JP2014096239A - Microwave discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microwave discharge lamp lighting device using a solid-state element power supply capable of reducing an operation frequency without increasing the size of the device and that is long in life and low in cost.SOLUTION: The microwave discharge lamp lighting device comprises: a metal chamber 10; a discharge lamp 30 that is disposed in the chamber, and that has a light-emission part 31 having a discharge space 31a therein, first and second encapsulation parts 32r and 32f sandwiching the light-emission part, and first and second electrode members 36r and 36f respectively buried in the first and second encapsulation parts so that each front end part is protruded into the discharge space; an antenna 20 connected with the first electrode member, and guiding a microwave introduced from the chamber exterior to the discharge lamp; and a metal member 50 disposed in the vicinity of the second encapsulation part, and electrically connected with the chamber.

Description

  The present invention relates to a microwave discharge lamp lighting device.

  Patent Document 1 discloses a microwave discharge lamp device that operates using a microwave of 2.45 GHz. The discharge lamp of the literature consists of a discharge vessel (10B) and an antenna portion (10D) provided so that one end protrudes into the discharge vessel and the other end is exposed to the outside of the discharge vessel. Further, the lighting device of the same document includes a waveguide part (14) connected to an antenna part, and the waveguide part includes an inner cylindrical member (14A) and an outer cylindrical member (14B), and electromagnetic waves are generated between the two members. The electromagnetic wave from the part to the discharge lamp is guided. And in the same document, in order to improve the luminous efficiency, a configuration is disclosed in which a high impedance portion is provided in a portion located in the discharge vessel of the antenna, and the microwave is locally concentrated near the tip of the antenna. .

  Patent Document 2 discloses a microwave discharge lamp having a metal chamber. In this document, a lamp (1) and an impedance adjusting mechanism (10) are arranged in a metal chamber (7) for preventing leakage of microwaves. In the impedance adjustment mechanism, impedance matching is performed by adjusting the dimensions of the inner conductor and outer conductor of the coaxial line connected to the lamp. In this document, the operating frequency is 2.45 GHz.

JP 2007-115534 A JP 2009-181762 A

  By the way, as disclosed in Patent Document 1, a microwave of 2.45 GHz has generally been used in a microwave discharge lamp. There are two types of 2.45 GHz microwave power sources: a power source using a solid element (semiconductor) and a power source including a magnetron. Here, a power source using a solid element has low efficiency and is expensive, while a magnetron has a problem that it is inexpensive but has a short life. Therefore, it is desired to realize a microwave discharge lamp device using a low-frequency (100 MHz to 1 GHz) solid-state power source that has a long life and is inexpensive as an alternative to the 2.45 GHz power source.

  However, in general, when the frequency of the microwave guided to the lamp is lowered, the wavelength becomes longer. Therefore, in order to obtain appropriate impedance matching, it is necessary to increase the dimensions of the discharge lamp and the chamber covering the discharge lamp. According to Patent Document 1 that discloses an apparatus having no chamber, it is taught that the length of the projecting portion (which occupies most of the discharge lamp) is 1/4 of the wavelength λ is efficient. Yes. Further, in the case of an apparatus in which a discharge lamp is arranged in a chamber as in Patent Document 2, it is necessary to enlarge the chamber as the operating frequency decreases. For the capacitive component 1 / (ωC) of the impedance component, it is necessary to increase the capacity (C) of the entire apparatus in order to compensate for the decrease in the frequency (ω = 2πf). It is necessary to do. As described above, in the microwave discharge lamp lighting device, there is a problem that the device becomes large when the operating frequency is lowered.

  Therefore, an object of the present invention is to provide a device using a solid-state power supply that has a long life and is low in cost, without increasing the size of the device, in a microwave discharge lamp lighting device.

  The microwave discharge lamp lighting device according to the present invention includes a metal chamber, a light emitting part disposed in the chamber and having a discharge space therein, and first and second sandwiching the light emitting part. A discharge lamp having a sealing portion, and first and second electrode members embedded in the first and second sealing portions, respectively, such that a tip portion projects into the discharge space; and a first electrode member And an antenna that guides microwaves introduced from the outside of the chamber to the discharge lamp, and a metal member that is disposed in proximity to the second sealing portion and is electrically connected to the chamber. With this configuration, the operating frequency can be lowered without increasing the size of the microwave discharge lamp lighting device.

