JP3260354B2 - High pressure metal vapor discharge lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD The present invention relates to a high-pressure metal vapor discharge lamp having an arc tube made of a transparent ceramic.

[Background Art] Conventionally, as a high-pressure metal vapor discharge lamp of this type, FIG.
Is known which is equipped with a quartz arc tube shown in FIG. That is, an arc tube 34 made of quartz having a pair of main electrodes 31 and 32 and one auxiliary electrode 33 is provided inside, and one auxiliary electrode 33 is provided adjacent to one main electrode 32. ing. The light emitting tube 34 includes a light emitting portion 35 serving as a discharge space and sealing portions 3 provided at both ends thereof.
6, 37. The sealing portions 36 and 37 include electrode rods 38 and 39 holding the main electrodes 31 and 32 at the tips, respectively.
Metal foils 40 and 41 made of molybdenum with the rear ends of the electrode rods 38 and 39 connected to one end, and a metal foil 4 at one end.
External lead wires 42 and 43 to which the other ends of 0 and 41 are connected.
And a metal foil made of molybdenum with an auxiliary electrode rod 44 holding an auxiliary electrode 33 at the tip and a rear end of the auxiliary electrode rod 44 connected at one end. 45 and an external lead wire 46 having one end connected to the other end of the metal foil 45. The auxiliary electrode current supply conductor is integrated, and the main electrodes 31, 32 and the auxiliary electrode 33 at the end are light emitting parts. It is crush-sealed so as to be located within 35. Further, a Ne—N ₂ mixed gas is sealed in the outer tube 2.

In such a high-pressure metal vapor discharge lamp, an auxiliary discharge is first generated between one main electrode 32 and one auxiliary electrode 33 adjacent to the main electrode 32 at the time of starting. Thereafter, a transition is made to the main discharge between the main electrodes 31 and 32.

[0004] In particular, metal halide lamps, which are a kind of high-pressure metal vapor discharge lamps having such a configuration, have become mainstream as inexpensive ballasts for mercury lamps can be used as they are.

Japanese Patent Application Laid-Open No. Sho 62-62 concerning a ceramic discharge lamp
Japanese Patent Application Publication No. 150646 discloses a ceramic arc tube having the following configuration. That is, as shown in FIG. 10, the conductive cermet disks 53a and 53b holding the main electrode rods 52a and 52b at the end of the arc tube 51 are hermetically sealed, and the auxiliary electrode 54 is mainly provided on one disk 53a. The configuration held by the electrode rod 52a and the insulating layer 55 is shown.

Further, Japanese Patent Application Laid-Open No. H10-106491 related to a high-pressure metal vapor discharge lamp discloses the following configuration. That is, as shown in FIG. 11, a ceramic thin tube 63 in which electrode introduction wires 62a and 62b as electrode introduction bodies are sealed at both ends of a main tube 68 made of a translucent ceramic.
a, a translucent ceramic disk 64a provided with 63b,
A light emitting tube 61 is shown having a structure provided with a ceramic thin tube 63c for auxiliary electrodes on one disk 64a.

[0007] However, the above-mentioned various discharge lamps have the following problems.

In the conventional high-pressure metal vapor discharge lamp shown in FIG. 9 comprising an arc tube using quartz, the sealing portion of the arc tube is formed by crush-sealing at the time of manufacture. This variation in shape has caused variations in lamp characteristics.

If the shape of the sealing portion is large, heat loss from the discharge space of the arc tube becomes large, and it is difficult to obtain sufficient efficiency and high color rendering, so that the shape of the sealing portion is made as small as possible. There is a need. However, in the case of a quartz arc tube, since the metal foil 41 on the main electrode side and the metal foil 45 on the auxiliary electrode side must be sealed at a predetermined interval without being in contact with each other, the shape of the sealing portion 37 is changed. It was difficult to make it smaller.

