JP2004221069A - Manufacturing method of high-pressure discharge lamp, high-pressure discharge lamp and lamp unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of surely manufacturing a high pressure discharge lamp having high pressure-resistant strength. <P>SOLUTION: The high pressure discharge lamp 100 comprises an arc tube 1 in which a luminescent material is filled and a sealing part 2 for holding airtightness of the arc tube 1, and the sealing part 2 has a first glass section 8 extending from the arc tube 1 and a second glass section 7 provided at least at a part inside the first glass section 8, and the sealing part 2 has a portion (20) on which compressive stress is impressed, and mercury bromide (HgBr<SB>2</SB>) is filled in the arc tube 1. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a high-pressure discharge lamp, a high-pressure discharge lamp, and a lamp unit. In particular, the present invention relates to a method of manufacturing a high pressure discharge lamp used for general lighting, a projector, a headlight of an automobile, and the like in combination with a reflector.

  In recent years, image projection apparatuses such as liquid crystal projectors and DMD projectors have been widely used as systems for realizing large-screen images. In such image projection apparatuses, high-pressure discharge lamps exhibiting high luminance are generally widely used. ing. FIG. 12 schematically shows a configuration of a conventional high-pressure discharge lamp 1000. The lamp 1000 shown in FIG. 12 is a so-called extra-high pressure mercury lamp, and is disclosed in, for example, Patent Document 1.

  The lamp 1000 has an arc tube (bulb) 101 made of quartz glass, and a pair of sealing portions (seal portions) 102 extending from both ends of the arc tube 101. A luminous substance (mercury) 106 is sealed in the discharge tube 101 (discharge space), and a pair of tungsten electrodes (W electrodes) 103 made of tungsten are opposed to each other at a predetermined interval. Is arranged. One end of the W electrode 103 is welded to a molybdenum foil (Mo foil) 104 in the sealing portion 102, and the W electrode 103 and the Mo foil 104 are electrically connected. An external lead (Mo bar) 105 made of molybdenum is electrically connected to one end of the Mo foil 104. The arc tube 101 also contains argon (Ar) and a small amount of halogen in addition to the mercury 106.

  The operation principle of the lamp 1000 will be briefly described. When a starting voltage is applied between the W electrodes 103 and 103 via the external lead 105 and the Mo foil 104, a discharge of argon (Ar) occurs. The temperature in the discharge space 101 rises, whereby the mercury 106 is heated and vaporized. Thereafter, mercury atoms are excited at the center of the arc between the W electrodes 103 to emit light. The higher the mercury vapor pressure of the lamp 1000 is, the more radiated light is. Therefore, the higher the mercury vapor pressure is, the more suitable it is as a light source of the image projection apparatus. However, from the viewpoint of the physical pressure resistance of the arc tube 110, it is 15-20 MPa (150 The lamp 1000 is used at mercury vapor pressures in the range (-200 atm).

As a related document, there is Patent Document 2 described later.
JP-A-2-148561 JP 2001-23570 A

  The above-described conventional lamp 1000 has a pressure resistance of about 20 MPa, and research and development for further increasing the pressure resistance have been performed to further improve the lamp characteristics (for example, see Patent Document 2). In order to realize a higher-performance image projection device today, a lamp with higher output and higher power is required, and a lamp with higher pressure resistance is required to satisfy this demand. Because.

  More specifically, in the case of a high-output, high-power lamp, in order to prevent the electrode from evaporating faster with an increase in current, more mercury is enclosed than usual to increase the lamp voltage. There is a need. If the amount of enclosed mercury is not enough for the lamp power, the lamp voltage cannot be increased to the required level, increasing the lamp current and consequently evaporating the electrodes quickly, realizing a practical lamp. Can not. In other words, from the viewpoint of realizing a high-power lamp, it is only necessary to increase the lamp power and to produce a short-arc lamp in which the distance between the electrodes is shorter than that of the conventional lamp. In order to produce a high-power, high-power lamp, it is necessary to improve the pressure resistance and increase the amount of enclosed mercury. In today's technology, a high-pressure discharge lamp that can be practically used with an extremely high pressure resistance (for example, about 30 MPa or more) has not yet been realized.

  The present inventors have succeeded in developing a high-pressure discharge lamp exhibiting extremely high pressure resistance (for example, about 30 MPa or more), and disclosed it in Japanese Patent Application No. 2002-351524. However, it has been found that even such an excellent high-pressure discharge lamp can be further improved by improving the manufacturing method.

  The present invention has been made in view of the above points, and a main object of the present invention is to provide a method for more effectively manufacturing a high-pressure discharge lamp having high pressure resistance.

A method for manufacturing a high-pressure discharge lamp according to the present invention is a method for manufacturing a high-pressure discharge lamp including a light-emitting tube in which a light-emitting substance is sealed in a tube, and a sealing portion for maintaining the airtightness of the light-emitting tube. A step of preparing a discharge lamp glass pipe having a light emitting tube part to be the light emitting tube and a side tube part extending from the light emitting tube part; and introducing mercury bromide (HgBr ₂ ) into the light emitting tube part. And forming the sealing portion from the side tube portion, wherein the step of forming the sealing portion has a lower softening point than the first glass constituting the side tube portion. Inserting a glass member made of glass of No. 2 into the side tube portion, and then heating the side tube portion to bring the glass member into close contact with the side tube portion; At a temperature higher than the strain point temperature of the second glass, And it includes a heating step of heating the at least containing part of the side tube portion.

  Preferably, the heating step is performed at a temperature lower than a strain point temperature of the first glass.

In a preferred embodiment, the glass member is a glass tube or a glass plate composed of SiO ₂ and at least one of Al ₂ O ₃ of 15% by weight or less and B of 4% by weight or less.

Another method for manufacturing a high-pressure discharge lamp of the present invention is a method for manufacturing a high-pressure discharge lamp including a light-emitting tube in which a light-emitting substance is sealed in a tube, and a pair of sealing portions extending from both ends of the light-emitting tube. A step of preparing a glass pipe for a discharge lamp having an arc tube part to be an arc tube of a high-pressure discharge lamp and a pair of side tube parts extending from both ends of the arc tube part; A glass tube made of a second glass having a lower softening point than the first glass constituting the side tube portion, and an electrode structure including at least an electrode rod, into one of the side tube portions; Next, a step of forming one sealing portion of the pair of sealing portions by heat shrinking the side tube portion; and after forming the one sealing portion, inside the arc tube portion, introducing a luminous substance and mercury bromide (HgBr _2); After introducing the luminescent substance, a glass tube made of the second glass and an electrode structure including at least an electrode rod are inserted into the other side tube portion with respect to the one, and then the side tube portion is inserted. Forming a light emitting tube in which the other sealing portion and the light emitting substance are sealed with respect to the one by heating and shrinking; and a lamp completed body in which both the sealing portion and the light emitting tube are formed. A heating step of heating a portion including at least the glass tube and the side tube portion at a temperature higher than the strain point temperature of the second glass, and at a temperature lower than the strain point temperature of the first glass; ;

  The heating step is preferably performed for 2 hours or more.

  In a preferred embodiment, the heating step is performed for 100 hours or more.

In a preferred embodiment, when the sealing portion is measured by using a sensitive color plate method utilizing a photoelastic effect, the region formed of the second glass has a thickness of 10 kgf / cm ^{2 to} 50 kgf / cm ^2. The heating step is performed so that the following compressive stress in the longitudinal direction of the side tube portion exists.

  In a preferred embodiment, the compressive stress is generated in each of the pair of sealing portions.

  In a preferred embodiment, the heating is performed by disposing the completed lamp body in a furnace having a temperature higher than the strain point of the second glass and lower than the strain point of the first glass. Be executed.

  In a preferred embodiment, the inside of the furnace is in a vacuum or reduced pressure state.

In a preferred embodiment, the first glass contains 99% by weight or more of SiO ₂ and the second glass contains at least 15% by weight or less of Al ₂ O ₃ and 4% by weight or less of B. One includes SiO ₂ .

  In a preferred embodiment, the temperature of the heating is 1030 ° C. ± 40 ° C.

In one embodiment, the high-pressure discharge lamp is a high-pressure mercury lamp, and contains 150 mg / cm ³ or more of mercury as the luminescent substance based on the inner volume of the arc tube.

A high-pressure discharge lamp according to the present invention includes a light emitting tube in which a light emitting substance is sealed in a tube, and a sealing portion for maintaining the airtightness of the light emitting tube, wherein the sealing portion extends from the light emitting tube. A first glass part and a second glass part provided at least partially inside the first glass part, and the sealing part is a part to which a compressive stress is applied. And the mercury bromide (HgBr ₂ ) is sealed in the arc tube.

Another high-pressure discharge lamp of the present invention includes a light-emitting tube in which a light-emitting substance is sealed in a tube, and a pair of sealing portions that maintain the hermeticity of the light-emitting tube, and each of the pair of sealing portions is A first glass portion extending from the arc tube, a second glass portion provided at least partially inside the first glass portion, and the pair of sealing portions; Each has a portion to which a compressive stress is applied, and the compressive stress is the second glass when the sealing portion is measured using a sensitive color plate method utilizing a photoelastic effect. In the region corresponding to the portion, the pressure is 10 kgf / cm ² or more and 50 kgf / cm ² or less, and a pair of electrode rods are arranged in the arc tube so as to face each other. Is connected to a metal foil, and the metal foil is And at least a connection portion between the metal foil and the electrode bar is located in the second glass portion, and the arc tube contains mercury bromide (HgBr ₂ ) as a halogen precursor. Is enclosed.

In one embodiment, the high-pressure discharge lamp is a high-pressure mercury lamp, and 150 mg / cm ³ or more of mercury is filled as the luminescent substance based on the inner volume of the arc tube.

In a preferred embodiment, mercury as the luminescent substance is enclosed in an amount of 220 mg / cm ³ or more based on the inner volume of the arc tube.

In a preferred embodiment, mercury as the luminescent substance is sealed in at least 300 mg / cm ^{3 based} on the inner volume of the arc tube.

  In a preferred embodiment, the arc tube is a chipless arc tube.

  A lamp unit according to the present invention includes the high-pressure discharge lamp described above and a reflector that reflects light emitted from the high-pressure discharge lamp.

  In one embodiment, the electrode structure includes the electrode rod, a metal foil connected to the electrode rod, and an external lead connected to the metal foil.

  It is preferable that 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 electrode rod.

  In one embodiment, a coil having at least a surface of at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re is wound around at least a part of the electrode rod.

  In one embodiment, a small-diameter portion in which the inner diameter of the side tube portion is smaller than other portions is provided around a boundary between the side tube portion and the arc tube portion in the discharge lamp glass pipe. .

