JP2007087937A - Electric discharge plasma generation auxiliary device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric discharge plasma generation auxiliary device having longer life than convention and the reliability thereof is improved. <P>SOLUTION: The electric discharge plasma generation auxiliary device for assisting the generation of electric discharge plasma used for a light emitting device including a sealed container 1 having an electric discharge medium gas sealed therein, and a pair of electrodes 2a and 2a being energy supply means placed in the sealed container 1 to supply energy for generating the plasma by electric discharging the gas. The electric discharge plasma generation auxiliary device has an electron source 10 placed in the sealed container 1 to supply electron into the gas, and a secondary electron emitting part 20 placed in the sealed container 1 to emitt the secndary electron into the gas by collision of electrons emitted from the electron source 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a discharge plasma generation auxiliary device used in a light emitting device using discharge plasma such as a plasma display panel, an ultraviolet lamp, and a fluorescent lamp.

Conventionally, an airtight container in which a gas as a discharge medium is sealed, and a pair of electrodes that are provided in the airtight container and that supply energy for generating discharge plasma and that applies an electric field to the gas are provided. In a discharge plasma generation auxiliary device that is used in a light emitting device and assists the generation of discharge plasma, a field emission type electron source capable of supplying electrons into a gas is provided in an airtight container, and the electron source is appropriately driven to discharge It is known that effects such as reduction of the starting voltage, reduction of the sustaining voltage of the discharge plasma, and stabilization of the discharge plasma can be obtained (for example, see Patent Document 1). Here, in Patent Document 1, as an application example of the discharge plasma generation auxiliary device, in addition to a plasma display panel in which a phosphor layer that emits light by being excited by ultraviolet light generated by discharge plasma or the like is provided on the inner surface of an airtight container. Describes the application to ultraviolet lamps, fluorescent lamps, and the like.
JP 2002-150944 A

  By the way, in the light emitting device disclosed in Patent Document 1, it is necessary to supply a sufficient amount of electrons into the gas in order to ensure the start of discharge plasma and the stabilization of discharge. However, in the above-described discharge plasma generation auxiliary device, in order to increase the amount of electrons supplied to the gas, it is necessary to increase the amount of electrons emitted from the electron source. It is necessary to lengthen the driving period of the source. For example, the airtight container such as a straight tube type ultraviolet lamp or a fluorescent lamp is long, the discharge path is long, and the discharge plasma needs to be stabilized for a long time. When used in a light-emitting device, it is necessary to drive the electron source under more severe conditions, and it is considered that the lifetime and reliability of the electron source become a problem. In the discharge plasma generation assisting device described above, when the electron source is exposed to plasma, the electron source may be damaged by ion bombardment or the like, resulting in a shortened life and reduced reliability.

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a discharge plasma generation auxiliary device capable of extending the life and improving the reliability as compared with the conventional configuration.

  According to a first aspect of the present invention, an energy-tight container in which a gas as a discharge medium is sealed, and energy that is disposed in at least one of the inside and the outside of the air-tight container and discharges the gas to generate discharge plasma is supplied. A discharge plasma generation auxiliary device that is used in a light emitting device having an energy supply means and assists the generation of discharge plasma, the electron source being arranged in an airtight container and supplying electrons into the gas, and the airtight container And a secondary electron emission unit that emits secondary electrons into the gas by collision of electrons emitted from an electron source.

  According to the present invention, the electron source that is arranged in the hermetic container and supplies electrons into the gas and the secondary electron that is arranged in the hermetic container and emits secondary electrons into the gas by collision of the electrons emitted from the electron source. Since the secondary electron emission part is provided, not only the electrons emitted from the electron source but also the secondary electrons emitted from the secondary electron emission part are supplied into the gas. Compared to the conventional configuration for supplying the electron beam, the electron source can be driven under relatively gentle driving conditions so that the amount of emitted electrons is reduced, and the life can be extended and the reliability can be improved as compared with the conventional configuration. .

  The invention of claim 2 is characterized in that, in the invention of claim 1, the secondary electron emission portion is disposed in a space where discharge plasma is generated in the hermetic vessel.

  According to this invention, since the secondary electrons are emitted even when the electrons in the discharge plasma collide with each other in the secondary electron emission portion, it is possible to reduce the electron emission amount of the electron source. The service life can be extended and the reliability can be improved.

