JP2005026128A - Ultra-high pressure discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultra-high pressure discharge lamp capable of restraining a foil float-up phenomenon and increasing lamp operation pressure, with high brightness and a long life of usage. <P>SOLUTION: In the ultra-high pressure discharge lamp, the rear end of an inside lead rod and metal foil are embedded in a side tube of a light-emitting tube made of quartz glass. Defining stress in a radius direction imposed on the glass of the side tube while the lamp is lighting, and provided that the accumulated value of the stress at the area where the stress becomes negative within a range of 2 mm from the rear end of the inside lead rod in an axial direction is A(MPa mm), and the accumulated value of the stress at the area where the stress becomes positive is B(MPa mm) with a pulling direction as positive, the sum D(MPa mm) of absolute values fulfilling the condition that D=-(¾A¾+¾B¾) when ¾A¾>¾B¾, and D=(¾A¾+¾B¾) when ¾A¾≤¾B¾ fulfills an equation; -60≤D≤30(MPa mm). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultra high pressure discharge lamp, and more particularly to an ultra high pressure discharge lamp suitably used as a light source for a liquid crystal display device or the like.
[0002]
[Prior art]
A projection-type projector device is required to illuminate an image uniformly and with sufficient color rendering on a rectangular screen. For this reason, a short arc type discharge lamp such as a metal halide lamp, xenon lamp or mercury lamp in which mercury or a metal halide is enclosed is used as the light source.
[0003]
Since the liquid crystal projector according to the above technical field is not widespread so as to be installed in each conference room, it is often carried around, and the reduction in size and weight is an important issue. For this reason, liquid crystal panels for liquid crystal projectors have been miniaturized year by year, and in order to efficiently collect light on the miniaturized liquid crystal panels, further miniaturization of the light source is required. . In order to achieve miniaturization of the light source, shortening the arc length is the optically most effective means. However, if the arc length is simply shortened with the conventional specifications, the lamp voltage is lowered. End up. In order to make up for this and to input a predetermined lamp power, the lamp current must be increased. However, since the lighting device is increased in size to increase the lamp current, the concept of downsizing the liquid crystal projector device is deviated, and eventually, means for shortening the arc length cannot be employed.
[0004]
Therefore, in order to shorten the arc length without reducing the lamp voltage, means for increasing the arc impedance, in other words, increasing the pressure of the discharge medium during lighting, has been adopted. According to this, it is said that the color rendering property can be improved while improving the illuminance maintenance factor. Recently, a high-pressure discharge lamp in which a large amount of mercury is enclosed so that the operating pressure becomes 10 MPa or more. It has been suitably used (see Patent Documents 1 and 2).
[0005]
By the way, in the above-mentioned high-pressure discharge lamp, the pressure in the arc tube becomes extremely high when the lamp is turned on. Therefore, in the side tube portion extending on both sides of the arc tube portion, the quartz glass layer and electrodes constituting the side tube portion, In a lamp in which the metal foil needs to be sufficiently and firmly adhered, and the pressure during lamp operation is extremely high as described above, the internal lead bar having the tip of the electrode and the rear end of the lead bar A sealing structure in which the connected metal foil and the external lead rod connected to the end of the metal foil and led out from the end of the side tube are embedded in the side tube by a shrink seal method is preferable. (See Patent Document 3).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2-148561 [Patent Document 2]
JP-A-6-52830 [Patent Document 3]
JP 2003-109504 A
[Problems to be solved by the invention]
However, in the above lamp, when the connection between the metal foil and the glass constituting the side tube portion is cut and the metal foil floats inside the side tube portion (hereinafter referred to as “foil floating”), the side tube portion. As a result, the pressure strength of the lamp may be reduced, and the side tube portion of the lamp may be damaged. For this reason, it is desired to further increase the brightness, that is, increase the lamp operating pressure, but there is a problem that this cannot be realized.
