JP2003157795A - High pressure discharge lamp and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure discharge lamp with excellent characteristics. SOLUTION: The high pressure discharge lamp 100 is provided with a luminous tube 10 with a pair of electrodes (12, 12') arranged in opposition, and inside the luminous tube 10, at least mercury and halogen are contained, and that, at least one kind of metal selected from among the group of Pt, Ir, Rh, Ru, Re exists.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure discharge lamp and a method for manufacturing the same. In particular, the present invention relates to a high-pressure discharge lamp used for general lighting, a projector, a vehicle headlight, and the like in combination with a reflector.

[0002]

2. Description of the Related Art In recent years, image projection devices such as liquid crystal projectors and DMD projectors have been widely used as a system for realizing a large-screen image. In such image projection devices, a high-pressure discharge lamp showing high brightness is generally used. Widely used. The structure of a conventional high pressure discharge lamp 1000 is schematically shown in FIG. The lamp 100 shown in FIG.
0 is a so-called ultra-high pressure mercury lamp.

The lamp 1000 has an arc tube (bulb) 110 made of quartz glass, and a pair of sealing parts (seal parts) 120 extending from both ends of the arc tube 110. A luminous substance (mercury) 118 is enclosed in the interior of the arc tube 110 (discharge space), and a pair of tungsten electrodes (W electrodes) 11 made of tungsten is used.
2 are arranged so as to face each other at regular intervals. One end of the W electrode 112 is welded to a molybdenum foil (Mo foil) 124 in the sealing portion 120,
And Mo foil 124 are electrically connected. Mo foil 1
An external lead (Mo rod) 126 made of molybdenum is electrically connected to one end of 24. In addition to mercury 118, argon (A
r) and a small amount of halogen are also encapsulated.

The operating principle of the lamp 1000 will be briefly described. W through the external lead 126 and the Mo foil 124.
When a starting voltage is applied between the electrodes 112, 112, a discharge of argon (Ar) occurs, and this discharge raises the temperature in the discharge space of the arc tube 110, thereby heating and vaporizing the mercury 118. Then, the W electrodes 112, 1
Mercury atoms are excited at the center of the arc between 12 and emit light. The higher the mercury vapor pressure of the lamp 1000 is, the more suitable it is as a light source of the image projection apparatus, but from the viewpoint of the physical pressure resistance of the arc tube 110, it is 15 to 20 MPa (150 to 200 MPa).
The lamp 1000 is used with mercury vapor pressures in the pressure range.

[0005]

The conventional lamp 10 described above is used.
00 has a withstand pressure strength of about 20 MPa, and research and development has been conducted to further increase the withstand pressure strength in order to further improve the lamp characteristics. However, with extremely high pressure resistance (for example, about 30 MPa or more),
A practical high-pressure discharge lamp has not yet been realized. In addition, it is desired to extend the life of the lamp, and the arc tube 1
It is preferable that the high-pressure discharge lamp is capable of effectively preventing the blackening within 10.

The present invention has been made in view of the above points, and its main purpose is to provide a high-pressure discharge lamp exhibiting superior characteristics (for example, high withstand voltage strength and long life) to those of the conventional high-pressure discharge lamp. To do.

[0007]

A first high-pressure discharge lamp according to the present invention is a high-pressure discharge lamp having an arc tube in which a pair of electrodes are arranged so as to face each other in the tube. Contains at least mercury and halogen,
In addition, Pt, Ir, Rh, Ru, Re are placed in the arc tube.
There is at least one metal selected from the group consisting of:

In a preferred embodiment, the enclosed amount of mercury per unit volume of the arc tube is 230 mg / cc or more.

The amount of mercury enclosed per unit volume of the arc tube is preferably 300 mg / cc or more.

In a preferred embodiment, the operating pressure in the arc tube is 23 MPa or more.

The operating pressure in the arc tube is preferably 30 MPa or more.

The metal present in the arc tube is preferably Pt.

A second high-pressure discharge lamp according to the present invention includes an arc tube having a pair of electrodes facing each other in the tube, and a sealing portion extending from the arc tube and having a part of the electrode inside. And Pt, Ir, Rh, Ru, R on at least a part of the surface of the electrode located in the sealing portion.
A metal film made of at least one metal selected from the group consisting of e is formed.

In a preferred embodiment, the electrode is connected to a metal foil provided in the sealing portion by welding, and the metal film is not formed at a connection point with the metal foil. Instead, it is formed on the surface of the electrode embedded in the sealing portion.

It is preferable that a part of the metal forming the metal film exists inside the arc tube.

In a preferred embodiment, the metal film is a film made of Pt.

In the metal film, the lower layer is an Au layer and the upper layer is Pt.
It may have a multilayer structure composed of layers.

In a third high pressure discharge lamp according to the present invention, an arc tube in which a pair of electrodes are arranged so as to face each other in the tube, a metal foil connected to the electrodes by welding, and extending from the arc tube, A sealing part for sealing the metal foil, wherein the metal foil and a part of the electrode are embedded in the sealing part, and the one of the electrodes embedded in the sealing part. A metal film made of at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re is formed on the surface of the portion, and the metal film is welded to the metal foil and the electrode. When the thickness of the metal film is A and the thickness of the metal film other than the welded portion is B, A <
It is characterized by being B.

According to a fourth high pressure discharge lamp of the present invention, an arc tube in which a pair of electrodes are arranged to face each other in the tube, a metal foil connected to the electrodes by welding, and extending from the arc tube, A sealing part for sealing the metal foil, wherein the metal foil and a part of the electrode are embedded in the sealing part, and the one of the electrodes embedded in the sealing part. A metal film made of at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re is formed on the surface of the portion, and the metal film is welded to the metal foil and the electrode. When the width of the metal foil is C and the outer diameter of the electrode at the welding location is D, C <2
It is characterized by being D.

It is preferable that a part of the metal forming the metal film exists inside the arc tube.

In a preferred embodiment, the metal film is a film made of Pt.

In the metal film, the lower layer is an Au layer and the upper layer is Pt.
It may have a multilayer structure composed of layers.

A fifth high pressure discharge lamp according to the present invention is a discharge tube having a pair of electrodes facing each other in the tube, and a sealing portion extending from the discharge tube and having a part of the electrodes inside. And a coil having on its surface at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re is wound around the electrode in a portion located inside the sealing portion.

A sixth high-pressure discharge lamp according to the present invention comprises an arc tube having a pair of electrodes facing each other in the tube, a metal foil connected to the electrodes by welding, and extending from the arc tube. A sealing part for sealing the metal foil, wherein the metal foil and part of the electrode are embedded in the sealing part, and selected from the group consisting of Pt, Ir, Rh, Ru and Re. A coil having at least one kind of metal formed on its surface is wound around the electrode embedded in the sealing portion.

It is preferable that a part of the metal forming the metal film exists in the arc tube.

In a preferred embodiment, the coil has a metal film made of Pt on its surface.

In a preferred embodiment, the coil has, on its surface, a metal film having a multilayer structure in which a lower layer is an Au layer and an upper layer is a Pt layer.

In a preferred embodiment, the arc tube contains at least mercury and halogen, and Pt, Ir, Rh, Ru, and
There is at least one metal selected from the group consisting of Re.

In a preferred embodiment, the enclosed amount of mercury per unit volume of the arc tube is 230 mg / cc or more.

The amount of mercury enclosed per unit volume of the arc tube is preferably 300 mg / cc or more.

In a preferred embodiment, the operating pressure in the arc tube is 23 MPa or more.

The operating pressure in the arc tube is preferably 30 MPa or more.

The metal present in the arc tube is preferably Pt.

In the method for manufacturing a high pressure discharge lamp according to the present invention, a step (a) of preparing a glass tube having an arc tube portion which becomes an arc tube of the high pressure discharge lamp and a side tube portion extending from the arc tube portion (a) And an electrode structure in which one end of the electrode rod is connected to the metal foil by welding, and at least a part of the surface of the portion of the electrode rod positioned in the side tube portion has a P
a step (b) of preparing an electrode structure on which a metal film composed of at least one metal selected from the group consisting of t, Ir, Rh, Ru and Re is formed; Step (c) of inserting the electrode structure into the side tube portion so as to be located in the arc tube portion, and heating the side tube portion so that the side tube portion and the metal foil are in close contact with each other. Encapsulating step (d) is included.

In a preferred embodiment, the step (b)
In the above, when the thickness of the metal film at the welded portion of the metal foil and the electrode rod is A and the thickness of the metal film other than the welded portion is B, the electrode structure is A <B Is prepared.

In a preferred embodiment, the step (b)
In C, where C is the width of the metal foil at the welded portion of the metal foil and the electrode rod and D is the outer diameter of the electrode rod at the welded portion, the electrode structure having C <2D is prepared. To be done.

In a preferred embodiment, the metal film in the step (b) is a film composed of Pt.

In a preferred embodiment, in the metal film in the step (b), the lower layer is an Au layer and the upper layer is P layer.
It has a multilayer structure composed of t layers.

It is preferable that a part of the metal forming the metal film is introduced into the arc tube portion by the heating in the step (d).