This type of high-pressure metal vapor discharge lamp is used as a starting gas for the purpose of lowering the starting voltage at the start of discharge.
Ne-Ar mixed gas is used. However, since Ne transmits through quartz, which is a material for the arc tube, it is necessary to seal a mixed gas containing Ne into the outer tube 2 in order to prevent the transmission. However, when gas is sealed in the outer tube 2, heat loss from the arc tube 34 increases, and in order to obtain sufficient characteristics, it is necessary to increase the lamp tube wall load by tolerating the deterioration of the life characteristics to some extent. there were. Since such deterioration of the life characteristics is caused by a reaction between the quartz on the arc tube wall and the enclosed metal halide, it is possible to suppress the reaction between the quartz as the arc tube material and the encapsulated metal halide. Was desired.

On the other hand, in the case of a lamp described in JP-A-62-150646 in which ceramics are used for an arc tube,
Variations in the shape of the arc tube are suppressed, and an improvement in quality can be expected without depending on the presence or absence of gas in the outer tube. However, since the conductive cermet 56 having the auxiliary electrode 54 is hermetically sealed with the sealing material 57 at a location where the temperature becomes relatively high during the operation of the lamp, the arc tube leaks during lighting, or the sealing material and the encapsulated metal. Reaction is inevitable, and particularly in the case of a metal halide lamp using a metal halide as a luminescent metal, a severe reaction occurs.

Further, in the case of the lamp described in Japanese Patent Application Laid-Open No. H10-106491 in which the electrode-introducing body is sealed in a ceramic tube, the reaction between the sealing material and the sealing metal can be avoided. In order to obtain the reliability of the strength, it is difficult to shorten the distance between the main electrode 65a and the auxiliary electrode 66, and the shape of the end portion of the arc tube is restricted. difficult.

DISCLOSURE OF THE INVENTION [0013] The present invention has been made to solve such a problem, and prevents the occurrence of characteristic variations caused by variations in the shape of an arc tube, such as a quartz arc tube, Highly efficient and stable life characteristics independent of the presence or composition of gas in the outer tube can be obtained, suppressing characteristic changes due to leakage during lighting and reaction between the sealing material and the enclosure, and stable lamp starting characteristics. Another object of the present invention is to provide a high-pressure metal vapor discharge lamp which has a free arc tube design.

The high-pressure metal vapor discharge lamp according to the present invention has a light-transmitting ceramic light-emitting tube in which mercury, a rare gas and a light-emitting metal are sealed in an outer tube hermetically sealed by a stem. The pipe comprises: a main pipe; a first disk and a second disk integrated with openings at both ends of the main pipe; a thin pipe having two through holes integrated with the first disk; A thin tube having one through hole integrated with the disc, a pair of main electrodes disposed in the main tube, and an auxiliary electrode disposed in the main tube, wherein the pair of main electrodes are Each of the auxiliary electrodes is connected to an electrode introduction body sealed with a sealing material in a through hole of the thin tube, the auxiliary electrode is connected to an auxiliary electrode introduction body, and the auxiliary electrode introduction body connected to the auxiliary electrode is connected to the main electrode. Electrode introduction body connected to electrodes and electricity Characterized in that it is sealed by the sealing material in the through hole independently remainder of capillary having the two through holes. Further, the high-pressure metal vapor discharge lamp of the present invention has mercury and mercury in an outer tube hermetically sealed by a stem.
An arc tube made of translucent ceramics in which a rare gas and a luminous metal are sealed, wherein the arc tube has a main tube, a thin tube having two through holes provided at one end of the main tube, A thin tube having one through-hole disposed at the other end of the main tube, a pair of main electrodes disposed in the main tube, and an auxiliary electrode disposed in the main tube; Are respectively connected to an electrode introduction body sealed by a sealing material in a through hole of each of the thin tubes, and the auxiliary electrode is connected to the auxiliary electrode introduction body, and the auxiliary electrode introduction body connected to the auxiliary electrode. Is characterized in that the main electrode is sealed with a sealing material in the remaining through-hole of the narrow tube having the two through-holes electrically independently of the electrode introduction body to which the main electrode is connected.