  Here, the metal member may be a metal sleeve placed on the second sealing portion. Further, the metal member may be a metal wire wound around the second sealing portion. With this configuration, the microwave discharge lamp lighting device can be realized with a simple configuration. Further, flexible adjustment is possible by using the metal member as one element for impedance matching adjustment.

  The metal member and the chamber are preferably connected by a metal wire. With this configuration, the microwave discharge lamp lighting device can be realized without impairing optical characteristics.

  Moreover, it is preferable that a metal member is arrange | positioned spaced apart from the light emission part. With this configuration, the microwave discharge lamp lighting device with high reliability can be realized by reliably preventing a back arc from the electrode in the light emitting portion toward the metal member.

  Moreover, it is preferable that the front-end | tip part of a 2nd sealing part is exposed from a metal member. With this configuration, it is possible to reliably prevent the failure of the discharge lamp due to the oxidation of the metal portion exposed from the second sealing portion and to realize the highly reliable microwave discharge lamp lighting device.

1 is a partial cross-sectional view showing a microwave discharge lamp lighting device according to a first embodiment of the present invention. It is a figure explaining the discharge lamp used in the 1st example. It is a fragmentary sectional view which shows the microwave discharge lamp lighting device by the 2nd Example of this invention. It is a fragmentary sectional view which shows the microwave discharge lamp lighting device by the 3rd Example of this invention. It is a fragmentary sectional view which shows the microwave discharge lamp lighting device by the 4th Example of this invention. It is a fragmentary sectional view explaining the microwave discharge lamp lighting device by the 3rd and 4th example of the present invention. It is sectional drawing which shows the microwave discharge lamp lighting device by the 1st modification of this invention. It is sectional drawing which shows the microwave discharge lamp lighting device by the 2nd modification of this invention. It is a fragmentary sectional view which shows the microwave discharge lamp lighting device by the 3rd modification of this invention. It is a fragmentary sectional view which shows the microwave discharge lamp lighting device by the 4th modification of this invention. It is a fragmentary sectional view showing a general microwave discharge lamp lighting device.

Example 1.
FIG. 1 is a partial sectional view of a microwave discharge lamp lighting device (hereinafter referred to as “lighting device”) according to a first embodiment of the present invention. The lighting device 1 includes a chamber 10, an antenna 20, a connector 25, a discharge lamp 30, a reflecting mirror 40, a sleeve 50 (metal member), and a connection member 51. In the following description, the light emission side (right direction in the figure) is referred to as the front, and the microwave introduction side (left direction in the figure) is referred to as the rear.

  The chamber 10 is made of metal and has a front lamp housing portion 11 and a rear antenna housing portion 12. The lamp housing part 11 has a reflector mounting part 11b provided on the inner wall of the side wall 11a. The reflecting mirror 40 is fixed to the reflecting mirror mounting portion 11b, and the emitted light from the discharge lamp 30 is taken out from the front opening 11c. In the present embodiment, a housing made of a substantially rectangular parallelepiped hollow body is shown as the lamp housing portion 11, but the lamp housing portion 11 may have a cylindrical shape or a polygonal tubular shape with the opening portion 11 c as a bottom surface.

  The antenna housing portion 12 is formed such that its inner wall has a predetermined separation distance from the antenna 20. The connector 25 comprises a coaxial transmission line, and an outer conductor of the connector 25 is coupled to the rear end face of the antenna housing portion 12, and the inner conductor of the connector 25 and the antenna 20 are connected so as to be able to guide microwave power. Microwave power is propagated to the connector 25 from a microwave generator (not shown). The microwave introduced into the chamber 10 is guided to a discharge lamp 30 described later via the antenna 20. Here, the input impedance to the discharge lamp 30 is determined by adjusting the separation distance between the inner wall of the antenna housing portion 12 and the antenna 20. That is, the antenna housing part 12 plays a role as an impedance adjustment part of the lighting device 1.