Another method for manufacturing a high-pressure discharge lamp according to the present invention is a step of preparing a glass tube having an arc tube portion serving as an arc tube of the high-pressure discharge lamp and a side tube portion extending from the arc tube portion ( a) and an electrode structure in which one end of an electrode rod is connected to a metal foil by welding, and Pt, Ir, Rh, R
a step (b) of providing an electrode structure in which a coil having at least one metal selected from the group consisting of u and Re on its surface is wound around the electrode rod in a portion positioned in the side tube portion; The step (c) of inserting the electrode structure into the side tube portion so that the tip of the electrode rod is located in the arc tube portion, and the side tube portion and the metal foil are closely attached to each other. Step (d) of heating and sealing the side tube portion
Includes and.

In a preferred embodiment, the step (b) of preparing the electrode structure includes a step of inserting a coil having the at least one metal on its surface into the electrode rod of the electrode structure. Welding the coil inserted into the electrode rod to the electrode rod.

In a preferred embodiment, the coil in the step (b) has a metal film made of Pt on its surface.

In a preferred embodiment, the coil in the step (b) has a lower layer of Au on its surface.
It has a multi-layered metal film in which the upper layer and the upper layer are Pt layers.

It is preferable that part of the metal covering the surface of the coil is introduced into the arc tube portion by the heating in the step (d).

In a preferred embodiment, the method further includes the step of introducing at least mercury and halogen into the arc tube portion.

In the introducing step, the amount of mercury enclosed per unit volume of the arc tube is preferably 230 mg / cc or more.

In the introducing step, the amount of mercury enclosed per unit volume of the arc tube is more preferably 300 mg / cc or more.

[0048]

BEST MODE FOR CARRYING OUT THE INVENTION The inventor of the present invention has developed a high-pressure mercury lamp which is a kind of high-pressure discharge lamp (in particular, an ultra-high-pressure mercury lamp)
In carrying out multifaceted studies to improve the characteristics of No. 1, it was found by experiments that the inclusion of Pt element in the arc tube can effectively prevent blackening occurring in the arc tube. This finding will be further described.

When this kind of lamp is operated, the minimum temperature of the inner wall of the arc tube is generally about 900 ° C., and it was considered that no substance can function as a getter at such a high temperature. However, when the inventor of the present application conducted a life test of an ultra-high pressure mercury lamp in which Pt was enclosed in an arc tube,
It has been found that Pt functions as an oxygen getter and can suppress blackening. It was also found that the function of the oxygen getter at a high temperature during lamp operation can be exhibited not only by Pt but also by a platinum group element such as Ir, Rh, Ru and Re. In addition, A
It was also confirmed that u did not function as an oxygen getter but did not promote blackening. In addition, when Pt, which was found to have a function as an oxygen getter, was coated on the surface of the electrode rod in the portion buried in the sealing portion and the characteristics of the lamp were investigated by the present inventor, the breakdown voltage of the lamp was found. Another finding was found that the strength can be significantly improved. The present invention has been made based on these new findings.

Embodiments according to the present invention will be described below with reference to the drawings. In the following drawings, for simplification of description, components having substantially the same function are designated by the same reference numeral. The present invention should not be limitedly interpreted by the following embodiments. (Embodiment 1) FIGS. 1A and 1B schematically show the cross-sectional structure of a high-pressure discharge lamp according to this embodiment. FIG. 1A is a plan view, while FIG. 1B is a side view thereof.

The lamp 100 includes a pair of electrodes (1
2, 12 ') arc tubes (bulbs) 1 arranged opposite to each other
0 and a pair of sealing parts 20 and 20 ′ connected to the arc tube 10. The arc tube 10 is made of quartz glass, and the glass portion of the sealing portion (20, 20 ′) extends from the arc tube 10. Electrode (12,1
2 ') part (root part) is a sealing part (20, 20')
Embedded in the inside of the seal and the sealing part (20, 2
0 '), Pt, Ir, Rh, Ru, Re are formed on at least a part of the surfaces of the electrodes (12, 12') located inside.
A metal film 30 made of at least one metal selected from the group consisting of is formed. In the present embodiment, the metal film 30 containing Pt is plated (12,
12 '), and Pt in the metal film 30 is formed.
Is present in the arc tube 10.

The electrodes (12, 12 ') are 0.2-5 mm
The electrodes (1) are arranged in the arc tube 10 at intervals (arc length) D of about (for example, 0.6 to 1.0 mm).
Each of the electrodes 2, 12 ') is composed of a tungsten (W) electrode rod 16. One end of the electrode rod 16 has a metal foil (24, 2) provided in the sealing portion (20, 20 ′).
4 ') is connected by welding. The metal film 30 containing Pt is not formed at the welded portion (connection portion) 32 between the electrode rod 16 and the metal foil 24, and the sealing portion (20, 2) is formed.
0 ') is formed on the surface of the electrode rod 16 which is embedded inside. The coil 14 is wound around the other end (tip) of the electrode rod 16 for the purpose of lowering the temperature of the electrode tip during lamp operation.

In this embodiment, in order to improve the adhesion with the tungsten forming the electrode rod 16, the metal film 30 is used.
Has a multilayer structure in which the lower layer is an Au layer and the upper layer is a Pt layer. The Au layer and the Pt layer are formed by plating, and the Au layer has a thickness of, for example, 0.01 to 0.1.
μm, and the length of the Au layer in the longitudinal direction (plating length) is
It is about 2 mm. Then, Pt formed on the Au layer
The layer thickness is from about 0.01 to about 10 μm (preferably
The length of the Pt layer in the longitudinal direction (plating length) is about 2 mm, which is the same as the plating length of the Au layer.
The plating amount is, for example, about 1 to 4 micrograms of Au and about 4 micrograms of Pt per electrode rod 16.

Further, the metal film 30 need not be a multilayer film of Au layer and Pt layer, but may be a film made of Pt. P
In the case of the metal film 30 composed of only t, although the adhesion is slightly lower than that in the case of the multilayer film of the Au layer and the Pt layer,
This is because it was confirmed by an experiment by the inventor of the present application that a sufficient level of adhesiveness that does not cause a problem in actual use can be ensured. The metal film 30 made of only Pt is composed of Au layer and Pt.
Compared with a multi-layer film including layers, there is an advantage that it is easy to form. Here, the thickness of the metal film 30 made of Pt is, for example, about 0.01 μm to about 1.0 μm.

The metal foil (24, 24 ') provided in the sealing portion (20, 20') is, for example, a rectangular molybdenum foil (Mo foil), and the electrodes (12, 12 ') are located on the metal foil (24, 24'). A lead wire (external lead) 26 is provided by welding on the side opposite to the side. The pair of lead wires 26 will be electrically connected to a lighting circuit (not shown). The sealing part (20, 20 ′) is composed of the glass part of the sealing part and the metal foil (2
4, 24 ') are pressure-bonded to each other to maintain the airtightness of the discharge space in the arc tube 10. Sealing part (20,
The sealing mechanism according to 20 ') will be briefly described as follows.

Since the quartz glass forming the glass portion of the sealing portion (20, 20 ′) and the molybdenum forming the metal foil (24, 24 ′) have different thermal expansion coefficients, from the viewpoint of the thermal expansion coefficient. As you can see, the two are not integrated. However, in the case of this configuration, the metal foil (24, 24 ′) is plastically deformed by the pressure from the glass portion of the sealing portion, and the gap between the two can be filled. As a result, the metal foils (24, 24 ') and the glass portion can be pressed to each other, and the inside of the arc tube 10 can be sealed by the sealing portion (20, 20'). That is, the sealing portion (20, 2 ') is formed by the foil sealing by pressure bonding between the metal foil (24, 24') and the glass portion.
0 ') is sealed.

The metal foil (24, 24) of the sealing portion (20, 20 ')
24 ') is different from the portion where the electrode rod 16 is embedded, the glass portion of the sealing portion and the electrode rod 16 are not in close contact with each other in the portion where the electrode rod 16 is embedded, and there is no visible gap between them. There is a gap that cannot be seen. This gap is created due to the difference in thermal expansion coefficient between tungsten and quartz glass. That is, during cooling, tungsten, which is a metal, shrinks more than quartz glass. Unlike molybdenum, tungsten does not cause plastic deformation that fills the gap between the glass portion and the electrode rod 16.

The lamp 100 according to the present embodiment includes the arc tube 10.
There is a small amount of Pt and Au inside. this is,
During heating during the manufacturing process of the lamp, part of Pt and Au forming the metal film 30 formed on the surface of the base of the electrode rod 16 is evaporated, and the glass portion of the sealing portion and the electrode rod 16 are evaporated.
The particles are scattered into the arc tube 10 through the gap between them. Conventionally, it has been thought that when a metal such as Pt is present in the arc tube 10, it reacts with a filling material in the arc tube 10, thereby promoting blackening and shortening the lamp life. However, when the inventor of the present application examined the characteristics of the lamp 100, it was confirmed that Pt can effectively prevent the blackening of the arc tube 10 instead of promoting the blackening. P
The mechanism by which the blackening can be prevented by t is not clear at present, but it is thought that Pt functions as an oxygen getter during the lamp operation, and as a result, the blackening can be suppressed. In addition, when operating this kind of lamp,
The minimum temperature of the inner wall of the arc tube 10 is generally about 900 ° C., and it has been conventionally considered that at such a high temperature, no substance can function as a getter.