  A high-pressure discharge lamp according to one embodiment includes a light emitting tube in which a light emitting substance is sealed in a tube, and a sealing portion for maintaining the airtightness of the light emitting tube, and the sealing portion extends from the light emitting tube. It has a first glass part and a second glass part provided on at least a part of the inside of the first glass part, and executes a strain measurement by a sensitive color plate method utilizing a photoelastic effect. Then, a compressive stress is observed in at least a part of a region corresponding to the second glass portion in the sealing portion.

  The distortion measurement may be performed using a SVP-200 distortion inspection device manufactured by Toshiba.

In the present invention, since the mercury bromide (HgBr ₂ ) is introduced into the arc tube portion, the composition deformation of the second glass can be suppressed. Therefore, compression strain can be effectively applied to the second glass part, or cracks can be prevented from being generated between the second glass part and the first glass part. As a result, a high pressure discharge lamp having high pressure resistance can be manufactured more effectively.

  The present invention can be applied not only to a high-pressure mercury lamp but also to other high-pressure discharge lamps such as a metal halide lamp and a xenon lamp, and can also be applied to a mercury-free mercury-free metal halide lamp. Since the mercury-free metal halide lamp according to the present invention has a high pressure resistance, a rare gas can be sealed at a high pressure, and as a result, the efficiency can be easily improved, and the startability of lighting can be improved. The present invention can be applied not only to a high-pressure mercury lamp but also to a light bulb (for example, a halogen light bulb), whereby the explosion can be prevented more than the conventional one.

According to the present invention, since the mercury bromide (HgBr ₂ ) is sealed in the arc tube, the composition deformation of the second glass can be suppressed, and as a result, a high-pressure discharge lamp having high pressure resistance can be obtained more reliably. Manufactured and provided.

  First, before describing an embodiment of the present invention, a high-pressure mercury lamp having an extremely high withstand voltage having a lighting operating pressure of about 30 to 40 MPa or more (about 300 to 400 atm or more) will be described. The details of these high-pressure mercury lamps are disclosed in Japanese Patent Application No. 2001-371365. Japanese Patent Application No. 2002-351524 discloses a mechanism in which distortion occurs in a sealing portion of a high-pressure discharge lamp disclosed in Japanese Patent Application No. 2001-371365. Here, these patent applications are incorporated herein by reference.

  It has been extremely difficult to develop a high-pressure mercury lamp that can withstand practical use even though the operating pressure is about 30 MPa or more. For example, by adopting a configuration as shown in FIG. Successfully completed the lamp. FIG. 1B is a cross-sectional view taken along line bb in FIG. 1A.

  The high-pressure discharge lamp (for example, a high-pressure mercury lamp or an ultra-high-pressure mercury lamp) 100 shown in FIG. 1 is disclosed in Japanese Patent Application No. 2001-371365, and maintains the luminous tube 1 and hermeticity of the luminous tube 1. A pair of sealing portions 2 is provided, and at least one of the sealing portions 2 is provided on the first glass portion 8 extending from the arc tube 1 and at least a part inside the first glass portion 8. The second sealing portion 2 includes a portion (20) to which a compressive stress is applied.

It is sufficient that the compressive stress applied to a part of the sealing portion 2 exceeds substantially zero (that is, 0 kgf / cm ² ). Due to the presence of this compressive stress, the pressure resistance can be improved as compared with the conventional structure. This compressive stress is preferably about 10 kgf / cm ² or more (about 9.8 × 10 ⁵ N / m ² or more), and about 50 kgf / cm ² or less (about 4.9 × 10 ⁶ N / m ² or more). ² or less). If it is less than 10 kgf / cm ² , the compressive strain is weak, and the pressure resistance of the lamp may not be sufficiently increased. This is because there is no practical glass material for realizing such a configuration exceeding 50 kgf / cm ² . However, even if it is less than 10 kgf / cm ² , if the value substantially exceeds 0, the withstand voltage can be increased as compared with the conventional structure, and a practical configuration capable of achieving a configuration exceeding 50 kgf / cm ² can be realized. If a suitable material is developed, the second glass part 7 may have a compressive stress exceeding 50 kgf / cm ² .

The first glass part 8 in the sealing part 2 contains 99% by weight or more of SiO ₂ and is made of, for example, quartz glass. On the other hand, the second glass portion 7 contains at least one of Al ₂ O ₃ of 15% by weight or less and B of 4% by weight or less and SiO _2, and is made of, for example, Vycor glass. I have. When Al ₂ O ₃ or B is added to SiO ₂ , the softening point of the glass is lowered, so that the softening point of the second glass part 7 is lower than the softening point temperature of the first glass part 8. In order to lower the softening point of the second glass part 7 as described above, the total amount of Al ₂ O ₃ and B contained in the second glass part 7 is preferably more than 1% by weight. Vycor glass (Vycor glass; trade name) is a glass in which an additive is mixed into quartz glass to lower the softening point and improve workability compared to quartz glass. -It can be produced by chemical treatment to approximate the characteristics of quartz. The composition of Vycor glass is, for example, 96.5% by weight of silica (SiO ₂ ), 0.5% by weight of alumina (Al ₂ O ₃ ), and 3% by weight of boron (B). In the present embodiment, the second glass part 7 is formed from a glass tube made of Vycor glass. Instead of the glass tube made of Vycor, SiO _2: 62 wt%, Al ₂ O _3: 13.8 wt%, CuO: may 23.7% by weight using a glass tube whose components.

  The electrode rod 3 whose one end is located in the discharge space is connected by welding to a metal foil 4 provided in the sealing portion 2, and at least a part of the metal foil 4 is placed in the second glass portion 7. positioned. In the configuration shown in FIG. 1, the portion including the connection portion between the electrode bar 3 and the metal foil 4 is configured to be covered by the second glass portion 7. As shown in FIG. 1B, the entire periphery of the metal foil 4 is covered with the second glass part 7 in a cross section of the sealing part 2 (a cross section orthogonal to the longitudinal direction of the sealing part 2). . Thus, at least a part of the metal foil 4 is entirely covered in the width direction by the second glass part 7, and the edge part of the metal foil 4 is surrounded by the second glass part 7 in this part. ing. When the size of the second glass part 7 in the configuration shown in FIG. 1 is exemplified, the length in the longitudinal direction of the sealing part 2 is about 2 to 20 mm (for example, 3 mm, 5 mm, 7 mm). The thickness of the second glass part 7 sandwiched between the glass part 8 and the metal foil 4 is about 0.01 to 2 mm (for example, 0.1 mm). The distance H from the end face of the second glass part 7 on the arc tube 1 side to the discharge space 10 of the arc tube 1 is about 0 mm to about 6 mm (for example, 0 mm to about 3 mm, or 1 mm to 6 mm). When it is not desired to expose the second glass part 7 in the discharge space 10, the distance H is larger than 0 mm, for example, 1 mm or more. The distance B from the end face of the metal foil 4 on the arc tube 1 side to the discharge space 10 of the arc tube 1 (in other words, the length buried in the sealing portion 2 by the electrode rod 3 alone) is, for example, It is about 3 mm.

  Next, the compression strain in the sealing portion 2 will be described. 2 (a) and 2 (b) schematically show the distribution of compressive strain along the longitudinal direction (the electrode axis direction) of the sealing portion 2, and FIG. 2 (a) shows the second glass portion. 2B shows a case of a configuration of a lamp 100 provided with a second glass part 7, while FIG. 2B shows a case of a configuration of a lamp 100 ′ without a second glass part 7 (comparative example).

  In the sealing portion 2 shown in FIG. 2A, a compressive stress (compression strain) exists in a region (shaded region) corresponding to the second glass portion 7, and a portion of the first glass portion 8 ( The magnitude of the compressive stress in the hatched area) is substantially zero. On the other hand, as shown in FIG. 2B, in the case of the sealing portion 2 without the second glass portion 7, there is no portion where the compressive strain exists locally, and the compressive stress of the first glass portion 8 does not exist. Is substantially zero.

  The inventor of the present application actually measured the distortion of the lamp 100 quantitatively and observed that a compressive stress was present in the second glass part 7 of the sealing part 2. Quantification of this distortion was performed using a sensitive color plate method utilizing the photoelastic effect. The measuring instrument used for quantifying the strain is a strain tester (SVP-200, manufactured by Toshiba). When this strain tester is used, the magnitude of the compressive strain of the sealing portion 2 is determined by the sealing portion. 2 can be obtained as an average value of the stress applied.

  With reference to FIG. 13, the principle of strain measurement by the sensitive color plate method utilizing the photoelastic effect will be briefly described. FIGS. 13A and 13B schematically show a state in which linearly polarized light transmitted through a polarizing plate is incident on glass. Here, assuming that the oscillation direction of the linearly polarized light is u, u can be regarded as a result of combining u1 and u2.

As shown in FIG. 13A, when the glass has no distortion, u1 and u2 pass through the glass at the same speed, so that there is no deviation between the transmitted light u1 and u2. On the other hand, as shown in FIG. 13B, when the glass is distorted and the stress F is applied, u1 and u2 do not pass through the glass at the same speed. Shift occurs between them. That is, one of u1 and u2 is later than the other. This delayed distance is called an optical path difference. The optical path difference R is proportional to the stress F and the passing distance L of the glass.
R = C ・ F ・ L
Can be represented by Here, the unit of each symbol is R (nm), F (kgf / cm ² ), L (cm), and C ({nm / cm} / {kgf / cm ² }), respectively. C is made of a material such as glass and is called a photoelastic constant. As can be seen from the above equation, if C is known, F can be obtained by measuring L and R.

  The inventor of the present application measures the transmission distance L of light in the sealing portion 2, that is, the outer diameter L of the sealing portion 2, and uses a strain standard to determine the optical path from the color of the sealing portion 2 at the time of measurement. The difference R was read. As the photoelastic constant C, a photoelastic constant 3.5 of quartz glass was used. These were substituted into the above equation, and the compressive strain in the longitudinal direction of the metal foil 4 was quantified from the result of the calculated stress value.

  In this measurement, the stress in the longitudinal direction of the sealing portion 2 (the direction in which the electrode axis 3 extends) was observed, but this does not mean that there is no compressive stress in other directions. Absent. It is measured whether or not a compressive stress exists in the radial direction of the sealing portion 2 (the direction from the central axis toward the outer circumference or the opposite direction) or the circumferential direction of the sealing portion 2 (for example, clockwise). In this case, it is necessary to cut the arc tube 1 and the sealing portion 2, but as soon as such cutting is performed, the compressive stress of the second glass portion 7 is reduced. Therefore, since it is the compressive stress in the longitudinal direction of the sealing portion 2 that can be measured without cutting the lamp 100, the present inventor quantified at least the compressive stress in that direction. It is.

