid electrode 4 and the surface electrode 17 so that the grid electrode 4 has a high potential, the electron source 3 The electrons emitted from 3 are attracted to the grid electrode 4. Since the grid electrode 4 has the opening as described above, electrons can be supplied to the space between the anode electrode 2a and the cathode electrode 2b through the opening.

[0035] As the grid electrode 4, for example, a grid electrode made of a conductive material such as nickel, aluminum, or stainless steel, and each mesh opening is used. Alternatively, a plate-like member made of a conductive material may be used in which a plurality of circular or rectangular holes are formed as openings.

As shown in FIG. 1C, in the discharge device according to Embodiment 1, the current-voltage characteristics between the anode electrode 2a and the force sword electrode 2b change greatly before and after the start of discharge. Note that point P1 in Fig. 1C shows the current-voltage characteristics before discharge, but in this case, almost no current flows. Point P2 is a force indicating the current-voltage characteristics after discharge. In this case, the current increases while the voltage decreases. That is, in the discharge tube A, when the discharge is started, the impedance, current, and voltage between the discharge electrodes 2a and 2b change rapidly.

[0037] The discharge detection means 6 detects the discharge state of the discharge tube A based on a change in impedance between the discharge electrodes 2a, 2b. Therefore, discharge of discharge tube A is caused by impedance change. The start of electricity can be detected. The discharge detection means 6 may detect the start of discharge of the discharge tube A based on a change in current or a change in voltage that is not a change in impedance between the discharge electrodes 2a and 2b. . In either case, the discharge start of the discharge tube A can be reliably detected by the change in the electrical characteristics between the discharge electrodes 2a and 2b.

[0038] As described above, the discharge device according to Embodiment 1 has the electron source so as to suppress the collision of positive ions with the electron source 3 when the discharge detection means 6 detects the start of discharge of the discharge tube A. Control means 7 for controlling the potential of 3 is provided. Then, as shown in FIG. 1B, after the discharge is started, the driving of the electron source 3 is stopped, and positive ions from the discharge plasma 10 are prevented from colliding with the electron source 3.

[0039] A drive voltage is applied between the surface electrode 17 and the lower electrode 15, a grid voltage is applied between the grid electrode 4 and the surface electrode 17, and the anode electrode 2a and the force sword electrode 2b Assume that the potential distribution in the state before the discharge of the discharge tube A is as shown in FIG. 3A when the discharge start voltage is applied in the meantime. In this case, before the discharge of the discharge tube A, the surface electrode 17 has a low potential with respect to the anode electrode 2a in order to efficiently supply the electrons emitted from the electron source 3 to the space between the discharge electrodes 2a and 2b. I prefer to be! /.

[0040] If any one of the grid electrode 4, the surface electrode 17 and the lower electrode 15 has the same potential as the anode electrode 2a, the control of the potential by the control means 7 becomes easy. However, in order to increase the electron emission efficiency, it is desirable that the grid electrode 4 and the anode electrode 2a have the same potential. In FIG. 3A, “surface potential”, “lower potential”, “grid potential”, “anode potential”, and “force sword potential” are the surface electrode 17, the lower electrode 15, the grid electrode 4, and the anode potential, respectively. Show the potential of pole 2a and force sword electrode 2b!

[0041] As shown in FIG. 3B, when the discharge detection means 6 detects the start of discharge (that is, after the start of discharge), the control means 7 determines that the potential of the electron source 3 and the potential of the grid electrode 4 are The potentials of the surface electrode 17, the lower electrode 15 and the grid electrode 4 are controlled so as to be higher than the potential of the electrode 2a (positive noise). That is, when the discharge detection means 6 detects the start of discharge, the control means 7 controls the potential of the electron source 3 to be higher than the potential before the detection. In the example shown in FIG. 3B, the surface electrode 17, the lower electrode 15, and the grid electrode 4 are at the same potential. The control means 7 may be configured by a microcomputer or the like. [0042] As described above, in the discharge device according to Embodiment 1, the control means 7 stops driving the electron source 3 when the discharge detection means 6 detects the start of discharge of the discharge tube A, and The potential of the electron source 3 is controlled so as to suppress the collision of positive ions with the electron source 3. For this reason, collision of positive ions to the electron source 3 can be suppressed without providing a protective member, the discharge start voltage can be reduced, and the life of the electron source 3 can be extended. The opening area of the opening of the grid electrode 4 can be made sufficiently larger than the opening area of the mesh when a mesh body is used as a protective member for the purpose of preventing the entry of positive ions. For this reason, the electron emission efficiency of the auxiliary device (idanator) is increased, and the discharge start voltage can be further reduced.

[Embodiment 2]

Embodiment 2 of the present invention will be described below. However, the basic configuration of the discharge device including the auxiliary device according to the second embodiment is the same as that of the discharge device according to the first embodiment, and only the operation of the control means 7 is different. Therefore, the operation of the control means 7 will be mainly described below with reference to FIGS. 4A to 4C.

[0044] As described above, in the discharge device according to the first embodiment, the auxiliary device including the electron source 3 and the grid electrode 4 has a force sword electrode 2b with respect to the anode electrode 2a in the vicinity of the anode electrode 2a. It is arranged on the opposite side. For this reason, depending on the form of the electric field, electrons emitted from the auxiliary device are absorbed by the anode electrode 2a, and the amount of electrons supplied to the space between the anode electrode 2a and the force sword electrode 2b decreases. There are things to do.

Therefore, as shown in FIG. 4A, in the control means 7 according to the second embodiment, the potential of the grid electrode 4 is first set higher than that of the anode electrode 2a before discharging, so that the auxiliary device cap In addition, the emission of electrons is started, thereby preventing the absorption of electrons at the anode electrode 2a. The life in the airtight container 1 of the electron which has also released the auxiliary device force is on the order of milliseconds.

[0046] Therefore, as shown in FIG. 4B, the control means 7 detects the potential of the anode electrode 2a before the millisecond time elapses, that is, before it recombines with the electron force S ions and disappears. Increase discharge to start discharging. In the example shown in FIG. 4B, the potential of the anode electrode 2a is increased to the same potential as that of the grid electrode 4. [0047] As shown in FIG. 4C, as in the case of Embodiment 1, the control means 7 detects the start of discharge by the discharge detection means 6 (that is, after the start of discharge). The potentials of the surface electrode 17, the lower electrode 15, and the grid electrode 4 are controlled so that the potential and the potential of the grid electrode 4 become higher (positively biased) than the potential of the anode electrode 2a.

[0048] In Embodiments 1 and 2, the control means 7 controls the potential of the electron source 3 to be higher than the potential of the anode electrode 2a when the discharge detection means 6 detects the start of discharge. However, it may be controlled so as to have the same potential as the anode electrode 2a. Control means 7 Force When the voltage source is applied between the anode electrode 2a and the force sword electrode 2b after driving the electron source 3, the voltage is applied between the anode electrode 2a and the force sword electrode 2b. Thus, the delay time until power discharge is started can be shortened. In the procedure of `` (Emitting electrons from the electron source) → (Apply voltage to the discharge electrode) → (Discharge generation) → (Switch the electron source to the protective potential) J '' or `` (Apply voltage to the discharge electrode ) → (Emitting electrons from the electron source) → (Discharge generation) → (Switch the electron source to the protective potential) J h In the procedure, the potential of the electron source is still at the protective potential in the instant the discharge occurs. Therefore, there is a possibility that the electron source may be damaged because of the switchover, so that the electron source power is also released until the emitted electron loses energy. If the operation is performed, the electron source is already switched to the protective potential at the moment when the discharge occurs. , Can prevent damage.

[0049] If the control means 7 restarts the electron source 3 when an abnormal discharge is detected by the discharge detection means 6 after the discharge detection means 6 detects the start of discharge, an abnormal discharge occurs. The electron source 3 is re-driven to supply electrons. This facilitates the transition from abnormal discharge to normal discharge.

[0050] In the first and second embodiments, the auxiliary device including the electron source 3 and the grid electrode 4 is disposed in the vicinity of the anode electrode 2a. However, the auxiliary device may be disposed on the side opposite to the anode electrode 2a with respect to the force sword electrode 2b in the vicinity of the force sword electrode 2b, rather than being disposed in the vicinity of the anode electrode 2a. In this case, when the control means 7 detects the start of discharge by the discharge detection means 6, the potential of the electron source 3 and the potential of the grid electrode 4 are set to the potential of the anode electrode 2a and the force sword electrode 2b. Come to control the potential between the potential! For example, the collision of positive ions with the electron source 3 disposed in the vicinity of the force sword electrode 2b can be suppressed.

[0051] Further, the auxiliary device may be disposed between the anode electrode 2a and the force sword electrode 2b. In this case, when the control means 7 detects the start of discharge by the discharge detection means 6, the potential of the electron source 3 and the potential of the grid electrode 4 are changed between the potential of the anode electrode 2a and the potential of the force sword electrode 2b. If the potential is controlled between them, the collision of positive ions to the electron source 3 disposed between the anode electrode 2a and the force sword electrode 2b can be suppressed.

In the first and second embodiments, the phosphor layer is provided on the inner surface of the hermetic container 1 of the discharge tube A, but the discharge tube A may be an ultraviolet lamp without providing the phosphor layer.

In the electron source 3 according to the first and second embodiments, the lower electrode 15 is formed on one surface side of the insulating substrate 14. However, instead of the insulating substrate 14, a semiconductor substrate such as a silicon substrate is used, and the lower electrode is composed of the semiconductor substrate and a conductive layer (for example, an ohmic electrode) stacked on the back side of the semiconductor substrate. Even so.