On the other hand, it was confirmed that Au, unlike Pt, did not function as an oxygen getter, but did not promote blackening. The function of the oxygen getter at high temperature during lamp operation is Ir, Rh, Ru, in addition to Pt.
It can also be exhibited by a platinum group element such as Re. Lamp 100
In, the Pt is scattered from the metal film 30 and the arc tube 10
The reason why it is introduced into is that an appropriate amount of Pt can be easily enclosed in the arc tube 10. That is, according to this method,
Pt in an amount sufficient to act as a getter
Can be easily put in the arc tube 10 to the extent that the arc tube 10 is not fogged. It is preferable that the arc tube 10 is not clouded because it is possible to prevent the amount of light emitted from the arc tube 10 from decreasing.

The method of introducing an appropriate amount of Pt into the arc tube 10 is not limited to the above-described method, and Pt may be directly introduced into the arc tube 10, or a metal film or metal block containing Pt. May be provided in the arc tube 10. Further, the method of forming the metal film 30 is not limited to plating, but may be sputtering, vapor deposition, or a method of applying a metal solution and baking it.

The lamp 100 of the present embodiment in which the metal film 30 is formed at the base of the electrode rod 16 has a conventional blackening effect of about 20 MPa (about 2 MPa) in addition to the blackening prevention effect by the getter action of Pt.
High withstand pressure exceeding 00 atm (for example, 23 MPa or 25 MPa or higher, or 30 to 40 MP)
a or more, in other words, operating pressure of about 230 atm or 250 atm or more, or about 300 atm.
Up to 400 atm or higher). In the lamp 100, since the metal film 30 is formed on the surface of the electrode rod 16 which is embedded in the sealing portion (20, 20 ′), minute cracks are formed in the glass around the electrode rod 16. Can be prevented. This will be described in more detail below.

The metal film 3 is formed on the electrode rod 16 located in the sealing portion.
In the case of a lamp without 0, after forming the sealing portion in the lamp manufacturing process, the glass of the sealing portion and the electrode rod 16 are brought into close contact with each other once, and then, at the time of cooling, due to a difference in thermal expansion coefficient between the both, Will be separated. At this time, the electrode rod 16
The quartz glass around the cracks cracks. Due to the existence of these cracks, it has hitherto been very difficult to realize a lamp having a pressure resistance strength such that the operating pressure exceeds about 200 atm. That is, when the lamp is used at an operating pressure exceeding 200 atm, the arc tube 10 leaks, that is, the seal structure of the sealing portion (20, 20 ′) is destroyed. Therefore, from the viewpoint of pressure resistance, an ultra-high pressure mercury lamp exceeding about 20 MPa has not been realized conventionally.

In the case of the lamp 100 of the present embodiment, since the metal film 30 having the Pt layer on the surface is formed on the surface of the electrode rod 16, the quartz glass of the sealing portion (20, 20 ′) and the electrode rod 16 are formed. The wettability with the surface of 16 (Pt layer) is poor. In other words, the wettability between the metal and the quartz glass is worse in the case of the combination of platinum and the quartz glass than in the case of the combination of tungsten and the quartz glass, so that they are easy to separate without being stuck. Of. As a result, due to the poor wettability between the electrode rod 16 and the quartz glass, the electrode rod 16 and the quartz glass are well separated from each other during cooling after heating, and it is possible to prevent generation of fine cracks. The lamp 100 manufactured based on the technical idea of preventing the generation of cracks by utilizing such poor wettability has a pressure of 30 to 40 MPa exceeding 20 MPa which has been difficult or impossible to achieve in the related art. It is an epoch-making lamp that can achieve operating pressure.

According to the lamp 100 which can realize such high pressure resistance, the following advantages can be obtained. recent years,
In order to obtain a high-pressure and high-power high-pressure mercury lamp, a short-arc type mercury lamp (for example, D is 2 mm or less) having a short arc length (distance D between electrodes) is under development. In this case, it is necessary to enclose a larger amount of mercury than usual in order to prevent the evaporation of the electrode from becoming faster as the current increases. As described above, in the conventional configuration, there is an upper limit in the pressure resistance strength, and therefore, there is an upper limit in the enclosed mercury amount (for example, about 200 mg / cc or less), and it is possible to realize a lamp that exhibits further excellent characteristics. There were restrictions. The lamp 100 of the present embodiment can remove such a limitation in the related art, and can promote the development of a lamp exhibiting excellent characteristics that could not be realized in the related art. In the lamp 100 of the present embodiment, it is possible to realize a lamp in which the amount of enclosed mercury exceeds about 200 mg / cc, about 300 mg / cc or more.

The amount of enclosed mercury is 300 to 400 mg /
cc or higher (lighting operating pressure 30-40MP
The technology that can realize a) is, in particular, a lighting operating pressure of 20.
Lamps above the MPa level (ie 15
A lamp having a lighting operating pressure in excess of a lamp of MPa to 20 MPa. For example, a lamp having a pressure of 23 MPa or more or a pressure of 25 MPa or more) has the significance of ensuring its safety and reliability. That is, when a large number of lamps are mass-produced, the characteristics of the lamps may inevitably vary. Therefore, even if the lamp has a lighting operating pressure of about 23 MPa, it is necessary to secure a withstand voltage with a margin in mind. There are 30 technologies that can achieve a pressure resistance of 30 MPa or more.
Even for lamps having a pressure of less than MPa, there are great advantages from the viewpoint of being able to actually supply products. Of course, 30MP
If a lamp that can withstand a pressure of 23 MPa or less is manufactured by using a technique capable of achieving a withstand voltage of a or higher, safety and reliability can be improved.

The inventor of the present application conducted a life test on the lamp 100 of the present embodiment in which the base of the electrode rod 16 is plated with the metal film 30 and a comparative lamp having the same structure as the lamp 100 but not plated with the metal film 30. I went. The life test was performed by repeating lighting for 60 minutes and extinction for 15 minutes. When the lamp 100 was turned on at 30 MPa or higher, it was confirmed that there was no leakage or damage within 1500 hours of turning on. In the lamp of the comparative example, there was a crack around the electrode rod 16, so it was confirmed that it was impossible to turn on the lamp at 30 MPa.

FIG. 2 shows changes in the luminous flux maintenance factor of the lamp 100 of this embodiment and the lamp of the comparative example during the life test. Since the lamp of the comparative example cannot be lit at 30 MPa, the amount of mercury is set to a value corresponding to 20 MPa (about 200 mg / cc), and the interelectrode distance D is adjusted to change the electrical characteristics of the lamp to that of the lamp 100. It is the same as the one. As shown in FIG. 2, the lamp 1
The luminous flux maintenance factor of 00 is about 95 even at 1500 hours.
% Maintained. On the other hand, the luminous flux maintenance factor of the comparative example begins to decrease from a relatively early period and is 90% at 1500 hours.
It fell to about 85%. From this result, lamp 1
It can be seen that 00 exhibits excellent properties.

The conditions of the lamp 100 of the present embodiment are exemplarily shown as follows. The arc tube 10 is made of high-purity silica glass having a low alkali metal impurity level (for example, 1 ppm or less), and has a substantially spherical shape.
The outer diameter of the arc tube 10 is, for example, about 5 mm to 20 mm, and the glass thickness of the arc tube 10 is, for example, about 1 mm to 5 mm. The volume of the discharge space in the arc tube 10 is, for example, 0.
It is about 01 to 1 cc (0.01 to 1 cm ³ ). In this embodiment, an arc tube 10 having an outer diameter of about 9 mm, an inner diameter of about 4 mm, and a discharge space capacity of about 0.06 cc is used.
Mercury is used as the light-emitting substance 18, and is about 300 mg / cc or more (for example, 300 mg to 400 mg).
Of mercury, a rare gas (for example, argon) of 5 to 30 kPa, and a small amount of halogen are enclosed in the arc tube 10.

The enclosed halogen is charged during operation of the lamp.
W (tungsten) evaporated from the poles (12, 12 ')
Role of halogen cycle to return to electrodes (12, 12 ') again
It is responsible for this, for example, bromine. Haloge to be enclosed
Not only in the form of a simple substance but also in the form of a halogen precursor.
In the present embodiment, halogen is CH.₂Br₂
Is introduced into the arc tube 10 in the form of. In addition, this embodiment
CH in the state₂Br ₂The enclosed amount is 0.0017-0.
It is about 17 mg / cc, which is
Converted to a logen atom density, 0.01 to 1 μmol /
Equivalent to about cc. The pressure resistance of the lamp 100
(Operating pressure) is 20 MPa or more (for example, 30 to 40
MPa, or higher). Well
Also, the tube wall load is, for example, 60 W / cm²From degree 2
00W / cm²Range of degree (preferably 80 to 150)
W / cm²Lamp) can be realized. Na
The rated power is, for example, 150 W (in that case, the negative wall
The load is about 130 W / cm²Is equivalent to).

Further, in the lamp 100 of this embodiment,
Since the surface of the root portion of the electrode rod 16 is protected by the metal film 30, it is possible to enclose more halogen than usual. The reason will be described below. When a large amount of halogen is present in the arc tube 10, an excessive amount of halogen other than the amount that contributes to the halogen cycle attacks the root of the electrode rod 16 and thins the root. In order to continue the halogen cycle satisfactorily and prevent blackening effectively, it is often preferable to use a slightly excessive amount of halogen. The root of 16 is thinned, which causes shortening of life. However, in the lamp 100 of the present embodiment, since the root part of the lamp 100 is protected by the metal film 30, it is possible to avoid the problem of the root thinning of the electrode rod 16, and therefore the amount is larger than usual. The halogen can be enclosed in the arc tube 10.
Therefore, in the lamp 100 of the present embodiment, the metal film 3
0 can be made to function as a halogen attack prevention film, and the amount of halogen can be up to about 100 times the conventional amount (for example,
(Up to about 0.17 to 17 mg / cc). It should be noted that it is not required for the lamp 100 to contain more halogen than necessary, and a specific amount of halogen may be appropriately determined so that desired characteristics of the lamp can be obtained.