  In the lamp 100 of the present embodiment, since the second glass portion 7 provided at least partially inside the first glass portion 8 has a compressive strain (at least a compressive strain in the longitudinal direction), a high pressure is applied. The pressure resistance of the discharge lamp can be improved. In other words, the lamp 100 of the present embodiment shown in FIGS. 1 and 2A can have a higher pressure resistance than the lamp 100 'of the comparative example shown in FIG. 2B. The lamp 100 of the present embodiment shown in FIG. 1 can be operated at an operating pressure of 30 MPa or more, which exceeds the conventional maximum operating pressure of about 20 MPa.

  Next, with reference to FIG. 14, the reason why the compressive strain is applied to the second glass portion 7 and the pressure resistance of the lamp 100 increases will be described. FIG. 14A is an enlarged view of a main part of the sealing part 2 of the lamp 100, while FIG. 14B is an enlarged view of a main part of the sealing part 2 of the lamp 100 'of the comparative example.

  Although there is actually no clear explanation of the mechanism for increasing the pressure resistance of the lamp 100, the inventor of the present application has inferred the following as follows.

  First, as a premise, since the metal foil 4 in the sealing portion 2 is heated and expanded during the lamp operation, a stress from the metal foil 4 is applied to the glass portion of the sealing portion 2. More specifically, in addition to the fact that metal has a higher coefficient of thermal expansion than glass, the metal foil 4 that is thermally connected to the electrode rod 3 and through which current flows is sealed. Since the heating portion is more easily heated than the glass portion of the stop portion 2, stress is easily applied to the glass portion from the metal foil 4 (particularly, from the side surface of the foil having a small area).

  Here, as shown in FIG. 14A, it is considered that when a compressive stress is applied in the longitudinal direction of the second glass portion 7, the generation of the stress 16 from the metal foil 4 can be suppressed. In other words, it is considered that the generation of the large stress 16 can be suppressed by the compressive stress 15 of the second glass portion 7. As a result, for example, cracks are generated in the glass portion of the sealing portion 2, and the occurrence of leakage between the glass portion of the sealing portion 2 and the metal foil 4 is reduced, and the strength of the sealing portion 2 is improved. Will be.

  On the other hand, as shown in FIG. 14B, in the case of the structure without the second glass portion 7, the stress 17 from the metal foil 4 is larger than in the case of the structure shown in FIG. I think it will be. That is, since there is no region to which a compressive stress is applied around the metal foil 4, the stress 17 from the metal foil 4 seems to be larger than the stress 16 shown in FIG. Therefore, it is inferred that the configuration shown in FIG. 14A can improve the withstand pressure strength more than the configuration shown in FIG. 14B. This idea seems to be compatible with the general property of glass that glass tends to break when it has tensile strain (tensile stress) and hardly breaks when it has compressive strain (compression stress).

  However, it cannot be inferred from the fact that the sealing portion 2 of the lamp 100 has a high pressure resistance because of the general property of the glass that the glass is hardly broken when a compressive stress is applied. This is because even if the strength of the glass in the region where the compressive strain is applied is increased, the load is generated as compared with the case where there is no strain when viewed as a whole of the sealing portion 2. This is because the idea that the strength of the sealing portion 2 as a whole decreases rather can be established. The result that the pressure resistance of the lamp 100 was improved was found only when the inventor of the present invention prototyped and experimented with the lamp 100 and could not be derived from theory alone. If an unnecessarily large compressive stress remains in the second glass portion 7 (or a peripheral region thereof), the sealing portion 2 is actually damaged when the lamp is turned on, and the life of the lamp is rather shortened. It might be shorter. Considering such a thing, it is considered that the structure of the lamp 100 having the second glass portion 7 shows its high pressure resistance under an exquisite balance. When the portion of the arc tube 1 is cut, it is inferred from the fact that the stress distortion of the second glass portion 7 is relieved. The load caused by the stress distortion of the second glass portion 7 is well received by the entire arc tube 1. Maybe.

  It is also considered that the structure exhibiting the high pressure resistance is provided by the portion 20 to which the compressive stress generated by the difference in the compressive stress between the first glass portion 8 and the second glass portion 7 is applied. Can be That is, substantially no compressive stress is applied to the first glass portion 8, and the second glass portion 7 (or the periphery thereof) located closer to the center than the portion 20 to which the compressive stress is applied. It can be inferred that the compression strain was successfully confined to only the region, and that excellent pressure resistance characteristics were successfully exhibited. As a result of the stress values being discretely shown due to the principle of strain measurement by the sharp color plate method, the portion 20 to which compressive stress is applied is clearly shown in FIG. 14 and the like. However, even if the actual stress value can be continuously shown, it is considered that the stress value changes sharply in the portion 20 to which the compressive stress is applied, and in the region where the steep change occurs, It is thought that the part 20 to which the compressive stress is applied can be defined.

When manufacturing the lamp 100, first, after forming a sealing portion from one side tube portion of the glass pipe for a discharge lamp, as shown in FIG. The issuing material (mercury) 6 is introduced thereinto, and at this time, as shown by an arrow 60 in the figure, CH ₂ Br ₂ which is a halogen precursor substance which is decomposed into halogen is introduced. Next, the electrode structure 50 including the electrode rod 3 is inserted into the other side tube portion 2 '. FIG. 3B shows a cross section taken along line bb in FIG. 3A. Finally, when the side tube portion 2 'is sealed, a lamp having the sealing portion 2 having the second glass portion 7 is obtained.

To extend the life of a high-pressure discharge lamp, it is necessary to use a halogen cycle. To achieve a long-life lamp, a halogen precursor (CH ₂ Br ₂ ) that decomposes to generate halogen is introduced. The process becomes important. Alternatively, HBr may be introduced instead of CH ₂ Br ₂ . Regarding the amount of halogen required to maintain a good halogen cycle, refer to International Application No. PCT / JP00 / 04561 (International filing date: July 6, 2000, applicant: Matsushita Electric Industrial Co., Ltd.). It is detailed. Here, International Application No. PCT / JP00 / 04561 is incorporated herein by reference. Although bromine itself (Br ₂ ) can be used as a halogen species, bromine is a highly reactive substance. Considering handling, a halogen precursor (for example, CH ₂ Br ₂ , HBr).

In the state shown in FIG. 3, if there is no glass tube 70 serving as the second glass part 7, there is no particular problem in introducing CH ₂ Br ₂ or HBr. The inventor of the present application has introduced a halogen precursor (for example, CH ₂ Br ₂ ) as a halogen species as in the case where the glass tube 70 is not inserted, but has noticed that the following problem occurs. Was.

The glass tube 70 is made of glass (for example, Vycor glass) having a melting point lower than that of the quartz glass constituting the side tube portion 2 ′. As described above, this glass is made by mixing an additive into quartz glass. It has a form. The halogen precursor (CH ₂ Br ₂ or HBr) does not substantially react with the quartz glass (side tube portion 2 ′), but affects the glass (Vycor glass) constituting the glass tube 70, It changes its composition. In particular, after the state shown in FIG. 3A in which the introduction of the halogen precursor is completed, when the periphery of the side tube portion 2 ′ is heated with a burner or the like to form a sealing portion, the glass tube 70 is heated. Since the gas consisting of the halogen precursor which is attached and exists in the arc tube portion 1 'acts as a corrosive gas for the glass tube 70, the glass tube 70 is exposed to a high-temperature corrosive gas. Would. Then, the composition of the glass tube 70 changes due to the disappearance of, for example, the Na component of the glass tube 70. As a result, the thermal properties of the glass change with the composition change, and for example, the strain point increases. If the strain point of the glass constituting the glass tube 70 increases and approaches the strain point of the quartz glass too much, the second glass portion 7 is hardly subjected to distortion (compression distortion) or cannot enter. Alternatively, a crack may be formed between the first glass part 8 and the second glass part 7.

  Further, when impurities in the glass constituting the glass tube 70 are affected by the halogen or the halogen precursor and the impurities penetrate (exude) into the arc tube 1, the halogen cycle is caused by the impurities. It can be hindered. Unless the halogen cycle is operated well, it is difficult to realize a lamp having a long life.

The inventor of the present application examined the use of mercury bromide (HgBr ₂ ) as a halogen precursor in order to prevent deterioration of the glass tube 70. If mercury bromide (HgBr ₂ ) was used, the use of mercury bromide (HgBr ₂ ) It has been found that alteration can be suppressed, and the present invention has been achieved. Mercury bromide (HgBr ₂ ) is a solid, unlike gaseous CH ₂ Br ₂ or HBr, so that the influence on the glass tube 70 can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, components having substantially the same function are denoted by the same reference numeral for simplification of description. Note that the present invention is not limited to the following embodiments.

(Embodiment 1)
In the high-pressure discharge lamp according to the embodiment of the present invention, mercury bromide (HgBr ₂ ) is sealed in the arc tube. In this regard, a halogen precursor (for example, CH ₂ Br ₂ , HBr) or a halogen (for example, Br) is used. ) Is not particularly limited as long as it is sealed, or is different from the high-pressure discharge lamp shown in FIG. 1 in which halogen may not be sealed in some cases. Other points are basically the same as the configuration shown in FIG. 1, and therefore, the high-pressure discharge lamp according to the first embodiment of the present invention will be described with reference to FIG. For the sake of simplicity, the high-pressure discharge lamp according to the present embodiment is also denoted by reference numeral “100”, and points overlapping with the configuration shown in FIG. 1 are omitted or simplified.

  The lamp 100 of the present embodiment is a double-end type lamp including two sealing portions 2. As shown in FIG. 1, the arc tube 1 is chipless. Therefore, the luminous substance and the halogen need to be introduced from the side tube portion, instead of providing the luminous tube 1 with an opening. Further, when the second glass portion 7 is arranged so as to cover at least the welded portion between the electrode rod 3 and the metal foil 4, the probability of breakage can be reduced even under an ultra-high withstand voltage condition of, for example, 35 MPa. preferable. As a configuration example covering the welded portion between the electrode rod 3 and the metal foil 4, a configuration in which the entire metal foil 4 embedded in the sealing portion 2 and a part of the electrode rod 3 are arranged so as to cover the welded portion. There is also.

Mercury bromide (HgBr ₂ ) is sealed in the arc tube 1 as a halogen precursor that decomposes to generate halogen. Halogen (ie, Br) generated by decomposition from HgBr ₂ plays a role of a halogen cycle in which W (tungsten) evaporated from the electrode rod 3 during the lamp operation is returned to the electrode rod 3 again. The enclosed amount of HgBr ₂ is, for example, about 0.002 to 0.2 mg / cc, which corresponds to, for example, about 0.01 to 1 μmol / cc in terms of the halogen atom density during lamp operation.