  The invention of claim 3 is the invention of claim 2, further comprising an electrode disposed in the hermetic container as the energy supply means, wherein the secondary electron emission portion also serves as an electrode.

  According to the present invention, since the secondary electron emission portion can be used also as an electrode, the light emitting device can be easily manufactured and the cost can be reduced.

  According to a fourth aspect of the present invention, in the second aspect of the invention, the secondary electron emission portion is arranged in an oblique direction with respect to an electron emission surface of the electron source.

  According to this invention, it becomes possible to arrange the electron source so as not to be exposed to the discharge plasma, it is possible to suppress damage to the electron source due to the ions of the discharge plasma, and to extend the life and Reliability can be improved.

  According to a fifth aspect of the present invention, in the first to third aspects of the invention, the electron source is protected from the ions of the discharge plasma generated in the hermetic container and disposed so as to surround the electron source in the hermetic container. A protective cover is provided, and the protective cover is provided with an aperture through which electrons emitted from the electron source pass, and the secondary electron emission portion is disposed in the aperture of the protective cover. And

  According to the present invention, the electron source can be protected from the ions of the discharge plasma by the protective cover, and the lifetime can be further improved and the reliability can be improved.

  According to a sixth aspect of the present invention, in the first to third aspects of the present invention, the electron source is protected from ions of discharge plasma generated in the hermetic container and disposed so as to surround the electron source in the hermetic container. A protective cover is provided, the protective cover is provided with an opening through which electrons emitted from the electron source pass, and the secondary electron emission part is disposed outside the protective cover. .

  According to the present invention, the electron source can be protected from the ions of the discharge plasma by the protective cover, and the lifetime can be further improved and the reliability can be improved. Since it is arranged on the outer side, it is possible to increase the amount of secondary electrons emitted from the secondary electron emission portion compared to the invention of claim 5.

  The invention of claim 7 includes a protective cover that is disposed so as to surround the electron source in the hermetic container and protects the electron source from ions of discharge plasma generated in the hermetic container, An opening for allowing electrons emitted from the electron source to pass therethrough is provided, and the secondary electron emission portion is composed of at least a part of a protective cover.

  According to the present invention, the electron source can be protected from the ions of the discharge plasma by the protective cover, and the lifetime can be further improved and the reliability can be improved. Since it is composed of at least a part, the secondary electron emission part and the protective cover are separated from each other as compared with the case where the secondary electron emission part and the protective cover are separate from each other. Variations in the amount of electrons can be eliminated and manufacturing is facilitated.

  According to an eighth aspect of the present invention, in the first to sixth aspects of the present invention, a plurality of the secondary electron emission portions are provided in the hermetic container.

  According to the present invention, since the amount of secondary electrons supplied into the gas can be increased, the amount of electrons emitted from the electron source can be further reduced, and the life and reliability can be further increased. Can improve the performance.

  The invention of claim 1 has the effect that the lifetime can be extended and the reliability can be improved as compared with the conventional case.

(Embodiment 1)
The light-emitting device in the present embodiment is an ultraviolet lamp, and is disposed in an airtight container 1 in which a gas (for example, a rare gas such as Xe) as a discharge medium is sealed, as shown in FIG. A pair of electrodes 2a and 2a for discharging the gas to generate discharge plasma in the plasma generation space 3 in the hermetic vessel 1, and an electron source 10 arranged in the hermetic vessel 1 and supplying electrons into the gas. And a material (for example, Cs, Ag, BaO, MgO, amorphous carbon, diamond, etc.) that is disposed in the hermetic container 1 and emits secondary electrons into the gas by collision of electrons emitted from the electron source 10. The secondary electron emission unit 20 is provided, and ultraviolet rays can be emitted by discharging the gas in the hermetic container 1. Here, the ultraviolet lamp in the present embodiment is a straight tube type ultraviolet lamp, and the hermetic container 1 is formed in a cylindrical shape by a translucent material (for example, glass, translucent ceramic, etc.), and is in the longitudinal direction. The above-mentioned electrodes 2a and 2a are respectively disposed in both ends of the first electrode 2a, the secondary electron emission unit 20 is disposed on the side of one electrode 2a, and the position farther from the plasma generation space 3 than the secondary electron emission unit 20 is. The electron source 10 is arranged on the front side.

