JP5072665B2 - Sealing structure of short arc type discharge lamp - Google Patents

Description

  The present invention relates to a sealing structure of a short arc discharge lamp, and relates to a structure in a sealing tube of a short arc discharge lamp used in the field of manufacturing semiconductors and liquid crystals, for example.

  In order to improve production efficiency in the field of manufacturing semiconductors and liquid crystals, the power of short arc discharge lamps is increasing. For this reason, problems have arisen, for example, when the metal foil is subjected to a great deal of stress during lamp manufacture and the sealing portion is damaged. As a countermeasure, it is effective to make the sealing portion have a double sealing structure. In the double sealing structure, since a great stress is not applied to the metal foil at the time of manufacturing the lamp, a problem that the metal foil is broken can be solved. In addition, even if the electrode becomes large and very heavy, the mounting parts can be accurately welded to the sealing tube, the mechanical strength of the sealing part is increased, and the risk of breakage during lamp manufacturing and transportation is reduced. . Below, the prior art of the double sealing structure of a short arc type discharge lamp is demonstrated.

  A conventional double arc structure short arc discharge lamp proposed by the present applicant in Patent Document 1 will be described with reference to FIGS. FIG. 7 is a cross-sectional view of a conventional short arc type discharge lamp having a double sealed structure. As shown in FIG. 7, there is an arc tube 1 that forms a discharge space. In the arc tube 1, a pair of electrodes (anode 2 and cathode 3) are arranged to face each other. The discharge space S is a space in which mercury and a rare gas are enclosed and discharge occurs. The thick internal glass tube 236 is an internal glass tube having an outer diameter enlarged toward the discharge space side.

  FIG. 8 is a cross-sectional view of a sealing portion of a short arc type discharge lamp. In FIG. 8, the electrode support rod 4 is a metal member that supports the anode. The lead bar 5 is a conductive member for supplying electric power. The outer sealing tube 11 is a cylindrical portion that is an extension of the arc tube. The inner sealing tube 12 is a cylindrical glass member for hermetic sealing, and is an inner sealing tube having a larger outer diameter than the outer inner sealing tube. The outer sealing tube 13 is a cylindrical glass member for hermetic sealing, and is an inner sealing tube having a smaller outer diameter than the inner inner sealing tube. The glass rod 18 is a glass member that structurally connects the lead rod 5 and the electrode support rod 4. The thick internal glass tube 236 is an internal glass tube whose outer diameter expands toward the discharge space, and is a member that holds the electrode support rod 4. The small diameter portion 237 is a portion where the diameter of the thick inner glass tube is small. The large diameter portion 238 is a portion where the diameter of the thick inner glass tube is large.

  The inclined portion 239 is a portion between the large diameter portion and the small diameter portion of the thick inner glass tube. The external glass tube 7 is a glass member that holds the lead rod 5. The metal foil 8 is a metal member that is interposed between the glass rod 18 and the outer sealing tube 13 and electrically connects the inner metal ring and the outer metal ring. The fixing ring 9 is a quartz member that suppresses the movement of the outer sealing tube 13 in the axial direction. The internal metal ring 14 is a metal member that electrically connects the electrode support rod 4 and the metal foil 8. The external metal ring 15 is a metal member that electrically connects the lead bar 5 and the metal foil 8. The weld end 224 is a circumferential end on the discharge space side of the weld between the thick inner glass tube and the outer sealing tube. The welding end diameter D1 is the diameter of the welding end on the discharge space side of the thick inner glass tube.

  Inside the outer sealing tube 11 connected to the arc tube 1, the inner sealing tube 12 is interposed up to the vicinity of the inclined portion 239 of the thick inner glass tube 236. The internal sealing tube 12 is not exposed to the discharge space S. Therefore, as compared with a conventional double sealing structure, the number of crack generation factors is reduced, the reliability is improved, and the inspection time for the welded state can be shortened.

  As described above, in the conventional double sealing structure, the mounting part is constructed by using a thick inner glass tube having a small diameter part and a large diameter part as a sealing part structure of a short arc type discharge lamp. The end of the inner sealing tube on the discharge space side is aligned between the small diameter portion and the large diameter portion of the inner glass tube so that the end of the inner sealing tube on the discharge space side is not exposed to the discharge space. Since the thick inner glass tube and the outer sealing tube were welded, the reliability and manufacturing efficiency of the double sealing structure could be improved.