  FIG. 2 shows a schematic diagram of the discharge lamp 30. The discharge lamp 30 includes a light emitting portion 31, sealing portions 32r and 32f, electrodes 33r and 33f, metal foils 34r and 34f, and leads 35r and 35f. The light emitting portion 31 has a discharge space 31a formed therein, and a gas, mercury, or the like serving as a discharge material is sealed in the discharge space. The rear sealing portion 32r and the front sealing portion 32f are formed with the light emitting portion 31 interposed therebetween. The light emitting part 31 and the sealing parts 32r and 32f are made of quartz glass. The electrodes 33r and 33f are arranged so that one end of each of the electrodes 33r and 33f protrudes into the discharge space 31a, and the other end is embedded in the sealing portions 32r and 32f. The metal foils 34r and 34f are made of, for example, molybdenum foil, are embedded in the sealing portions 32r and 32f, and one end of each is joined to the other end of the electrodes 33r and 33f. Leads 35r and 35f are connected to the metal foils 34r and 34f, and the metal foil 34r is connected to the antenna 20 via the leads 35r. The lead 35f is cut at the end of the sealing portion 32f, but the lead 35f may be omitted. In this specification, the electrode 33r, the metal foil 34r, and the lead 35r are collectively referred to as an electrode member 36r, and the electrode 33f, the metal foil 34f, and the lead 35f (the electrode 33f and the metal foil 34f when there is no lead 35f). Are collectively referred to as an electrode member 36f.

  The reflecting mirror 40 is fixed to the reflecting mirror mounting portion 11b of the chamber 11 at the opening peripheral edge portion 40a. The sealing portion 32r of the discharge lamp 30 is fixed to the insertion portion of the neck portion 40b of the reflecting mirror 40 so that the light emitting portion 31 of the discharge lamp 30 is at a desired position in the optical design of the reflecting mirror 40.

  The sleeve 50 is a metal cylindrical member, and is covered with the sealing portion 32 f and electrically connected to the chamber 10 by the connection member 51. Since the sleeve 50 is exposed to a high temperature while the lamp is lit, it is desirable that the sleeve 50 be made of a material having a predetermined heat resistance. For example, the sleeve 50 may be made of stainless steel. By disposing the inner surface of the sleeve 50 and the outer surface of the sealing portion 32f so as to be close to each other, the sleeve 50 is disposed close to the sealing portion 32f. In the present specification, the term “closely arranged” includes being placed in contact with each other and being placed close to each other with a predetermined separation distance. The predetermined separation distance is assumed to be about 2 mm or less. Therefore, the inner surface of the sleeve 50 may be in contact with the outer surface of the sealing portion 32f, or there may be a gap between the outer surface of the sealing portion 32f. In short, the sleeve 50 may be disposed so as to form a desired degree of capacitive coupling with the electrode member 36f (particularly, the metal foil 34f) embedded in the sealing portion 32f.

  Regarding the positioning of the sleeve 50, the sealing portion 32f may support the gravity of the sleeve 50 (that is, the upper inner surface of the sleeve 50 is supported by the upper outer surface of the sealing portion 32f). The sleeve 50 may be positioned by rigidity. However, the inner diameter of the sleeve 50 is preferably slightly larger than the outer diameter of the sealing portion 32f. This is because the thermal expansion coefficient is different between the sleeve 50 made of metal and the sealing portion 32f made of glass, so that the stress that can be generated between the both in the heat cycle by turning on / off is reduced. Because.

  For example, the connecting member 51 may be formed of a metal wire such as aluminum or nickel, and may be formed of a plate-like member without being limited to the wire. The connecting member 51 may be joined to the sleeve 50 by welding or the like, and may be fixed to the chamber 10 by welding, screwing, a fitting structure or the like. That is, as long as the connection member 51 is configured to electrically connect the sleeve 50 and the chamber 10, any connection form may be used.

  When the connecting member 51 is made of a wire, the connecting member 51 is not shaded in the outgoing light reflected from the light emitting unit 31 to the reflecting mirror 40, which is preferable in terms of optical characteristics. On the other hand, when the connecting member 51 is formed of a plate-like member, variations in the shape and arrangement of the connecting member 51 and the position of the sleeve 50 held by the connecting member 51 are unlikely to occur, and the form of the connecting member 51 in impedance matching described later. This is preferable because the variation caused by the is reduced. Further, when the connecting member 51 is formed of a plate-like member, the radiant heat received by the sleeve 50 from the discharge lamp 30 can be radiated to the chamber 10 via the connecting member 51, and the temperature of the sleeve 50 or the sealing portion 32f increases. Can be suppressed.