A first advantage of using HgBr ₂ as the halogen precursor is that the second glass portion 7 can be prevented from being deteriorated, and a compressive strain can be appropriately generated in the second glass portion 7. . As a result, a high-voltage high-pressure discharge lamp can be realized more reliably.

A _second advantage of using HgBr ₂ is that what occurs after HgBr ₂ is decomposed is Br and Hg. In other words, mercury is the same as the element in which components other than halogen are already enclosed. In this point, it is different from CH ₂ Br ₂ or HBr in which hydrogen (H) can be generated. Since hydrogen can be re-coupled with halogen, the amount of free halogen may not be determined depending on the amount of free hydrogen. As disclosed in the above-mentioned International Application No. PCT / JP00 / 04561, a halogen contributing to a halogen cycle is always ensured in the arc tube 1 so that the halogen cycle is surely executed. 1 can be positively prevented. However, assuming that hydrogen (free hydrogen) generated by decomposition is generated, the halogen associated with the free hydrogen cannot always be said to be a halogen contributing to the halogen cycle, and therefore can definitely contribute to the halogen cycle. Since the amount of free halogen is not determined, there is a possibility that blackening cannot be prevented positively.
Then, it can be seen that HgBr ₂ , which can eliminate such a possibility, is easier to calculate the halogen introduction amount and has a greater advantage. Since HgBr ₂ is a solid, there is a possibility that impurities may be attached to HgBr _{2. In} such a case, it is necessary to determine the amount of HgBr ₂ to be introduced in consideration of the impurities or to take measures to eliminate the impurities. What should I do?

In the present embodiment, the number of moles of halogen generated from HgBr ₂ sealed in the arc tube 1 is a metal element (excluding the tungsten element and the mercury element) having a property of binding to halogen, and It is preferable that the total number of moles of the metal elements existing in the light emitting element 1 and the number of moles of tungsten present in the arc tube 1 evaporate from the electrode 3 during lamp operation. By doing so, halogen that contributes to the halogen cycle can always be secured in the arc tube 1, and the halogen cycle can be reliably executed. A typical example of a metal element having a property of binding to halogen is an alkali metal element (such as Na, K, and Li) excluding a tungsten element and a mercury element.

The pressure resistance (operating pressure) of the lamp 100 of the present embodiment can be set to 20 MPa or more (for example, about 30 to 50 MPa or more). The tube wall load is, for example, about 60 W / cm ² or more, and there is no particular upper limit. When exemplarily shown, the tube wall load is, for example, from above about ^{60W / cm 2, 300W / cm} 2 in the range of about (preferably, 80~200W / cm about ²⁾ can be achieved lamp. If cooling means is provided, it is possible to achieve a tube wall load of about 300 W / cm ² or more. The rated power is, for example, 150 W (the tube wall load in that case corresponds to about 130 W / cm ² ).

  The configuration of the present embodiment is described below in further detail.

The arc tube 1 of the lamp 100 has a substantially spherical shape, and is made of quartz glass, like the first glass portion 8. In order to realize a high-pressure mercury lamp (especially an ultra-high-pressure mercury lamp) exhibiting excellent characteristics such as a long life, quartz glass constituting the arc tube 1 has a low alkali metal impurity level (for example, Na, It is preferable to use high-purity quartz glass. Of course, it is also possible to use a quartz glass having a normal alkali metal impurity level. The outer diameter of the arc tube 1 is, for example, about 5 mm to 20 mm, and the glass thickness of the arc tube 1 is, for example, about 1 mm to 5 mm. The volume of the discharge space (10) in the arc tube 1 is, for example, about 0.01 to 1 cc (0.01 to 1 cm ³ ). In this embodiment, an arc tube 1 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.

  In the arc tube 1, a pair of electrode rods (electrodes) 3 are arranged to face each other. The tips of the electrode rods 3 are arranged in the arc tube 1 at intervals (arc lengths) of about 0.2 to 5 mm (for example, 0.6 to 1.0 mm), and each of the electrode rods 3 is made of tungsten. (W). It is preferable to use a tungsten electrode rod 3 having a low alkali metal impurity level (for example, the amount of each of Na, K, and Li is 1 ppm or less). It is also possible to use. A coil 12 is wound around the tip of the electrode rod 3 for the purpose of lowering the electrode tip temperature during lamp operation. In the present embodiment, a coil made of tungsten is used as the coil 12, but a coil made of thorium-tungsten may be used. Further, as the electrode rod 3, not only a tungsten rod but also a rod made of thorium-tungsten may be used.

Mercury 6 is sealed in the arc tube 1 as a luminous substance. When operating the lamp 100 as an ultra-high pressure mercury lamp, for example, about 200 mg / cc or more (220 mg / cc or more, 230 mg / cc or more, or 250 mg / cc or more) based on the internal volume of the arc tube 1; Preferably, mercury 6 of about 300 mg / cc or more (for example, 300 mg / cc to 500 mg / cc), a rare gas (for example, argon) of 5 to 30 kPa, and HgBr ₂ as a halogen precursor are formed in the arc tube 1. Enclosed within.

  As described above, the cross-sectional shape of the sealing portion 2 is substantially circular, and the metal foil 4 is provided at a substantially central portion thereof. The metal foil 4 is, for example, a rectangular molybdenum foil (Mo foil), and the width (the length of the short side) of the metal foil 4 is, for example, about 1.0 mm to 2.5 mm (preferably 1.0 mm). About 1.5 mm). The thickness of the metal foil 4 is, for example, about 15 μm to 30 μm (preferably, about 15 μm to 20 μm). The ratio between the thickness and the width is about 1: 100. The length (length of the long side) of the metal foil 4 is, for example, about 5 mm to 50 mm.

  On the side opposite to the side where the electrode rod 3 is located, an external lead 5 is provided by welding. An external lead 5 is connected to a side of the metal foil 4 opposite to a side to which the electrode bar 3 is connected, and one end of the external lead 5 extends outside the sealing portion 2. By electrically connecting the external leads 5 to a lighting circuit (not shown), the lighting circuit and the pair of electrode rods 3 are electrically connected. The sealing part 2 has a role of pressing the glass parts (7, 8) of the sealing part and the metal foil 4 to keep the discharge space 10 in the arc tube 1 airtight. The sealing mechanism by the sealing portion 2 will be briefly described below.

  Since the material forming the glass part of the sealing part 2 and the molybdenum forming the metal foil 4 have different coefficients of thermal expansion, they are not integrated from the viewpoint of the coefficient of thermal expansion. . However, in the case of this configuration (foil sealing), the metal foil 4 undergoes plastic deformation due to the pressure from the glass part of the sealing portion, and the gap created between the two can be filled. Thereby, the glass part of the sealing part 2 and the metal foil 4 can be pressed against each other, and the sealing inside the arc tube 1 can be performed by the sealing part 2. That is, the sealing of the sealing portion 2 is performed by foil sealing by pressure bonding between the glass portion of the sealing portion 2 and the metal foil 4. In the present embodiment, since the second glass portion 7 having a compressive strain is provided, the reliability of the seal structure is improved.

In the lamp 100 of the present embodiment, since the second glass portion 7 provided at least partially inside the first glass portion 8 has a compressive strain (at least a compressive strain in the longitudinal direction), a high pressure is applied. The pressure resistance of the discharge lamp can be improved. Since HgBr ₂ is introduced into the arc tube 1 as a halogen precursor, the composition deformation of the second glass portion 7 can be suppressed, and the improvement of the pressure resistance can be further ensured.

  In the configuration shown in FIG. 1, the second glass portion 7 is provided on each of the pair of sealing portions 2. However, the present invention is not limited to this. Even when the portion 7 is provided, the pressure resistance can be improved as compared with the lamp 100 ′ of the comparative example shown in FIG. However, it is preferable that both the sealing portions 2 are provided with the second glass portions 7 and that both of the sealing portions 2 have a portion to which a compressive stress is applied. This is because a higher withstand voltage can be achieved when both sealing portions 2 have a portion to which a compressive stress is applied than when one sealing portion is used. The leak probability at the sealing portion (ie, a certain level of high withstand voltage) is better when two sealing portions are provided than when one sealing portion having a portion to which compressive stress is applied is provided. This is because it is possible to reduce the probability of not being able to hold １ ／).

Further, in the present embodiment, a high-pressure mercury lamp in which a large amount of mercury 6 is enclosed (for example, an ultra-high pressure mercury lamp with a mercury enclosed amount of 150 mg / cm ³ or more) has been described. It can be suitably applied to a mercury lamp. This is because the fact that the lamp can be operated stably even at an extremely high operating pressure means that the reliability of the lamp is high. That is, when 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 about 1 MPa), the reliability of the lamp operating at the operating pressure is reduced. This is because it can be improved. In the configuration of the present embodiment, since the member of the second glass part 7 only needs to be introduced as a new member into the sealing part 2, the effect of improving the pressure resistance can be obtained with a small improvement. Therefore, it is very suitable for industrial use. Further, as a method for preventing the composition deformation of the second glass portion 7, HgBr ₂ is used as a halogen precursor in consideration of the mechanism of the composition deformation. Therefore, it is suitable for industrial use.

  Next, a method of manufacturing the lamp 100 according to the present embodiment will be described with reference to FIGS. 4 and 5 and diverting FIG.

  First, a discharge lamp glass pipe 80 having an arc tube portion 1 'to be the arc tube (1) of the lamp 100 and a side tube portion 2' extending from the arc tube portion 1 'is prepared. The glass pipe 80 of the present embodiment is formed by heating and expanding a predetermined position of a cylindrical quartz glass having an outer diameter of 6 mm and an inner diameter of 2 mm to form a substantially spherical arc tube part 1 ′. Further, a glass tube 70 serving as the second glass part 7 is separately prepared. The glass tube 70 of this embodiment is a Vycor glass tube having an outer diameter of 1.9 mm, an inner diameter of 1.7 mm, and a length (length in the longitudinal direction) of 7 mm. The outer diameter of the glass tube 70 is smaller than the inner diameter of the side tube 2 ′ so that it can be inserted into the side tube 2 ′ of the glass pipe 80.

  Next, as shown in FIG. 4, after fixing the glass tube 70 to the side tube portion 2 ′ of the glass pipe 80, the separately manufactured electrode structure 50 is attached to the side tube portion 2 ′ to which the glass tube 70 is fixed. Then, both ends of the glass pipe 80 after the insertion of the electrode structure 50 are attached to a rotatable chuck 82 while maintaining airtightness. The chuck 82 is connected to a vacuum system (not shown), and can reduce the pressure inside the glass pipe 80. After evacuating the inside of the glass pipe 80, a rare gas (Ar) of about 200 torr (about 20 kPa) is introduced. Thereafter, the glass pipe 80 is rotated in the direction of arrow 81 with the electrode rod 3 as the rotation center axis.