The present invention has been made based on the circumstances as described above, and the object thereof is to suppress the foil floating phenomenon during lamp lighting and to increase the lamp operating pressure, and to increase the brightness. It is an object of the present invention to provide an ultra-high pressure mercury lamp that can realize a long service life.
[0008]
[Means for Solving the Problems]
An ultra-high pressure discharge lamp according to the present invention comprises an arc tube made of quartz glass and having a substantially cylindrical side tube portion connected to the arc tube portion, an internal lead bar whose tip protrudes into the arc tube portion, and A metal foil hermetically embedded in the side tube portion and connected to the rear end portion of the internal lead rod, and 0.15 mg / mm ³ or more of mercury enclosed in the arc tube. In the high pressure discharge lamp, when the radial stress applied to the glass of the side tube portion during lamp lighting is positive in the tensile direction, the stress is in the range of 2 mm outward from the rear end of the internal lead rod in the axial direction. A and B satisfying the following relational expression, assuming that the value obtained by integrating the stress in the negative region is A (MPa · mm) and the value obtained by integrating the stress in the positive region is B (MPa · mm). The sum D (MPa · mm) of absolute values is −60 ≦ D ≦ 30 (MP a · mm).
(Expression) When | A |> | B |, D = − (| A | + | B |), and when | A | ≦ | B |, D = | A | + | B |
[0009]
An arc tube made of quartz glass with a substantially cylindrical side tube portion connected to the arc tube portion, an internal lead bar whose tip protrudes into the arc tube portion, and an air tight seal on the side tube portion An ultra-high pressure discharge lamp comprising: a metal foil embedded and connected to a rear end portion of the internal lead rod; and mercury of 0.15 mg / mm ³ or more enclosed in the arc tube. The bar is characterized in that a large number of voids are formed at the rear end.
[0010]
An arc tube made of quartz glass with a substantially cylindrical side tube portion connected to the arc tube portion, an internal lead bar with a tip projecting inside the arc tube portion, and an airtightly embedded in the side tube portion In an ultrahigh pressure discharge lamp comprising a metal foil to which a rear end portion of the internal lead bar is connected and 0.15 mg / mm ³ or more of mercury enclosed in the arc tube, the internal lead bar has Is characterized in that a hole having an opening at the rear end is formed.
[0011]
[Action]
When the lamp is turned on, the internal lead bar expands with heat. Since the glass of the side tube portion surrounds the rear end portion of the internal lead rod, the glass is pushed and spread in the radial direction by the internal lead rod. For this reason, the glass in which the metal foil is embedded is subjected to stress outward in the radial direction so as to be pulled by the glass. It is considered that when the tensile stress in the radial direction is large and the glass and the metal foil of the side tube portion are peeled off, the foil floats.
The inventors investigated the state of stress distribution at the interface between the side tube glass and the metal foil during lamp operation.
When the lamp is lit, the silica glass becomes a metal foil by suppressing the stress state in the 2 mm region from the rear end of the internal lead bar to the outside in the axial direction of the lamp to keep both the tensile and compressive stresses below a certain level. Is prevented from being peeled off, the contact state between the two can be maintained, the foil does not float, and the pressure resistance of the side tube portion can be maintained high. Furthermore, in the present invention, it is necessary to reduce not only the tensile stress but also the compressive stress. This is because when glass is subjected to a compressive stress in the radial direction, tensile stress acts in the lamp axial direction as a reaction force, and the density of the glass becomes sparse in the axial direction of the lamp. (Sodium) mobility is increased, and it is easy to gather in the high temperature part of the side tube part, that is, in the vicinity of the joint part between the internal lead bar and the metal foil, so that the bond between the metal foil and the glass is broken. Become.
According to the first aspect of the present invention, the adhesion strength between the glass and the metal foil can be maintained high, and the bond between the silica glass and the metal foil can be maintained for a long period of time, resulting in a foil floating phenomenon. It is possible to avoid breakage that occurs in the vicinity of the side tube portion without any problems.