The lamp 100 used in the lamp test
The conditions are as follows. The outer diameter and the inner diameter of the arc tube 10 are 9 mm and 4 mm, respectively. The volume of the arc tube 10 is about 0.06 cc. Electrode rod 16
Is a tungsten electrode rod having a rod diameter of 0.3 mm. The metal foil (24, 24 ') is a molybdenum foil having a width of 1.5 mm, and the lead wire 26 is a molybdenum lead wire.
The metal film 30 is a plated film (Au film thickness: 0.01 to 0.1 μm, Pt film thickness: about 0.
1 μm) and the plating length is about 2 mm. The plating amount is
About 1 to 4 μg of Au and 4 μt of Pt per electrode
It is g. The amount of mercury is 18 to 24 mg (the amount of mercury per arc tube inner volume is 300 to 400 mg / cc).
Therefore, the filling pressure of the rare gas (Ar) containing halogen is 2
It is 00 torr. And the amount of CH ₂ Br ₂ enclosed is
It is about 0.017 mg / cc, and the halogen atom density during operation is about 0.1 μmol / cc.

In the lamp 100 shown in FIG. 1, the metal film 30 is not formed on the welded portion 32 between the electrode rod 16 and the metal foil (24, 24 ').
This is to prevent the foil from floating. A more specific description will be given.

The inventor of the present application found that the metal film 3 up to the welded portion 32.
When a lamp in which 0 was formed was manufactured and the lamp was observed, it was found that a so-called “foil floating” phenomenon occurred in a lamp in which mercury was sealed at 300 mg / cc or more.
That is, part of the plated metal film 30 (Pt, Au) evaporates due to heat during sealing in the lamp manufacturing stage, and the glass portion of the sealing portion (20, 20 ′) and the metal foil (24, 2).
4 '), and as a result, adheres to a part of the metal foil. Then, a very small gap is formed between the glass portion and the metal foil which are in close contact with each other, which causes the foil to float. This foil floating is not preferable because it causes leakage and damage, but the metal film 30 is not formed on the welded portion 32.
In the case of the configuration of the lamp 100 in which the foil is not formed, the foil floating can be effectively prevented. The amount of mercury is 300 mg /
In the case of cc or more, leakage due to the foil floating remarkably occurs, and in such a case, it is preferable not to form the metal film 30 on the welded portion 32. The amount of mercury is 3
If it is less than 00 mg / cc, the phenomenon of foil floating is not so remarkable, so that the metal film 30 up to the welded portion 32 is not formed.
Can also be formed.

Further, the present invention is not limited to the structure in which the metal film 30 is not formed at the welded portion 32, and the effect of preventing the foil floating can be obtained even if the metal film 30 in the welded portion 32 is made thinner than the other portions. It is possible to obtain In other words, welding point 3
When the thickness of the metal film 30 in 2 is A and the thickness of the metal film 30 other than the welded portion 32 is B, a configuration may be such that A <B, for example, A is B / 2. Or less, or B / 4 or less. According to the experiment by the inventor of the present application, the foil floating can be suppressed in the configuration when B is 1 μm. Therefore, it is preferable that B is 1 μm, and in order to suppress the foil floating more effectively, B
Is more preferably 0.1 μm or less.

In this embodiment, the metal film 30 is formed of Pt / Au.
Since it has a two-layer structure, the wettability between the metal film 30 (Pt layer) and the quartz glass can be deteriorated to make it difficult to stick to the quartz glass, and the metal film 30 (Au layer).
It is possible to improve the adhesion between the electrode and the electrode rod (W rod) 16. When the adhesion between the metal film 30 and the electrode rod 16 is improved, the amount of evaporation of the metal film 30 during heating can be effectively suppressed, so that the foil floating can be more reliably suppressed. In addition, since the film strength is increased, it is possible to prevent film peeling due to contact between electrodes during storage or manufacturing. Although the metal film 30 has a two-layer structure in the present embodiment, it may have a one-layer structure or a three-layer structure. In addition, a structure in which a two-layer structure of Pt / Au is repeated (four layers, six layers
Layers). In the configuration of the lamp 100, Pt
The metal film 30 containing P was used, but instead of Pt, or P
A metal film 30 containing Ir, Rh, Ru, and Re together with t
May be used.

Further, the metal film 30 has a sealing portion (20, 2).
0 ′) may not be formed on the entire surface of the electrode rod 16 that is embedded in 0 ′), or may be formed on a part thereof. For example, even if the area of the metal film 30 shown in FIG.
It was confirmed by experiments that blackening prevention and crack prevention effects can be exhibited. Although not contributing to the crack prevention effect, the metal film 30 may be formed on the surface of the electrode rod 16 exposed in the arc tube 10. However, in that case, it is desirable to design so that Pt or the like is not introduced into the arc tube 10 more than necessary, that is, the inside of the arc tube 10 is not clouded. According to the experiment by the inventor of the present application, when the thickness of the metal film 30 is 0.01 μm or more, the effect of the metal film 30 is remarkable. 0.01μ
If it is less than m, the metal film 30 is scattered due to evaporation during heating,
As a result, the effect of preventing cracks has diminished. On the other hand, when the film thickness exceeds 10 μm, the amount of metal that flies in the arc tube 10 increases, which causes a fogging phenomenon in the arc tube 10. Therefore, it can be said that the thickness of the metal film 30 is preferably about 0.01 μm to 10 μm.

In order to more positively avoid the problem of foil floating, the structure shown in FIG. 3 may be used. In the lamp 200 shown in FIG. 3, the width of the metal foil 24 at the welded portion 32 is narrowed so that the metal evaporated and scattered from the metal film 30 by heating does not adhere to the metal foil (24, 24 ′) as much as possible. is there. Specifically, the welding point 32
C is the width of the metal foil 24 at C, and D is the outer diameter of the electrode at the welding point 32, so that C <2D. Since the influence of evaporation and scattering from the metal film 30 located near the end of the electrode rod 16 is relatively large, in the present embodiment, the width C and The outer diameter D was determined. Even in the case of the configuration shown in FIG. 3, the thickness of the metal film 30 at the welding point 32 is, as described above, A <B (A: film thickness of the welding point 32, B: film other than the welding point 32). It is preferable that the metal film 30 is not formed in the welded portion 32.

Next, a method of manufacturing the lamp 100 according to this embodiment will be described with reference to FIG. FIG. 4 is a process cross-sectional view at a stage in which the electrode structure 55 including the electrode 12 is inserted into the discharge lamp glass pipe 50.

First, the part which becomes the arc tube 10 (arc tube part)
And a glass tube 50 for a discharge lamp, which has a pair of side tube portions 22 to be the glass portion of the sealing portion (20, 20 ′). The side tube portion 22 extends from the arc tube portion 10, and both (10, 22) are made of quartz glass. In this embodiment, high-purity quartz glass having a low level of alkali metal impurities (eg, 1 ppm or less) is used as the quartz glass. However, the present invention is not limited to such a case, and a glass tube for a discharge lamp, which is made of quartz glass whose alkali impurity level is not so low, may be prepared and used. The outer diameter and the inner diameter of the arc tube portion 10 of the prepared glass pipe 50 are 10 mm and 5 mm, respectively, and the side tube portion 22
The outer and inner diameters of are 6 mm and 2 mm, respectively.

Separately, an electrode structure 55 in which one end of the electrode rod 16 on which the metal film 30 is formed is connected to the metal foil 24 is prepared. The electrode structure 55 is a metal foil 24 (Mo foil).
The electrode rod 16 (electrode 12) and the lead wire 26 are welded to each other.
Supporting member 2 for fixing the electrode structure 55 to the inner surface of
8 are provided. Although the support member 28 shown in FIG. 4 is a molybdenum tape (Mo tape) made of molybdenum, a ring-shaped spring made of molybdenum may be used instead.

A metal film 30 is formed on a portion of the electrode rod 16 positioned inside the side tube portion 22. Also,
In order to prevent the foil from floating, the metal film 30 is not formed on the portion 32 that becomes the welding white with the Mo foil 24. Where A
It is also possible to use the electrode structure 55 that satisfies the condition of <B (A; film thickness of the welded portion 32, B; film thickness other than the welded portion 32). When manufacturing the lamp 200, C <
2D (C; width of the metal foil 24 at the welding point 32, D;
The electrode structure 55 satisfying the condition of (the outer diameter of the electrode rod 16 at the welding point 32) may be used. In addition, in this example, the metal film 30 is not formed in the portion exposed in the arc tube 10. The metal rod 16 has a diameter of 0.3 m, for example.
It is a tungsten rod of m, and the width of the Mo foil 24 is 1.5.
mm, and the lead wire 26 is a molybdenum lead wire having a diameter of 0.5 mm.

Next, the electrode structure 55 is inserted into the side tube portion 22 of the glass pipe 50 so that the tip of the electrode rod 16 is located inside the arc tube portion 10 (electrode inserting step). After this step, the state shown in FIG. 4 is obtained. The coil wound around the tip of the electrode rod 16 is omitted in FIG.