[0054] The electron source 3 according to the first and second embodiments is a BS D (ballistic electron surface emission electron source) that emits electrons by a ballistic electron emission phenomenon. However, the electron source 3 is not limited to BSD, and other types of electron sources may be used. For example, an MIM type electron source using an insulator layer as an electron passage layer instead of the drift layer 16, passing electrons between the semiconductor layer on the lower electrode 15 side and the insulator layer on the surface electrode 17 side instead of the drift layer 16 The MIS (Metal-Insulator-Semiconductor) type electron source used as the layer, etc. may be used as well as those that can be used at low vacuum like BSD. In this case, the life of the electron source 3 can be extended and the reliability can be improved as compared with the case where a Spindt-type electrode is used. BSD is advantageous in terms of reducing the discharge start voltage and the discharge sustain voltage because the energy of the emitted electrons is relatively large! /.

[Embodiment 3]

Embodiment 3 of the present invention will be described below. The discharge device (light emitting device) according to Embodiment 3 is an ultraviolet lamp.

As shown in FIG. 5, the discharge device including the auxiliary device according to the third embodiment includes an airtight container 1 in which a discharge gas (for example, a rare gas such as xenon) as a discharge medium is sealed, and an airtight container 1 is disposed in 1 and discharge plasma is generated in the plasma generation space 8 in the hermetic vessel 1 by discharge of the discharge gas 1 A pair of discharge electrodes 2a and 2b and an electron in the discharge gas placed in the hermetic vessel 1 And an electron source 3 to be supplied. This discharge device (ultraviolet lamp) emits ultraviolet rays by discharging the discharge gas in the hermetic vessel 1.

As shown in FIGS. 6A and 6B, the discharge device further includes a protective member 20 that protects the surface electrode 17 of the electron source 3 from the ion source of the discharge plasma generated in the hermetic vessel 1. The protective member 20 has a plurality of openings 22a through which electrons emitted from the electron source 3 are passed.

[0057] The discharge device according to Embodiment 3 is a straight tube type ultraviolet lamp. The hermetic container 1 is formed in a cylindrical shape from a light-transmitting material such as glass or light-transmitting ceramic. Discharge electrodes 2a and 2b are disposed in the airtight container 1 in the vicinity of both ends in the longitudinal direction, respectively. In the vicinity of the discharge electrode 2a, the electron source 3 is disposed at a position where the space force between the discharge electrodes 2a and 2b is separated.

In the discharge device according to Embodiment 3, when the electron source 3 is driven, the electrons emitted from the electron source 3 are supplied into the discharge gas. Note that the arrows in FIG. 5 indicate the flow of electrons emitted from the electron source 3. As described above, by starting driving of the electron source 3 and supplying electrons into the discharge gas before applying a voltage between the discharge electrodes 2a and 2b, the discharge between the discharge electrodes 2a and 2b is started. The starting voltage can be reduced. Further, if the electron source 3 is driven even after a voltage is applied between both the discharge electrodes 2a and 2b, the stability of the discharge plasma can be improved and the discharge sustaining voltage can be reduced. Power consumption can be reduced.

[0059] In the third embodiment, a pair of discharge electrodes 2a and 2b arranged inside the hermetic vessel 1 constitutes energy supply means for supplying energy for generating discharge plasma by discharging the discharge gas. ing. Further, the electron source 3 and the protective member 20 constitute an auxiliary device (discharge plasma generation auxiliary device) that assists the generation of discharge plasma.

[0060] The configuration and function of the electron source 3 according to Embodiment 3 are basically the same as the configuration and function of the electron source 3 according to Embodiment 1. The configuration and function of the drift layer 16 of the electron source element 3a according to Embodiment 3 are the same as the configuration and function of the drift layer 16 according to Embodiment 1. (See Figure 2B). The drive voltage applied to the electron source 3 may be a constant DC voltage or a pulsed voltage. If the drive voltage is a pulsed voltage, apply a drive voltage, and sometimes apply a reverse bias voltage.

[0061] Electron emission in the electron source element 3a according to the third embodiment also occurs in the same model as the electron emission in the electron source element 3a according to the first embodiment. In the third embodiment, as in the first embodiment, the insulating film can be formed using an acid process, a nitriding process, or an oxynitriding process.

[0062] The protective member 20 includes an insulating protective member 21 formed of an insulating material (for example, an insulating resin such as a fluorine-based resin, an insulating ceramic), and a conductive material (for example, nickel, And conductive protection member 22 made of aluminum, stainless steel, or the like. The insulating protection member 21 is formed in a rectangular parallelepiped shape, and one surface (lower surface) of the insulating protection member 21 is fully open. The insulating protective member 21 has a front wall facing the electron emission surface of the electron source 3. A rectangular window hole 21a is provided in the front wall forming a part of the insulating protective member 21, and the conductive protective member 22 is disposed in the window hole 21a. The conductive protection member 22 has a plurality of openings 22a for allowing electrons emitted from the electron source 3 to pass therethrough.

As described above, the portion of the protective member 20 that faces the surface electrode 17 of the electron source 3 includes the conductive protective member 22 that has the opening 22a and is formed of a conductive material. Here, the conductive protection member 22 is formed in a mesh shape or a lattice shape, and the mesh-shaped mesh portion or the lattice-shaped hole portion forms a square opening 22a.

[0064] In Embodiment 3, the conductive protection member 22 is generally called 30 mesh, and one side of the square mesh portion is 0.6 mm, and the diameter of the wire is 0.25 mm. -A net made of nickel is used. However, the size of the mesh, that is, the size of the opening 22a is not limited to this, and electrons emitted from the electron source 3 can pass therethrough and are generated in the plasma generation space 8. Any material can be used as long as it can suppress the entry of ions having a discharge plasma power. For example, the length of one side of the square opening 22a is 0. lmn! It can be appropriately set within a range of about 2 mm. In Embodiment 3, since the conductive protection member 22 is formed in a net shape, the production of the conductive protection member 22 is easy. [0065] As described above, in the auxiliary device according to the third embodiment, a part of the electrons emitted from the electron source 3 is supplied into the discharge gas in the plasma generation space 8 through the opening 22a. As the electron density increases, the discharge start voltage and the discharge sustain voltage can be reduced. Here, before the voltage is applied between the discharge electrodes 2a and 2b, the driving of the electron source 3 is started to supply electrons, and the supply of electrons is continued even after the discharge plasma is generated. Both the discharge start voltage and the discharge sustain voltage can be reduced. Note that the discharge start voltage is usually higher than the discharge sustain voltage, so it may be possible to stop supplying electrons after the discharge has started.

[0066] The auxiliary device according to Embodiment 3 has an opening 22a through which electrons emitted from the electron source 3 pass, and the surface electrode of the electron source 3 from the ion plasma of the discharge plasma generated in the hermetic vessel 1 1 Protective member 20 for protecting 7 is provided. For this reason, the number of ions colliding with the surface electrode 17 can be reduced, and the life of the electron source 3 can be extended and the reliability can be improved.

[0067] In the auxiliary device according to the third embodiment, the portion of the protective member 20 that faces the surface electrode 17 has an opening 22a and is formed from the conductive protective member 22 formed of a conductive material. Become. Therefore, at least a portion of the protective member 20 that faces the surface electrode 17 can be prevented from being charged by electrons. For this reason, it is possible to prevent a problem that electrons emitted from the electron source 3 cannot pass through the opening 22a due to charging.

In Embodiment 3, the electron source element 3a is formed on the insulating substrate 14, and the protective member 20 has a shape that does not cover part of the insulating substrate 14. However, the protective member 20 may have a shape surrounding the entire electron source 3 or a shape surrounding only the electron source element 3a. Further, it may be a shape that covers only the front portion of the electron source 3. The shape of the protective member 20 may be appropriately designed according to the shape of the airtight container 1, the arrangement of the discharge electrodes 2a and 2b, the arrangement of the electron source 3, and the like.

In general, when the protective member 20 is provided in the plasma generation space 8, the discharge plasma tends to spread along the conductive portion of the protective member 20. For this reason, the state of the discharge plasma may be disturbed by the provision of the protective member 20. The form of implementation In state 3, not all of the protective member 22 is formed of a conductive material, but only the conductive protective member 22 is formed of a conductive material, and a portion other than the conductive protective member 22 is formed of an insulating material. The conductive protection member 22 is electrically insulated from other parts. For this reason, even if the discharge plasma is in contact with the conductive protection member 22, it is possible to prevent the discharge plasma from being unnecessarily widened.

[0070] In Embodiment 3, the conductive protection member 22 and the surface electrode 17 are short-circuited outside the hermetic container 1, so that the conductive protection member 22 and the surface electrode 17 have the same potential. Yes. Therefore, it is possible to increase the amount of electrons emitted from the electron source 3 and passing through the opening 22a of the conductive protection member 22 while suppressing the entry of negative ions and positive ions into the protection member 20.

[0071] Further, when the electron source 3 and the protection member 20 are arranged in a place where they are not exposed to the discharge plasma, a potential adjusting means for applying a voltage so that the conductive protection member 22 is at a high potential with respect to the surface electrode 17. When the potential of the conductive protection member 22 is kept higher than the potential of the surface electrode 17, electrons emitted from the electron source 3 are accelerated. For this reason, the amount of electrons emitted from the electron source 3 and passing through the opening 22a of the conductive protection member 22 can be increased.

[0072] When the electric potential of the conductive protection member 22 is set higher than the electric potential of the surface electrode 17, the planar shape of the surface electrode 17 and the opening shape of the opening 22a are made the same, or the surface electrode If the size of the opening 22a is made slightly larger than the size of the pole 17, the amount of emitted electrons can be increased while reducing the power consumption. In this case, if the potential difference between the conductive protection member 22 and the surface electrode 17 is too small, the electrons are not accelerated so much, and if it is too large, the electrons are strongly attracted to the conductive protection member 22 and the amount of electrons passing through the opening 22a. Less. Therefore, the potential difference between the conductive protection member 22 and the surface electrode 17 is preferably set so that, for example, the electric field strength between the conductive protection member 22 and the surface electrode 17 is about lkVZcm.