According to the second aspect of the present invention, since the internal lead bar has a large number of voids at the rear end, the degree of thermal expansion is small and the stress applied to the glass can be reduced. The stress that peels off can be reduced.
According to the invention described in claim 3 above, since the hole having the opening at the rear end is formed in the internal lead bar, even if the portion is thermally expanded, it is crushed inward in the radial direction. The stress which peels off metal foil and glass can be made small, without receiving stress.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an explanatory cross-sectional view showing an example of the configuration of an ultrahigh pressure mercury lamp according to the present invention, and is a view showing a cross section cut in the plane direction of a metal foil. FIG. 2 is an enlarged cross-sectional view showing one side tube portion in FIG. 1 in an enlarged manner. In FIG. 2, the tube shaft is shown as a section rotated by 90 ° with respect to the lamp of FIG.
In FIG. 1, an arc tube 10 of an ultra-high pressure mercury lamp is made of quartz glass, and has an arc tube part 11 that is substantially elliptical and forms a main discharge space. Inside the arc tube part 11, a cathode side electrode 20 and The anode side electrodes 20 ′ are arranged so as to face each other. Further, side tube portions 12, 12 'are formed so as to extend from both ends of the arc tube portion 11, and metal foils 30, 30', usually made of molybdenum, are hermetically sealed in these side tube portions 12, 12 '. It is buried in.
Internal lead bars 21 and 21 'are connected to the cathode side electrode 20 and the anode side electrode 20', respectively, and rear end portions 21A and 21A 'of the internal lead bars 21 and 21' are formed of the metal foils 30 and 30 '. External lead rods 22 and 22 ′ that are welded to the end portions and project to the outside are connected to the other ends of the metal foils 30 and 30 ′, respectively. Stress buffering portions B and B ′ are formed at the rear end portions 21A and 21A ′ of the internal lead rods 21 and 21 ′.
The arc tube portion 10 is filled with 0.15 mg / mm ³ or more of mercury, a predetermined rare gas, and a halogen gas.
[0013]
The stress buffer B buffers the radial stress applied to the glass of the side tube portions 12 and 12 'during lamp operation, and this will be described below.
In the enlarged view shown in FIG. 2, when the stress applied in the radial direction to the glass of the side tube portion 12 during lamp operation is defined as positive (plus: +) in the tensile direction, the rear end 21a of the internal lead bar 21 In a region S 2 mm axially outward from A, the value obtained by integrating negative (minus :-) stress is A (MPa · mm), and the value obtained by integrating positive stress is B (MPa · mm). When A |> | B |, D = − (| A | + | B |) is satisfied, and when | A | ≦ | B |, D = | A | + | B | The sum D (MPa · mm) of the absolute values of B is set in a range of −60 ≦ D ≦ 30 (MPa · mm).
[0014]
In the region S of 2 mm outward in the axial direction from the rear end 21a of the internal lead bar 21, when the relationship between A and B is | A |> | B |, that is, the compressive stress component is larger than the tensile stress component. When D satisfying D = − (| A | + | B |) is −60 MPa · mm or more, the alkali metal is prevented from concentrating at the location, and the metal foils 30, 30 ′ and A decrease in adhesion strength with glass is suppressed. When D is less than −60 MPa · mm, the density of the glass is low and alkali metals are easily collected. For this reason, when an alkali metal moves to the side tube portion 12, the bond between the metal foil 30 and the glass is cut, and the foil floats easily.
On the other hand, in the region S 2 mm axially outward from the rear end 21a of the internal lead bar 21, when the relationship between A and B is | A | ≦ | B |, that is, the tensile stress component is the stress component in the compression direction. When D is more, D satisfying D = | A | + | B | is 30 MPa · mm or less, so that the adhesion strength between the glass and the metal foil 30 is a force for peeling the glass from the metal foil 30. And the occurrence of foil floating can be suitably prevented.