With this configuration, unlike the conventional high-pressure metal vapor discharge lamp using a quartz arc tube, the shape variation of the arc tube, which cannot be avoided in the past, can be eliminated. Variation can be reduced. In addition, the reaction between the sealed metal and the arc tube can be suppressed, the variation in the optical characteristics of the lamp is small, and the characteristic change during the life can be reduced.

Further, it is possible to lower the temperature of the sealing material during lighting, it is easy to prevent the sealing material from eroding due to the reaction between the encapsulating metal and the sealing material, and it is possible to reduce the temperature of the conventional sealing portion. Reliability can be increased.

Further, since the auxiliary electrode introduction body connected to the auxiliary electrode and the electrode introduction body connected to the main electrode are sealed in a common thin tube, the auxiliary electrode and the main electrode adjacent thereto are sealed. Can be shortened, and the starting voltage can be reduced. Further, since only one thin tube is required to be attached to each end of the arc tube, the arc tube can be designed relatively freely.

Further, according to the present invention, in the above configuration, a spare main electrode is used instead of (or in addition to) the auxiliary electrode, and the main electrode or the spare main electrode is selected by a switching element to turn on the lamp. You can also.

With this configuration, the frequency of exposure of the main electrode or the spare main electrode to spatter due to a high voltage at the time of starting the lamp or to a high temperature during the operation of the lamp is reduced, so that the consumption of each electrode can be suppressed.

[Best Mode for Carrying Out the Invention] Hereinafter, embodiments of the present invention will be described.

(Embodiment 1) A high-pressure metal vapor discharge lamp with a rated lamp power of 100 W according to a first embodiment of the present invention shown in FIG. 1 has an arc tube 1 made of translucent ceramic inside an outer tube 2. In preparation for.
A stem 3 is provided at one end of the outer tube 2, and the outer tube 2 is hermetically sealed by the stem 3. Introducing support lines 4a and 4b are provided adjacent to the stem 3, and the arc tube 1 is held by an arc tube supporting plate 5 provided on the introducing support line 4a.

At both ends of the arc tube 1, a first main electrode 6a and a second main electrode 6b are provided so as to be present in a main tube 17 which is a discharge space. On the side of the main electrode 6a, the auxiliary electrode 9 is provided at an appropriate distance from the main electrode 6a so as to be located in the main pipe 17, which is also a discharge space.

External introduction line 7 for supplying current to main electrode 6a
A connection line 8a connected to the introduction support line 4a is connected to an end of the main electrode 6a opposite to the main electrode 6a. Then, a current is supplied to the main electrode 6a via the introduction support line 4a, the connection line 8a, and the external introduction line 7a.

On the other hand, a current is supplied to the main electrode 6b through the introduction support line 4b, the connection line 8b, and the external introduction line 7b.

External introduction line 7 for supplying current to auxiliary electrode 9
c is connected to one end of a connection line 8d.
The other end of the current limiting resistor 12 is connected to one end of the current limiting resistor 1.
The other end of 2 is connected via a connection line 8c to a bimetal 11 which is a thermally responsive element having a bimetal pin 10 at the end. The bimetal 11 is connected to a bimetal support line 13. The bimetal support wire 13 has an insulator 14 at the center, and both ends of the bimetal support wire 13 are electrically insulated. One end of the bimetal support line 13 is connected to the bimetal 11 via a connection line 8c connected to the current limiting resistor 12 and is fixed by the electrically insulated arc tube support plate 5 at the same time. .
The other end of the bimetal support line 13 is connected to the introduction support line 4b. Bimetal pins 10 are bimetal support wires 13
Is provided so as to come into contact with and separate from the side of the introduction support line 4b. By the operation of the bimetal pin 10, the introduction support wire 4b and the bimetal 11 are electrically disconnected.

As a result, the auxiliary electrode 9 has the introduction support line 4b, the bimetal support line 13, the bimetal pin 10,
Bimetal 11, connection line 8c, current limiting resistor 12, connection line 8
d, A current is supplied via the external introduction line 7c. Then, after the transition to the main discharge, the operation of the bimetal 11 separates the bimetal pin 10 from the bimetal support wire 13 connected to the introduction support wire 4b, and stops the current supply to the auxiliary electrode 9.