  In the light emitting device according to the present embodiment, by driving the electron source 10, electrons emitted from the electron source 10 and secondary electrons emitted from the secondary electron emission unit 20 are supplied into the gas (note that 1, the arrow on the right side of the electron source 10 indicates the flow of electrons emitted from the electron source 10, and the arrow on the right side of the secondary electron emission unit 20 in FIG. (The flow of electrons passing through the electron emission unit 20 and secondary electrons emitted from the secondary electron emission unit 20 is shown), so that the electron source 10 is driven before a voltage is applied between the pair of electrodes 2a and 2a. By starting the process and supplying electrons to the gas, the discharge start voltage, which is the voltage between the electrodes 2a and 2a necessary for starting the discharge, can be reduced, and the voltage between the pair of electrodes 2a and 2a can be reduced. Even after applying voltage to the electron source 1 With attained stabilization of the discharge plasma when to drive the discharge sustain voltage can be reduced, whereby power consumption can be reduced.

  Here, in the present embodiment, a pair of electrodes 2a and 2a are arranged inside the hermetic container 1, and constitute energy supply means for supplying energy for discharging the gas and generating discharge plasma. The source 10 and the secondary electron emission unit 20 constitute a discharge plasma generation assisting device that assists the generation of discharge plasma.

  As shown in FIG. 2A, the electron source 10 has a rectangular film-like insulating substrate (for example, an insulating glass substrate, an insulating ceramic substrate) 11 on a surface of a metal film (for example, , A tungsten film or the like), a strong electric field drift layer 6 is formed on the lower electrode 12, and a surface electrode 7 made of a metal thin film (for example, a gold thin film) is formed on the strong electric field drift layer 6. Has been.

  In the electron source 10 in the present embodiment, the strong electric field drift layer 6 constitutes an electron passage layer, and electrons are emitted through the surface electrode 7 by the lower electrode 12, the strong electric field drift layer 6 as the electron passage layer, and the surface electrode 7. The electron source element 10a is configured.

  As shown in FIG. 2B, the strong electric field drift layer 6 of the electron source element 10a includes at least columnar polycrystalline silicon grains (semiconductor crystals) 51 arranged on the surface side of the lower electrode 12, and grains. A thin silicon oxide film 52 formed on the surface of the silicon 51, a number of nanometer-order silicon microcrystals (semiconductor microcrystals) 63 interposed between the grains 51, and a silicon microcrystal 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 crystal grain size of 63. Here, each grain 51 extends in the thickness direction of the lower electrode 12 (that is, extends in the thickness direction of the insulating substrate 11).

In order to emit electrons from the above-described electron source element 10a, a driving voltage is applied between the surface electrode 7 and the lower electrode 12 by a driving power source so that the surface electrode 7 is on the high potential side with respect to the lower electrode 12. The electrons injected from the lower electrode 12 into the strong electric field drift layer 6 drift through the strong electric field drift layer 6 and are emitted through the surface electrode 7 (the arrow in FIG. 2B is emitted through the surface electrode 7). electronic e ^- shows the flow of).

  Here, in the electron source element 10a in the present embodiment, electrons can be emitted even when the driving voltage applied between the surface electrode 7 and the lower electrode 12 is a low voltage of about 10 to 20V. The electron source element 10a of the present embodiment is characterized in that the electron emission characteristics are less dependent on the degree of vacuum, and a popping phenomenon does not occur during electron emission, and electrons can be stably emitted with high electron emission efficiency. Have. The driving voltage applied to the electron source 10 may be a constant DC voltage or a pulsed voltage. When the drive voltage is a pulse voltage, a reverse bias voltage may be applied when the drive voltage is not applied.

The basic configuration of the electron source element 10a in this embodiment is well known, and it is considered that electron emission occurs in the following model. That is, by applying a voltage between the surface electrode 7 and the lower electrode 12 with the surface electrode 7 set to the high potential side, electrons e ⁻ are injected from the lower electrode 12 into the strong electric field drift layer 6. On the other hand, since most of the electric field applied to the strong electric field drift layer 6 is applied to the silicon oxide film 64, the injected electrons e ⁻ are accelerated by the strong electric field applied to the silicon oxide film 64, and the strong electric field drift layer 6. 2 drifts in the direction of the arrow in FIG. 2B (upward in FIG. 2B) toward the surface and tunnels through the surface electrode 7 and is emitted. Thus, in the strong electric field drift layer 6, electrons injected from the lower electrode 12 are almost scattered by the silicon microcrystal 63, are accelerated by the electric field applied to the silicon oxide film 64, and drift through the surface electrode 7. Since the heat generated in the strong electric field drift layer 6 is dissipated through the grains 51, no popping phenomenon occurs during electron emission, and electrons can be stably emitted.