[0073] (Embodiment 4)

Embodiment 4 of the present invention will be described below. However, the basic configuration of the auxiliary device of the discharge device according to the fourth embodiment is almost the same as that of the auxiliary device according to the third embodiment, and FIG. As shown in FIG. 5, the only difference is that it includes an extraction electrode 30 made of a metal plate (for example, a nickel plate) disposed outside the protective member 20 and facing the surface electrode 17. Therefore, hereinafter, differences from the third embodiment will be mainly described with reference to FIG.

As shown in FIG. 7, the auxiliary device according to the fourth embodiment includes an extraction electrode 30 that is disposed outside the protective member 20 and faces the surface electrode 34. Therefore, it is possible to accelerate the electrons by keeping the potential of the extraction electrode 30 higher than the potential of the surface electrode 17, and to increase the amount of the electrons emitted from the electron source 3 through the opening 22a. it can. In the fourth embodiment, the extraction electrode 30 is disposed away from the conductive protection member 22 so that a gas exists between the protection member 20 and the extraction electrode 30.

[0075] (Embodiment 5)

Embodiment 5 of the present invention will be described below. However, the basic configuration of the auxiliary device of the discharge device according to the fifth embodiment is substantially the same as that of the auxiliary device according to the third embodiment, and only the differences are described below. Therefore, hereinafter, differences from Embodiment 3 will be mainly described with reference to FIGS. 8A and 8B.

As shown in FIGS. 8A and 8B, in Embodiment 5, the planar shape of the surface electrode 17 of the electron source 3 is formed in a stripe shape, and the planar shape of the surface electrode 17 is an opening shape of the opening 22a. The planar shape of the conductive protection member 22 is a stripe shape so as to be the same. And the surface electrode 17 is located in the projection area | region to the electron source 3 side of the opening part 22a. Other points are the same as in the third embodiment.

[0077] By comparison, in Embodiment 5, it is possible to reduce the amount of electrons that collide with the peripheral portion of the opening 22a of the protective member 20, that is, electrons that do not pass through the opening 22a (useless electrons). At the same time, the power consumption of the electron source 3 can be reduced. The electron source 3 according to the fifth embodiment is a BSD having the same operation principle as that of the third embodiment, except that the shape of the surface electrode 17 is different. Therefore, compared with the Spindt type electron source, the electron emission angle is small and the straightness of the emitted electrons is good, so the above effect is particularly remarkable. In the fifth embodiment, the extraction electrode 30 may be provided as in the fourth embodiment.

[0078] (Embodiment 6)

The sixth embodiment of the present invention will be described below. However, the discharge according to Embodiment 6 The basic configuration of the auxiliary device of the apparatus is almost the same as that of the auxiliary device according to the third embodiment. As shown in FIG. 9, the electron emitted from the electron source 3 is disposed between the protective member 20 and the surface electrode 17. The only difference is that it has a secondary electron emission member 40 that emits secondary electrons upon collision. Therefore, the differences from Embodiment 3 will be mainly described below with reference to FIG.

[0079] As shown in FIG. 9, the secondary electron emission member 40 has a secondary material that also has a material force for emitting secondary electrons to a base material in which holes for allowing electrons to pass through a flat plate material are provided. It is formed by applying an electron emission film. In Embodiment 6, MgO is used as the material that emits secondary electrons. However, this material is not limited to MgO, and other materials such as Cs, Ag, BaO, MgO, amorphous carbon, and diamond may be used.

[0080] Fortunately, in the auxiliary device according to the sixth embodiment, the secondary electrons emitted from the secondary electron emitting member 40, which is not only the electrons emitted from the electron source 3, are also supplied to the discharge gas. As a result, the amount of electrons supplied to the discharge gas can be increased. In the sixth embodiment, as in the fourth embodiment, the extraction electrode 30 may be provided. Further, the secondary electron emission member 40 similar to that of the sixth embodiment may be provided in other embodiments.

[0081] (Embodiment 7)

Embodiment 7 of the present invention will be described below. However, the basic configuration of the auxiliary device of the discharge device according to the seventh embodiment is almost the same as that of the auxiliary device according to the third embodiment, and as shown in FIG. 10, the electron source 3 and the protection member 20 are made of an airtight container. The only difference is that it is arranged in the vicinity of the inner wall surface of the hermetic container 1 in the middle part in the longitudinal direction of 1. Other points are the same as in the third embodiment.

In Embodiments 3 to 6, the shape of the hermetic container 1 is cylindrical, but the hermetic container 1 is not limited to a cylindrical one. For example, it may be a spherical shape such as a light bulb, or may be a rectangular parallelepiped shape or a cubic shape. Further, it may be a flat type airtight container composed of a pair of flat plates and a frame interposed between the flat plates.

In Embodiments 3 to 6, a pair of discharge electrodes 2a and 2b are arranged in the cylindrical hermetic vessel 1 as energy supply means so as to be separated from each other in the longitudinal direction of the hermetic vessel 1. But, The arrangement and configuration of the energy supply means are not limited to this. The voltage applied to the energy supply means may be appropriately selected from DC voltage, AC voltage, pulse voltage, and the like.

In the third to sixth embodiments, an ultraviolet lamp is exemplified as the discharge device. However, the discharge device is not limited to an ultraviolet lamp, but may be a fluorescent lamp for illumination, a plasma display panel, or the like. In the case of a fluorescent lamp, a phosphor layer that emits light by being excited by ultraviolet rays may be provided at an appropriate site on the inner surface of the hermetic container 1.

In the discharge devices according to Embodiments 3 to 6, xenon gas is used as the discharge gas sealed in the hermetic container 1. However, the discharge gas is not limited to xenon gas. Any gas that causes discharge by supplying energy can be used. For example, Ar gas, He gas, Ne gas, Kr gas, N gas, CO gas , Hg vapor, or a mixture of these

2

It may be.

In the electron source 3 according to Embodiments 3 to 6, the lower electrode 15 is formed on one surface side of the insulating substrate 14. However, as described in Embodiment 2, instead of the insulating substrate 14, a semiconductor substrate such as a silicon substrate is used, and the lower electrode is configured by the semiconductor substrate and the conductive layer laminated on the back side of the semiconductor substrate. May be. Further, the electron source 3 according to Embodiments 3 to 6 is BSD. However, as described in the second embodiment, other types of electron sources such as MIM type electron sources and MIS type electron sources may be used instead of BSD.

(Embodiment 8)

Embodiment 8 of the present invention will be described below. The discharge device (light emitting device) according to Embodiment 8 is an ultraviolet lamp.

As shown in FIG. 11, the discharge device including the auxiliary device according to the eighth embodiment includes an airtight container 1 in which a discharge gas (for example, a rare gas such as xenon) as a discharge medium is enclosed, and an airtight container 1 A plasma generation space in the hermetic vessel 1 is discharged by discharging the discharge gas inside the gas chamber 8 〖This generates a discharge plasma A pair of discharge electrodes 2a, 2b and an electron in the discharge gas placed in the hermetic vessel 1 And an electron source 3 for supplying This discharge device (ultraviolet lamp) emits ultraviolet rays by discharging the discharge gas in the hermetic vessel 1. [0088] Further, the discharge device is a material (for example, Cs, Ag, BaO, MgO, and the like) that is disposed in the hermetic vessel 1 and emits secondary electrons into the discharge gas by collision of electrons emitted from the electron source 3. It has a secondary electron emission part 25 containing morphous carbon, diamond, etc.).

[0089] The discharge device according to Embodiment 8 is a straight tube type ultraviolet lamp. The hermetic container 1 is formed in a cylindrical shape with a material having translucency, such as glass and translucent ceramic. Discharge electrodes 2a and 2b are disposed in the airtight container 1 in the vicinity of both ends in the longitudinal direction. Here, the secondary electron emission portion 25 is disposed on the side of one discharge electrode 2a. The electron source 3 is arranged at a position farther from the plasma generation space 8 than the secondary electron emission unit 25.

In the discharge device (light-emitting device) according to Embodiment 8, when the electron source 3 is driven, electrons emitted from the electron source 3 are supplied into the discharge gas. In FIG. 11, the arrow on the right side of the electron source 3 indicates the flow of electrons emitted from the electron source 3. In FIG. 11, the arrow on the right side of the secondary electron emitter 25 indicates the electrons emitted from the electron source 3 and passed through the secondary electron emitter 25 and the secondary electrons emitted from the secondary electron emitter 25. It shows the flow of electrons. Before the voltage is applied between the discharge electrodes 2a and 2b, the electron source 3 is started to supply electrons to the discharge gas, thereby reducing the discharge start voltage between the discharge electrodes 2a and 2b. Can. Further, if the electron source 3 is driven even after a voltage is applied between the discharge electrodes 2a and 2b, the stability of the discharge plasma can be improved and the discharge sustaining voltage can be reduced. , Power consumption can be reduced.

[0091] In Embodiment 8, a pair of discharge electrodes 2a, 2b arranged inside the hermetic container 1 constitutes energy supply means for supplying energy for discharging discharge gas to generate discharge plasma. ing. Further, the electron source 3 and the secondary electron emission unit 25 may constitute an auxiliary device that assists the generation of discharge plasma.

The configuration and function of the electron source 3 according to Embodiment 8 are basically the same as the configuration and function of the electron source 3 according to Embodiment 1. The configuration and function of the drift layer 16 of the electron source element 3a according to Embodiment 8 are also the same as the configuration and function of the drift layer 16 according to Embodiment 1 (see FIG. 2B). The drive voltage applied to the electron source 3 may be a constant DC voltage or a pulsed voltage. Also, if the drive voltage is a pulse voltage, the drive Apply a dynamic voltage, and sometimes apply a reverse bias voltage.

[0093] Electron emission in the electron source element 3a according to the eighth embodiment occurs in the same model as the electron emission in the electron source element 3a according to the first embodiment. In the eighth embodiment, as in the case of the first embodiment, the insulating film can be formed using an acid process, a nitriding process, or an oxynitriding process.