The base 15 is provided at one end of the outer tube 2 and is provided from an external lighting circuit or the like (not shown).
a and 4b are supplied with current. Further, a fluororesin film 16 is applied and formed on the surface of the outer tube 2 in preparation for damage to the outer tube.

An arc tube 1 according to the present embodiment shown in FIG.
A first disk 18a and a second disk 18b made of a translucent ceramic containing alumina as a main component are shrink-fitted into openings at both ends of a main pipe 17 made of a translucent ceramic containing alumina as a main component. And hermetically sealed. First disk 18
a has one end of a two-hole thin tube 26 and the second disk 1.
8b, one ends of the thin tubes 27 are similarly integrated by shrink fitting.

The two-hole thin tube 26 has two through holes substantially parallel to the longitudinal direction, and as shown in FIG.
One of the through holes has a cylindrical sealing body 23a made of niobium which simultaneously serves as an external introduction line 7a, and an electrode introduction body, that is, a first main electrode introduction line 24a made of molybdenum.
And a first main electrode shaft 20a made of tungsten are inserted, and a sealing body 2 made of niobium, which simultaneously serves as an external introduction wire 7c, is inserted into the other through hole.
3c, an auxiliary electrode introducing body, that is, an auxiliary electrode introducing line 25 made of molybdenum, and an integrated auxiliary electrode shaft 21 made of tungsten having an auxiliary electrode 9 at its tip are inserted. The body 23a and the sealing body 23c are sealed with a glass-like sealing material 19 containing alumina and silica as main components. First main electrode shaft 20a
An electrode coil 22a made of tungsten is attached to the tip of the first main electrode 6a to constitute the first main electrode 6a. The electrode coil 22a, that is, the first main electrode 6a is arranged so as to exist in the main pipe 17.

As shown in FIG. 2, a through hole in the thin tube 27 has a cylindrical sealing body 23b made of niobium which simultaneously serves as an external introduction wire 7b and a second main body made of an electrode introduction body, that is, molybdenum. The one into which the electrode introduction wire 24b and the second main electrode shaft 20b made of tungsten are integrated is inserted, and the thin tube 27 and the sealing body 23b are made of a glass-like sealing material 19 containing alumina and silica as main components. Is hermetically sealed.

Next, as shown in FIGS. 2 and 3, the sealing members 23a and 23
An arc tube 1 having a distance L to the discharge space side end surface of b, 23c of 4 mm was manufactured, mounted on the high-pressure metal vapor discharge lamp shown in FIG. 1, and turned on for 5.5 hours and turned off for 0.5 hours. The presence or absence of an arc tube leak until 3000 hours had passed was examined, and a comparison was made with a comparative product. When an arc tube leak occurs, the colored enclosure squirts from the leak location of the arc tube and adheres to the inner surface of the outer tube, so that the leak can be easily confirmed visually. Table 1 shows the results.

As a comparative product, a high-pressure metal vapor discharge lamp (hereinafter referred to as a leak comparative product) having a ceramic arc tube having a structure described in Japanese Patent Application Laid-Open No. 62-150646 shown in FIG. 10 was used. That is, conductive cermet disks 53a and 53b holding main electrode rods 52a and 52b are hermetically sealed at both ends of the arc tube 51, and an auxiliary electrode 54 is held on one disk 53a in an insulated state from the main electrode rod 52a. Have been. Other configurations are the same as those of the high-pressure metal vapor discharge lamp of the present embodiment.

In both discharge lamps, a predetermined amount of mercury, a Ne-Ar mixed gas as a starting gas, and sodium, thallium, indium and lithium iodides as metal halides are sealed in the arc tube. Have been. A Ne—N ₂ mixed gas is sealed in the outer tube 2 and 10
The situation at the time of lighting at 0 W was examined. The arc tube 1 of the discharge lamp of the present invention has a maximum outer diameter of the main tube 17 of 11 mm, an outer diameter of the two-hole thin tube 26 of 4.0 mm, and an outer diameter of the thin tube 27 of 2.1.
mm, sealing bodies 23a, 23b, 23 made of niobium
The outer diameter of c was set to 0.9 mm.