[0015]
Here, an embodiment of the stress buffer portion will be described with reference to FIGS. 3 (a) and 3 (b). FIGS. 3A and 3B are perspective views showing only the cathode side electrode (20) side internal lead rod (21) in FIGS.
[1]
FIG. 3A is a view for explaining an embodiment of the invention as set forth in claim 2. In the figure, the stress buffering portion B is made of a sintered body obtained by compressing and sintering a metal powder, for example, and a large number of voids are formed therein. In the present embodiment, the stress buffer B is preferably made of a sintered body having a theoretical density of 55 to 65%, for example, and when the outer diameter of the internal lead bar 21 is 0.7 mm, the stress buffer B Is preferably formed to a length of 1.0 mm or more.
The stress buffer B made of this sintered body, for example, compresses tungsten powder into a substantially cylindrical shape having the same diameter as the tungsten rod constituting the main body portion of the internal lead rod (21) to produce a powder compact. By connecting this to the rear end face of the tungsten rod and sintering, it can be manufactured integrally with the tungsten rod. An example of the sintering conditions is, for example, heating in a vacuum atmosphere at about 1200 ° C. for about 0.5 hours, further increasing the temperature and heating at 1700 ° C. for about 0.5 hours.
According to the third aspect of the present invention, since a large number of voids can be formed inside the stress buffer portion B, the degree of thermal expansion can be reduced, and the side tube portion in which the metal foil is embedded can be applied to the glass. Stress can be reduced. As a result, the force in the direction of peeling the glass of the side tube portion from the metal foil is reduced, the connection between the two is difficult to cut, the foil floating can be prevented, and the resistance of the side tube portion of the lamp can be kept high. It becomes like this.
[2]
FIG. 3B is a view for explaining an embodiment of the invention as set forth in claim 3. As shown in the figure, the invention described in claim 3 is an example in which the stress buffering portion B is provided by forming a bottomed hole 210 in the axial direction from the rear end surface 21 a of the internal lead bar 21. One or many holes 210 may be provided. In addition, it is preferable that this hole 210 is 0.7-1.0 mm, for example in the tube-axis direction of a lamp | ramp.
According to the third aspect of the present invention, even if the temperature of the internal lead bar 21 rises and thermally expands, the stress buffer B is crushed radially inward by the reaction force when pressing the glass. Therefore, the stress applied to the glass is reduced, and the force applied in the direction of peeling the glass of the side tube portion from the metal foil is reduced. As a result, the bond between the glass and the metal foil is difficult to cut, and the foil can be prevented from floating and the resistance of the side tube portion of the lamp can be maintained high.
Of course, as long as the stress to the glass can be reduced as compared with the conventional internal lead rod, the present invention is not limited to the above embodiment, and any form may be used.
[0016]
[Experimental example]
A lamp according to the present invention was manufactured according to the following procedure.
First, a lamp according to an embodiment of the present invention was manufactured. Here, nine lamps in which the internal lead bar is provided with a stress buffering portion were manufactured by means of [1] shown in FIG. The specifications are as follows. Here, the lamp according to the embodiment is referred to as the lamp No. Called 1-9.
[Luminescent tube (10)] Material: silica glass, light emitting portion (11) inner volume: 75 mm ² , light emitting portion (11) maximum outer diameter: φ10.0 mm, side tube portion (12, 12 ′) outer diameter: φ6. 0mm, side tube (12,12 ') length: 16.0mm
[Encapsulated matter] Mercury 0.22 mg / mm ³ , halogen (bromine) 3.0 × 10 ⁻⁴ μmol / mm ³
[Electrodes (20, 20 ')] Material: Tungsten (pure tungsten)
[Internal lead bar (21, 21 ′)] Material: Tungsten, outer diameter: φ0.7 mm, total length: 8.5 mm, length of stress buffer (B, B ′): 1.0 mm
[Metal foil (30, 30 ')] Material: Molybdenum, Thickness: 20 μm, Axial length: 11.0 mm, Width: 1.5 mm
[0017]
Next, in the lamp according to the comparative example corresponding to the prior art of the present invention, that is, the lamp of the above-described embodiment, the internal lead bar is composed of one tungsten bar and the stress buffering part is formed at the rear end. Twelve lamps that were not used were made. Except for the internal lead rod, the other specifications were the same as above. Here, the lamps according to these comparative examples are referred to as lamp Nos. 10-21.