  In the above-described strong electric field drift layer 6, the silicon oxide film 64 constitutes an insulating film and an oxidation process is employed for forming the insulating film, but a nitriding process or an oxynitriding process is employed instead of the oxidation process. Alternatively, when the nitriding process is adopted, each of the silicon oxide films 52 and 64 becomes a silicon nitride film, and when the oxynitriding process is adopted, each of the silicon oxide films 52 and 64 is silicon oxynitride. Become a film.

  By the way, as described above, the secondary electron emission unit 20 disposed in the plasma generation space 3 which is a space where discharge plasma is generated in the hermetic vessel 1 is a secondary electron emission film made of a material that emits secondary electrons. Is installed on the base material 21 shown in FIG. In addition, although the base material 21 shown to Fig.3 (a) forms many circular holes 21b in the flat plate member 21a, the shape of the base material 21 is not specifically limited, For example, As shown in FIG. 3 (b), a flat plate member 21a may be formed with a number of rectangular holes 21b, or may have a mesh shape as shown in FIG. 3 (c). If a secondary electron emission film is deposited on at least the surface facing the electron source 10, electrons and secondary electrons emitted from the electron source 10 into the space on the base 21 opposite to the electron source 10 side are provided. Secondary electrons emitted from the emission film can be supplied. Moreover, although the base material 21 shown to Fig.3 (a) forms the above-mentioned hole 21b in the flat plate member 21a as shown to Fig.4 (a), as shown to FIG.4 (b). The aforementioned hole 21b may be formed in the curved plate member 21a, or the aforementioned hole 21b may be formed in the spherical plate member 21a as shown in FIG. 4A, 4B, and 4C are schematic side views of the plate member 21a.

  Therefore, in the discharge plasma generation assisting device of the present embodiment, since the electron source 10 and the secondary electron emission unit 20 are provided in the hermetic container 1, only the electrons emitted from the electron source 10 into the gas. In addition, secondary electrons emitted from the secondary electron emission unit 20 are also supplied, and the electron source 10 has a smaller amount of emitted electrons than the conventional configuration in which electrons are supplied only from the electron source 10. It is possible to drive under moderately gentle driving conditions, and it is possible to extend the life and improve the reliability compared to the conventional configuration. In addition, since the secondary electron emission unit 20 is disposed in the space where the discharge plasma is generated in the hermetic vessel 1, the secondary electron emission unit 20 also generates secondary electrons when the electrons in the discharge plasma collide with each other. As a result, the amount of electron emission from the electron source 10 can be reduced, and the lifetime can be extended and the reliability can be improved.

  Here, the base material 21 of the secondary electron emission unit 20 is formed of a conductive material (for example, nickel, stainless steel, aluminum, etc.), a driving voltage is applied to the electron source element 10a, and the secondary electron emission unit If an acceleration voltage is applied between the base material 21 and the surface electrode 7 so that the 20 base materials 21 are on the high potential side with respect to the surface electrode 7, the electron source element 10a is driven by the drive voltage. Then, electrons are emitted through the surface electrode 7, and the electrons emitted through the surface electrode 7 are accelerated by the acceleration voltage and irradiated to the secondary electron emission film. Therefore, the secondary voltage can be appropriately set by appropriately setting the acceleration voltage. Since the electron efficiency can be increased and the amount of secondary electrons emitted can be increased, the amount of electrons emitted from the electron source 10 can be reduced, and the lifetime and reliability of the electron source 10 can be increased. Hakare improved, consequently, thereby improving the long service life and reliability of the discharge plasma generating an auxiliary device.