[0034]

[Table 1]

As is evident from Table 1, according to the product of the present invention, a sealing structure without leakage can be obtained. This is because the sealing members 23a, 23b, and 23c maintain a certain distance from the main pipe 17, which becomes high in temperature during lighting, so that the sealing members and the thin tubes can be broken even under thermal shock caused by repeated lighting and extinguishing. This is because the temperature is too low to reach. In the present embodiment, the sealing bodies 23a, 23
Although niobium is used as b and 23c, similar effects can be obtained by using any one of tantalum, platinum, rhenium, and conductive cermet.

Further, after the product of the present invention was lit for 1 hour with the base 15 facing upward, the product was stored in a cool and dark place for 12 hours while being kept in the same direction as when lit, and then the lamp starting voltage was measured. Rated 20 for every 5V from 120V to lamp lighting circuit
The voltage was applied for 10 seconds to 0 V, respectively, and the voltage when the lamp was turned on was defined as the lamp starting voltage.

Further, as a life test, lighting for 5.5 hours 30
The luminous flux maintenance ratio and color temperature change when the light was turned on for up to 3000 hours in a minute light-off cycle were examined and compared with comparative products. Both the luminous flux and the color temperature were measured using a spherical photometer, and the luminous flux maintenance ratio and the color temperature change were compared with the measured values before the life test was started.

With respect to the product of the present invention, an experiment was performed by changing the filling pressure of the starting gas (Ne—Ar mixed gas) in the arc tube in two ways. Table 2 shows the results.

As a comparative product, FIG.
A high-pressure metal vapor discharge lamp having a ceramic arc tube having a structure described in Japanese Patent Application Laid-Open No. 10-106491 (hereinafter referred to as a lamp starting comparative product) was used. That is, at one end of the translucent ceramic arc tube 61, a thin tube 63 a through which a main electrode shaft 62 a integrated with a main electrode 65 a penetrates and a thin tube through which an auxiliary electrode shaft 67 integrated with an auxiliary electrode 66 passes. A thin tube 6 provided with two thin tubes 63c and a main electrode shaft 62b integrated with the main electrode 65b penetrated at the other end.
3b is provided. The first main electrode 65a and the second main electrode 65b are provided so as to be present in the main tube 68 which is a discharge space, and the auxiliary electrode 66 is similarly provided on the main electrode 65a side. The main 68
The main electrode 65a is provided at an appropriate distance from the main electrode 65a. Other configurations are the same as those of the high-pressure metal vapor discharge lamp of the present embodiment.

[0040]

[Table 2]

As is clear from Table 2, the product of the present invention has a lower lamp starting voltage, suppresses occurrence of poor starting, and can obtain stable characteristics even in a life test as compared with the lamp starting comparative product. It could be confirmed. This decrease in the starting voltage is because the distance between the adjacent main electrode and auxiliary electrode is 3 mm in the comparative start product and 1 mm in the product of the present invention, so that the discharge starting voltage decreases. Further, when the filling gas pressure is increased, the discharge starting voltage also increases, but the glow-to-arc time at the time of starting the lamp is shortened, electrode consumption is suppressed, and the luminous flux maintenance rate is improved. That is, by setting the filled gas pressure appropriately, the lamp starting voltage is low, and stable characteristics can be obtained in the life test.

In the present embodiment, the arc tube 1 has the main tube 17 with the first disk 18a and the second disk 18b shrink-fitted therein, the first disk 18a having one end of the two-hole thin tube 26, and The structure in which one end of the thin tube 27 is similarly shrink-fitted to the two disks 18b is used. For example, by forming at least two parts integrally in advance like the first disk 18a and the two-hole thin tube 26, the light emitting tube is formed. Can be further improved in the airtight adhesion reliability. Of course, the main tube, the disc, the two-hole thin tube, and the thin tube may all be integrally formed in advance.