[0018]
<Stress measurement>
Lamp No. according to the above examples and comparative examples. About 1-21, the stress of the side pipe part during lamp lighting was measured.
{Circle around (1)} A birefringence measuring device (Mizojiri Optical Industry, ELP-150ART type, light source: He—Ne laser light, wavelength 633 nm) was used for measuring the device stress.
{Circle over (2)} Principle FIG. 4 is a configuration diagram of the entire birefringence measuring apparatus as viewed from the side. Laser light from the He-Ne laser device 51 passes through the condenser lens and enters the sample as spot light having a diameter of 0.05 mm. First, the He—Ne laser light passes through the polarizer 52 to be linearly polarized light having an azimuth of 45 ° with respect to the optical path, and is made to turn counterclockwise circularly polarized light through the quarter-wave plate 53 and set inside the lamp lighting fixture 54. Incident on the sample. The polarization state is examined from the phase difference of light passing through the glass of the sample, that is, Δ (deg), R (nm) and the azimuth angle (axis tilt) φ (deg) of elliptically polarized light, and the amount of distortion is measured. The stress applied to the glass is estimated by evaluating the magnitude of the measured strain.
[0019]
In this experiment, the lamp L as a sample was lit in the lamp lighting lamp 54, the stepping motor 55 was driven together with the lamp lighting lamp 54, and the lamp was moved in the vertical and horizontal directions, and the polarization state of a predetermined region was measured. In this experiment, in order to prevent light from the lamp L from entering the detector 56, a 633 nm band pass filter 57 (half-value width: about 1.5 nm) is installed in front of the lamp 54 and the detector 56. did.
[0020]
<Procedure>
(1) Processing of the lamp With respect to the sample lamp, the side tube portion was processed with a polishing machine in order to avoid laser light from being irregularly reflected on the surface of the lamp side tube portion.
In this processing, as shown in the perspective view for explanation of the sample lamp in FIG. 5, the incident light enters the direction (Z direction) perpendicular to the foil thickness direction (Y direction). A flat surface is obtained. The strain measurement region includes the rear end portion 21A of the inner lead bar 21 and the metal foil 30, the length of the lamp tube axial direction (X direction) is 10.0 mm on the polished surface of the side tube portion, and the thickness of the metal foil 30 The length in the length direction (Y direction) was a substantially rectangular portion having a length of 2.5 mm.
[0021]
(2) Strain measurement FIG. 6 is a detailed view of the lamp lighting fixture (54) in the birefringence measuring apparatus. The whole is a substantially rectangular box, and quartz glass window members 541 and 541 are installed in a laser beam passage portion. Further, a shutter S is provided to block direct light from the lamp shown in FIG. A black heat-resistant paint was applied to the entire surfaces of the shutter S and the lighting lamp 54 in order to prevent reflection of lamp light.
The lamp L was installed in the lighting lamp 54, and the lamp L was turned on by moving to a position where the laser light passes only through the quartz glass windows 541 and 541. After the lamp L became stable (for example, about 5 minutes after lighting), the quarter-wave plate was corrected. Thereby, the thermal strain of the quartz glass windows 541 and 541 is canceled, and the amount of strain of the glass in the lamp side tube portion during lighting can be accurately measured.
Thereafter, the strain measurement region in the above-mentioned lamp side tube portion was irradiated with a laser at an interval of 0.1 mm, and the strain was measured at a point to perform mapping.
[0022]
(3) Data evaluation The polarization state (Δ, R, φ) due to the distortion of the lamp side tube glass was measured by the above procedure. Based on this, the phase difference R value [nm] was converted to the stress value [MPa] by the following equation.