  In the lighting device 1 configured as described above, the microwave guided from the microwave generator to the lamp 30 via the connector 25 and the antenna 20 generates an electric field in the discharge space 31a. By this electric field, the discharge substance enclosed in the discharge space 31a is ionized, and the light emitting unit 31 emits light. The intensity of the electric field generated in the discharge space 31a is adjusted by impedance matching.

  Here, the impedance matching can be adjusted by the separation distance, arrangement, and the like between the inner wall of the antenna housing portion 12 and the antenna 20 as described above. However, the amount of impedance adjustment required when the operating frequency is changed from 2.45 GHz to 450 MHz in a chamber of the same size cannot be obtained only by the amount of adjustment by the antenna accommodating portion 12. For example, in the lighting device 8 having a general configuration without the sleeve 50 and the connecting member 51 as shown in FIG. 11, assuming that impedance matching is taken at a frequency of 2.45 GHz, the absorption rate in the lighting device 8 is 90 to 90. It becomes about 95%. The absorptance is defined by the ratio of lamp power consumption to input power. The lower the absorptance, the higher the ratio of input power that is not used for lamp lighting and reflected by the lamp portion. Here, it is confirmed that when the lighting device 8 is operated at a frequency of 450 MHz, the above-described absorption rate is 20% or less even if the dimensions of the antenna housing portion 12 and the antenna 20 are adjusted to the maximum. Has been.

  On the other hand, in the lighting device 1 of the present embodiment, the sleeve 50 is disposed close to the sealing portion 32f, and the sleeve 50 is electrically connected to the chamber 10 by the connecting member 51, whereby the electrode member 32f and the sleeve 50 are connected. A capacitance is formed between them. That is, in the lighting device 1, the capacitive coupling between the electrode member 36 f and the chamber 10 is increased as compared with the lighting device 8. Therefore, in the impedance matching, with respect to the capacitive impedance component 1 / (ωC) between the electrode member 36f and the chamber 10, the increase in the coupling capacitance component by the sleeve 50 causes the decrease in ω due to the decrease in frequency to the capacitance component ( It can be compensated by an increase in C). Therefore, even in the lighting device 1 having the same size as the lighting device 8 for 2.45 GHz, impedance matching can be obtained at 450 MHz.

  When attention is paid to the variability of the capacitance formed between the electrode member 36f and the sleeve 50, the impedance matching can be adjusted by adjusting the capacitance. For example, the impedance matching can be adjusted by adjusting the size, shape, material, and the like of the sleeve 50. In the above description, the position where the sleeve 50 covers the sealing portion 32f is fixed in the optical axis direction, but the position may be variable in the optical axis direction. By making the axial position of the sleeve 50 variable, the capacitance between the sleeve 50 and the electrode member 36f can be made variable, and the variability of this capacitance can be used for fine adjustment of impedance matching. In particular, impedance matching based on the settings of the antenna housing portion 12 and the antenna 20 is a gradual adjustment based on the selection of the antenna housing portion 12 and the antenna 20, while impedance matching based on the axial position movement of the sleeve 50 is a linear adjustment. be able to.

Table 1 shows the measurement results of the absorptance using the lighting device 1 (this example) and the lighting device 8 (comparative example). The lamp housing 11, the discharge lamp 30 and the reflecting mirror 40 of the chamber 10 of the lighting device 1 and the lighting device 8 are the same. In the measurement, it is assumed that the inner diameter of the antenna housing portion 12 and the length of the antenna 20 are adjusted so that the absorption rate is maximized within a range that can be adjusted in each lighting device. The length and outer diameter of the sealing portion 32f in each lighting device are 25 mm and about 5.6 mm, respectively, and the length and inner diameter of the sleeve 50 in the lighting device 1 are 35 mm and 6 mm, respectively. Further, the connecting member 51 in the lighting device 1 is composed of a φ0.6 nickel wire.