Although a description has been given here of a lamp of 100 W, a similar effect was confirmed with lamps of 250 W and 400 W.

As described above, the high-pressure metal vapor discharge lamp of the present embodiment according to the present invention can provide a sealed structure without arc tube leakage. In addition, since the distance between the main electrode and the auxiliary electrode can be reduced, the lamp starting voltage can be reduced, so that stable starting characteristics can be obtained and the life characteristics can be improved.

(Embodiment 2) Next, a second embodiment of the present invention will be described.

This embodiment is different from the high-pressure metal vapor discharge lamp of the first embodiment in that a spare main electrode 28 is inserted instead of the auxiliary electrode as shown in FIG.
6, two main electrodes are attached to the first main electrode 6a or the spare main electrode 2 when the lamp is turned on by the switching element 29.
8 is selected.

With such a configuration, since the frequency of use of each main electrode can be reduced, a change in the lamp voltage during the life caused by a change in the discharge length due to the consumption of the main electrode is suppressed, and a stable characteristic is obtained. Can be.

The number of through-holes in the thin tube may be at least three, the number of main electrodes may be increased, or an auxiliary electrode may be inserted into one or more through-holes to reduce the starting voltage. .

(Embodiment 3) Next, a third embodiment of the present invention will be described.

This embodiment is different from the high pressure metal vapor discharge lamp of the first embodiment in that the main tube 17 and the two-hole narrow tube 26 are omitted from the arc tube 1 as shown in FIG.
Each end of the thin tube 27 is shrink-fitted and hermetically sealed.

According to such a configuration, the heat capacity of the end portion of the main pipe 17 can be reduced, the heat loss can be suppressed, and the end portion can be designed freely. It is possible to control the temperature of the coldest spot that determines the vapor pressure. As a result, desired light emission can be obtained, and the lamp efficiency can be increased.

Also, by forming at least two parts integrally in advance, such as the main tube 17 and the two-hole thin tube 26, the reliability of the hermetic sealing of the arc tube can be further improved. Of course, the main tube, the two-hole thin tube, and the thin tube may all be integrally formed in advance.

Embodiment 4 Next, a fourth embodiment of the present invention will be described.

The present embodiment has a configuration in which the auxiliary electrode coil 30 is provided at the tip of the auxiliary electrode 9 as shown in FIG. 6 in the high-pressure metal vapor discharge lamp of the first embodiment.

With such a configuration, the distance between the first main electrode 6a and the auxiliary electrode 9 is further reduced, and not only the electric field strength is increased, but also the electric field is applied to the coil portion at an incident angle, so that the electron emission is reduced. Easier to do.

In this configuration, the auxiliary electrode coil can be coated or impregnated with an electron emitting material. The following effects can be obtained by coating or impregnating only the auxiliary electrode with the electron emitting material. That is, the auxiliary electrode electrically separated by the bimetal during stable operation of the lamp is not directly exposed to a high temperature due to discharge, so that scattering of the electron-emitting material can be prevented. As a result, it is possible to prevent the leak by suppressing the reaction between the electron emitting material and the filling material and the arc tube material, and suppressing the reaction between the electron emitting material and the sealing material, while securing stable starting characteristics throughout the life.

(Embodiment 5) Next, a fifth embodiment of the present invention will be described.

In the present embodiment, in the high-pressure metal vapor discharge lamp of the first embodiment, as shown in FIG. 7, a part of the auxiliary electrode 9 is a two-hole thin tube 26 into which the auxiliary electrode 9 is inserted. Is arranged closer to the main electrode 6a side than the inner wall surface of the through hole.

The tip of the auxiliary electrode 9 is made of a heat-resistant and halogen-resistant material such as tungsten or molybdenum, has a wire diameter of about 0.3 mm or less, has sufficient elasticity, and is previously deformed into a predetermined shape. After that, it is configured to be restored to the original shape inside the arc tube by being inserted through the through hole.