(Embodiment 2)
The basic configuration of the light emitting device and the discharge plasma generation auxiliary device in the present embodiment is substantially the same as that in the first embodiment, and as shown in FIG. 5, the secondary electron emission unit 20 is one of a pair of electrodes 2a and 2a. This is characterized in that it also serves as the electrode 2a (left electrode 2a in FIG. 5). In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  Thus, in the discharge plasma generation auxiliary device of this embodiment, since the secondary electron emission unit 20 also serves as the one electrode 2a, the number of parts of the light emitting device is reduced, the structure is simplified, and the manufacturing process is simplified. As a result, the cost of the light emitting device can be reduced.

(Embodiment 3)
The basic configuration of the light emitting device and the discharge plasma generation auxiliary device in the present embodiment is substantially the same as that in the first embodiment, and is arranged so as to surround the electron source 10 as shown in FIG. Since the other structure is the same as that of Embodiment 1, the illustration and description are omitted.

  The protective cover 30 is formed in a rectangular parallelepiped shape that is opened on one surface by an insulating material (for example, an insulating resin such as a fluorine-based resin, an insulating ceramic, etc.). An opening 31 through which electrons emitted from the electron source 10 pass is provided. Further, in the present embodiment, since the secondary electron emission unit 20 is disposed so as to overlap the front wall of the protective cover 30, the secondary electron emission unit 20 is discharged while the electron source 10 is not exposed to the discharge plasma. Can be exposed to plasma. As the secondary electron emission unit 20, for example, a mesh-like base material 21 (FIG. 3C) described in the first embodiment and a secondary electron emission film may be used. Is appropriately set, it is possible to pass electrons from the electron source 10 and to protect the electron source 10 from discharge plasma ions.

  In the secondary electron emission unit 20, the base material 21 is formed of a conductive material, and the potential of the secondary electron emission unit 20 is the same as that of the surface electrode 7 (see FIG. 2) of the electron source 10 or a surface electrode. It is preferable to set appropriately so as to be a high potential with respect to 7. Here, the secondary electron emission portion 20 is set to the same potential as the surface electrode 7 of the electron source 10 so that the electrons emitted from the electron source 10 can sufficiently pass through, while the mesh-like secondary electron emission portion is passed. It is possible to prevent the plasma from entering the protective cover 30 through 20 and giving an impact to the electron source 10.

  Thus, according to the discharge plasma generation assisting device of the present embodiment, the electron source 10 can be protected from the ions of the discharge plasma by the protective cover 30, and the life can be further improved and the reliability can be further improved.

(Embodiment 4)
The basic configuration of the light emitting device and the discharge plasma generation assisting device in this embodiment is substantially the same as that of the third embodiment, and the secondary electron emission unit 20 is placed in the opening 31 of the protective cover 30 as shown in FIG. The difference is that they are arranged and serve as one of the pair of electrodes 2a, 2a. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 3, and description is abbreviate | omitted.

  Thus, according to the discharge plasma generation assisting device of the present embodiment, since the secondary electron emission unit 20 also serves as the one electrode 2a, the number of parts of the light emitting device can be reduced, the structure can be simplified, and the manufacturing process can be performed. Simplification can be achieved, and as a result, the cost of the light-emitting device can be reduced.

(Embodiment 5)
The basic configuration of the light emitting device and the discharge plasma generation auxiliary device in the present embodiment is substantially the same as that in the third embodiment, and as shown in FIG. 8, the secondary electron emission portion 20 is formed in the protective cover 30 and the opening portion 31 is formed. The point that the protective member 40 made of a conductive material is disposed on the front surface of the protective cover 30 facing the electron source 10 on the side facing the electron source 10. Is different. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 3, and description is abbreviate | omitted.

  Therefore, according to the discharge plasma generation auxiliary device of the present embodiment, the secondary electron emission unit 20 can be more reliably exposed to the discharge plasma. Here, a voltage is applied between the secondary electron emission unit 20 and the protection member 40 so that the secondary electron emission unit 20 has a high potential with respect to the protection member 40, and the applied voltage is set as the secondary electron. If the secondary electron emission efficiency in the emission part 20 is set to be substantially the maximum value, secondary electrons can be generated efficiently, so that the amount of electrons emitted from the electron source 10 can be further reduced. Also. In the discharge plasma generation auxiliary device of this embodiment, the potential of the protection member 40 is set as appropriate so that the potential of the protection member 40 is the same as that of the electron source 10 or the potential of the protection member 40 is higher than the surface electrode 7 of the electron source 10. Thus, it is possible to prevent the plasma from entering the protective cover 30 through the mesh-like protective member 40 and giving an impact to the electron source 10 while allowing the electrons emitted from the electron source 10 to pass sufficiently. It becomes possible.