After that, the side tube portion 22 is heated and sealed so that the side tube portion 22 and the Mo foil 24 are in close contact with each other (sealing portion forming step). More specifically, when the inside of the glass pipe 50 is depressurized (for example, less than 1 atm) and the side tube portion 22 is heated and softened by, for example, a burner, the side tube portion 22 and the Mo foil 24 are separated. Both of them adhere to each other, whereby the sealing portion 20 is obtained. At the time of this step, the electrode rod 16 located in the side tube portion 22 is buried in the sealing portion 20. In the present embodiment, since the metal film 30 that deteriorates the wettability with the quartz glass is formed on the surface of the electrode rod 16 in the sealing portion 20, the metal film 30 is positioned around the electrode rod 16 during cooling after heating. It is possible to suppress the occurrence of cracks in the glass. Further, during the process of forming the sealing portion, the electrode rod 16 having the metal film 30 is also heated, and a part of the metal film 30 evaporates and scatters.

Next, the side tube portion 22 which is not yet sealed
Then, an enclosure such as mercury 18 is introduced, and then the side tube portion 22 is also subjected to the electrode inserting step and the sealing portion forming step to obtain the sealing portion 20 ′. Finally, the sealing part (2
0, 20 ′) is cut into a suitable length to expose the lead wire 26, and the lamp 100 of the present embodiment is obtained.
In the arc tube 10 of the lamp 100, there is Pt evaporated and scattered from the metal film 30 during heating in the sealing portion forming step. It should be noted that Pt may be heated by heating during the sealing portion forming step.
The Pt may be introduced into the arc tube 10 by heating the metal film 30 with a laser or the like without being limited to the case of introducing Pt into the arc tube 10.

Next, the manufacturing method of this embodiment will be described in more detail with reference to FIGS.

First, after preparing the glass pipe 50 having the arc tube portion 10 and the side tube portion 22, as shown in FIG. 5A, the electrode structure 55 is inserted into one side tube portion 22.
The metal film 30 is formed on a part of the electrode 12 of the electrode structure 55. The glass pipe 50 is rotatably supported by the chuck 52. The Mo tape 28 is omitted in FIG.

Next, after fixing the electrode structure 55 at a predetermined position, the glass pipe 50 is made depressurizable, the inside of the arc tube 10 is evacuated, and then Ar of about 200 torr is introduced.

Next, as shown in FIG. 5B, while the glass pipe 50 is being rotated, the side pipe portion 22 is heated by the oxygen-hydrogen burner 54 to perform shrink sealing. After the shrink sealing of one side tube portion 22 is completed, the arc tube portion 1
Into 0, 18 to 24 mg of mercury (the amount of mercury per inner volume of the arc tube is 300 to 400 mg / cc) is introduced.

Then, the side tube portion 22 which is not sealed
Then, the electrode structure 55 including the Mo foil 24 'is inserted and fixed at a predetermined position. Next, the inside of the arc tube unit 10 is evacuated, and then Ar gas containing bromine is sealed at 200 torr.

Next, while cooling the mercury in the arc tube section 10 with liquid nitrogen, the remaining side tube section 22 is heated and shrink-sealed as in the step of FIG. 5B. Thereby, as shown in FIG. 5C, the pair of sealing parts (20,
20 ') is formed and the discharge tube 15 has a discharge space 15.
0 is obtained.

Finally, the unnecessary portion of the side tube portion 22 is cut to expose the lead wire 26, and the lamp 100 is completed as shown in FIG. 5 (d).

In the lamp 100 of this embodiment, Pt, I
Since at least one metal selected from the group consisting of r, Rh, Ru, and Re is present in the arc tube 10, a high-pressure discharge lamp that effectively prevents blackening and has a long life is realized. It becomes possible to do.

Further, at least a part of the surfaces of the electrodes (12, 12 ′) located in the sealing portion (20, 20 ′) are selected from the group consisting of Pt, Ir, Rh, Ru and Re. Metal film 30 composed of at least one metal
Since it is formed, it is possible to prevent the occurrence of cracks that occur in the glass located around the base of the electrode, and as a result, it is possible to realize a high pressure discharge lamp having an extremely high pressure strength that could not be achieved conventionally. Become.

Further, by not forming the metal film 30 at the welded portion 32, the effect of preventing the foil floating can be obtained. Then, A <B (A: film thickness of the welded portion 32, B: film thickness other than the welded portion 32), or C <2D (C: welded portion 3)
The effect of preventing foil floating can also be obtained by setting the width of the metal foil 24 in 2 to D; the outer diameter of the electrode rod 16 in the welded portion 32).

The lamps 100 and 2 of this embodiment are the same.
In 00, the configuration of the pair of electrodes (12, 12 ′) and the pair of sealing portions (20, 20 ′) is symmetrical, but the configuration is not limited to this. This is because, if the metal film 30 is formed on at least one of the electrodes, it is possible to obtain the above-mentioned effects as compared with the conventional lamp. Further, it is of course possible to use one as a sealing portion such as the lamp 100 and the other as a sealing portion such as the lamp 200. In addition, since the lamps 100 and 200 have an AC lighting type configuration, the pair of electrodes (12, 1
The configuration of 2 ') is symmetrical, but in the case of a DC lighting type configuration, the electrode shape can be changed according to the cathode and the anode. (Second Embodiment) A high pressure discharge lamp 300 according to a second embodiment of the present invention will be described with reference to FIG. Figure 6
Shows schematically the configuration of the lamp 300.

The lamp 300 of the present embodiment has the sealing portion (2
0,20 '), the electrode 40 having a surface covered with Pt is wound around the electrode rod 16 in the portion located inside the sealing portion (20,20'). This is different from the lamp 100 of Embodiment 1 in which the surface of the lamp is covered with Pt. The other points are basically the same as the configuration of the lamp 100. In order to simplify the description of the present embodiment and the embodiments described below, the points different from the first embodiment will be mainly described below, and the description of the same points as the first embodiment will be omitted or simplified.

The coil 40 in the lamp 300 is, for example, Pt (upper layer) / Au on the surface of a tungsten coil.
(Lower layer) is plated. That is, the metal film 30 according to the first embodiment is formed on the surface of the coil 40. The two-layer structure in which the Au layer is formed as the lower layer is for improving the adhesiveness. Where P
Without forming a two-layer structure of t (upper layer) / Au (lower layer) plating,
As described in the first embodiment, it is possible to secure sufficient practical adhesion even with the coil 40 that is plated only with Pt. Further, the method of forming the metal layer (30) is not limited to plating, but may be sputtering, vapor deposition, or a method of applying a metal solution and baking it. Instead of plating the coil surface, a coil containing Pt as a material (including a Pt coil) may be used. Further, as in the first embodiment, instead of Pt, or together with Pt, a white metal element such as Ir, Rh, Ru, or Re may be used.

The diameter of the coil 40 is preferably 1/2 or less of the diameter of the electrode rod 16 in consideration of peeling and cracking of the metal foil 24. In this embodiment, a tungsten rod 16 having a diameter of 0.3 mm is wound with a tungsten coil having a coil diameter of 0.06 mm. The lamp 300 shown in FIG.
Then, the coil is wound about 20 to 50 times so that there is no gap between the coils. However, the invention is not limited to this, and the coil may be wound with a gap between the coils as shown in FIG. Good.

As in the lamp 300 of the present embodiment, the coil 4 having a Pt-plated surface on a portion (root portion of the electrode) where the electrode rod 16 is embedded in the sealing portion (20, 20 ').
By winding 0, the same effect as in the first embodiment can be obtained. That is, P on the surface of the coil 40
It is possible to introduce Pt into the arc tube 10 by evaporating and scattering Pt from the t-plating (metal film 30). In addition, the poor wettability between Pt and quartz glass can be used to prevent the glass around the electrode rod 16 from cracking.

Compared to the lamp 100 of the first embodiment,
The lamp 300 of this embodiment has a great advantage in the manufacturing process. That is, in the case of the lamp 300, a large number of pre-plated coils 40 can be prepared. Then, the coil 40 may be wound around the base of the electrode rod 16 of the electrode structure that is normally used (the electrode structure 55 of FIG. 4 in which the metal film 30 is not provided).

In order to manufacture the lamp 300, the electrode structure (55) around which the coil 40 is wound is used, and as shown in FIG.
The steps (a) to (d) may be executed. here,
"Wrap a coil around an electrode rod" means to insert a coil that has been wound by winding a metal wire into the electrode rod, and arrange the inner surface of the tubular coil so that the inner surface contacts or comes close to the electrode rod. , A metal wire for a coil is wound around an electrode rod to directly produce a coil arranged on the outer periphery of the electrode rod. In the case of mass production, it is, of course, preferable to prepare a completed coil in advance, insert the coil into the electrode rod, and dispose the coil around the electrode rod.

When preparing the coils 40 (in particular, when preparing a large number of pre-plated coils 40),
After preparing the metal wire 41 as shown in FIG. 8A, a first-stage coil 42 is made from the metal wire 41 as shown in FIG. 8B, and then as shown in FIG. As shown, this coil 42 is plated so that at least the surface is Pt.
A coil 43 provided with the metal film 30 having is obtained. The metal film 30 may be formed not only by plating but also by vapor deposition or the like. Finally, by cutting the coil 43 into a predetermined length, the coil 40 having the metal film 30 formed thereon can be obtained. Of course, after the steps shown in FIGS. 8A and 8B, as shown in FIG.
2 is cut into a predetermined length to form a coil 44, and then the coil 44 is plated as shown in FIG.
The coil 40 having the metal film 30 may be manufactured.