  Note that the electrode structure 50 includes the electrode rod 3, the metal foil 4 connected to the electrode rod 3, and the external lead 5 connected to the metal foil 4. The electrode rod 3 is a tungsten electrode rod, and a tungsten coil 12 is wound around its tip. At one end of the external lead 5, a support member (metal clasp) 11 for fixing the electrode structure 50 to the inner surface of the side tube portion 2 'is provided. The support member 11 shown in FIG. 4 is a molybdenum tape (Mo tape) made of molybdenum, but a molybdenum ring-shaped spring may be used instead.

  Next, by heating and shrinking the side tube portion 2 'and the glass tube 70 to seal the electrode structure 50, the first glass portion which was the side tube portion 2' as shown in FIG. The sealing portion 2 provided with the second glass portion 7, which was the glass tube 70, is formed inside 8. The sealing portion 2 is formed by sequentially removing the side tube portion 2 ′ and the glass tube 70 from the boundary between the arc tube portion 1 ′ and the side tube portion 2 ′ to the vicinity of the middle of the external lead 5. This is performed by heating and shrinking. By this sealing portion forming step, the sealing portion 2 including the portion where the compressive stress is applied at least in the longitudinal direction (the axial direction of the electrode rod 3) is obtained from the side tube portion 2 'and the glass tube 70. Note that heating and shrinkage may be performed from the external lead 5 toward the arc tube portion 1 '.

Thereafter, a predetermined amount of mercury 6 (for example, about 200 mg / cc, about 300 mg / cc, or more) is introduced from the open end of the side tube 2 ′. At this time, solid HgBr ₂ is also introduced. The order of introduction of mercury 6 and HgBr ₂ is not particularly limited. Both may be performed simultaneously or one of them may be introduced first.

After the introduction of mercury 6 and HgBr ₂ , the same process as described above is performed on the other side tube 2 ′. As shown in FIG. 3, after inserting the electrode structure 50 into the unsealed side tube portion 2 ′, the inside of the glass pipe 80 is evacuated (preferably, the pressure is reduced to about 10 ⁻⁴ Pa). ), Enclose a rare gas, and then heat seal. At this time, the heat sealing is preferably performed while cooling the arc tube portion 1 'in order to prevent mercury from evaporating. In this way, when both side tube portions 2 'are sealed, a lamp having the second glass portion 7 in the sealing portion 2 is completed. It is also possible to insert the electrode structure 50 after introducing mercury 6 first, and then introduce HgBr ₂ .

  Next, a mechanism in which a compressive stress is applied to the second glass portion 7 (or a peripheral portion thereof) in the sealing portion forming step will be described with reference to FIGS. This mechanism is assumed by the inventor of the present application, and it cannot be said that the mechanism is exactly the same. However, for example, as shown in FIG. 3A, it is a fact that a compressive stress (compressive strain) exists in the second glass portion 7 (or a peripheral portion thereof), and the compressive stress is applied. It is also true that the withstand voltage is improved by the sealing portion 2 including the bent portion.

FIG. 15A schematically shows a cross-sectional configuration when the second glass part 7a in the state of the glass tube 70 is inserted into the first glass part 8 in the state of the side tube part 2 ′. 15 (b) schematically shows a cross-sectional configuration at the time when the second glass portion 7a is softened to the molten state 7b in the configuration of FIG. 15 (a). In the present embodiment, the first glass part 8 is made of quartz glass containing 99 wt% or more of SiO ₂ , and the second glass part 7a is made of Vycor glass.

First, as a premise, the presence of compressive stress (compressive strain) often causes a difference in the thermal expansion coefficient between materials that come into contact with each other. That is, the reason why the compressive stress is applied to the second glass portion 7 provided in the sealing portion 2 is generally considered to be that there is a difference in the thermal expansion coefficient between the two. However, in this case, there is actually no large difference between the two thermal expansion coefficients, and it can be said that they are almost equal. More specifically, when the thermal expansion coefficients of the metals tungsten and molybdenum are about 46 × 10 ⁻⁷ / ° C. and about 37 to 53 × 10 ⁻⁷ / ° C., respectively, the first glass part 8 Is about 5.5 × 10 ⁻⁷ / ° C., and the thermal expansion coefficient of Vycor glass is about 7 × 10 ^−, which can be regarded as the same level as the thermal expansion coefficient of quartz glass. ⁷ / ° C. With such a small difference in thermal expansion coefficient, it is unlikely that a compressive stress of about 10 kgf / cm ² or more is generated between the two. The difference between the two properties lies in the softening point or strain point rather than the coefficient of thermal expansion, and if attention is paid to this point, it can be explained that compressive stress is applied by the following mechanism. The softening point and strain point of quartz glass are 1650 ° C. and 1070 ° C. (the annealing point is 1150 ° C.), respectively, while the softening point and strain point of Vycor glass are 1530 ° C. and 890 ° C., respectively. (An annealing point is 1020 ° C.).

  When the first glass part 8 (side tube part 2 ') is heated from the outside and shrunk from the state shown in FIG. 15A, the gap 7c between the two is first filled and the two are in contact with each other. After shrinking, as shown in FIG. 15 (b), the first glass portion 8 having a high softening point and having a large area that comes into contact with the outside air is first released from the softened state (that is, when the first glass portion 8 hardens) However, the second glass part 7b located on the inner side and having a lower softening point still has a point in time in which it is still softened (in a molten state). At this time, the second glass portion 7b has fluidity as compared with the first glass portion 8, and the thermal expansion coefficients of the two at the normal time (at the time when they are not in a softened state) are substantially the same. However, it is considered that the properties (for example, elastic modulus, viscosity, density, etc.) of the two at this point are greatly different. Then, after a further lapse of time, the second glass portion 7b having the fluidity cools down and the temperature of the second glass portion 7b becomes lower than the softening point. It hardens like the glass part 8. Here, if the softening points of the first glass part 8 and the second glass part 7 are the same, both glass parts will be hardened so that they are gradually cooled from the outside and no compressive strain remains. In the case of the configuration of the present embodiment, the outer glass portion (8) solidifies early, and after a while, the inner glass portion (7) solidifies. Seems to remain. Considering such a thing, it may be said that the second glass part 7 is in a state where a kind of pinching is indirectly performed.

  If such a compressive strain remains, the close contact between the two (7, 8) will usually end at a certain temperature due to the difference in the coefficient of thermal expansion between them. In the case of the configuration of the embodiment, since the thermal expansion coefficients of the two are almost equal, it is presumed that the close contact state of the two (7, 8) can be maintained even if compressive strain exists.

Further, in order to apply a compressive stress of about 10 kgf / cm ² or more to the second glass part 7, the strain point of the second glass part is required for the lamp (completed lamp) completed by the above-described manufacturing method. It turned out that it was necessary to heat at a temperature higher than the temperature. And it turned out that it is preferable to heat at 1030 degreeC for 2 hours or more. Specifically, the completed lamp 100 may be placed in a furnace at 1030 ° C. and annealed (for example, vacuum baking or reduced pressure baking). The temperature of 1030 ° C. is merely an example, and may be any temperature higher than the strain point temperature of the second glass part (Vycor glass) 7. In other words, it is sufficient that the strain point temperature of Vycor is higher than 890 ° C. A suitable range is a temperature higher than the strain point temperature of 890 ° C. of Vycor and lower than the strain point temperature of the first glass part (quartz glass) (1070 ° C. of SiO ₂ ). In some cases, the effect was obtained when the present inventor conducted experiments at a temperature of about ° C.

For comparison, the high-pressure discharge lamp that was not annealed was measured by the sensitive color plate method, and it was found that the second glass portion 7 was provided in the sealing portion of the high-pressure discharge lamp. Nevertheless, no compressive stress of about 10 kgf / cm ² or more was observed in the sealed portion.

  There is no particular upper limit for the annealing (or vacuum baking) time as long as it is 2 hours or more, except for the upper limit from an economic viewpoint. A suitable time may be appropriately set within a range of 2 hours or more. If the effect is observed even in less than 2 hours, heat treatment (annealing) may be performed in less than 2 hours. This annealing step may have achieved higher purity of the lamp, in other words, reduction of impurities. This is because annealing of the completed lamp can release moisture (e.g., moisture in Vycor) that is considered to adversely affect the lamp from the lamp. If the annealing is performed for 100 hours or more, it is possible to almost completely remove the moisture in Vycor from the inside of the lamp.

In the above description, the example in which the second glass portion 7 is made of Vycor glass has been described. However, SiO ₂ : 62 wt%, Al ₂ O ₃ : 13.8 wt%, CuO: 23.7 wt% It was also found that even when the second glass portion 7 was formed from the glass (trade name: SCY2, manufactured by SEMCOM; strain point: 520 ° C.), at least a compressive stress was applied in the longitudinal direction.

  Next, with reference to FIG. 16, a mechanism inferred by the inventor of the present application to apply a compressive stress to the second glass portion 7 of the lamp when the completed lamp is annealed at a predetermined temperature for a predetermined time or more will be described. explain.

  First, as shown in FIG. 16A, a completed lamp is prepared. The method for producing the completed lamp is as described above.

  Next, when the completed lamp is heated, the mercury (Hg) 6 starts to evaporate as shown in FIG. 16B, and as a result, pressure is also applied to the inside of the arc tube 1 and the second glass portion 7. . The arrows in the figure represent the pressure of the vapor of mercury 6 (for example, 100 atm or more). The reason why the vapor pressure of the mercury 6 is applied not only to the inside of the arc tube 1 but also to the second glass portion 7 is that there is a gap 13 in the sealing portion of the electrode rod 3 which is invisible to the naked eye.

  If the heating temperature is further increased and the heating is continued at a temperature exceeding the strain point of the second glass part 7 (for example, 1030 ° C.), the vapor pressure of the mercury becomes the second pressure while the second glass part 7 is in a soft state. , A compressive stress is generated in the second glass part 7. It is estimated that the time for generating the compressive stress is, for example, about 4 hours when heated at the strain point and about 15 minutes when heated at the slow cooling point. This time is derived from the definition of the strain point and the annealing point. That is, the strain point means a temperature at which the internal strain can be substantially removed when kept at this temperature for 4 hours, and the annealing point means a temperature at which the internal stress can be substantially removed when kept at this temperature for 15 minutes. From the meaning, the above time is estimated.

  Next, the heating is stopped and the completed lamp is cooled. Even after the heating is stopped, as shown in FIG. 16 (c), since the mercury remains evaporated, the temperature of the second glass part 7 becomes lower than the strain point while continuing to receive the pressure of the mercury vapor, and as a result, As shown in FIG. 19, the compressive stress remains in the second glass part 7 not only in the longitudinal direction of the metal foil 4 but also in the radial direction, etc. Can only be confirmed).