  By the way, in Embodiment 3-5 mentioned above, although the protective cover 30 and the secondary electron emission part 20 are separate bodies, it is made to comprise the secondary electron emission part 20 by at least one part of the protection cover 30. FIG. If such a configuration is adopted, the electron source 10 can be protected from the ions of the discharge plasma by the protective cover 30, and the lifetime can be further improved and the reliability can be improved. Compared with the case where the electron emission unit 20 and the protective cover 30 are separate, the variation in the amount of secondary electrons due to the relative positional relationship between the secondary electron emission unit 20 and the protective cover 30 is eliminated. And easy to manufacture.

(Embodiment 6)
The basic configurations of the light emitting device and the discharge plasma generation auxiliary device in this embodiment are substantially the same as those in the fifth embodiment, and are different in that a plurality of secondary electron emission portions 20 are provided as shown in FIG. Here, in the present embodiment, three mesh-shaped secondary electron emission portions 20 are arranged along the normal direction of the electron emission surface (the upper surface in FIG. 9) of the electron source 10. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 5, and description is abbreviate | omitted.

  Therefore, according to the discharge plasma generation auxiliary device of the present embodiment, the amount of secondary electrons supplied into the gas can be increased, so that the amount of electrons emitted from the electron source 10 can be further reduced. It is possible to extend the life and improve the reliability. In the present embodiment, the plurality of secondary electron emission portions 20 are arranged along the normal direction of the electron emission surface of the electron source 10, but may be arranged in parallel in a plane parallel to the electron emission surface. Good.

  Further, in the discharge plasma generation assisting device of the present embodiment, the potential of each of the plurality of secondary electron emission portions 20 arranged along the normal direction of the electron emission surface of the electron source 10 increases as the distance from the electron source 10 increases. If so, the multiplication effect of secondary electron emission occurs, so that the amount of secondary electrons emitted can be increased and the amount of electrons emitted from the electron source 10 can be further reduced. In other embodiments, a plurality of secondary electron emission portions 20 may be provided.

  By the way, in each said embodiment, although the airtight container 1 is made into the cylindrical shape, the shape of the airtight container 1 is not restricted to a cylindrical shape, For example, a spherical shape like a light bulb may be sufficient, and a rectangular parallelepiped shape It may be a shape, a cubic shape, or the like, or a flat type airtight container constituted by a pair of flat plates and a frame interposed between the flat plates.

  Further, in each of the above embodiments, as the energy supply means, a pair of electrodes 2a and 2a are arranged inside the cylindrical airtight container 1 so as to be separated from each other in the longitudinal direction of the airtight container 1 as shown in FIG. However, the arrangement and configuration of the energy supply means are not particularly limited. For example, the energy supply means is disposed close to the airtight container 1 outside the cylindrical airtight container 1 as shown in FIG. A pair of planar shapes arranged along the longitudinal direction of the hermetic container 1 outside the cylindrical hermetic container 1 as shown in FIG. 10 (c). The electrodes 2b and 2b may be configured, or as shown in FIG. 10 (d), the electrode 2a disposed at one end in the longitudinal direction inside the hermetic container 1 and the hermetic container 1 outside the hermetic container 1 Planar shape arranged along the longitudinal direction The electrode 2b may be configured, or as shown in FIG. 10 (e), two electrodes 2a and 2a arranged in the cylindrical airtight container 1 one at each of both ends in the longitudinal direction and the airtight It may be composed of at least one (two in the illustrated example) annular electrode 2b arranged outside the container 1, or a cylindrical airtight container 1 as shown in FIG. It may be constituted by two pairs of electrodes 2a, 2a, 2a, 2a arranged inside, or as shown in FIG. 10 (g), in the longitudinal direction of the airtight container 1 outside the cylindrical airtight container 1. It may be constituted by a plurality (five in the illustrated example) of annular electrodes 2b arranged at a predetermined interval, or as shown in FIG. 10 (h), the airtightness is outside the cylindrical airtight container 1. A plurality (in the example shown in the figure,) arranged at predetermined intervals in the longitudinal direction of the container 1 Or a pair of electrodes 2a and 2a arranged inside a rectangular parallelepiped airtight container 1 as shown in FIG. 10 (i). As shown in FIG. 10 (j), a pair of electrodes 2a and 2a arranged in parallel in the airtight container 1 may be used.