  As shown in Table 1, in the lighting device 8 that can ensure an absorption rate of 90% or higher at a frequency of 2.45 GHz, even if the inner diameter of the antenna accommodating portion 12 and the length of the antenna 20 are changed within a possible range, Was confirmed to be 20% or less. On the other hand, in the lighting device 1 provided with the sleeve 50 and the connecting member 51 in the chamber 10 and the discharge lamp 30 that are substantially the same size as the lighting device 8, a high absorption rate (95%) can be realized at an operating frequency of 450 MHz. I understand that. It is confirmed that the absorptance of 94% can be achieved even when the length of the sleeve 50 is 25 mm and the connecting member 51 is composed of an aluminum plate having a width of 10 mm and a thickness of 4 mm (the thickness direction is arranged parallel to the light emitting direction). It was done. In this embodiment, the operating frequency is 450 MHz, but the operating frequency can be set to about 100 M to 1 GHz by appropriately adjusting impedance matching.

  Thus, according to the configuration of the present embodiment, a microwave discharge lamp device using a low-frequency solid-state power source that achieves low frequency without increasing the size of the lighting device and has a long life and is simple is configured. Can be realized.

Example 2
In the first embodiment, the metal member disposed in proximity to the sealing portion 32f is made of a metal sleeve, but in this embodiment, the metal member is made of a metal wire. FIG. 3 shows a partial cross-sectional view of the lighting device 2 according to the present embodiment. Since the lighting device 2 is the same as the lighting device 1 shown in FIG.

  As shown in FIG. 3, in this embodiment, the metal member is composed of a metal wire 52 wound spirally around the sealing portion 32f. According to this configuration, since the metal member can be configured simply by winding the metal wire 52 around the sealing portion 32f, the manufacture is easy. Further, by forming the metal wire 52 in a coil shape, it is possible to provide an inductor component for capacitive coupling between the electrode member 36f and the chamber 10. Therefore, elements such as the number of turns of the metal wire 52, the winding layer, and the density of the winding method can be used as one element of impedance matching, and impedance matching can be performed more flexibly.

  Further, when the connection member 51 and the metal wire 52 are made of the same metal wire, the metal wire 52 and the connection member 51 may be made of a series of wire materials. Thereby, the joining process of the metal member and the connection member 51 required in the first embodiment is not necessary, and the manufacture of the lighting device is further facilitated.

Example 3
In the first embodiment, the sleeve constituting the metal member is configured to cover the entire sealing portion 32f. However, in the present embodiment, an example in which the position of the rear end portion of the sleeve is devised is shown. FIG. 4 shows a partial cross-sectional view of the lighting device 3 according to this embodiment. Since the lighting device 3 is the same as the lighting device 1 shown in FIG. 1 except for the sleeve, its description is omitted.

  As shown in FIG. 4, in this embodiment, the metal member is formed of a sleeve 53, and the rear end portion 53 r of the sleeve 53 is spaced apart from the light emitting unit 31. As a result, it is possible to prevent a back arc that may occur when the rear end 53r is disposed close to the light emitting unit 31. The back arc is a discharge that can be generated from the front electrode 33f toward the rear end 53r, and can cause blackening or failure of the light emitting unit 31. Therefore, by ensuring the separation distance between the front electrode 33f and the rear end portion 53r, the back arc can be reliably prevented.

  The absorptance of the lighting device 3 was measured under the same conditions except for the measurement of the absorptance shown in Table 1 and the configuration of the sleeve. In this measurement, it is assumed that the inner diameter of the antenna housing portion 12 and the length of the antenna 20 are adjusted so that the absorption rate is maximized within the adjustable range. The length and inner diameter of the sleeve 53 were 20 mm and 6 mm, respectively, and the separation distance between the light emitting portion 31 and the rear end portion 53r of the sleeve 53 was 5 mm. The connecting member 51 was composed of an aluminum plate having a width of 10 mm and a thickness of 4 mm. As a result, an absorption rate of 94% was achieved.

  Thus, according to the configuration of the present embodiment, it is possible to prevent the back arc and improve the reliability of the discharge lamp 30 while obtaining the same effect as that of the first embodiment.