The coil 40 thus manufactured is
It is inserted into the electrode rod 16 and then subjected to the lamp manufacturing process. For example, as shown in FIG. 10A, after preparing an electrode structure 55 having the electrode rod 16 and the metal foil 24 and the like, as shown in FIG. Insert the coil 40. Thereafter, if necessary, as shown in FIG. 10C, a predetermined portion of the coil 40 (for example, one portion in the middle) is welded, and the welding portion 34 fixes the coil 40 to the electrode rod 16. .

As shown in FIG. 10C, the coil 4
When 0 is fixed to the electrode rod 16, the coil 40 can be floated (separated) from the electrode rod 16 except for the welded portion 34, so that a gap can be formed between the coil 40 and the electrode rod 16. The pressure load applied to the electrode rod 16 by the coil 40 can be reduced. In particular, when realizing a discharge lamp having a long life with light output, an electrode rod made of extremely high-purity tungsten is often used as the electrode rod 16, and the high-purity tungsten rod is not so high in purity. Compared with this, since the strength is reduced, when using a high-purity tungsten rod, the significance of adopting a pressure load reducing means due to the gap becomes significant.

As an example of a suitable high-purity electrode rod, the content of sodium (Na), potassium (K), and lithium (Li) contained in the electrode rod is 1 each.
It is below ppm. A lamp using such a high-purity electrode rod has an effect of effectively suppressing the blackening that may occur due to the presence of an alkali metal and suppressing the yellowing of the light color. be able to. This high-purity electrode rod is disclosed in WO 01
/ 298862 pamphlet (corresponding US application; 10/1
No. 11,067), which are hereby incorporated by reference.

The conditions such as the typical size of the coil 40 are as follows. Coil wire diameter is about 0.06m
m (about 60 μm), and the pitch center interval (spacing from the center of one line to the center of an adjacent line) is about 0.1 mm
(About 100 μm). The distance between the lines adjacent to each other is 0.04 mm (about 40 μm).
The reason why the coil is wound at intervals is that it is more difficult to wind the coil tightly without an interval than when the coil is wound at intervals.

If the metal film 30 in the first and second embodiments is made of Pt only, the following effects can be obtained. When the metal film 30 is made of Pt only, Pt (upper layer)
/ Au (lower layer), the adhesiveness is lower than that of the two-layer structure, but practically sufficient adhesiveness can be ensured, and only Pt can be made to exist in the arc tube 10. Since no Au is used, Au arc tube 1
Mixing into 0 can be prevented. As mentioned above, A
Although u is not an element that promotes blackening, Au is the arc tube 1.
When present in 0, the viscosity of the mercury 18 in the arc tube 10 increases, and in some cases, a phenomenon in which the mercury 18 connects the electrodes 12 and 12 ′ (so-called mercury bridge) is likely to occur. It turned out by experiment. In the case of the metal film 30 made of only Pt, the generation of such a mercury bridge can be mitigated. As a measure for preventing the generation of the mercury bridge, the electrode rod and the electrode rod may be displaced from each other. Specifically, the high-pressure mercury lamp (short arc type) when the arrangement distance D between one electrode and the other electrode of the pair of electrodes is 2 mm or less and the total enclosed mass of mercury is 150 mg / cm ³ or more. Mercury lamp)
, The shortest distance d (cm) between the tip of one electrode and the tip of the other electrode is calculated from the numerical value of (6M / 13.6π) ^1/3 when the total mass of enclosed mercury is M (g). Should be large. The measures to prevent the occurrence of this mercury bridge are:
Japanese Patent Application No. 2001-149500 (corresponding US application;
09 / 865,964), where:
These specifications are incorporated herein by reference. (Third Embodiment) A high pressure discharge lamp 400 according to a third embodiment of the present invention will be described with reference to FIG. FIG. 11 schematically shows the configuration of the lamp 400.

The lamp 400 of the present embodiment has the electrode rod 16
The region 21 containing the Vycor glass covers the sealing portion (20,
20 ') is different from the lamp 100 of the first embodiment. That is, in the lamp 400 of the present embodiment, the region 21 containing the Vycor glass is sealed so as to cover a part of the electrode rod 16 having the metal film 30 on the surface and a part of the metal foil (24, 24 ′). Stop (20,
20 '). In this structure, the periphery of the welded portion 32 is also covered with the region 21.

Vycor glass (trade name) is a glass in which an additive is mixed with quartz glass to lower the softening point to improve workability as compared with quartz glass, and its composition is, for example, Silica (SiO ₂ ) 96.5
% By weight, 0.5% by weight of alumina (Al ₂ O ₃ ) and 3% by weight of boron (B). During the sealing process in the lamp manufacturing stage, the composition in the region 21 is a mixture of Vycor glass and quartz glass, but more than half (or most) of the region 21 in the present embodiment.
Is occupied by Vycor glass. In the configuration shown in FIG. 11, more specifically, the Vycor glass contained in the region 21 includes the electrode rod 16 and the metal foil (24,
24 ') is distributed toward the outer wall of the sealing part (20, 20') (that is, from the center to the outer wall), and a large amount of Vycor glass is near the electrode rod and the metal foil (that is, toward the center). include.

As a result of an experiment conducted by the inventor of the present invention, the compressive strength of the lamp 400 of the present embodiment in which the region 21 is provided in the structure of the lamp 100 is surprisingly higher than that of the lamp 100. I found that it could be improved. The lamp 100 has a structure capable of raising the conventional pressure resistance strength of about 20 MPa at the highest to 30 MPa or more, but the lamp 400 of the present embodiment is further higher, up to about 40 MPa or more. The pressure resistance could be increased. 30MP
While a lamp having a pressure resistance of about a has not been realized, a pressure resistance of 40 MPa or more means
It can be said that the pressure resistance is amazing.

When the inventor of the present application conducted an experiment, when the enclosed mercury amount was 200 mg / cm ³ (corresponding to an operating pressure of 20 MPa), the color rendering index Ra was 60, but the enclosed mercury amount was 400 mg / cm ^3. In the case of (operating pressure of 40 MPa), the color rendering index Ra improved to 70. The arc brightness is 1.0 at 200 mg / cm ^3.
When it was set to 0, it was improved to 1.20 at 400 mg / cm ³ .

A method of manufacturing the lamp 400 will be described with reference to FIG. FIG. 12 shows a glass sleeve 21 'made of Vycor glass in the configuration shown in FIG.
At the base of the electrode rod 16, the welding point 32, and the metal foil 2.
It was covered so as to cover a part of the circumference of No. 4. The glass sleeve 21 'made of Vycor glass prepared in this embodiment has a cylindrical shape, and its outer diameter is 1.9 mm.
The inner diameter is 1.7 mm and the length is 5 mm. It is also possible to use a glass pipe in which the inner diameter of the side tube portion 22 near the boundary between the arc tube 10 and the side tube portion 22 of the glass pipe 50 is narrowed so that the glass sleeve 21 ′ can be easily fixed. In addition,
Prepare a glass sleeve made of quartz glass, and on the inner surface,
It is also possible to deposit Vycor glass powder and form the region 21 from the Vycor glass powder.

After performing the electrode inserting step as shown in FIG. 12, the lamp 400 is obtained by performing each step as shown in FIGS. 5A to 5D.

The structure provided with region 21 can be applied not only to the structure of lamp 100 but also to lamps 200 and 300. When applied to the lamp 300 shown in FIGS. 6 and 7, a coil 40 wound around the electrode rod 16 and
Over the part where the metal foil (24, 24 ') is located,
The area 21 may be provided.

The reason why the pressure-resistant strength is improved by the region 21 containing the Vycor glass is not clear at this point. Probably by vicor glass
It is speculated that the adhesiveness in the sealing part (20, 20 ′) may have increased. The region 21 may have a structure in which copper oxide or copper particles are dispersed. In order to disperse the copper oxide or the copper particles in the region 21, the copper oxide or the copper powder may be attached to the inner surface of the glass sleeve shown in FIG. 12, and then the sealing portion forming step may be performed. Inclusion of copper oxide or copper in the Vycor glass can be advantageous for increasing the pressure resistance. When copper oxide or copper is mixed in the region 21, black, red, or brown particle-like portions or glass-like portions are scattered in the glass. (Embodiment 4) The high pressure discharge lamps of Embodiments 1 to 3 can be combined with a reflecting mirror to form a lamp with a mirror or a lamp unit. FIG. 13 schematically shows a cross section of a lamp 900 with a mirror including the lamp 100 of the first embodiment.

The lamp 900 with a mirror is provided with a lamp 100 having a substantially spherical arc tube 10 and a pair of sealing portions (20, 20 '), and a reflecting mirror 60 for reflecting the light emitted from the lamp 100. ing. The lamp 100 is an example, and may be any of the lamps 200 to 400 of the above embodiment. The lamp with mirror 900 may further include a lamp house that holds the reflecting mirror 60. Here, the structure provided with the lamp house is included in the lamp unit.

The reflecting mirror 60 is, for example, a lamp 1 so that a parallel light flux, a condensed light flux that converges in a predetermined minute area, or a divergent light flux equivalent to that diverged from a predetermined minute area.
00 to reflect the emitted light. As the reflecting mirror 60, for example, a parabolic mirror or an ellipsoidal mirror can be used.