  Note that the voltage applied to the energy supply means may be appropriately selected from a DC voltage, an AC voltage, a pulse voltage, and the like. Here, as the energy supply means, when a plurality of electrodes 2b are arranged at predetermined intervals in the longitudinal direction of the hermetic container 1 as shown in FIG. 10 (g), for example, FIG. As shown in FIGS. 11 (b) and 11 (c), as shown in FIGS. 11 (b) and 11 (c), as shown in FIGS. 11 (b) and 11 (c), as shown in FIGS. When the rectangular dimension AC voltage V1 applied to one electrode group and the rectangular waveform AC voltage V2 applied to the other electrode group have opposite phases, the longitudinal dimension of the hermetic container 1 is relatively long. However, it is possible to generate discharge plasma over substantially the entire length in the hermetic vessel 1. Similarly, when the plurality of electrodes 2b are arranged at predetermined intervals in the longitudinal direction of the hermetic container 1 as shown in FIG. 10H, for example, as shown in FIG. As shown in FIGS. 12 (b) and 12 (c), the rectangular electrodes are applied to one electrode group and applied to the other electrode group as shown in FIGS. 12 (b) and 12 (c). The rectangular wave AC voltage V2 may be in an opposite phase.

  In each of the above embodiments, the ultraviolet lamp is exemplified as the light emitting device. However, the light emitting device is not limited to the ultraviolet lamp, and may be, for example, a fluorescent lamp for illumination or a plasma display panel. As shown in FIG. 13, a phosphor layer 5 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. 13, the discharge plasma generation auxiliary device is not shown). is there).

  Moreover, in each said embodiment, although the ultraviolet lamp is illustrated as a light-emitting device and the airtight container 1 is formed with the translucent material, the discharge plasma production | generation auxiliary | assistance apparatus of this invention is shown in FIG.14 and FIG.15. As described above, it is also possible to apply to a light emitting device in which only a part of the airtight container 1 is formed by the light transmitting plate 1b made of a light transmitting material (for example, glass). In the light emitting device of FIG. 14, ultraviolet rays are radiated to the outside of the airtight container 1 through the light transmitting plate 1b. In the light emitting device of FIG. 15, visible light emitted from the phosphor layer 5 passes through the light transmitting plate 1b. Radiated to the outside.

  Moreover, in each said embodiment, although the shape of the airtight container 1 is a cylindrical shape, as shown in FIG. 16, for example, the airtight container 1 is made into a rectangular parallelepiped shape, and the secondary electron emission part 20 is made into an electron source. 10 is arranged in an oblique direction with respect to the electron emission surface (lower surface in FIG. 16), only the secondary electron emission unit 20 is exposed to the plasma generation space 3, and the electron source 10 is removed from the plasma generation space 3. It is possible to dispose the electron source 10 so that the electron emission surface of the electron source 10 is not easily exposed to the discharge plasma generated in the plasma generation space 3, and the electron source 10 is damaged by the ions of the discharge plasma. Therefore, it is possible to extend the life and improve the reliability.

Further, in the light emitting device in each of the above embodiments, Xe gas is adopted as the gas sealed in the hermetic container 1, but the gas sealed in the hermetic container 1 is not limited to Xe gas. Any gas that causes discharge by supplying energy such as Ar gas, He gas, Ne gas, Kr gas, N ₂ gas, CO gas, Hg vapor, or a mixed gas thereof may be used.

  In the electron source 10 in each of the above-described embodiments, the lower electrode 12 is formed on the one surface side of the insulating substrate 11, but a semiconductor substrate such as a silicon substrate is used instead of the insulating substrate 11, You may make it comprise a lower electrode with the electroconductive layer (for example, ohmic electrode) laminated | stacked on the back surface side of the said semiconductor substrate. The electron source 10 in each of the above embodiments is an electron source that emits electrons by a ballistic electron emission phenomenon and is called a ballistic electron surface-emitting device (BSD). The electron source 10 is not limited to BSD. For example, an MIM type electron source that employs an insulator layer instead of the strong electric field drift layer 6 as the above-described electron passage layer, or a strong electric field drift layer 6 as the above-described electron passage layer. Instead, a so-called MIS type electron source employing a semiconductor layer on the lower electrode 12 side and an insulator layer on the surface electrode 7 side can be used at a low vacuum like BSD. The lifetime of the electron source 10 can be increased and the reliability can be improved as compared with the case where a Spindt-type electrode is employed. In addition, since the energy of emitted electrons is relatively large in BSD, it is advantageous in terms of reducing the discharge start voltage and the discharge sustain voltage.