Example 4
In the first embodiment, the configuration in which the sleeve constituting the metal member covers the entire sealing portion 32f is shown, but in this embodiment, an example in which the position of the front end portion of the sleeve is devised is shown. FIG. 5 shows a partial cross-sectional view of the lighting device 4 according to the present embodiment. Since the lighting device 4 is the same as the lighting device 1 shown in FIG. 1 except for the sleeve, its description is omitted.

  When the sleeve covers the front end portion (front end portion) of the sealing portion 32f, the metal portion exposed from the sealing portion 32f, that is, the end portion of the lead 35f becomes high temperature and is oxidized. When the oxidation of the exposed metal portion proceeds, a crack may occur in the sealing portion, and this crack may cause problems such as impedance matching mismatch and lamp failure. Therefore, in this embodiment, as shown in FIG. 5, the sleeve 54 is configured such that the front end portion 54f does not cover the front end portion of the sealing portion 32f. That is, the front end portion of the sealing portion 32 f is exposed from the sleeve 54. This prevents the metal portion exposed from the sealing portion 32f from being oxidized due to high temperature.

  The absorptance of the lighting device 4 was measured under the same conditions except for the measurement of the absorptivity shown in Table 1 and the configuration of the sleeve. In this measurement, it is assumed that the inner diameter of the antenna housing portion 12 and the length of the antenna 20 are adjusted so that the absorption rate is maximized within the adjustable range. The length and inner diameter of the sleeve 54 were 15 mm and 6 mm, respectively, and the sleeve 54 was brought into contact with the light emitting portion 31. The connecting member 51 was composed of a φ0.6 nickel wire. As a result, an absorption rate of 93% was realized.

  Therefore, according to the configuration of this embodiment, it is possible to improve the reliability of the lamp 30 by preventing the oxidation of the metal exposed from the sealing portion 32f while obtaining the same effect as that of the first embodiment.

  Note that the third embodiment and the fourth embodiment can be implemented individually or in combination. That is, as in the lighting device 5 shown in FIG. 6, the rear end 55r of the sleeve 55 is separated from the light emitting portion 31, and the front end 55f of the sleeve 55 does not cover (expose the tip of the sealing portion 32f). ) Configuration is also possible. Further, in the second embodiment, the rear end portion of the metal wire 52 may be spaced apart from the light emitting portion 31, or the front end portion of the metal wire 52 may not cover the tip portion of the sealing portion 32f. Good.

  Although the preferred embodiments of the present invention have been described above, various modifications as described below are possible without departing from the spirit of the present invention.

Modification 1
In each of the above-described embodiments, the metal member (sleeve 50 or the like) disposed close to the sealing portion 32f is configured to cover the entire circumference of the sealing portion 32f, but a part of the periphery of the sealing portion 32f is open. It is good also as the shape made. For example, the metal member of the present modification example includes a sleeve having an opening along the optical axis direction. FIG. 7 shows a cross section perpendicular to the optical axis of the sleeve 56 and the sealing portion 32f in this modification. As shown in the figure, the cross section of the sleeve 56 has an arc shape having an open portion 56a.

  According to this modification, the inner diameter of the sleeve 56 and the outer diameter of the sealing portion 32f can be made substantially the same. As described above, when the sleeve covers the entire circumference of the sealing portion and the both diameters are the same, due to the difference in coefficient of thermal expansion between the sleeve made of metal and the sealing portion made of glass, A state in which stress is generated from the sleeve to the sealing portion during the heat cycle may occur. However, according to the configuration of this modification, the stress generated between the sleeve 56 and the sealing portion 32f is absorbed by opening and closing of the opening portion 56a of the sleeve 56, so that the stress between the sleeve 56 and the sealing portion 32f is reduced. Can be reduced. Thus, the sleeve 56 is reliably held by the sealing portion 32f by making the inner diameter of the sleeve 56 and the outer diameter of the sealing portion 32f substantially the same. As a result, the positioning accuracy of the sleeve 56 in the optical axis direction with respect to the sealing portion 32f can be improved, and displacement in the optical axis direction during use of the apparatus can be prevented.