Finally, when the cooling proceeds to about room temperature, a lamp 100 having a compressive stress of about 10 kgf / cm ² or more in the second glass part 7 is obtained as shown in FIG. As shown in FIGS. 16 (b) and (c), the vapor pressure of mercury applies pressure to both the second glass parts 7, and therefore, according to this method, both sealing parts 2 have a pressure of about 10 kgf. / Cm ² or more can be reliably applied.

This heating profile is schematically shown in FIG. First, when heating is started (time O), the temperature reaches the strain point (T ₂ ) of the second glass part 7 (time A). Next, at a temperature between the strain point of the second glass portion 7 (T ₂₎ and the strain point of the first glass portion 8 (T _1), holding the lamp a predetermined time. This temperature range can be basically regarded as a range in which only the second glass part 7 can be deformed. During this holding, as shown in the schematic diagram of FIG. 18, a compressive stress is applied to the second glass part 7 by a mercury vapor pressure (for example, 100 atm or more).

Incidentally, by mercury vapor pressure to the second glass portion 7 is the application of pressure, seems a method using an annealing process most effectively, holding the lamp at T ₂ or T ₁ following temperatures in FIG. 17 If it is possible to apply some force to the second glass part 7, not only the mercury vapor pressure but also that force (for example, by pressing the external lead 5) will apply to the second glass part 7. It is presumed that compressive stress can be applied.

Next, when the heating is stopped, the lamp cools down, and after time B, the temperature of the second glass part 7 falls below the strain point (T ₂ ). Below the strain point (T ₂ ), the compressive stress of the second glass part 7 remains. In the present embodiment, after maintaining at 1030 ° C. for 150 hours, by cooling (natural cooling), the compressive stress of the second glass portion 7 is applied and left.

  Since the compressive stress is generated by the mercury vapor pressure by the mechanism described above, the magnitude of the compressive stress depends on the mercury vapor pressure (in other words, the amount of enclosed mercury).

  Generally, as the amount of mercury increases, the lamp is more likely to burst. However, when the sealing structure of the present embodiment is used, the compressive stress increases as the amount of mercury increases, and the pressure resistance improves. In other words, according to the configuration of the present embodiment, a higher breakdown voltage structure can be realized as the amount of mercury is increased, so that stable lighting with an extremely high breakdown voltage, which cannot be realized with the current technology, is enabled. .

  In the state shown in FIG. 4, it is also possible to use a long glass tube (long-by-cold tube) 70 as shown in FIG. The diameter of the glass tube 70 shown in FIG. 6 is reduced at one end (i.e., at the end opposite to the arc tube portion 1 '), whereby the glass tube 70 is fixed. As a fixing method, the external lead 5 may be pressed at a place where the diameter becomes small, or the pipe 80 is made substantially vertical, and then the place where the diameter of the glass tube 70 becomes small is made of metal foil ( (Molybdenum foil) 4 may be hooked on the corner.

According to the method for manufacturing a high-pressure discharge lamp of the present embodiment, mercury bromide (HgBr ₂ ) is introduced as a halogen precursor into the arc tube part 1 ′, so that deterioration of the second glass part 7 is suppressed. Can be. As a result, compressive strain can be effectively applied to the second glass portion 7, and a high-pressure discharge lamp with high withstand voltage can be more reliably realized. Further, it is possible to prevent a crack from being generated between the second glass part 7 and the first glass part 8.

(Embodiment 2)
A high-pressure discharge lamp according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 7 schematically shows a configuration of the high-pressure discharge lamp 200 of the present embodiment. The point that mercury bromide (HgBr ₂ ) is sealed as a halogen precursor in the arc tube 1 of the lamp 200 is the same as the high-pressure discharge lamp 100 of the first embodiment. Note that mercury bromide (HgBr ₂ ) is omitted in the drawings in the present embodiment and the first embodiment.

  In order to further improve the pressure resistance of the lamp 100 of the first embodiment, at least a part of the surface of the electrode rod 3 in the portion embedded in the sealing portion 2 as in the lamp 200 shown in FIG. It is preferable to form a metal film (for example, a Pt film) 30. The metal film 30 may be made of at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re. The metal film 30 may be, for example, a single layer made of a Pt layer, or from the viewpoint of adhesiveness, the lower layer may be made of an Au layer and the upper layer may be made of, for example, a Pt layer.

  In the lamp 200, since the metal film 30 is formed on the surface of the electrode bar 3 in the portion embedded in the sealing portion 2, it is possible to prevent the occurrence of minute cracks in the glass located around the electrode bar 3. Can be prevented. That is, in the lamp 200, in addition to the effect obtained by the lamp 100, an effect of preventing the occurrence of cracks is also obtained, so that the pressure resistance can be further improved. Hereinafter, the crack prevention effect will be described.

  In the case of a lamp having no metal film 30 on the electrode rod 3 located in the sealing part 2, after the glass of the sealing part 2 and the electrode rod 3 once adhere to each other at the time of forming the sealing part in the lamp manufacturing process, During cooling, the two are separated due to the difference in the coefficient of thermal expansion between them. At this time, cracks occur in the quartz glass around the electrode rod 3. Due to the presence of the crack, the pressure resistance is lower than that of an ideal lamp having no crack.

  In the case of the lamp 200 shown in FIG. 7, since the metal film 30 having a Pt layer on the surface is formed on the surface of the electrode rod 3, the quartz glass of the sealing portion 2 and the surface of the electrode rod 3 (Pt layer) The wettability between them is getting worse. In other words, in the case of the combination of platinum and quartz glass, the wettability between the metal and the quartz glass is worse than in the case of the combination of tungsten and quartz glass, so that the two are easily separated without being attracted. It is. As a result, due to poor wettability between the electrode rod 3 and the quartz glass, separation between the electrode rod 3 and the glass during the cooling after heating is improved, and it is possible to prevent the generation of fine cracks. The lamp 200 manufactured based on the technical idea of preventing the occurrence of cracks by utilizing such poor wettability exhibits a higher pressure resistance than the lamp 100.

  Note that the configuration of the lamp 200 shown in FIG. 7 may be replaced with the configuration of the lamp 300 shown in FIG. In the lamp 300, in the configuration of the lamp 100 shown in FIG. 1, a coil 40 whose surface is covered with a metal film 30 is wound around the surface of the electrode rod 3 embedded in the sealing portion 2. In other words, the lamp 300 has a configuration in which the coil 40 having at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re on the surface thereof is wound around the root of the electrode rod 3. I have. In the configuration shown in FIG. 8, the coil 40 is wound up to the portion of the electrode rod 3 located in the discharge space 10 of the arc tube 1. In the configuration of the lamp 300 shown in FIG. 8 as well, the wettability between the electrode rod 3 and the quartz glass can be reduced by the metal film 30 on the surface of the coil 40. As a result, the occurrence of fine cracks can be prevented. it can.

  The metal on the surface of the coil 40 may be formed, for example, by plating. As in the configuration shown in FIG. 7, here, the metal film 30 may be a single layer made of, for example, a Pt layer, or from the viewpoint of adhesion, the lower layer is made of an Au layer, and the upper layer is made of, for example, a Pt layer. It may be. From the viewpoint of adhesion, it is preferable to first form a lower Au layer on the coil 40, and then to form an upper Pt layer, for example, but Pt (upper layer) / Au (lower) plating Even if the coil 40 is only Pt-plated without using the two-layer structure described above, practically sufficient adhesion can be ensured.

  In the case where at least one metal selected from the group consisting of Pt, Ir, Rh, Ru, and Re (also referred to as “Pt or the like”) is provided on the surface of the electrode rod 3 or the surface of the coil 40, As in the configuration of the embodiment of the present invention, the existence of the second glass portion 7 around the metal foil 4 is very significant. This will be further described. Since metal such as Pt may evaporate to some extent due to heating during processing in the lamp manufacturing process (sealing process), if it diffuses to the metal foil 4, it weakens the adhesion between the metal foil and the glass. This may result in lowering the breakdown voltage. However, when the second glass portion 7 is provided around the metal foil 4 and a compressive strain is present there as in the configuration of the present embodiment, the poor wettability between Pt or the like and the glass no longer occurs. It becomes irrelevant, and as a result, it is possible to prevent a decrease in breakdown voltage caused by diffusion of Pt or the like.

In the configuration shown in FIG. 7 and FIG. 8, as a sealing form of halogen (more specifically, a halogen precursor), HgBr ₂ (at room temperature) is used rather than using a gas such as CH ₂ Br _2. It should be added that it is preferable to adopt a solid form. The reason is that the metal such as Pt may be etched by the gaseous halogen in the same way that the Vycor glass reacts with the gaseous halogen and deteriorates when sealed.

  Also in the lamps 200 and 300 of the present embodiment, as shown in FIG. 6, the second glass portion 7 that covers the entire metal foil 4 is formed using the glass tube 70 that covers the entire metal foil 4. May be.

  Furthermore, the lamps 100, 200, and 300 of the embodiment of the present invention can be combined with a reflecting mirror to form a lamp with a mirror or a lamp unit.

  FIG. 9 schematically shows a cross section of a mirror-equipped lamp 900 including the lamp 100 of the present embodiment.

  The mirror-equipped lamp 900 includes a lamp 100 having a substantially spherical arc tube 1 and a pair of sealing portions 2, and a reflecting mirror 60 that reflects light emitted from the lamp 100. In addition, the lamp 100 is an example, and of course, the lamp 200 or 300 may be used. The lamp with mirror 900 may further include a lamp house that holds the reflecting mirror 60. Here, the configuration provided with the lamp house is included in the lamp unit.

  The reflecting mirror 60 reflects the radiated light from the lamp 100 so as to be, for example, a parallel light beam, a condensed light beam converging on a predetermined minute region, or a divergent light beam diverging from the predetermined minute region. Is configured. As the reflecting mirror 60, for example, a parabolic mirror or an elliptical mirror can be used.

  In the present embodiment, a base 56 is attached to one sealing portion 2 of the lamp 100, and the external lead (5) extending from the sealing portion 2 and the base 56 are electrically connected. The sealing portion 2 and the reflecting mirror 60 are fixed and integrated with, for example, an inorganic adhesive (for example, cement or the like). A lead wire 65 is electrically connected to the external lead 5 of the sealing portion 2 located on the front opening side of the reflecting mirror 60. It extends to the outside of the reflecting mirror 60 through the lead wire opening 62. For example, a front glass can be attached to the front opening of the reflecting mirror 60.