It is a schematic block diagram of the light-emitting device using the discharge plasma production auxiliary device in Embodiment 1. It is explanatory drawing of the electron source in the same as the above. It is explanatory drawing of the base material of the secondary electron emission part in the same as the above. It is explanatory drawing of the base material of the secondary electron emission part in the same as the above. It is a schematic block diagram of the light-emitting device using the discharge plasma production auxiliary | assistance apparatus in Embodiment 2. FIG. It is a schematic block diagram of the discharge plasma production auxiliary | assistance apparatus in Embodiment 3. It is a schematic block diagram of the light-emitting device using the discharge plasma production auxiliary | assistance apparatus in Embodiment 4. It is a schematic block diagram of the discharge plasma production auxiliary | assistance apparatus in Embodiment 5. FIG. It is a schematic block diagram of the discharge plasma production auxiliary | assistance apparatus in Embodiment 6. It is explanatory drawing of the structural example of the energy supply means in a light-emitting device. It is explanatory drawing of the structural example of the energy supply means in a light-emitting device. It is explanatory drawing of the structural example of the energy supply means in a light-emitting device. It is a schematic block diagram of the other structural example of a light-emitting device. It is a schematic block diagram of the other structural example of a light-emitting device. It is a schematic block diagram of the other structural example of a light-emitting device. It is a schematic block diagram of the other structural example of a light-emitting device.

Explanation of symbols

1 Airtight container 2a, 2a Electrode (energy supply means)
3 Plasma generation space 10 Electron source 20 Secondary electron emission part 30 Protective cover 31 Opening part

Claims (8)

  An airtight container in which a gas as a discharge medium is sealed, and an energy supply unit that is disposed in at least one of the inside and the outside of the airtight container and supplies energy for generating discharge plasma by discharging the gas. A discharge plasma generation assisting device that is used in a light emitting device and assists the generation of discharge plasma, and is disposed in an airtight container and supplies electrons into the gas, and is disposed in the airtight container and emitted from the electron source. And a secondary electron emission unit that emits secondary electrons into the gas by collision of electrons.   2. The discharge plasma generation auxiliary device according to claim 1, wherein the secondary electron emission unit is disposed in a space where discharge plasma is generated in the hermetic vessel.   3. The discharge plasma generation auxiliary device according to claim 2, further comprising an electrode disposed in the hermetic container as the energy supply means, wherein the secondary electron emission unit also serves as an electrode.   3. The discharge plasma generation auxiliary device according to claim 2, wherein the secondary electron emission portion is arranged in an oblique direction of an electron emission surface of the electron source.   A protective cover is provided so as to surround the electron source in the hermetic container and protects the electron source from ions of discharge plasma generated in the hermetic container, and the protective cover includes electrons emitted from the electron source. The discharge according to any one of claims 1 to 3, wherein an opening through which the gas passes is provided, and the secondary electron emission unit is disposed in the opening of the protective cover. Plasma generation assist device.   A protective cover is provided so as to surround the electron source in the hermetic container and protects the electron source from ions of discharge plasma generated in the hermetic container, and the protective cover includes electrons emitted from the electron source. The discharge plasma generation according to any one of claims 1 to 3, wherein an opening through which the gas passes is provided, and the secondary electron emission portion is disposed outside a protective cover. Auxiliary device.   A protective cover is provided so as to surround the electron source in the hermetic container and protects the electron source from ions of discharge plasma generated in the hermetic container, and the protective cover includes electrons emitted from the electron source. 4. The discharge plasma generation assisting device according to claim 1, wherein an opening through which the gas passes is provided, and the secondary electron emission unit is formed of at least a part of a protective cover. apparatus.   The discharge plasma generation auxiliary device according to any one of claims 1 to 6, wherein a plurality of the secondary electron emission portions are provided in the hermetic vessel.

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