In the present embodiment, the base 56 is attached to one sealing portion 20 'of the lamp 100, and the sealing portion 2
The lead wire 26 extending from 0 ′ and the base 56 are electrically connected. The sealing portion 20 ′ and the reflecting mirror 60 are fixed and integrated with, for example, an inorganic adhesive (for example, cement). A lead wire 65 is electrically connected to the lead wire 26 of the sealing portion 20 located on the front opening side of the reflecting mirror 60, and the lead wire 65 extends from the lead wire 26 to the reflecting wire of the reflecting mirror 60. It extends to the outside of the reflecting mirror 60 through the lead wire opening 62. Reflector 6
A front glass can be attached to the front opening of No. 0, for example.

Such a lamp or lamp unit with a mirror can be attached to an image projection device such as a projector using liquid crystal or DMD, and is used as a light source for the image projection device. The high-pressure discharge lamp and the lamp or lamp unit with a mirror according to the above-described embodiment are used for a light source for an image projection device, a light source for an ultraviolet stepper, a light source for a competition stadium or a headlight of an automobile, and a projector for illuminating a road sign. It can also be used as a light source. (Other Embodiments) In the above embodiment, a mercury lamp using mercury as a light emitting substance has been described as an example of a high pressure discharge lamp, but in the present invention, the airtightness of the arc tube is maintained by the sealing portion (sealing portion). It can be applied to any high-pressure discharge lamp having a configuration. For example, it can be applied to a high pressure discharge lamp such as a metal halide lamp in which a metal halide is enclosed. This is because it is preferable to prevent leaks and cracks even in a metal halide lamp. Further, in recent years, a mercury-free metal halide lamp that does not contain mercury has been developed, but the present invention can be applied to such a mercury-free metal halide lamp.

Further, in the above-described embodiment, the case where the mercury vapor pressure is about 20 MPa or more (so-called ultra-high pressure mercury lamp) has been described, but application to a high pressure mercury lamp having a mercury vapor pressure of about 1 MPa is excluded. Not a thing. That is, the present invention can be applied to all high pressure discharge lamps including ultra high pressure mercury lamps and high pressure mercury lamps. In addition, the stable operation even at an extremely high operating pressure means that the lamp has high reliability. That is, the configuration of the present embodiment is applied to a lamp whose operating pressure is not so high (the operating pressure of the lamp is less than about 30 MPa, for example, about 20 MPa to 1MP.
When applied to a), it means that the reliability of the lamp operating at the operating pressure can be improved. Therefore, the configuration of the present embodiment can improve the lamp characteristics also in terms of reliability. Further, in the lamp of the above-described embodiment, the sealing part (20, 20 ′) is manufactured by the shrink method, but the one manufactured by the pinching method is not excluded.

In addition, the distance (arc length) between the pair of electrodes 12 and 12 'may be of a short arc type or longer than that. The lamp according to the above-described embodiment can be used in either an AC lighting type or a DC lighting type of lighting method. Moreover, the configurations of the above-described embodiments can be mutually adopted, that is, the first embodiment.
It is also possible to have a configuration in which any of the configurations 1 to 3 is combined.

The preferred examples of the present invention have been described above, but the description is not a limitation, and various modifications can of course be made.

In the case of a mercury lamp having a relatively high mercury vapor pressure, the following can be cited as known techniques in which the structure of the sealing portion is devised.

In Japanese Patent Laid-Open No. 2001-23570, 1
A sealing structure for improving the pressure resistance performance of an ultrahigh pressure mercury lamp of about 90 atm (19 MPa) is disclosed. An enlarged view of the main part of the sealing portion structure is shown in FIGS. 15 (a) and 15 (b). 15A is a plan view of a portion (electrode base portion) in which the electrode 112 is embedded in the sealing portion 120, and FIG. 15B is a cross-sectional view taken along the line BB. As shown in the figure, there is a gap 132 between the glass portion of the sealing portion 120 and the electrode 112.
A peeling layer 134 is formed on the surface of the glass portion on the second side. The peeling layer 134 is peeled from the surface of the electrode 112 during cooling after sealing in the lamp manufacturing stage, and thus the sealing portion 120.
A gap 132 is formed between the glass portion of the electrode and the electrode 112. According to the publication, it is stated that the gap 132 can prevent generation of fine cracks on the inner surface of the sealing portion 120.

As can be easily understood from FIG. 15, this sealing part structure is one in which the peeling layer 134 is brought into close contact with the surface of the glass part, and the electrode 1 embedded in the sealing part 120.
12 does not have a structure in which a metal film is formed on the surface.
In addition, the use of a metal film having poor wettability with the glass portion is incompatible with the technique of the publication because the peeling layer 134 needs to be in close contact with the surface of the glass portion.

In Japanese Patent Laid-Open No. 11-260315, 1
A foilless closure structure for a 50 W ultra high pressure mercury lamp is disclosed. FIG. 16 shows a cross-sectional configuration diagram of this closing structure. The closing structure 121 closes the arc tube 110 and has a conductive component-containing region (molybdenum-containing region) and a conductive component-free region (molybdenum-free region). The electrode mandrel 112 is arranged in the central hole of the closed part structure 121 so as to be tightly baked. The surface of the electrode mandrel 112 located in the center hole of the conductive component-free region is covered with the high-melting-point metal thin film 135, and the surface of the electrode mandrel 112 located in the center hole of the conductive component-containing region is The high melting point metal powder 136 is applied. A cathode terminal 127 is embedded and fixed in the conductive component-containing region. According to this publication, when the electrode core rod 112 is tightly baked in the central hole of the closed structure 121, even if the electrode core rod 112 is strongly hardened, the refractory metal thin film 135 and the refractory metal powder 136 do not cause cracks. It is stated that you can do so.

As can be easily understood from FIG. 16, the closing part structure 121 has no foil and is manufactured by the baking process. Therefore, the basic configuration is different from that of the present embodiment.

[0128]

According to the present invention, it is possible to provide a high-pressure discharge lamp exhibiting characteristics (for example, high withstand pressure strength and long life) superior to those of the conventional high-pressure discharge lamp. Pt, I
When at least one metal selected from the group consisting of r, Rh, Ru and Re is present in the arc tube, it is possible to provide a high pressure discharge lamp that effectively prevents blackening and prolongs its life. Can be provided. Further, Pt, Ir, R are formed on at least a part of the surface of the electrode in the sealing portion.
at least 1 selected from the group consisting of h, Ru, and Re
When a metal film composed of seed metal is formed,
It is possible to suppress the generation of cracks in the sealing portion located around the electrodes, and it is possible to provide a high-pressure discharge lamp having high withstand voltage strength. Further, when the metal film is not formed at the welded portion, the effect of preventing the foil from floating can be obtained. Even when the coil having on its surface at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re is wound around the electrode in the portion located inside the sealing portion, cracks Occurrence can be suppressed.

[Brief description of drawings]

FIG. 1A is a plan sectional view schematically showing a configuration of a high pressure discharge lamp 100 according to a first embodiment of the present invention. (B) is a side sectional view thereof.

FIG. 2 is a graph showing a relationship between a lighting time (h) and a luminous flux maintenance factor.

FIG. 3 is a sectional view schematically showing a configuration of a lamp 200 according to the first embodiment.

FIG. 4 is a process cross-sectional view for explaining an electrode inserting process.

5A to 5D are process cross-sectional views for explaining each process of the manufacturing method according to the first embodiment.

FIG. 6 is a sectional view schematically showing the configuration of a lamp 300 according to a second embodiment.

FIG. 7 is a sectional view schematically showing a configuration of a modified example of the lamp 300 according to the second embodiment.

8A to 8D are process charts for explaining a method for manufacturing the coil 40.

9A and 9B are process drawings for explaining another method for manufacturing the coil 40.

10 (a) to 10 (c) show the coil 40 and the electrode rod 16;
FIG. 7 is a process drawing for explaining a step of inserting / fixing into / from.

FIG. 11 is a sectional view schematically showing a configuration of a lamp 400 according to a third embodiment.

FIG. 12 is a process sectional view for explaining the electrode insertion process.

FIG. 13 is a sectional view schematically showing the configuration of a lamp with a mirror 900.

FIG. 14 is a cross-sectional view schematically showing the configuration of a conventional high pressure mercury lamp.

15 (a) and 15 (b) are cross-sectional views showing a configuration of a known sealing portion structure.

FIG. 16 is a cross-sectional view showing the configuration of a known closed part structure.