In the eighth embodiment, as described above, the secondary electron emission unit 25 is disposed in the plasma generation space 8 in which discharge plasma is generated in the hermetic vessel 1. The secondary electron emission section 25 has a structure in which a secondary electron emission film having a material force for emitting secondary electrons is installed on the substrate 26 shown in FIG. 12A. The base material 21 shown in FIG. 12A is not limited to the form of the force base material 26 in which a large number of circular holes 26b are formed in a flat plate member 26a.

[0095] For example, as shown in FIG. 12B, a flat plate member 26a may be formed with a number of rectangular holes 26b. Further, as shown in FIG. 12C, a mesh shape may be used. If a secondary electron emission film is deposited on the side facing the electron source 3 at least, the electrons emitted from the electron source 3 and the secondary electrons emitted from the secondary electron emission film are separated. Electrons can be supplied to the space opposite to the electron source 3 with respect to the base material 26.

[0096] A base material 26 shown in FIG. 12A is obtained by forming a hole 26b in a flat plate member 26a as shown in FIG. 13A. However, the hole 26b may be formed in the curved plate member 26a as shown in FIG. 13B, or the hole 26b may be formed in the spherical plate member 26a as shown in FIG. 13C. It ’s good.

[0097] Fortunately, in the auxiliary device according to the eighth embodiment, since the electron source 3 and the secondary electron emission unit 25 are provided in the hermetic container 1, the discharge gas contains electrons. Not only the electrons emitted from the source 3 but also the secondary electrons emitted from the secondary electron emission unit 25 are supplied. For this reason, the electron source 3 can be driven under relatively gentle driving conditions with a smaller amount of emitted electrons than when only the electron source 3 supplies strong electrons. In addition, since the secondary electron emission unit 25 is disposed in the space where the discharge plasma is generated in the hermetic container 1, the secondary electron emission unit 25 collides with electrons in the discharge plasma. Secondary electrons are also emitted. This can also reduce the electron emission amount of the electron source 3. Therefore, the electric As a result, the life of the discharge device 3 and the discharge device can be extended, and the reliability can be improved.

Here, the base material 26 is formed of a conductive material (for example, nickel, stainless steel, aluminum, etc.), a driving voltage is applied to the electron source element 3a, and the base material 26 is applied to the surface electrode 17. If an acceleration voltage is applied between the base material 26 and the surface electrode 17 so as to be on the high potential side, the electron source element 3a is driven by the driving voltage and emits electrons through the surface electrode 17. Then, the electrons emitted through the surface electrode 17 are accelerated by the acceleration voltage and irradiated to the secondary electron emission film. Therefore, by appropriately setting the acceleration voltage, the secondary electron efficiency can be increased and the amount of secondary electrons emitted can be increased. For this reason, the amount of electrons emitted from the electron source 3 can be reduced, and the life of the electron source 3 and thus the discharge device can be extended and the reliability can be improved.

[0099] (Embodiment 9)

Embodiment 9 of the present invention will be described below. However, the basic configuration of the discharge device according to the ninth embodiment or the auxiliary device thereof is almost the same as that of the auxiliary device according to the eighth embodiment, and as shown in FIG. 14, the secondary electron emission unit 25 is a pair. The only difference is that it also serves as one of the discharge electrodes 2a and 2b.

[0100] As a matter of fact, in the discharge device according to Embodiment 9, since the secondary electron emission portion 25 also serves as the negative discharge electrode 2a, the number of parts of the discharge device is reduced, the structure is simplified, Simplify the manufacturing process. As a result, the cost of the discharge device can be reduced.

[0101] (Embodiment 10)

The tenth embodiment of the present invention will be described below. However, the basic configuration of the discharge device according to the tenth embodiment or the auxiliary device thereof is substantially the same as that of the auxiliary device according to the eighth embodiment, and is disposed so as to surround the electron source 3 as shown in FIG. The plasma ion force also differs only in that a protective cover 27 is provided to protect the electron source 3.

[0102] In the tenth embodiment, the protective cover 27 is formed in a rectangular parallelepiped shape with an insulating material (for example, insulating grease such as fluorine-based grease, insulating ceramic, etc.), and one surface thereof ( The lower surface is fully open. The protective cover 27 faces the electron emission surface of the electron source 3. It has a front wall. The front wall of the protective cover 27 is provided with an opening 28 for allowing electrons emitted from the electron source 3 to pass therethrough.

In the tenth embodiment, the secondary electron emission part 25 is arranged so as to overlap the front wall part of the protective cover 27. Therefore, the secondary electron emission unit 25 can be exposed to the discharge plasma while preventing the electron source 3 from being exposed to the discharge plasma. As the secondary electron emission unit 25, for example, a mesh-like base material 26 (see FIG. 12C) according to the eighth embodiment may be used. In this case, by appropriately setting the mesh size, the electrons emitted from the electron source 3 can be passed, and the ion force of the discharge plasma can protect the electron source 3.

[0104] The secondary electron emitting portion 25 preferably has its base material 26 formed of a conductive material. In this case, it is preferable that the potential of the substrate 26 is appropriately set so as to be the same potential as the surface electrode 17 (see FIG. 2A) or a high potential with respect to the surface electrode 17. By setting the secondary electron emission part 25 to the same potential as the surface electrode 17, the plasma passes through the mesh-like secondary electron emission part 25 while allowing the electrons emitted from the electron source 3 to pass sufficiently. It is possible to prevent the electron source 3 from being struck and damaged (damaged).

[0105] By comparison, according to the auxiliary device according to the tenth embodiment, the electron source 3 can be protected from the ion source of the discharge plasma by the protective cover 27, and the lifetime can be further improved and the reliability can be improved. Can be achieved.

[Embodiment 11]

The following describes Embodiment 11 of the present invention. However, the basic configuration of the discharge device according to the eleventh embodiment or the auxiliary device thereof is almost the same as that of the auxiliary device according to the tenth embodiment, and as shown in FIG. The only difference is that it is disposed in the opening portion 28 of 27 and also serves as one of the pair of discharge electrodes 2a, 2b.

[0107] By comparison, according to the discharge device according to the eleventh embodiment, since the secondary electron emission portion 25 also serves as the negative discharge electrode 2a, the number of parts of the discharge device is reduced and the structure is simplified. In addition, the manufacturing process can be simplified, and as a result, the cost of the discharge device can be reduced. In Embodiments 8 to 11, the secondary electron emission member 25 is formed on the base material 26. The substrate 26 may be partially or entirely formed of a secondary electron emission material.

[Embodiment 12]

The following describes Embodiment 12 of the present invention. However, the basic configuration of the discharge device or the auxiliary device according to the twelfth embodiment is substantially the same as that of the discharge device or the auxiliary device according to the tenth embodiment, and is different only in the following points.

As shown in FIG. 17, in the twelfth embodiment, the secondary electron emission portion 25 is arranged so that the front wall force of the protective cover 27 is also separated. An opening 28 is formed on the front wall of the protective cover 27. Further, a mesh-like protective member 29 having a conductive material force is disposed on the front wall of the protective cover 27 facing the electron source 3. Other points are the first embodiment.

Same as 0.

[0110] In summary, according to the twelfth embodiment, the secondary electron emitter 25 can be more reliably exposed to the discharge plasma. Here, a voltage is applied to the secondary electron emitter 25 so as to have a higher potential than that of the protective member 29, and this voltage is applied so that the secondary electron emission efficiency of the secondary electron emitter 25 is almost the maximum value. If set to, secondary electrons can be generated efficiently, and the amount of electrons emitted from the electron source 3 can be more effectively reduced.

[0111] In the auxiliary device according to the twelfth embodiment, the potential of the protective member 29 is set to the same potential as that of the electron source 3, or the potential of the protective member 29 is set higher than the surface electrode 17 of the electron source 3. By appropriately setting the electric potential to be sufficient, the electrons emitted from the electron source 3 are allowed to pass sufficiently, while the plasma penetrates into the protective cover 27 through the mesh-shaped protective member 29, and the electron source. 3 can be prevented from giving an impact.

[Embodiment 13]

The thirteenth embodiment of the present invention will be described below. However, the basic configuration of the discharge device (light emitting device) or the auxiliary device according to the thirteenth embodiment is almost the same as that of the auxiliary device according to the twelfth embodiment, and only the following points are different. .

As shown in FIG. 18, in the thirteenth embodiment, a plurality of secondary electron emission portions 25 are provided. In the example shown in FIG. 18, three mesh-like secondary electron emission portions 25 are arranged in series in a direction (normal direction) perpendicular to the electron emission surface (the upper surface in FIG. 18) of the electron source 3. . The other points are the same as in the twelfth embodiment. [0114] By comparison, the auxiliary device according to Embodiment 13 can increase the amount of secondary electrons supplied to the discharge gas. Therefore, the amount of electrons emitted from the electron source 3 can be further reduced, and the life of the electron source 3 or the discharge device can be extended and the reliability can be improved more effectively. In the thirteenth embodiment, a plurality of secondary electron emission portions 25 are arranged in series in a direction perpendicular to the electron emission surface of the electron source 3. You may arrange | position in parallel in a parallel surface.

[0115] Here, if the potentials of the plurality of secondary electron emission portions 25 arranged in series in the direction perpendicular to the electron emission surface are set so as to become higher as the distance from the electron source 3 increases, secondary electrons can be obtained. A release multiplication effect occurs. As a result, the amount of secondary electrons emitted can be increased, and the amount of electrons emitted by three electron sources can be further reduced. In other embodiments, a plurality of secondary electron emission portions 25 may be provided.

Incidentally, in Embodiments 8 to 13, the hermetic container 1 is cylindrical, but the shape of the hermetic container 1 is not limited to a cylindrical shape. For example, it may be a spherical shape like a light bulb, a rectangular parallelepiped shape or a cubic shape. Further, it may be a flat type airtight container composed of a pair of flat plates and a frame located between both flat plates.