(Formula) F [MPa] = R / C · L * 0.098
However, C: Photoelastic constant [(nm · cm ⁻¹ ) / (kg · cm ⁻² )], L: Optical path length (foil width) (mm) = 1.5.
In this experiment, since the sample was silica glass, the photoelastic constant C was set to 3.5. The measured value is an integration of the entire glass in the thickness direction, but the optical path length L was calculated as optical path length = foil width (1.5 mm) because stress is considered to occur in the width portion of the metal foil.
[0023]
7 shows the lamp No. of the example. It is a stress distribution figure which shows an example of the result of having analyzed 1 distortion. For easy understanding, an enlarged view of the vicinity of the rear end portion (21A) of the internal lead rod of the lamp is shown. In the figure, the vertical axis represents the stress (MPa) in the radial direction of the side tube portion (12) with the pulling direction as positive, and the horizontal axis represents the distance from the rear end (21a) of the internal lead rod (21).
Here, within a distance of 2 mm from the rear end (21a) of the internal lead bar, the integrated value A (MPa · mm) of the stress in the compressive stress region a is −12, and the stress in the region b where the tensile stress is applied. The integrated value B (MPa · mm) of was 10. That is, in this lamp, since | A |> | B |, D is −22 MPa · mm.
[0024]
Similarly, the integrated values A, B, and D (MPa) of the stress of the side tube glass were measured for the lamps according to other examples and comparative examples.
[0025]
[Observation of side tube]
The lamp after the stress measurement was taken out from the lamp lighting fixture, lit at the rated power, and the state of the metal foil inside the side tube portion was observed. After the lamp is lit, the contact state between the metal foil and the side tube part is broken and it is determined that there is a gap between the metal foil and the side tube. It was determined that the foil did not float.
[0026]
Furthermore, the axial length of the gap formed between the foil and the glass was measured for a lamp in which a gap was recognized at the interface between the metal foil and the glass and it was determined that “the foil floated”. Here, the maximum length in the axial direction was measured from the rear end of the internal lead bar, excluding the overlapping portion of the metal foil and the internal lead bar. Hereinafter, the length of the gap is simply referred to as “foil floating distance”.
[0027]
The above lamp No. The result of having observed the stress and the foil floating state about 1-21 is summarized and shown in a table in FIG.
As a result, all of the lamps (lamps No. 1 to No. 9) according to the examples provided with the stress buffer portion have an integrated value D (MPa · mm) of stress between 2 mm from the rear end of the internal lead bar, − 60 ≦ D ≦ 30 was satisfied. And as for the lamp | ramp (Lamp No.1-No.9) which concerns on an Example, foil floating was not recognized.
The numerical value in the parenthesis in the right column of the figure is the foil lifting distance (mm) of the lamps recognized as “present” (that is, lamps No. 10 to No. 21).
As is clear from the figure, it was found that the foil floating occurred in any lamp within a range of 2 mm from the rear end of the internal lead rod and did not occur beyond 2 mm. From this result, it was found that the foil floating can be effectively suppressed by suppressing the stress of the side tube portion within a range of 2 mm from the rear end of the internal lead bar.
[0028]
As described above, in this experimental example, the lamp was manufactured with the configuration of the internal lead rod shown in FIG. 3A, but the present inventors manufactured using the internal lead rod shown in FIG. 3B. It was confirmed that good results were obtained with the lamp as well.
Of course, the stress buffering portion provided on the internal lead rod is not limited to that of the above embodiment, and can be formed by various methods. The point is that the integrated value D (MPa · mm) of the stress acting on the side tube portion, that is, the stress between 2 mm from the rear end of the internal lead rod is set to −60 ≦ D ≦ 30. It is possible to obtain a lamp that can maintain a good contact state with the side tube and can suitably avoid breakage of the side tube portion.
[0029]
【The invention's effect】
As described above, according to the first aspect of the present invention, the foil floating phenomenon during lamp lighting can be suppressed, the lamp operating pressure can be increased, high brightness can be realized, and a long service life can be realized. Can be provided.