[Explanation of symbols]

10 arc tube 12, 12 'electrode (W electrode) 14 coils 15 Discharge space (inside tube) 16 electrode rod (W rod) 18 Luminescent substance (mercury) 20, 20 'sealing part 21 Area containing Vycor glass 21 'glass sleeve 22 Side tube part (glass part) 24, 24 'Metal foil (Mo foil) 26 Lead wire (external lead) 28 Mo tape (support member) 30 metal film 32 Welding points (connection points) 40 coils 50 glass pipes 52 chuck 54 burner 55 Electrode structure 56 mouthpiece 60 reflector 62 Lead wire opening 65 lead wire 100, 200, 300, 400 High-pressure discharge lamp 900 Lamp with mirror (lamp unit) 110 arc tube 112 W electrode 118 Luminescent substance (mercury) 120 sealing part 121 Block 124 Metal foil 126 External lead 134 Release layer 1000 super high pressure mercury lamp

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01J 9/395 H01J 9/395 D 61/073 61/073 B 61/12 61/12 A 61/36 61 / 36 B (72) Inventor Makoto Horiuchi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Tomoyuki Seki 1006 Kadoma, Kadoma City, Osaka Prefecture Inventor, Matsushita Electric Industrial Co., Ltd. (72) Ichibankase Go 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Shinichiro Hataoka 1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 5C012 AA08 LL01 RR09 5C015 JJ08 QQ46 QQ48 RR01 5C043 AA07 AA20 CC03 CD05 DD12 DD18 EA09 EB14 EC01

Claims (41)

[Claims] 1. A high-pressure discharge lamp comprising an arc tube in which a pair of electrodes are arranged so as to face each other, wherein the arc tube contains at least mercury and halogen, and the arc tube contains at least mercury. , Pt, Ir, R
at least 1 selected from the group consisting of h, Ru, and Re
A high-pressure discharge lamp in which the seed metal is present. 2. The high pressure discharge lamp according to claim 1, wherein the amount of mercury enclosed per unit volume of the arc tube is 230 mg / cc or more. 3. The high pressure discharge lamp according to claim 2, wherein the amount of mercury enclosed per unit volume of the arc tube is 300 mg / cc or more. 4. The high pressure discharge lamp according to claim 1, wherein the operating pressure in the arc tube is 23 MPa or more. 5. The high pressure discharge lamp according to claim 4, wherein the operating pressure in the arc tube is 30 MPa or more. 6. The metal present in the arc tube is Pt.
The high pressure discharge lamp according to claim 1, wherein 7. An arc tube in which a pair of electrodes are arranged so as to face each other in the tube, and a sealing section extending from the arc tube and having a part of the electrode therein are provided in the sealing section. A high-voltage discharge in which a metal film made of at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re is formed on at least a part of the surface of the electrode in the positioned portion. lamp. 8. The electrode is connected to a metal foil provided in the sealing portion by welding, the metal film is not formed at a connection portion with the metal foil, and the sealing is performed. The high pressure discharge lamp according to claim 7, which is formed on a surface of the electrode embedded in the portion. 9. The method according to claim 7, wherein a part of the metal forming the metal film exists inside the arc tube.
High-pressure discharge lamp described in. 10. The high pressure discharge lamp according to claim 7, wherein the metal film is a film made of Pt. 11. The high pressure discharge lamp according to claim 7, wherein the metal film has a multilayer structure in which a lower layer is an Au layer and an upper layer is a Pt layer. 12. An arc tube in which a pair of electrodes are arranged so as to face each other in the tube, a metal foil connected to the electrodes by welding, and a seal which extends from the arc tube and seals the metal foil. And a part of the metal foil and the electrode are embedded in the sealing part, and Pt, Ir are formed on the surface of the part of the electrode embedded in the sealing part. , Rh, Ru, Re, a metal film made of at least one metal selected from the group consisting of Re is formed, and the thickness of the metal film at a welding portion between the metal foil and the electrode is A. , A <B, where B is the thickness of the metal film other than the welded portion. 13. An arc tube in which a pair of electrodes are arranged so as to face each other in the tube, a metal foil connected to the electrodes by welding, and a seal which extends from the arc tube and seals the metal foil. And a part of the metal foil and the electrode are embedded in the sealing part, and Pt, Ir are formed on the surface of the part of the electrode embedded in the sealing part. , Rh, Ru, a metal film composed of at least one metal selected from the group consisting of Re is formed, the width of the metal foil at the welded portion of the metal foil and the electrode is C, A high pressure discharge lamp, wherein C <2D, where D is an outer diameter of the electrode at the welded portion. 14. The high pressure discharge lamp according to claim 12, wherein a part of the metal forming the metal film is present in the arc tube. 15. The high pressure discharge lamp according to claim 12, wherein the metal film is a film made of Pt. 16. The high pressure discharge lamp according to claim 12, wherein the metal film has a multilayer structure in which a lower layer is an Au layer and an upper layer is a Pt layer. 17. A Pt, Ir, Rh provided with an arc tube in which a pair of electrodes are arranged to face each other in the tube, and a sealing portion extending from the arc tube and having a part of the electrode therein. , Ru, Re, a high pressure discharge lamp in which a coil having at least one kind of metal selected from the group consisting of Ru, Re, is wound around the electrode in a portion located inside the sealing portion. 18. An arc tube in which a pair of electrodes are arranged so as to face each other in the tube, a metal foil connected to the electrodes by welding, and a seal which extends from the arc tube and seals the metal foil. And a part of the metal foil and the electrode are embedded in the sealing part, and at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re is surfaced. High-pressure discharge lamp, wherein the coil included in 1. is wound around the electrode embedded in the sealing portion. 19. The high pressure discharge lamp according to claim 17, wherein a part of the metal forming the metal film is present in the arc tube. 20. The coil has a metal film made of Pt on the surface thereof.
High-pressure discharge lamp described in. 21. The coil has a lower layer of A on the surface thereof.
The high pressure discharge lamp according to claim 17 or 18, wherein the u layer and the upper layer each have a metal film having a multi-layered structure including a Pt layer. 22. At least mercury and halogen are contained in the arc tube, and at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, Re is contained in the arc tube. Exists,
A high pressure discharge lamp according to any one of claims 7 to 21. 23. The high pressure discharge lamp according to claim 22, wherein the amount of mercury enclosed per unit volume of the arc tube is 230 mg / cc or more. 24. The high pressure discharge lamp according to claim 23, wherein the amount of mercury enclosed per unit volume of the arc tube is 300 mg / cc or more. 25. The operating pressure in the arc tube is 23 MPa.
The high pressure discharge lamp according to claim 22, which is as described above. 26. The operating pressure in the arc tube is 30 MPa.
The high pressure discharge lamp according to claim 25, which is as described above. 27. The metal present in the arc tube is P
23. The high pressure discharge lamp of claim 22, wherein t is t. 28. A step (a) of preparing a glass tube having a light emitting tube portion to be a light emitting tube of a high pressure discharge lamp and a side tube portion extending from the light emitting tube portion; and a metal foil having one end of an electrode rod. An electrode structure connected by welding to Pt, Ir, Rh, on at least a part of the surface of the portion of the electrode rod located in the side tube portion.
A step (b) of preparing an electrode structure on which a metal film made of at least one metal selected from the group consisting of Ru and Re is formed, and the tip of the electrode rod is located inside the arc tube portion. like,
A step (c) of inserting the electrode structure into the side tube portion, and a step (d) of heating and sealing the side tube portion so that the side tube portion and the metal foil are in close contact with each other. A method of manufacturing a high-pressure discharge lamp, including: 29. In the step (b), the thickness of the metal film at the welded portion of the metal foil and the electrode rod is A, and the thickness of the metal film other than the welded portion is B. 29. The method of manufacturing a high pressure discharge lamp according to claim 28, wherein the electrode structure with A, B <B is prepared. 30. In the step (b), the width of the metal foil at the welded portion of the metal foil and the electrode rod is C
And the outer diameter of the electrode rod at the welding location is D, the electrode structure with C <2D is prepared.
The method of manufacturing a high pressure discharge lamp according to claim 28. 31. The method according to claim 28, wherein the metal film in the step (b) is a film composed of Pt.
A method for manufacturing a high pressure discharge lamp according to any one of 1. 32. The high-voltage discharge according to claim 28, wherein the metal film in the step (b) has a multilayer structure in which a lower layer is an Au layer and an upper layer is a Pt layer. Lamp manufacturing method. 33. By the heating in the step (d),
33. The method for manufacturing a high pressure discharge lamp according to claim 28, wherein a part of the metal forming the metal film is introduced into the arc tube portion. 34. A step (a) of preparing a glass tube having a light emitting tube portion to be a light emitting tube of a high pressure discharge lamp and a side tube portion extending from the light emitting tube portion; and one end of the electrode rod being a metal foil. An electrode structure connected by welding to the coil, the coil having on the surface thereof at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, Re; Step (b) of preparing an electrode structure wound around the electrode rod
And so that the tip of the electrode rod is located in the arc tube portion,
A step (c) of inserting the electrode structure into the side tube portion, and a step (d) of heating and sealing the side tube portion so that the side tube portion and the metal foil are in close contact with each other. A method of manufacturing a high-pressure discharge lamp, including: 35. A step (b) of preparing the electrode structure.
Includes a step of inserting a coil having the at least one metal on a surface thereof into the electrode rod in the electrode structure, and a step of welding the coil inserted into the electrode rod to the electrode rod, The method of manufacturing a high pressure discharge lamp according to claim 34. 36. The method for manufacturing a high pressure discharge lamp according to claim 34, wherein the coil in the step (b) has a metal film made of Pt on the surface thereof. 37. The coil in the step (b) has a metal film having a multi-layer structure in which a lower layer is an Au layer and an upper layer is a Pt layer, on the surface thereof.
A method for manufacturing a high pressure discharge lamp according to. 38. By the heating in the step (d),
38. The method for manufacturing a high pressure discharge lamp according to claim 34, wherein a part of the metal coating the surface of the coil is introduced into the arc tube portion. 39. The method for manufacturing a high pressure discharge lamp according to claim 34, further comprising the step of introducing at least mercury and halogen into the arc tube portion. 40. The method of manufacturing a high pressure discharge lamp according to claim 39, wherein, in the introducing step, a mercury filling amount per unit volume of the arc tube is 230 mg / cc or more. 41. The method for producing a high pressure discharge lamp according to claim 39, wherein in the introducing step, the amount of mercury enclosed per unit volume of the arc tube is 300 mg / cc or more.