In Embodiments 8 to 13, as shown in FIG. 19A, as an energy supply means, a pair of discharge electrodes 2a disposed in the cylindrical airtight container 1 so as to be spaced apart from each other in the longitudinal direction. 2b is provided. However, the arrangement or configuration of the energy supply means is not limited to this. 19B to 19J show the configuration of other energy supply means.

For example, in the example shown in FIG. 19B, an induction coil 23 wound around the airtight container 1 is provided outside the cylindrical airtight container 1. In the example shown in FIG. 19C, a pair of planar discharge electrodes 2c arranged along the longitudinal direction is provided outside the cylindrical airtight container 1. In the example shown in FIG. 19D, the discharge electrode 2a arranged in the vicinity of one end in the longitudinal direction inside the hermetic container 1, and the planar shape arranged along the longitudinal direction outside the hermetic container 1. Discharge electrode 2c is provided.

[0119] In the example shown in Fig. 19E, two discharge electrodes 2a and 2b arranged one by one in the vicinity of both ends in the longitudinal direction inside the cylindrical airtight container 1, and outside the airtight container 1 One or a plurality of discharge electrodes 2c arranged in an annular shape are provided. As shown in Figure 19F In the example, two pairs of discharge electrodes 2a and 2b arranged inside a cylindrical airtight container 1 are provided. In the example shown in FIG. 19G, a plurality of (five in the example shown in FIG. 19G) annular discharge electrodes arranged at predetermined intervals in the longitudinal direction of the hermetic container 1 outside the cylindrical hermetic container 1. 2c is provided.

[0120] In the example shown in Fig. 19H, a plurality of (five in the example shown in Fig. 19H) planar surfaces arranged at predetermined intervals in the longitudinal direction of the hermetic vessel 1 outside the cylindrical hermetic vessel 1. Discharge electrode 2c is provided. In the example shown in FIG. 191, a pair of discharge electrodes 2a and 2b arranged in a perpendicular direction to each other are provided inside a rectangular parallelepiped hermetic container 1. In the example shown in FIG. 19J, a pair of discharge electrodes 2a and 2b arranged in parallel with each other are provided inside the hermetic container 1.

[0121] The voltage applied to the energy supply means may be appropriately selected from DC voltage, AC voltage, pulse voltage, and the like. For example, when the energy supply means shown in FIG. 19G is provided, as shown in FIG. 20A, a plurality of discharge electrodes 2c are connected so that adjacent discharge electrodes 2c belong to different electrode groups, and two sets of electrodes Divide into groups. In this case, as shown in FIGS. 20B and 20C, if the rectangular wave AC voltage VI applied to one electrode group and the rectangular wave AC voltage V2 applied to the other electrode group are in opposite phases, The length of the airtight container 1 in the longitudinal direction is relatively long! Even in a case, discharge plasma can be generated over almost the entire length of the hermetic vessel 1.

Similarly, when the energy supply means shown in FIG. 19H is provided, for example, as shown in FIG. 21A, a plurality of discharge electrodes 2c are connected so that adjacent discharge electrodes 2c belong to different electrode groups. However, it can be divided into two electrode groups. In this case, as shown in FIGS. 21B and 21C, the rectangular wave AC voltage VI applied to one electrode group and the rectangular wave AC voltage V2 applied to the other electrode group should be in opposite phases. ,.

[0123] In Embodiments 8 to 13, an ultraviolet lamp is exemplified as the discharge device, but the discharge device is not limited to the ultraviolet lamp. For example, a fluorescent lamp for lighting or a plasma display panel may be used. In the case of a fluorescent lamp, as shown in FIG. 22, a phosphor layer 24 that emits light by being excited by ultraviolet rays may be provided at an appropriate portion of the inner surface of the hermetic container 1. In FIG. 22, the auxiliary device is not shown. [0124] In Embodiments 8 to 13, the hermetic container 1 of the discharge device (ultraviolet lamp) is entirely formed of a translucent material. However, as shown in FIG. 23 or FIG. 24, only a part of the hermetic container 1 may be formed of a translucent plate lb made of a translucent material (for example, glass). In the discharge device shown in FIG. 23, ultraviolet rays are radiated to the outside of the airtight container 1 through the light transmitting plate lb. In the discharge device shown in FIG. 24, the light is emitted to the outside of the hermetic vessel 1 through the visible light transmitting plate lb emitted from the phosphor layer 24.

[0125] In Embodiments 8 to 13, the shape of the airtight container 1 is cylindrical. However, for example, as shown in FIG. 25, the airtight container 1 may have a rectangular parallelepiped shape. Here, if the secondary electron emission portion 25 is disposed in an oblique direction with respect to the electron emission surface (the lower surface in FIG. 25) of the electron source 3, only the secondary electron emission portion 25 is exposed to the plasma generation space 8. In this hermetic container 1, the electron source 3 is disposed at a position away from the plasma generation space 8, and the electron emission surface of the electron source 3 is disposed so as not to be exposed to the discharge plasma generated in the plasma generation space 8. can do. Therefore, the electron source 3 can be prevented from being damaged by the ions of the discharge plasma, and the life of the electron source 3 and thus the discharge device can be extended and the reliability can be improved.

In the discharge devices (light-emitting devices) according to Embodiments 8 to 13, xenon gas is used as the discharge gas sealed in the hermetic container 1. However, the discharge gas is not limited to xenon gas. Any gas may be used as long as it causes discharge by supplying energy, for example, Ar gas, He gas, Ne gas, Kr gas, N gas, CO gas, Hg vapor

2

Alternatively, or a mixed gas thereof may be used.

[0127] Also in the electron source 3 according to the eighth to thirteenth embodiments, as described in the second embodiment, a semiconductor substrate such as a silicon substrate is used instead of the insulating substrate 14, and the semiconductor substrate and the semiconductor substrate You may comprise a lower electrode with the electroconductive layer laminated | stacked on the back side. In addition, the electron source 3 according to the eighth to thirteenth embodiments may use other types of electron sources, for example, MIM type electron source, MIS type electron source, etc. instead of the force BSD which is BSD!

[Embodiment 14]

Embodiment 14 of the present invention will be described below. However, the basic configuration of the discharge device or the auxiliary device according to the fourteenth embodiment is almost the same as that of the auxiliary device according to the eighth embodiment. There are similarities, only differing in the following points.

That is, as shown in FIG. 26, in Embodiment 14, the electron source 3 is arranged so that the electron emission surface (surface electrode 17) faces the inner peripheral surface of the airtight container 1 with a slight inclination. Have been. That is, the electron source 3 is arranged such that its electron emission surface is not directly exposed to the discharge plasma. Further, the secondary electron emission portion 25 is disposed on the inner peripheral surface of the hermetic container 1 so as to be positioned obliquely in front of the electron emission surface of the electron source 3. Other points are the same as in the eighth embodiment. In FIG. 26, an arrow R1 indicates an electron emitted from the electron source 3, and an arrow R2 indicates a secondary electron emitted from the secondary electron emission unit 25.

In comparison, in Embodiment 14, the discharge starting voltage or the sustaining voltage is reduced by the secondary electrons emitted from secondary electron emitting portion 25. In addition, since the electron emission surface (surface electrode) of the electron source 3 is opposite to the discharge plasma 10 between the discharge electrodes 2a and 2b, it is effective to cause damage to the electron source 3 due to the discharge plasma. Can be prevented or suppressed. In the eighth embodiment, the secondary electron emission unit 25 prevents the ion source 3 from being damaged by preventing the intrusion of ions. However, in the fourteenth embodiment, the electron source 3 is turned away from the discharge plasma 10. This prevents the electron source 3 from being damaged by ions.

[Embodiment 15]

The fifteenth embodiment of the present invention will be described below. As shown in FIG. 27A, the discharge device according to Embodiment 15 is a discharge lamp La. The discharge lamp La has an airtight container 1 in which a discharge gas (here, xenon gas) is sealed, and a pair of discharge electrodes 2a and 2b arranged in the airtight container 1. Discharge electrode 2a is an anode electrode, and discharge electrode 2b is a force sword electrode (in Embodiment 15, “discharge electrode 2a” and “discharge electrode 2b” are appropriately referred to as “annode electrode 2a”, respectively. And “Power Sword Electrode 2b.”) Note that the discharge gas is not limited to xenon gas, for example, Ar gas, He gas, Ne gas, Kr gas, N gas, CO gas, H

2

gVapor or a mixed gas having two or more of these can be used as appropriate depending on the application of the discharge device.

As shown in FIG. 27A and FIG. 27B, the discharge device according to Embodiment 15 is an auxiliary device that assists the generation of discharge plasma, and an electron source 3 that supplies electrons into the discharge gas, and an electron source 3 First and second protective members 31 and 32 are provided. Electron source 3 is airtight In the vessel 1, it is disposed outside the desired discharge plasma generation space 8 between the anode electrode 2 a and the force sword electrode 2 b and in the vicinity of the force sword electrode 2 b.

[0133] Both protective members 31 and 32 are spaced apart from the electron source 3 on the electron emission side of the electron source 3, and electrons are generated from the ions of the discharge plasma generated in the discharge plasma generation space 8 in the hermetic vessel 1. Protect source 3. Both protective members 31 and 32 also serve as grid electrodes for accelerating electrons emitted from the electron source 3. The protective members 31 and 32 are formed with a plurality of openings 31a and 32a for passing electrons emitted from the electron source 3, respectively.

[0134] The discharge lamp La is a straight tube type discharge lamp, and the hermetic vessel 1 is formed in a cylindrical shape with a translucent material (for example, glass, translucent ceramic, etc.). The anode 2a is disposed near one end of the hermetic container 1 in the longitudinal direction (left side in FIG. 27A), and the force sword electrode 2b is disposed near the other end (right side in FIG. 27A). Yes. The auxiliary device composed of the electron source 3 and the two protection members 31 and 32 is disposed in the vicinity of the force sword electrode 2b on the side opposite to the anode electrode 2a with respect to the force sword electrode 2b. In short, the electron source 3 and the protective members 31 and 32 are disposed outside the discharge plasma generation space 8 in the hermetic vessel 1.