Further, according to the invention described in claims 2 and 3, the stress applied to the glass constituting the side tube portion during the lamp lighting is expected in the region of 2 mm axially outward from the rear end of the inner lead bar. Thus, the foil floating phenomenon during lamp lighting can be suppressed. As a result, it is possible to provide an ultrahigh pressure mercury lamp that can increase the lamp operating pressure, achieve high brightness, and obtain a long service life.
[Brief description of the drawings]
FIG. 1 is an explanatory cross-sectional view showing an example of the configuration of an extra-high pressure mercury lamp according to the present invention.
FIG. 2 is an enlarged cross-sectional view showing one side tube portion in FIG. 1 in an enlarged manner.
3 is an enlarged perspective view showing a cathode side electrode side internal lead rod in FIGS. 1 and 2 for explaining a stress buffering portion. FIG.
FIG. 4 is a configuration diagram of the entire birefringence measuring apparatus as viewed from the side.
FIG. 5 is a perspective view for explaining a sample lamp.
FIG. 6 is a detailed view of a lamp lighting lamp.
7 is a lamp No. in the example. It is a stress distribution figure which shows an example of the result of having analyzed 1 distortion.
FIG. It is a graph which shows the result of having observed the stress and the foil floating state about 1-21.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Light emission tube 11 Light emission part 12, 12 'side tube part 20 Cathode side electrode 20' Anode side electrode 21, 21 'Internal lead rod 21A, 21A' Rear end part 21a, 21a 'Rear end B Stress buffer part 210 Hole 22, 22 'external lead rods 30 and 30' metal foil 51 He-Ne laser device 52 polarizer 53 quarter wave plate 54 lamp lighting lamp 55 stepping motor 56 detector 57 633 nm band pass filter L lamp

Claims (3)

An arc tube made of quartz glass with a substantially cylindrical side tube portion connected to the arc tube portion, an internal lead bar with a tip projecting inside the arc tube portion, and an airtightly embedded in the side tube portion In an ultrahigh pressure discharge lamp comprising a metal foil to which a rear end portion of the internal lead rod is connected, and 0.15 mg / mm ³ or more of mercury enclosed in the arc tube,
When the lamp is lit, the stress in the radial direction applied to the glass of the side tube part, when the tensile direction is positive,
In the range of 2 mm axially outward from the rear end of the inner lead rod, A (MPa · mm) is a value obtained by accumulating stress in a region where stress is negative, and a value obtained by accumulating stress in a region where stress is positive. If B (MPa · mm),
An ultrahigh pressure discharge lamp characterized in that a sum D (MPa · mm) of absolute values of A and B satisfying the following relational expression satisfies −60 ≦ D ≦ 30 (MPa · mm).
When | A |> | B |, D = − (| A | + | B |), and when | A | ≦ | B |, D = | A | + | B | An arc tube made of quartz glass and having a substantially cylindrical side tube portion connected to the arc tube portion, an internal lead bar whose tip projects into the inside of the arc tube portion, and an airtightly embedded in the side tube portion In an ultrahigh pressure discharge lamp comprising a metal foil to which a rear end portion of the internal lead rod is connected, and 0.15 mg / mm ³ or more of mercury enclosed in the arc tube,
The ultra high pressure discharge lamp characterized in that a large number of gaps are formed in the rear end portion of the internal lead bar. An arc tube made of quartz glass and having a substantially cylindrical side tube portion connected to the arc tube portion, an internal lead bar whose tip projects into the inside of the arc tube portion, and an airtightly embedded in the side tube portion In an ultrahigh pressure discharge lamp comprising a metal foil to which a rear end portion of the internal lead rod is connected, and 0.15 mg / mm ³ or more of mercury enclosed in the arc tube,
An ultrahigh pressure discharge lamp characterized in that a hole having an opening at the rear end is formed in the internal lead bar.

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