With such a configuration, the starting voltage can be reduced by further reducing the distance between the first main electrode 6a and the auxiliary electrode 9.

The shape of the tip of the auxiliary electrode 9 is shown in FIG.
Is not limited to a shape in which the tip is bent toward the main electrode 6a as shown in FIG. For example, a portion slightly closer to the auxiliary electrode introduction line 25 from the tip may be bent into a “U” shape (“Ω” shape) so that the convex portion faces the main electrode 6a side. Further, as in the present embodiment, the auxiliary electrode 9 itself may be deformed, and the coil described in the fourth embodiment may be provided to further approach the main electrode 6a.

Embodiment 6 Next, a sixth embodiment of the present invention will be described.

In the present embodiment, in the high-pressure metal vapor discharge lamp of the second embodiment, as shown in FIG. 8, the spare main electrode 28 approaches the main electrode 6b opposite to the adjacent main electrode 6a. It has a configuration.

At the beginning of the lamp life, the switching element 29 is set so that discharge is performed between the main electrodes. In the latter half of the lifetime when the lamp voltage increases due to blackening of the arc tube and the likelihood of extinguishing occurs during the lifetime, the spare main electrode 28 is selected by the switching element 29. With such a configuration, since the arc length is shortened in the latter half of the life, the lamp voltage is lowered, and the lamp life can be extended by preventing the lamp from extinguishing.

As described above, according to the high-pressure metal vapor discharge lamps of the above embodiments according to the present invention, after the power is turned on, the auxiliary discharge is started between the main electrode and the auxiliary electrode, and immediately thereafter the main electrode is discharged. It shifts to the main discharge during this period, and maintains a stable discharge state. And, unlike the quartz arc tube, the variation in shape depending on the molding of the ceramic material, and
Lamp characteristics variations due to shape variations can be reduced, and ceramics with low reactivity with the enclosed iodide are used. A high-pressure metal vapor discharge lamp having stable luminous flux maintenance ratio and stable life characteristics with little change in color temperature can be obtained. Also, by using the spare main electrode, stable life characteristics and a longer lamp life can be achieved.

The embodiments described above are all intended to clarify the technical contents of the present invention, and the present invention should not be construed as being limited to such specific examples. Instead, various modifications may be made within the spirit of the invention and the scope of the appended claims, and the invention should be construed broadly. [Brief description of drawings]

FIG. 1 is a front view of a high-pressure metal vapor discharge lamp according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an arc tube used in the lamp of FIG. 1;

FIG. 3 is a sectional view of a two-hole thin tube used in the lamp of FIG. 1;

FIG. 4 is a front view of a high-pressure metal vapor discharge lamp according to a second embodiment of the present invention.

FIG. 5 is a sectional view of an arc tube of a high-pressure metal vapor discharge lamp according to a third embodiment of the present invention.

FIG. 6 is a sectional view of a two-hole thin tube of an arc tube of a high-pressure metal vapor discharge lamp according to a fourth embodiment of the present invention.

FIG. 7 is a sectional view of a two-hole thin tube of an arc tube of a high-pressure metal vapor discharge lamp according to a fifth embodiment of the present invention.

FIG. 8 is a sectional view of an arc tube of a high-pressure metal vapor discharge lamp according to a sixth embodiment of the present invention.

FIG. 9 is a front view of a conventional high-pressure metal vapor discharge lamp.

FIG. 10 is a cross-sectional view of an arc tube of another conventional high-pressure metal vapor discharge lamp (a leak comparison product).

FIG. 11 is a cross-sectional view of an arc tube of yet another conventional high-pressure metal vapor discharge lamp (lamp start comparison product).