The configuration and function of the electron source 3 according to Embodiment 15 are basically the same as the configuration and function of the electron source 3 according to Embodiment 1. The film thickness of the conductive thin film constituting the surface electrode 17 is preferably set to about 10 to 15 nm. The conductive thin film may be either a single layer film or a multilayer film. The configuration and function of the drift layer 16 of the electron source element 3a according to Embodiment 15 are also the same as the configuration and function of the drift layer 16 according to Embodiment 1 (see FIG. 2B).

[0136] Electron emission in the electron source element 3a according to the fifteenth embodiment also occurs in the same model as the electron emission in the electron source element 3a according to the first embodiment. In the fifteenth embodiment, as in the first embodiment, the insulating film can be formed using an acid process, a nitridation process, or an oxynitridation process.

[0137] Both protective members 31, 32 are each formed in a net shape from a conductive material (eg, nickel, aluminum, stainless steel, etc.), and each net portion of the net shape is emitted from the electron source 3. Openings 31a and 32a are formed for passing the generated electrons. In the fifteenth embodiment, both the protective members 31 and 32 have a net shape, but the shape of the protective members 31 and 32 is not limited to the net shape. For example, a flat conductive substrate provided with openings 31a and 32a may be used.

[0138] The driving method of the auxiliary device according to the fifteenth embodiment is as follows. That is, for example, a DC voltage of about 14 V is applied between the surface electrode 17 and the lower electrode 15 from the drive power supply. At the same time, a DC voltage of about 100 V is applied between the first protective member 31 and the surface electrode 17 from the first acceleration power source (not shown), while the second acceleration power source. A DC voltage of about 90 V, for example, is applied between the second protective member 32 and the surface electrode 17 (not shown). As a result, electrons emitted from the electron source 3 are accelerated by the first protective member 31 and the second protective member 32, and enter the discharge plasma generation space 8 between the anode electrode 2a and the force sword electrode 2b. Supplied.

[0139] The potential of each component when the auxiliary device is driven is set as follows. That is, the potential relationship between the first protection member 31 and the second protection member 32 is set so that the potential of the first protection member 31 and the potential of the second protection member 32 are different from each other. The potential of the second protective member 32 is set to a potential lower than that of the anode electrode 2a and higher than that of the force sword electrode 2b. In this case, the potential of the second protective member 32 is such that the potential difference between the second protective member 32 and the anode electrode 2a (hereinafter referred to as “first potential difference”) is the second protective member 32 and the anode electrode. 2a, and the potential difference between the second protective member 32 and the force sword electrode 2b (hereinafter referred to as “second potential difference” t) is the second protective member. It is desirable to set it to be smaller than the discharge start voltage between 32 and the force sword electrode 2b. It is more desirable to set each potential difference to be lower than the discharge start voltage and lower than the discharge sustain voltage.

[0140] In the fifteenth embodiment, the output voltage of the power source V that applies a voltage between the anode electrode 2a and the force sword electrode 2b, the output voltage of the drive power source, the output voltage of the first acceleration power source, and the second

AK

The output voltage of the acceleration power source is controlled by a control unit (not shown) having a microcomputer power, for example. The control unit controls the potentials of the protective members 31, 32, the potential of the anode electrode 2a, and the potential of the force sword electrode 2b so that the above-described potential relationship is established. [0141] As described above, in the auxiliary device according to the fifteenth embodiment, both protection members 31, 32 have openings 31a, 32a for allowing electrons emitted from the electron source 3 to pass through, respectively. Yes. For this reason, by setting the respective aperture ratios of the protective members 31 and 32 appropriately, the electrons emitted from the electron source 3 can be prevented from colliding with the electron source 3 while the ions emitted from the electron source 3 are suppressed. It is possible to suppress the collision with 2 and to be captured, and to reduce the discharge start voltage.

[0142] Furthermore, since the potential of the second protective member 32 is lower than the potential of the anode electrode 2a and higher than the potential of the cathode electrode 2b, the second protective member 32 and the anode electrode 2a or force sword It is possible to prevent unnecessary discharge plasma from occurring between the electrode 2b. For this reason, the occurrence of damage to the electron source 3 can be suppressed, and the life of the electron source 3 can be extended.

Further, the potential relationship is set so that the potential of the second protective member 32 is lower than the potential of the first protective member 31. For this reason, while suppressing the electrons that have passed through the opening 31a of the first protective member 31 from being captured by the second protective member 32, the air gap between the anode electrode 2a and the force sword electrode 2b in the hermetic container 1 is reduced. It is possible to reduce damage to the electron source 3 due to the ions of the discharge plasma generated in the plasma.

In the auxiliary device according to the fifteenth embodiment, the aperture ratio of the second protection member 32 is smaller than the aperture ratio of the first protection member 31. For this reason, it is possible to more effectively reduce damage to the electron source 3 caused by ions of the discharge plasma generated between the anode electrode 2a and the force sword electrode 2b in the hermetic container 1. Here, if the opening 31a of the first protective member 31 is formed in a shape corresponding to the electron emission surface of the electron source 3, the electrons emitted from the electron source 3 are transferred to the first protective member 31 and the electron source. The probability that electrons emitted from the electron source 3 are captured by the first protective member 31 can be reduced while accelerating by the electric field between the first and second electrons.

By the way, the discharge plasma is generated between the anode electrode 2a and the force sword electrode 2b when the relationship represented by the following formula 1 is satisfied. It should be noted that the discharge between the anode electrode 2a and the force sword electrode 2b is maintained by the collision of ions with the force sword electrode 2b to generate secondary electrons. This principle is the same as that of the force sword electrode 2b. The same applies to the second protective member 32. y> l / (e ^ad -l) Equation 1 d: Distance between the anode and force sword electrodes

Electronic multiplication factor

γ: Secondary electron emission coefficient due to ions at the cathode electrode

[0146] Therefore, if the material of the second protective member 32 is formed of a material satisfying the relationship expressed by the following formula 2, unnecessary discharge plasma is generated between the second protective member 32 and the force sword electrode 2b. Can be prevented, and the life of the electron source 3 can be extended.

y≤l / (e ^ad -l) Formula 2 d: Distance between the second protective member and the cathode electrode

α: Electron multiplication factor in the space between the second protective member and the cathode electrode

Ύ: Secondary electron emission coefficient by ions of discharge plasma in hermetic vessel

Here, in order to lower the secondary electron emission coefficient γ, a material having a low secondary electron emission efficiency for ions may be used. Desirable materials of this type include, for example, Fe, Co, Ni, Cu, Zn, Ga, Ge, C, Si ゝ Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te , Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi or Po, or oxides, nitrides, and carbides thereof.

[0148] Even if a material other than the above materials is used for the second protective member 32, if the potential of the second protective member 32 is set so that α satisfies the relationship represented by the following Equation 3, It is possible to prevent unnecessary discharge plasma from being generated between the protective member 32 of 2 and the force sword electrode 2b, and to extend the life of the electron source 3. The second protective member 32 preferably has a low secondary electron emission efficiency with respect to ions, but in order to improve the electron emission efficiency of the auxiliary device force, it is preferable that the secondary electron emission efficiency with respect to the electron is high. desirable.

α≤1η {(1 / γ) + 1} / ά Equation 3 d: Distance between second protective member and cathode electrode

[0149] The electron source 3 according to Embodiment 15 is a BS D that emits electrons by a ballistic electron emission phenomenon. However, electron source 3 is not limited to BSD. For example, MIM Type electron sources, MIS type electron sources, Spindt type electron sources, SCE (Surface Conduction Electronitter) type electron sources, electron sources using carbon nanotube emitters, and more!ヽ. However, if BSD is used as the electron source 3, electrons can be emitted stably even in the discharge gas, so it is desirable to use BSD as the electron source 3.

[Embodiment 16]

The sixteenth embodiment of the present invention will be described below.

As shown in FIG. 28, the discharge device according to Embodiment 16 is a discharge lamp. This discharge lamp includes a hermetic container 1 in which a discharge gas (for example, a rare gas such as argon) as a discharge medium is sealed, a pair of discharge electrodes 2a and 2b disposed in the hermetic container 1, and an airtight container. 1 is provided with an electron source 3 that is disposed in 1 and supplies electrons into the discharge gas, and a grid electrode 35 that is disposed in the airtight container 1 so as to face the electron source 3. This discharge lamp emits visible light by causing the discharge electrodes 2a and 2b to discharge in the discharge gas in the hermetic vessel 1. Both discharge electrodes 2 a and 2 b apply an electric field to the discharge gas in the hermetic vessel 1 to generate a discharge plasma in a desired discharge plasma generation space 8 in the hermetic vessel 1.

[0151] As shown in Fig. 29, the grid electrode 35 has a plurality of openings 35a for allowing electrons emitted from the electron source 3 to pass therethrough. The grid electrode 35 is provided to accelerate the electrons emitted from the electron source 3. In the sixteenth embodiment, the electron source 3 and the grid electrode 35 constitute an auxiliary device that assists the generation of discharge plasma in the discharge plasma generation space 8.

[0152] The discharge device according to Embodiment 16 is a straight tube type discharge lamp. The airtight container 1 is formed in a cylindrical shape from a light-transmitting material (for example, glass, light-transmitting ceramic, etc.). Discharge electrode 2a arranged near one end of the hermetic container 1 in the longitudinal direction (left side in FIG. 28) constitutes an anode electrode, and discharge arranged near the other end (right side in FIG. 28) The electrode 2b constitutes a force sword electrode (in the sixteenth embodiment, “discharge electrode 2 aj and“ discharge electrode 2b ”are appropriately referred to as“ anode electrode 2a ”and“ force sword electrode 2b ”t, respectively)

[0153] The electron source 3 and the grid electrode 35 and the auxiliary device that also has a force are arranged in the vicinity of the force sword electrode 2b on the side opposite to the anode 2a. In short, electric The child source 3 and the grid electrode 35 are arranged outside the discharge plasma generation space 8 in the hermetic vessel 1.