Modification 2
In each of the above-described embodiments, the metal member (sleeve 50 or the like) disposed close to the sealing portion 32f is configured to cover the entire circumference of the sealing portion 32f, but covers a part of the periphery of the sealing portion 32f. It is good also as a structure. However, it is assumed that a desired capacity can be secured between the electrode member 36f and the metal member. In this modification, the metal member is made of a metal piece obtained by cutting a sleeve along the optical axis direction. In FIG. 8, the cross section perpendicular | vertical to the optical axis of the metal piece 57 and the sealing part 32f in this modification is shown. As shown in the figure, the cross section of the metal piece 57 has an arc shape of a semicircle or less.

  According to this modification, the separation distance between the electrode member 36f and the metal piece 57 can be adjusted. Thereby, for example, not only the position adjustment of the sleeve in the optical axis direction as shown in the first embodiment but also the separation distance can be adjusted, so that the adjustment range of impedance matching can be further expanded.

Modification 3
In each of the above-described embodiments, the connection member 51 is connected to the side wall 11a of the lamp accommodating portion 11 of the chamber 10, but may be configured to be connected to another location. For example, as shown in the partial cross-sectional view of the lighting device 6 in FIG. 9, when the metal mesh 13 is disposed in the opening 11 b of the chamber 10 in order to enhance prevention of microwave leakage, the connection member 51 is light It may be arranged parallel to the axis and connected to the metal mesh 13. With this configuration, the connection member 51 is positioned substantially symmetrically with respect to the optical axis, so that the light irradiation distribution can be made uniform with respect to the optical axis and the optical characteristics can be improved.

Modification 4
In each of the above embodiments, the metal member (sleeve 50 or the like) disposed in the vicinity of the sealing portion 32f is configured as a separate member from the sealing portion 32f, but the metal member and the sealing portion 32f are integrally formed. May be. For example, as shown in the partial cross-sectional view of the lighting device 7 in FIG. 10, the metal member may be a metal coating 58 formed on the sealing portion 32f. The metal coating 58 can be formed on the sealing portion 32f by vapor deposition, immersion, application, or the like. The connecting member 51 is disposed so as to contact the sealing portion 32f on which the metal coating 58 is applied. As shown in FIG. 10, when the connection member 51 is made of a metal wire, the vicinity of the tip of the metal wire may be wound around the sealing portion 32f.

  According to this modification, it is not necessary to consider the variation in positioning between the sealing portion 32f and the metal member. As a result, the metal member cannot be provided with an impedance matching adjustment function, but conversely, variations in impedance matching and fluctuations during use can be prevented.

  As described above, according to the present invention, the microwave discharge lamp lighting device includes the metal member that is disposed in the vicinity of the front-side sealing portion 32f and is electrically connected to the chamber 10, thereby increasing the size of the device. Therefore, it is possible to provide a device that uses a solid-state power supply that is low in operating frequency, long-life, and inexpensive.

1-7 Microwave discharge lamp lighting device 10 Chamber 20 Antenna 30 Discharge lamp 31 Light emitting part 31a Discharge space 32r, 32f Sealing part 36r, 36f Electrode member 50, 53-56 Sleeve (metal member)
51 Connection member 52 Metal wire (metal member)
57 Metal pieces (metal parts)
58 Metal coating (metal parts)

Claims (6)

A microwave discharge lamp lighting device,
A metal chamber;
A discharge lamp disposed in the chamber, wherein a light emitting part having a discharge space formed therein, first and second sealing parts sandwiching the light emitting part, and a tip projecting into the discharge space A discharge lamp having first and second electrode members embedded in the first and second sealing portions, respectively,
An antenna connected to the first electrode member and guiding a microwave introduced from outside the chamber to the discharge lamp;
A microwave discharge lamp lighting device comprising: a metal member disposed in proximity to the second sealing portion and electrically connected to the chamber.   The microwave discharge lamp lighting device according to claim 1, wherein the metal member is a metal sleeve that covers the second sealing portion.   The microwave discharge lamp lighting device according to claim 1, wherein the metal member is made of a metal wire wound around the second sealing portion.   The microwave discharge lamp lighting device according to any one of claims 1 to 3, wherein the metal member and the chamber are connected by a metal wire.   The microwave discharge lamp lighting device according to any one of claims 1 to 4, wherein the metal member is disposed separately from the light emitting unit.   The microwave discharge lamp lighting device according to any one of claims 1 to 5, wherein a tip end portion of the second sealing portion is exposed from the metal member.

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