  Such a lamp with a mirror or a lamp unit 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. An image projection apparatus can be configured by combining such a lamp with a mirror or a lamp unit with an optical system including an image element (such as a DMD (Digital Micromirror Device) panel or a liquid crystal panel). For example, a projector using a DMD (digital light processing (DLP) projector) or a liquid crystal projector (including a reflection type projector employing a liquid crystal on silicon (LCOS) structure) can be provided. Further, the lamp of the present embodiment, and a lamp or a lamp unit with a mirror, in addition to a light source for an image projection device, a light source for an ultraviolet stepper, or a light source for a sports stadium or a headlight of a car, or 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 luminescent substance has been described as an example of a high-pressure discharge lamp. However, the present invention is applicable to any high-pressure discharge lamp having a configuration in which a sealing section (seal section) is used to keep the arc tube airtight. It is also applicable to discharge lamps. For example, the present invention can be applied to a metal halide lamp enclosing a metal halide or a high-pressure discharge lamp such as xenon. This is because the higher the breakdown voltage is, the more preferable it is in a metal halide lamp and the like. That is, by preventing leakage and cracking, a highly reliable and long-life lamp can be realized. When the configuration of the above embodiment is applied to a metal halide lamp in which not only mercury but also a metal halide is sealed, the following effects can be obtained. That is, by providing the second glass portion 7, the adhesion of the metal foil 4 in the sealing portion 2 can be improved, and the reaction between the metal foil 4 and a metal halide (or a halogen and an alkali metal). Can be suppressed, and as a result, the reliability of the structure of the sealing portion can be improved. In particular, when the second glass part 7 is located at the metal rod 3 as in the configuration shown in FIGS. 1, 7 and 8, the metal rod 3 and the glass of the sealing part 2 The second glass portion 7 can effectively reduce the intrusion of a metal halide which enters through a small gap therebetween and reacts with the metal foil 4 to cause embrittlement of the foil. Thus, the configuration of the above embodiment can be suitably applied to a metal halide lamp.

  In recent years, the development of mercury-free metal halide lamps in which mercury is not sealed has been advanced, but the technology of the above-described embodiment can be applied to such mercury-free metal halide lamps. Hereinafter, this will be described in more detail.

  As a mercury-free metal halide lamp to which the technology of the above embodiment is applied, in the configuration shown in FIG. 7 or FIG. 8, mercury is not substantially sealed in the arc tube 1 and at least One in which the first halide, the second halide, and the rare gas are sealed is given. At this time, the metal of the first halide is a light-emitting substance, and the second halide has a higher vapor pressure than the first halide and has a higher vapor pressure than the metal of the first halide. In comparison, it is one or more halides of a metal that does not easily emit light in the visible region. For example, the first halide is one or more halides selected from the group consisting of sodium, scandium, and rare earth metals. The second halide is one or more halides of a metal that has a relatively high vapor pressure and is less likely to emit light in the visible region than the metal of the first halide. As a specific second halide, at least one selected from the group consisting of Mg, Fe, Co, Cr, Zn, Ni, Mn, Al, Sb, Be, Re, Ga, Ti, Zr, and Hf It is a metal halide. A second halide containing at least a halide of Zn is more preferable.

As another combination example, a light-transmitting light-emitting tube (airtight container) 1, a pair of electrodes 3 provided in the light-emitting tube 1, and a pair of sealing portions 2 connected to the light-emitting tube 1 In the arc tube 1 of the mercury-free metal halide lamp having the following, ScI ₃ (scandium iodide) and NaI (sodium iodide), and mercury substitutes InI ₃ (indium iodide) and TlI ( It contains thallium iodide) and a rare gas (for example, Xe gas of 1.4 MPa) as a starting auxiliary gas. In this case, the first halide is ScI ₃ (scandium iodide) and NaI (sodium iodide), and the second halide is InI ₃ (indium iodide) and TlI (thallium iodide). Note that the second halide may have a relatively high vapor pressure and play a role of mercury. For example, instead of InI ₃ (indium iodide) or the like, Zn iodide may be used. May be.

  The reason why the technique of the first embodiment can be suitably applied to such a mercury-free metal halide lamp will be described below.

  First, in the case of a mercury-free metal halide lamp using an alternative substance of Hg (such as a halide of Zn), the efficiency is lower than that of a mercury-containing lamp. In order to increase the efficiency, it is very advantageous to increase the lighting operating pressure. In the case of the lamp of the above embodiment, since the structure has an improved withstand pressure, a rare gas can be sealed at a high pressure, and the efficiency can be easily improved. Therefore, a practical mercury-free metal halide lamp can be easily realized. be able to. In this case, Xe having a low thermal conductivity is preferable as the rare gas.

  In the case of a mercury-free metal halide lamp, it is necessary to fill more halogen than a mercury-containing metal halide lamp because mercury is not filled. Accordingly, the amount of halogen reaching the metal foil 4 through the gap near the electrode rod 3 also increases, and the halogen reacts with the metal foil 4 (or the root portion of the electrode rod 3 in some cases). It becomes weak and leaks easily occur. In the configuration shown in FIGS. 7 and 8, the surface of the electrode rod 3 is covered with the metal film 30 (or the coil 40), so that the reaction between the electrode rod 3 and the halogen can be effectively prevented. In the case where the second glass portion 7 is located around the electrode bar 3 as shown in FIG. 1, the second glass portion 7 allows the entry of a halide (for example, a halide of Sc). Can be prevented, thereby making it possible to prevent the occurrence of leakage. Therefore, in the case of the mercury-free metal halide lamp having the structure of the above embodiment, higher efficiency and longer life can be achieved as compared with the conventional mercury-free metal halide lamp. This can be widely applied to lamps for general lighting. Speaking of lamps for car headlights, there are further advantages as follows.

  When used as a headlight of a car, there is a demand to obtain 100% light at the moment the switch is turned on. To meet this demand, it is effective to fill a rare gas (specifically, Xe) at a high pressure. However, if Xe is sealed at a high pressure in a normal metal halide lamp, the possibility of rupture increases. This is not preferable as a headlight lamp requiring higher safety. That is, failure of the headlight at night leads to a car accident. In the case of the mercury-free metal halide lamp having the structure of the above-described embodiment, the structure is improved in withstand voltage. Can be improved. In addition, since the service life is extended, it can be more suitably applied to a headlight.

  Further, in the above-described embodiment, the case where the mercury vapor pressure is about 20 MPa or about 30 MPa or more (so-called ultra-high pressure mercury lamp) has been described. It does not exclude doing. That is, the present invention can be applied to general high-pressure discharge lamps including ultra-high-pressure mercury lamps and high-pressure mercury lamps. Incidentally, the mercury vapor pressure of what is called an ultra-high pressure mercury lamp today is 15 MPa or more (the amount of enclosed mercury is 150 mg / cc or more).

  The fact that the lamp can be operated stably even at an extremely high operating pressure means that the reliability of the lamp is high. (For example, about 20 MPa to about 1 MPa), the reliability of the lamp operating at the operating pressure can be improved.

  The technical significance of the lamp capable of realizing high pressure resistance will be further described as follows. In recent years, in order to obtain a high-power, high-power high-pressure mercury lamp, a short arc type mercury lamp having a short arc length (distance between electrodes) (for example, a distance between electrodes of 2 mm or less) is being developed. In the case of the short arc type, it is necessary to fill a larger amount of mercury than usual in order to prevent the electrode from evaporating faster as the current increases. As described above, in the conventional configuration, there is an upper limit in the pressure resistance, and therefore, there is an upper limit (for example, about 200 mg / cc or less) in the amount of enclosed mercury. There were restrictions. The lamp of the present embodiment can eliminate such a conventional limitation, and can promote the development of a lamp exhibiting excellent characteristics, which could not be realized conventionally. In the lamp of the present embodiment, it is possible to realize a lamp having an enclosed mercury amount of more than about 200 mg / cc, about 300 mg / cc or more.

  As described above, a technique capable of realizing a sealed mercury amount of about 300 to 400 mg / cc or more (lighting operating pressure of 30 to 40 MPa) is particularly effective for lamps having a lighting operating pressure of more than 20 MPa (that is, today's lamps). (For example, a lamp having a lighting operation pressure exceeding 15 MPa to 20 MPa, such as a lamp having a pressure of 23 MPa or more or a lamp having a pressure of 25 MPa or more). In other words, when mass-producing a lamp, the characteristics of the lamp may inevitably vary. Therefore, even for a lamp having a lighting operating pressure of about 23 MPa, it is necessary to secure a withstand voltage in consideration of a margin. The technology capable of achieving a pressure resistance of 30 MPa or more has a great advantage from the viewpoint that products can be actually supplied to lamps of less than 30 MPa. Of course, if a lamp capable of withstanding a pressure of 23 MPa or less is manufactured using a technology capable of achieving a pressure resistance of 30 MPa or more, safety and reliability can be improved.

  Therefore, the configuration of the present embodiment can improve the lamp characteristics from the viewpoint of reliability and the like. In the lamp of the above embodiment, the sealing portion 2 is manufactured by the shrink method, but may be manufactured by the pinching method. Further, although the description has been given of the double-end type high-pressure discharge lamp, the technology of the above-described embodiment can be applied to a single-end type discharge lamp. In the above embodiment, for example, the second glass part 7 is formed from a glass tube (70) made of Vycor, but it is not always necessary to form the second glass part 7 from a glass tube. The glass structure is not limited to a glass tube as long as it is not limited to a configuration that covers the entire periphery of the metal foil 4 but may be a glass structure that can cause a compressive stress to be present in a part of the sealing portion 2 in contact with the metal foil 4. For example, a glass structure in which a slit is formed in a part of the glass tube 70 to form a “C” shape may be used, or a carat made of Vycor (glass piece or glass) may be in contact with one or both sides of the metal foil 4. (A glass plate) or a glass fiber made of Vycor, for example, so as to cover the periphery of the metal foil 4. However, even when using a glass powder, for example, a sintered glass body obtained by compressing and sintering a glass powder, a compressive stress may be present in a part of the sealing portion 2 instead of the glass structure. Since it is not possible, it is better not to use glass powder.

  In addition, the interval (arc length) between the pair of electrodes 3 may be a short arc type or a longer interval. The lamp of the above embodiment can be used in any of an AC lighting type and a DC lighting type. Further, the configurations and modifications shown in the above embodiments can be mutually adopted. Although the structure of the sealing portion including the metal foil 4 has been described, the configuration of the above-described embodiment can be applied to the sealing portion structure without foil. This is because it is important to increase the breakdown voltage and the reliability even in the case of the sealing portion structure without a foil. More specifically, one electrode rod (tungsten rod) 3 is used as the electrode structure 50 without using the molybdenum foil 4. A second glass part 7 is disposed on at least a part of the electrode rod 3, and a first glass part 8 is formed so as to cover the second glass part 7 and the electrode rod 3, thereby forming a sealing part structure. It is also possible to build. In the case of this configuration, the external lead 5 can also be configured by the electrode rod 3.