Moreover, in order to shorten the rise time at the time of lighting of a short arc type discharge lamp, it devised so that the heat capacity of a sealing part may be made small. The “short arc type mercury lamp” disclosed in Patent Document 2 is a large mercury lamp having a good rise characteristic. A pair of electrodes are arranged to face each other, and includes a light emitting portion in which mercury and a rare gas are sealed, and sealing portions formed at both ends thereof. The light emitting part is composed of a main light emitting space part and a root space part formed on the sealing part side of the main light emitting space part, and the ratio of the inner volume of the main light emitting space part to the inner volume of the root space part is , 0.01 to 0.09.
JP 2007-157513 JP JP 2007-128755 A

  However, in the conventional double sealing structure, there is a problem that stress concentrates on the sealing portion due to heat and it is easy to rupture, and a rise time until stable lighting becomes long.

  The reason why stress concentrates on the sealing portion and ruptures is as follows. In the short arc type discharge lamp, the outer diameter of the inner metal ring is determined by the number of metal foils corresponding to the lamp current. Since the conventional double sealing structure has a large diameter portion on the discharge space side of the thick inner glass tube, the welding end diameter D1 exposed in the discharge space is larger than that of the conventional single sealing structure lamp. Become. When the welding end diameter D1 is increased, a stress is concentrated on the welding end portion 224, so that a minute crack may be generated, which may be a starting point of rupture when the lamp is turned on.

  The reason why the rise time until stable lighting is long is as follows. It is desirable that the short arc type discharge lamp has a short time (rise time) to rise from the start of discharge to a rated lamp voltage that can be said to be a stable lighting state. In the conventional double sealing structure, since there is a large diameter portion on the discharge space side of the thick inner glass tube, the heat capacity of the thick inner glass tube 236 on the discharge space side is larger than that of the single tube sealed structure lamp. . For this reason, the vicinity of the thick internal glass tube 236 is the coldest part, and it is difficult to warm, mercury does not evaporate easily and does not contribute to the discharge, so it takes time to rise to the discharge voltage of steady lighting, and quickly to stable lighting Do not migrate.

  An object of the present invention is to solve the above-mentioned conventional problems, improve the reliability of the double sealing structure of a short arc type discharge lamp, and shorten the lighting rise time.

  In order to solve the above problems, in the present invention, a glass arc tube, a glass outer seal tube connected to the arc tube, and an inner seal coaxially welded inside the outer seal tube. A stop tube, a pair of electrodes sealed in the arc tube, a metal electrode support rod supporting the electrode, an internal metal ring electrically connected to the electrode, and a lead rod for supplying power to the electrode An outer metal ring electrically connected to the lead bar, an inner metal ring and a plurality of metal foils electrically connected to the outer metal ring, an outer glass tube supporting the lead bar, and a lead bar Sealing part of a short arc type discharge lamp having a double sealing structure comprising a glass rod supporting an inner metal ring, an outer metal ring, an electrode supporting rod and a metal foil, and an inner glass tube supporting the electrode supporting rod. The inner glass tube of the structure is more than the inner metal ring It has a larger diameter large diameter portion, and configured to have a small diameter portion having a smaller diameter than the large diameter portion to the light emitting tube side. The large diameter portion is a portion from the portion in contact with the inner metal ring to the small diameter portion. Alternatively, the inner glass tube has a base diameter portion having an outer diameter substantially equal to that of the inner metal ring in a portion in contact with the inner metal ring from the larger diameter portion, and the axial section of the large diameter portion has an angle.

  Constructed as described above, the diameter of the welding end of the double arc structure short arc type discharge lamp is reduced to the same extent as in the case of the single seal structure, thereby reducing the stress concentration that causes rupture. In addition, the reliability can be improved, and the inspection time for the welded state of the weld end can be shortened. Further, since the heat capacity on the discharge space side can be reduced to the same level as in the case of the single sealing structure even in the double sealing structure, the lighting start-up becomes quick. Further, even if the outer diameter of the sealing portion that requires strength is increased, the outer diameter of the base does not increase, and overheating of the base can be prevented. Furthermore, since a double sealing tube can be sealed at a time, even a double sealing structure is a sealing process equivalent to a single sealing, and the working time can be shortened.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to FIGS.

  In Example 1 of the present invention, the mount component is configured using a tapered inner glass tube having a small diameter portion on the discharge space side, and the end of the inner sealing tube on the discharge space side is formed on the end surface of the large diameter portion of the tapered inner glass tube. It is the sealing part structure of the short arc type discharge lamp sealed together.

  FIG. 1 is an overall cross-sectional view showing a sealing part structure of a short arc type discharge lamp in Example 1 of the present invention. In FIG. 1, an arc tube 1 is a quartz glass tube filled with mercury. The anode 2 is a positive electrode. The cathode 3 is a negative electrode. The discharge space S is a space in which mercury and a rare gas are enclosed and discharge occurs. The tapered inner glass tube 36 is an inner glass tube having a narrow diameter portion on the discharge space side.