Continuation of the front page (72) Inventor Masanori Higashi 2-8-725, Saiyukicho, Takatsuki-shi, Osaka (56) References JP-A-62-150646 (JP, A) JP-A-10-172513 (JP, A) Kaihei 10-106491 (JP, A) JP-A-51-55179 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 61/36 H01J 61/073 H01J 61/34

Claims (9)

(57) [Claims] 1. An outer tube hermetically sealed by a stem includes a light-transmitting ceramic light-emitting tube in which mercury, a rare gas, and a light-emitting metal are sealed, wherein the light-emitting tube comprises: a main tube; A first disk and a second disk respectively integrated with both end openings of the main tube, a thin tube having two through holes integrated with the first disk, and a single tube integrated with the second disk; A thin tube having a through hole, a pair of main electrodes disposed in the main tube, and an auxiliary electrode disposed in the main tube, wherein the pair of main electrodes is a sealing material in a through hole of each of the thin tubes. The auxiliary electrode is connected to an auxiliary electrode introducing body, and the auxiliary electrode introducing body connected to the auxiliary electrode is an electrode introducing body connected to the main electrode. The two through holes are electrically independent of A high-pressure metal vapor discharge lamp, which is sealed with a sealing material in a remaining through hole of a thin tube to be formed. 2. An outer tube hermetically sealed by a stem, a light-transmitting ceramic light-emitting tube in which mercury, a rare gas, and a light-emitting metal are sealed, wherein the light-emitting tube comprises: a main tube; 2 arranged at one end of the main pipe
A thin tube having two through holes, a thin tube having one through hole arranged at the other end of the main tube, a pair of main electrodes arranged in the main tube, and an auxiliary electrode arranged in the main tube The pair of main electrodes are respectively connected to an electrode introduction body sealed with a sealing material in a through hole of each of the thin tubes, and the auxiliary electrode is connected to an auxiliary electrode introduction body, and the auxiliary The auxiliary electrode introduction body connected to the electrode is sealed with a sealing material in the remaining through hole of the narrow tube having the two through holes electrically independently of the electrode introduction body connected to the main electrode. A high-pressure metal vapor discharge lamp characterized in that: 3. An outer tube hermetically sealed by a stem, a light-transmitting ceramic light-emitting tube in which mercury, a rare gas and a light-emitting metal are sealed, wherein the light-emitting tube comprises: a main tube; A thin tube having at least two through holes arranged at one end of the main tube, a thin tube having a through hole arranged at the other end of the main tube, and a pair of main electrodes arranged inside the main tube; The main tube comprises at least one spare main electrode, wherein the pair of main electrodes are respectively connected to an electrode introduction body sealed by a sealing material in a through hole of each of the thin tubes, The spare main electrode is connected to the auxiliary electrode introduction body, and the spare electrode introduction body connected to the spare main electrode electrically connects the at least two through holes independently of the electrode introduction body connected to the main electrode. Sealed with a sealing material in the remaining through hole of the thin tube A high-pressure metal vapor discharge lamp characterized in that: 4. An auxiliary electrode is further provided in the main tube, wherein the auxiliary electrode is connected to an auxiliary electrode introduction body, and the auxiliary electrode introduction body connected to the auxiliary electrode is connected to the electrode introduction to which the main electrode is connected. 4. The high-pressure metal vapor according to claim 3, wherein the main body and the auxiliary main electrode are sealed with a sealing material in the common narrow tube electrically independent of the auxiliary electrode introduction body to which the auxiliary main electrode is connected. Discharge lamp. 5. The high-pressure metal vapor discharge lamp according to claim 3, wherein the thin tube is directly connected to both ends of the main tube. 6. The high-pressure metal vapor discharge lamp according to claim 1, wherein the auxiliary electrode has a coil. 7. The high-pressure metal vapor discharge lamp according to claim 6, wherein the coil of the auxiliary electrode is coated or impregnated with an electron emitting material. 8. At least a part of the portion of the auxiliary electrode present inside the main tube is located on the side of the main electrode adjacent to the inner wall surface of the narrow tube into which the auxiliary electrode introduction body to which the auxiliary electrode is connected is inserted. The high-pressure metal vapor discharge lamp according to claim 1, 2 or 4, which is approaching. 9. The high-pressure metal vapor discharge lamp according to claim 3, wherein the tip of the spare main electrode is closer to the opposing main electrode than the tip of an adjacent main electrode.