In the discharge device according to the sixteenth embodiment, by driving the electron source 3, the electrons emitted from the electron source 3 can be supplied into the discharge gas. Therefore, before applying a voltage from the electric field application voltage source V to the anode electrode 2a and the force sword electrode 2b,

AK

Then, a voltage is applied to the electron source 3, and the driving of the electron source 3 is started to supply electrons into the discharge gas.

PS

By supplying it, it is possible to reduce the discharge start voltage between the anode electrode 2a and the force sword electrode 2b necessary for starting the discharge. If the electron source 3 is driven even after a voltage is applied between the anode electrode 2a and the force sword electrode 2b, the discharge plasma can be stabilized and the discharge sustaining voltage can be reduced. Therefore, power consumption can be reduced.

[0155] The configuration and function of the electron source 3 according to Embodiment 16 are basically the same as the configuration and function of the electron source 3 according to Embodiment 1. The film thickness of the conductive thin film constituting the surface electrode 17 is preferably set to about 10 to 15 nm. The conductive thin film may be either a single layer film or a multilayer film. Further, the configuration and function of the drift layer 16 of the electron source element 3a according to Embodiment 16 are the same as the configuration and function of the drift layer 16 according to Embodiment 1 (see FIG. 2B). The driving voltage applied to the electron source 3 may be a constant DC voltage or a pulsed voltage. Also, if the drive voltage is a pulse voltage, it may be possible to apply a reverse bias voltage after applying the drive voltage!

[0156] Electron emission in the electron source element 3a according to the sixteenth embodiment also occurs in the same model as the electron emission in the electron source element 3a according to the first embodiment. In the sixteenth embodiment, as in the first embodiment, the insulating film can be formed using an acid process, a nitridation process, or an oxynitridation process.

[0157] The grid electrode 35 is made of a conductive material (for example, nickel, aluminum, stainless steel, etc.) in a net shape. Each mesh-shaped mesh portion constitutes an opening 35a for allowing electrons emitted from the electron source 3 to pass through. In the sixteenth embodiment, as the grid electrode 35, a nickel mesh having a side of a square mesh of 0.6 mm and a wire diameter of 0.25 mm, which is called 30 mesh, is used. Yes. However, the mesh size That is, the size of the opening 35a is not limited to this. Any size can be used as long as the electrons emitted from the electron source 3 can pass through and the intrusion of ions of the discharge plasma power generated in the discharge plasma generation space 8 can be suppressed! / ヽ. For example, if the length of one side of the square opening 35a is 0. lmn! It may be set appropriately within a range of about 2 mm.

[0158] In Embodiment 16, the grid electrode 35 is formed in a net shape, but the grid electrode 35 is not limited to the net shape. For example, an opening having the same shape as the surface electrode 17 may be provided in a portion of the flat conductive substrate facing the surface electrode 17.

In the discharge device (discharge lamp) according to Embodiment 16, the potential relational force between grid electrode 35, force sword electrode 2b, and anode electrode 2a is greater than the potential of force sword electrode 2b. Is set to be higher and lower than the potential of the anode electrode 2a. Specifically, an output voltage of an electric field applying voltage source V that applies a voltage between the anode electrode 2a and the force sword electrode 2b, and a driving voltage is applied between the surface electrode 17 and the lower electrode 15. Driving

AK

The output voltage of the dynamic power source V and the voltage applied between the grid electrode 35 and the surface electrode 17

PS

The above potential relationship is satisfied by appropriately setting the output voltage of the child acceleration power source Vc and the output voltage of the power source V that applies a voltage between the grid electrode 35 and the force sword electrode 2b.

GK

I try to make it. The output voltage of each power supply V, V, Vc and V

AK PS GK

It is appropriately controlled by a control unit including a computer (not shown).

[0160] Hereinafter, one specific example of the discharge device (discharge lamp) according to Embodiment 16 will be described. In this embodiment, the pressure of argon gas sealed in the hermetic container 1 (hereinafter referred to as “discharge gas pressure”) is lOPa. The distance between the anode electrode 2a and the force sword electrode 2b (hereinafter referred to as “interelectrode distance”) is set to 10 cm. The distance between the grid electrode 35 and the force sword electrode 2b is set to 5 mm. The distance between the grid electrode 35 and the surface electrode 17 is set to 5 mm.

[0161] According to Noschen's law, discharge plasma is most likely to occur when the product of discharge gas pressure and inter-electrode distance d is lOOPa'cm (pXd = 100Pa'cm). Therefore, in the discharge device having a discharge gas pressure of lOPa according to this example, the anode electrode 2a and the force sword Discharge easily occurs both between the electrode 2b and between the anode electrode 2a and the grid electrode 35. In this embodiment, if a voltage of about 200 V is applied between the force anode electrode 2a and the force sword electrode 2b depending on the amount of electrons supplied from the electron source 3 and the energy of the electrons, the discharge plasma generation space 8 It is possible to generate a discharge plasma.

[0162] Therefore, with the potential of the force sword electrode 2b set to OV and the potential of the grid electrode 35 set to 100V, the voltage applied between the anode electrode 2a and the force sword electrode 2b is set to a voltage lower than 200V. When the voltage is raised, when the voltage between the anode electrode 2a and the force sword electrode 2b reaches 200V, a discharge plasma is generated in the discharge plasma generation space 8 between the anode electrode 2a and the force sword electrode 2b. Is done. At this point, the potential difference between the anode electrode 2a and the grid electrode 35 is 100V, and the distance between the anode electrode 2a and the grid electrode 35 is greater than the distance between the anode electrode 2a and the force sword electrode 2b. Since it is somewhat long, the voltage between the anode electrode 2a and the grid electrode 20 does not reach the discharge start voltage. Therefore, no unnecessary discharge plasma is generated between the anode 2a and the grid electrode 20!

[0163] In comparison, in the discharge device according to Embodiment 16, the potential difference between anode electrode 2a and grid electrode 20 is smaller than the potential difference between anode electrode 2a and force sword electrode 2b. When a voltage is applied between the anode electrode 2a and the force sword electrode 2b to generate a discharge plasma in a desired discharge plasma generation space 8, unnecessary discharge plasma is generated between the anode electrode 2a and the grid electrode 35. Can be suppressed. Furthermore, it is possible to prevent ions of the discharge plasma from entering the electron source 3 side from the grid electrode 35, so that the life of the electron source 3 can be extended and the reliability can be improved.

Incidentally, when the potential of the grid electrode 35 is increased in order to reduce the potential difference between the anode electrode 2a and the grid electrode 35, the potential difference between the grid electrode 35 and the surface electrode 17 increases. For this reason, unnecessary discharge plasma may be generated in the space between the grid electrode 35 and the electron source 3 and in the space between the grid electrode 35 and the force sword electrode 2b.

In the above embodiment, since the discharge gas pressure p is lOPa, discharge is most likely to occur! /, And the inter-electrode distance d is 10 cm (ie, p X d = 100 (Pa ′ cm)) ). On the other hand, since the distance between the grid electrode 35 and the force sword electrode 2b and the distance between the grid electrode 35 and the surface electrode 17 are 5 mm, there is usually no potential difference on the order of kV. As long as discharge plastic Zuma does not occur. Therefore, the discharge between the grid electrode 35 and the force sword electrode 2b, or between the grid electrode 35 and the surface electrode 17 and between the anode electrode 2a and the force sword electrode 2b (hereinafter referred to as “main discharge”). When an abnormal discharge (unnecessary discharge plasma) unrelated to) occurs and the electron source 3 is damaged, the above phenomenon should not be considered much.

[0166] However, in the case of a discharge device whose discharge gas pressure (argon pressure) is lOOPa ~: LkPa, the inter-electrode distance d is lmn! Discharge is most likely to occur at ~ lcm. For this reason, when the potential difference between the grid electrode 35 and the force sword electrode 2b, or the potential difference between the grid electrode 35 and the surface electrode 17 of the electron source 3 is about 200 V, Abnormal discharge (unnecessary discharge plasma) is generated between the grid electrode 35 and the surface electrode 17.

[0167] Therefore, the above potential relationship is set so as to be smaller than the potential difference force between the potential of the anode electrode 2a and the potential of the grid electrode 35 and the discharge start voltage between the anode electrode 2a and the grid electrode 35. For example, when the potential of the grid electrode 35 is increased in order to reduce the potential difference between the anode electrode 2a and the grid electrode 35, unnecessary discharge plasma is generated between the grid electrode 35 and the surface electrode 17 to generate electrons. Source 3 can be prevented from being damaged.

In Embodiment 16, when the voltage of anode electrode 2a is increased in order to increase the luminance of the discharge device (discharge lamp), the potential difference between anode electrode 2a and grid electrode 35 starts to discharge. There is a possibility that unnecessary discharge plasma is generated due to the voltage exceeding the voltage. Explaining in accordance with the above embodiment, when the potential of the anode electrode 2a is increased to 300V, the potential difference between the anode electrode 2a and the grid electrode 35 becomes 200V. Here, if the discharge start voltage force between the anode electrode 2a and the grid electrode 35 is the same as the discharge start voltage between the anode electrode 2a and the force sword electrode 2b, then the anode electrode 2a and the grid electrode 35 Unnecessary discharge plasma may be generated between them. However, in the positional relationship among the anode electrode 2a, the force sword electrode 2b, and the grid electrode 35 in the embodiment 16, the discharge start voltage between the anode electrode 2a and the grid electrode 35 is between the anode electrode 2a and the force sword electrode 2b. It is slightly higher than the discharge start voltage.