  In the above-described embodiment, the discharge lamp has been described. However, the technology of the first embodiment is not limited to the discharge lamp, but any lamp having a configuration in which the sealing portion (sealing portion) maintains the airtightness of the arc tube can be used. It is also applicable to lamps other than lamps (for example, light bulbs). FIGS. 10 and 11 show a light bulb to which the technology of the first embodiment is applied.

  The light bulb 500 shown in FIG. 10 is a double-ended light bulb (for example, a halogen light bulb) in which the filament 9 is provided in the arc tube 1 in the configuration shown in FIG. The filament 9 is connected to an inner lead (internal lead wire) 3a. An anchor may be provided in the arc tube 1.

  The light bulb 600 shown in FIG. 11 is a single-ended light bulb as can be seen from the figure. In this example, a single-ended halogen bulb is shown. The light bulb 600 includes, for example, a glass bulb 1 made of quartz, a sealing portion 2 (a first glass portion 8, a second glass portion 7, and a molybdenum foil 4), a filament 9, an inner lead 31, an anchor 32, and an outer lead ( (Introduction line) 5, an insulator 51, and a base 52. Even in such a halogen bulb, the problem of rupture is an important problem, and the technical significance of preventing the rupture by the technology of the above-described embodiment of the present invention is significant.

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

  As described above, the method for manufacturing a high-pressure discharge lamp, the high-pressure discharge lamp, and the lamp unit according to the present invention can suppress the composition deformation of the second glass in the high-pressure discharge lamp having the first and second glass parts. High pressure discharge lamps with high pressure resistance can be produced, and high pressure discharge lamps with high pressure resistance can be produced effectively, combined with general lighting and reflectors, projectors, automobile headlights, etc. It is useful as a high-pressure discharge lamp used for applications.

1A and 1B are cross-sectional views schematically showing a configuration of a high-pressure discharge lamp 100 according to an embodiment of the present invention. (A) and (b) are principal part enlarged views which schematically show the distribution of compressive strain along the longitudinal direction (electrode axis direction) of the sealing portion 2. (A) and (b) are process sectional views for explaining predetermined processes of the method of manufacturing the lamp 100. FIG. 7 is a process cross-sectional view for describing the method for manufacturing the lamp 100. FIG. 7 is a process cross-sectional view for describing the method for manufacturing the lamp 100. FIG. 7 is a process cross-sectional view for describing the method for manufacturing the lamp 100. FIG. 1 is a cross-sectional view schematically illustrating a configuration of a high-pressure discharge lamp 200 according to an embodiment of the present invention. FIG. 1 is a cross-sectional view schematically illustrating a configuration of a high-pressure discharge lamp 300 according to an embodiment of the present invention. It is sectional drawing which shows the structure of the lamp 900 with a mirror typically. FIG. 3 is a cross-sectional view schematically illustrating a configuration of a light bulb. FIG. 3 is a perspective view schematically showing a configuration of a light bulb 600. It is sectional drawing which shows the structure of the conventional high pressure mercury lamp typically. (A) And (b) is a figure for demonstrating the principle of the distortion measurement by the sharp color plate method using the photoelastic effect. (A) And (b) is a principal part enlarged view for explaining the reason why the pressure resistance of the lamp 100 is increased due to the compression strain in the second glass part. (A) And (b) is sectional drawing for demonstrating the mechanism into which a 2nd glass part receives a compressive strain. (A) to (d) are cross-sectional views for explaining a mechanism in which a compressive stress is applied by annealing. It is a graph which shows the profile of a heating process (annealing process) typically. It is the schematic for demonstrating the mechanism in which a 2nd glass part receives a compressive stress by mercury vapor. (A) is a figure which shows typically the compressive stress of the longitudinal direction which exists in a 2nd glass part, (b) is the sectional view on the AA line of (a).

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Arc tube 1 'Arc tube part 2 Sealing part 2' Side tube part 3 Electrode rod 4 Metal foil 5 External lead 6 Luminescent substance (mercury)
7 Second glass part 8 First glass part 9 Filament 10 Discharge space (in tube)
DESCRIPTION OF SYMBOLS 11 Support member 12 Coil 50 Electrode structure 56 Cap 60 Reflector 62 Lead wire opening 65 Lead wire 70 Glass tube 80 Glass tube for discharge lamp 82 Chuck 100, 200, 300 High pressure discharge lamp 500, 600 Light bulb (halogen bulb)
900 Lamp with mirror (lamp unit)
1000 Ultra-high pressure mercury lamp

Claims (19)

A method for manufacturing a high-pressure discharge lamp having a light-emitting tube in which a light-emitting substance is sealed in a tube, and a sealing portion for maintaining the airtightness of the light-emitting tube,
The method of manufacturing the high-pressure discharge lamp,
A step of preparing a discharge lamp glass pipe having a light-emitting tube part serving as a light-emitting tube of a high-pressure discharge lamp, and a side tube part extending from the light-emitting tube part;
Introducing mercury bromide (HgBr ₂ ) into the arc tube;
Forming the sealing portion from the side tube portion.
The step of forming the sealing portion,
A glass member made of a second glass having a lower softening point than the first glass constituting the side tube portion is inserted into the side tube portion, and then the side tube portion is heated to form the glass member. A step of bringing the side tube into close contact,
A heating step of heating at least a portion including the glass member and the side tube portion at a temperature higher than a strain point temperature of the second glass after the contacting step.   The method for manufacturing a high-pressure discharge lamp according to claim 1, wherein the heating step is performed at a temperature lower than a strain point temperature of the first glass. A method for manufacturing a high-pressure discharge lamp having a light-emitting tube in which a light-emitting substance is sealed in a tube, and a pair of sealing portions extending from both ends of the light-emitting tube,
A step of preparing a discharge lamp glass pipe having a light emitting tube part serving as a light emitting tube of a high pressure discharge lamp, and a pair of side tube parts extending from both ends of the light emitting tube part;
One side tube of the pair of side tubes includes a glass tube made of a second glass having a lower softening point than the first glass constituting the side tube, and at least an electrode rod. Inserting the electrode structure, and then, by heating and shrinking the side tube portion, forming one of the pair of sealing portions sealing portion,
Introducing a luminescent substance and mercury bromide (HgBr ₂ ) into the arc tube after forming the one sealing portion;
After introducing the luminescent substance, a glass tube made of the second glass and an electrode structure including at least an electrode rod are inserted into the other side tube portion with respect to the one, and then the side tube portion is inserted. Forming a luminous tube in which the other sealing portion for the one and the luminescent substance are sealed by heat shrinking;
At a temperature higher than the strain point temperature of the second glass, and at a temperature lower than the strain point temperature of the first glass, with respect to the completed lamp in which both the sealing portions and the arc tube are formed. A heating step of heating a portion including at least the glass tube and the side tube portion.   The method according to claim 1, wherein the heating step is performed for 2 hours or more.   The method according to claim 3, wherein the heating step is performed for 100 hours or more. When the sealing portion is measured by using a sensitive color plate method utilizing a photoelastic effect, the area of the second glass is not less than 10 kgf / cm ^{2 and not} more than 50 kgf / cm ² . The method for manufacturing a high-pressure discharge lamp according to claim 3, wherein the heating step is performed so that a longitudinal compressive stress is present.   The method for manufacturing a high-pressure discharge lamp according to claim 6, wherein the compressive stress is generated in each of the pair of sealing portions.   The heating is performed by placing the completed lamp body in a furnace having a temperature higher than the strain point of the second glass and lower than the strain point of the first glass. 3. The method for producing a high-pressure discharge lamp according to claim 1.   The method for manufacturing a high-pressure discharge lamp according to claim 8, wherein the inside of the furnace is in a vacuum or reduced pressure state. The first glass contains 99% by weight or more of SiO ₂ ,
The second glass comprises at least one of 15 wt% or less of Al ₂ O ₃ and 4 wt% or less of B, incl. And SiO _2, a high pressure according to any one of claims 1 9 Manufacturing method of discharge lamp.   The method for manufacturing a high-pressure discharge lamp according to claim 10, wherein the temperature of the heating is 1030 ° C. ± 40 ° C. 11. The high-pressure discharge lamp is a high-pressure mercury lamp,
Mercury as the luminous material, based on the internal volume of the luminous bulb enclosing 150 mg / cm ³ or more, a manufacturing method of a high-pressure discharge lamp according to any one of claims 1 to 11. A light emitting tube in which a light emitting substance is sealed in the tube,
A sealing portion for maintaining the airtightness of the arc tube,
The sealing section has a first glass section extending from the arc tube, and a second glass section provided at least partially inside the first glass section, and
The sealing portion has a portion where a compressive stress is applied,
A high-pressure discharge lamp in which mercury bromide (HgBr ₂ ) is sealed in the arc tube. A light emitting tube in which a light emitting substance is sealed in the tube,
A pair of sealing portions for maintaining the airtightness of the arc tube,
Each of the pair of sealing portions has a first glass portion extending from the arc tube and a second glass portion provided at least partially inside the first glass portion. And
Each of the pair of sealing portions has a portion to which a compressive stress is applied,
The compressive stress is, in a region corresponding to the second glass portion, 10 kgf / cm ² or more and 50 kgf / cm ² or less when the sealing portion is measured by using a sensitive color plate method utilizing a photoelastic effect. Yes,
In the arc tube, a pair of electrode rods are arranged facing each other,
Each electrode rod of the pair of electrode rods is connected to a metal foil,
The metal foil is provided in the sealing portion, and at least a connection portion between the metal foil and the electrode bar is located in the second glass portion,
A high-pressure discharge lamp in which mercury bromide (HgBr ₂ ) is sealed in the arc tube as a halogen precursor. The high-pressure discharge lamp is a high-pressure mercury lamp,
15. The high-pressure discharge lamp according to claim 13, wherein mercury is enclosed as the luminescent substance in an amount of 150 mg / cm ³ or more based on the inner volume of the arc tube. The mercury as a luminescent substance, based on the internal volume of the arc tube is enclosed 220 mg / cm ³ or more, the high-pressure discharge lamp according to claim 15. The mercury as a luminescent substance, based on the internal volume of the arc tube is enclosed 300 mg / cm ³ or more, the high-pressure discharge lamp according to claim 15.   The high-pressure discharge lamp according to any one of claims 13 to 17, wherein the arc tube is a chipless arc tube. A lamp unit, comprising: the high-pressure discharge lamp according to claim 13; and a reflecting mirror that reflects light emitted from the high-pressure discharge lamp.

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