Therefore, when the potential of the anode electrode 2a is increased as described above, the potential of the grid electrode 35 may be increased. As described above, when the discharge gas pressure (argon gas pressure) is about lOPa, between the grid electrode 35 and the force sword electrode 2b, or between the grid electrode 35 and the surface electrode 17 The discharge start voltage between and is in the order of kV, and unnecessary discharge plasma is unlikely to occur. However, if the discharge gas pressure is about lOOPa ~: LkPa, if the potential of the grid electrode 35 is increased, unnecessary discharge plasma may be generated in the space between the grid electrode 35 and the surface electrode 17. Arise.

[0170] Therefore, in order to prevent the generation of discharge plasma in the space between the grid electrode 35 and the surface electrode 17, the surface electrode 17 and the lower part of the electron source 3 are adjusted in accordance with the increase in the potential of the grid electrode 35. The potential of the electrode 15 may be increased. For example, when the potential of the grid electrode 35 is 150V, the potential difference between the grid electrode 35 and the surface electrode 17 is 60V when the potential of the surface electrode 17 is 90V and the potential of the lower electrode 15 is 75V. Therefore, it is possible to suppress the generation of discharge plasma in the space between the grid electrode 35 and the surface electrode 17. In this case, the driving voltage of the electron source 3 is 15V (= 90−75 = 15 (V)).

In Embodiment 16, force electron source 3 using BSD as electron source 3 is not limited to BSD. For example, an MIM type electron source, a Spindt type electron source, or an electron source using a carbon nanotube may be used. In the case of the MIM type electron source, the upper electrode (surface electrode) constitutes the electron emission portion. In the case of a Spindt-type electron source, a conical emitter forms the electron emission section. For electron sources using carbon nanotubes

The carbon nanotubes constitute an electron emission portion.

In the discharge device shown in FIG. 28, the auxiliary device having the electron source 3 and the grid electrode 35 is disposed in the airtight container 1 in the vicinity of the force sword electrode 2b. However, as shown in FIG. 30, the auxiliary device may be arranged in the vicinity of the anode electrode 2a, not in the vicinity of the force sword electrode 2b. By the way, when the auxiliary device is arranged in the plasma generation space 8, the auxiliary device is exposed to the discharge plasma even when the discharge plasma is not generated between the anode electrode 2a and the grid electrode 35. Therefore, ions may enter from the grid electrode 35 to the electron source 3 side.

On the other hand, in the discharge device shown in FIG. 30, the auxiliary device has the anode electrode 2a in the hermetic vessel 1 outside the plasma generation space 8 between the anode electrode 2a and the force sword electrode 2b. Located nearby. The grid electrode 35 is arranged closer to the anode electrode 2a than the electron source 3. In this way, the auxiliary device is placed outside the plasma generation space 8. Therefore, the auxiliary device can be prevented from being exposed to the discharge plasma generated in the plasma generation space 8. Further, since the auxiliary device is disposed near the anode electrode 2a and the grid electrode 35 is disposed closer to the anode electrode 2a than the electron source 3, it is emitted from the electron source 3 and enters the plasma generation space 8. Can increase the amount of electrons reaching

[0174] In Embodiment 16, the shape of the hermetic container 1 is cylindrical, but the shape of the hermetic container 1 is not limited to this. For example, the airtight container 1 may have a spherical shape like a light bulb, or may have a rectangular parallelepiped shape or a cubic shape. Further, the airtight container 1 may be a flat type constituted by a pair of flat plates and a frame interposed between the flat plates.

In the sixteenth embodiment, the energy supply means is disposed in the cylindrical airtight container 1 so as to be separated in the longitudinal direction of the pair of discharge electrodes 2a, 2b force hermetic container 1. However, instead of doing this, one of the pair of discharge electrodes 2a and 2b may be arranged outside the hermetic container 1. Further, when all the discharge electrodes 2a and 2b are arranged in the hermetic container 1, a plurality of pairs of discharge electrodes 2a and 2b may be provided.

[0176] In the sixteenth embodiment, a discharge lamp using argon gas will be exemplified as a discharge device. However, the discharge device is not limited to a discharge lamp, and may be a fluorescent lamp for illumination, a plasma display panel, or the like. In the case of a fluorescent lamp, a phosphor layer that emits light by being excited by ultraviolet rays or the like may be provided at an appropriate part of the inner surface of the hermetic container 1.

In the sixteenth embodiment, argon gas is used as the discharge gas sealed in the hermetic container 1. However, the discharge gas sealed in the hermetic vessel 1 is not limited to argon gas, and any gas may be used as long as it causes discharge by supplying energy. For example, as discharge gas, He gas, Ne gas, Xe gas, Kr gas, N gas, CO gas

2

Sm, Hg vapor, or a mixed gas thereof may be used.

[0178] As described above, it is obvious to those skilled in the art that the present invention is capable of many variations and modifications in addition to the forces described in connection with the specific embodiment. . Therefore, the present invention is not limited to such an embodiment. It should be limited by the scope of demand.

Industrial applicability

As described above, the discharge plasma generation auxiliary device according to the present invention reduces the discharge start voltage, discharge sustain voltage, etc. of the discharge plasma device or the light emitting device and stabilizes the discharge plasma while suppressing damage caused by ion bombardment. It is useful as a means for making it suitable for use in fluorescent lamps, ultraviolet lamps, plasma display panels and the like.

Claims

The scope of the claims

[1] an airtight container filled with a discharge medium gas;

Disposed in at least one of the inside and the outside of the hermetic container and provided in a discharge plasma apparatus provided with an energy supply unit that supplies energy for discharging the gas to generate discharge plasma. A discharge plasma generation auxiliary device for assisting generation,

A field emission electron source for supplying electrons into the gas;

A discharge plasma generation auxiliary device comprising: a protection means for protecting a field emission electron source such as an ion source of discharge plasma generated in an airtight container.

[2] a discharge detector for detecting discharge of the gas;

Control means for controlling the electric potential of the field emission electron source so as to suppress positive ions in the discharge plasma from colliding with the field emission electron source when the start of discharge of the gas is detected. The discharge plasma generation auxiliary device according to claim 1, wherein the discharge plasma generation auxiliary device is included.

[3] The energy supply unit includes at least one pair of discharge electrodes, and

3. The discharge plasma generation auxiliary device according to claim 2, wherein the discharge detector detects the start of discharge of the gas based on a change in impedance, current or voltage between the discharge electrode pair.

[4] The control means, wherein after the start of discharge of the gas is detected, the potential of the field emission electron source is controlled to be higher than the potential before the start of discharge is detected. A discharge plasma generation auxiliary device according to claim 1.

[5] The protective means includes a protective member having an electron passage portion for allowing electrons to pass therethrough and protecting the surface electrode of the field emission electron source from ions of discharge plasma.

The discharge plasma generation auxiliary device according to 1.

6. The discharge plasma generation assisting device according to claim 5, wherein at least a portion of the protective member facing the surface electrode is made of a conductive material and has an electron passage portion. .

7. The discharge bra of claim 5, wherein the protective member is formed in a net shape. Zuma generation assist device.

8. The discharge plasma generation assisting device according to claim 5, wherein the protective member is a secondary electron emission member.

9. The discharge plasma generation auxiliary device according to claim 5, wherein at least one of the inner side and the outer side of the protective member includes a secondary electron emission member.

[10] The potential of the protection member is controlled to be the same or higher than the potential of the electron emission portion of the field emission electron source, and Z or the electron emission of the protection member and the field emission electron source is controlled. 6. The discharge plasma generation auxiliary device according to claim 5, wherein a potential difference between the discharge portion and the discharge portion is controlled to be smaller than a discharge start voltage.

[11] The energy supply means includes a force sword electrode and an anode electrode, and

6. The discharge plasma generation assisting device according to claim 5, wherein the discharge plasma generation assisting device is controlled to be higher than a potential of the potential force sword electrode of the protective member and lower than a potential of the anode electrode.

[12] The energy supply means includes a force sword electrode and an anode electrode, and

6. The discharge plasma generation auxiliary device according to claim 5, wherein the potential difference between the potential of the anode electrode and the potential of the protective member is controlled to be smaller than the discharge start voltage.

[13] The energy supply means includes a force sword electrode and an anode electrode, and

If the distance between the protective member and the cathode electrode is d, the electron multiplication factor in the space between the protective member and the cathode electrode is α, and the secondary electron emission coefficient due to the ions of the discharge plasma is γ,

Protective member

y≤l / (e ^ad -l)

6. The discharge plasma generation assisting device according to claim 5, wherein the discharge plasma generation assisting device is formed of a material satisfying the following relationship.

[14] The energy supply means includes a force sword electrode and an anode electrode, and

The distance between the protective member and the cathode electrode is d, the electron multiplication factor in the space between the protective member and the cathode electrode is α, and the secondary electron emission coefficient due to the discharge plasma ions is γ. If

The potential of the protective member is

6. The discharge plasma generation auxiliary device according to claim 5, wherein the discharge plasma generation auxiliary device is controlled so as to satisfy the relationship of:

[15] The protective member includes a first protective member close to the field emission electron source and a second protective member far from the field emission electron source.

The potential of the first protective member is controlled to be higher than that of the field emission electron source, and the potential of the first protective member and the potential of the second protective member are different from each other. As well as being controlled

6. The discharge plasma generation auxiliary device according to claim 5, wherein the potential of the second protective member is controlled to be lower than the potential of the anode electrode and higher than the potential of the force sword electrode.

16. The discharge plasma generation auxiliary device according to claim 15, wherein the potential of the second protective member is controlled to be lower than the potential of the first protective member.

[17] The discharge plasma generation auxiliary device according to claim 15, wherein the aperture ratio of the second protective member is lower than the aperture ratio of the first protective member.

[18] The field emission electron source is arranged so as not to be directly exposed to the discharge plasma, while the secondary electron emission part is arranged obliquely in front of the electron emission surface of the field emission electron source. The discharge plasma generation auxiliary device according to claim 1.

19. The field emission electron source is a ballistic electron surface emission electron source.

The discharge plasma generation auxiliary device according to any one of -18.

[20] An illumination device comprising the discharge plasma generation auxiliary device according to claim 1, 2, 5, or 18.