  FIG. 2 is a partial cross-sectional view showing a sealing portion structure of a short arc type discharge lamp. In FIG. 2, the electrode support rod 4 is a metal member that supports the anode. The lead bar 5 is a conductive member for supplying electric power. The metal foil 8 is a metal member that is interposed between the glass rod 18 and the inner glass tube 6 and electrically connects the inner metal ring and the outer metal ring. The fixing ring 9 is a quartz member that suppresses the movement of the inner sealing tube in the axial direction. The outer sealing tube 11 is a cylindrical portion that is an extension of the arc tube. The inner sealing tube 12 is a cylindrical glass member for hermetic sealing, and is an inner sealing tube having a larger outer diameter than the outer sealing tube. The outer sealing tube 13 is a cylindrical glass member for hermetic sealing, and is an inner sealing tube having a smaller outer diameter than the inner inner sealing tube. The internal metal ring 14 is a metal member that electrically connects the electrode support rod 4 and the metal foil 8. The external glass tube 15 is a glass member that holds the lead rod 5.

  The inner end portion 16 is an end portion of the inner sealing tube 10 on the discharge space side. The outer end portion 17 is an end portion of the inner sealing tube 10 on the fixing ring side. The glass rod 18 is a glass member that structurally connects the lead rod and the electrode support rod 4. The welding end portion 24 is a cylindrical end on the discharge space side of the welding portion between the tapered inner glass tube and the outer sealing tube. In other words, the discharge space side of the thick inner glass tube 236 is shaped like a counterbore, and the weld end 24 is thin. The outer metal ring 25 is a metal member that electrically connects the lead bar and the metal foil. The tapered internal glass tube 36 is an internal glass tube having a narrow diameter portion on the discharge space side, and is a member that holds the electrode support rod 4. The small diameter portion 37 is a portion where the diameter of the tapered inner glass tube is small. The large diameter portion 38 is a portion where the diameter of the tapered inner glass tube is large. The large-diameter portion end surface 39 is an end surface of the large-diameter portion on the inner metal ring side. The sealed tube inner diameter D2 is the diameter of the surface of the tapered inner glass tube exposed to the discharge space.

  FIG. 3 is a cross-sectional view showing a state in which the mount component having the sealing portion structure of the short arc type discharge lamp is inserted into the inner sealing tube. In FIG. 3, the fixing ring 9 is a ring-shaped component for suppressing the movement of the external sealing tube in the axial direction. The inner sealing tube 22 before welding is an inner sealing tube before being welded with a reduced diameter due to heat from a burner or the like, and has an inner diameter that is the same as the outer sealing tube but larger in outer diameter. It is a sealed tube. The outer sealing tube 23 before welding is an outer sealing tube before welding, and is an inner sealing tube having the same inner diameter and a smaller outer diameter as compared with the inner sealing tube. The inner end portion 26 is an end portion on the discharge space side of the inner sealing tube before welding. The outer end 27 is the end opposite to the discharge space of the outer sealing tube before welding. The mount component 19 is a mount component using a tapered internal glass tube.

  FIG. 4 is a cross-sectional view showing a state in which the mount component having the sealing portion structure of the short arc type discharge lamp is inserted into the outer sealing tube and disposed at a desired position. In FIG. 4, the outer sealing tube 21 before welding is an outer sealing tube before being welded with a diameter reduced by heat from a burner or the like.

  The sealing part structure and manufacturing method of the short arc type discharge lamp in Example 1 of the present invention configured as described above will be described. First, the overall structure of a short arc type discharge lamp will be described with reference to FIGS. 1 and 2. The short arc type discharge lamp has an arc tube 1 having a swelled central portion, and a pair of an anode 2 and a cathode 3 which are opposed to each other in the arc tube 1. Furthermore, it has a mount part 19 composed of a series of metallic parts for supplying electric power from the outside to the internal electrodes of the discharge lamp and glass parts for holding them. Specifically, the mount component 19 includes an anode 2, an electrode support rod 4, a lead rod 5, a glass rod 18, a tapered inner glass tube 36, an outer glass tube 7, a metal foil 8, an inner metal ring 14, and an outer metal ring 15. Composed.

  Next, the mount component will be described with reference to FIG. Using the tapered inner glass tube 36, the tapered mount component 19 is produced in the same manner as the conventional one. The produced taper mount component 19 is inserted into the inner sealing tube 22 before welding and the outer sealing tube 23 before welding, and the axial movement is stopped by the fixing ring 9.

  As shown in FIG. 3, the inner end portion 26 of the inner sealing tube 22 before welding comes into contact with the large-diameter end surface 39 of the tapered inner glass tube 36 and stops. The large-diameter end face 39 functions as a stopper that locks one end of the internal sealing tube 22. The outer end portion 27 of the outer sealing tube 23 before welding is in contact with the fixing ring 9. Therefore, the large-diameter end face 39 and the fixing ring 9 can suppress the axial movement of the inner sealing tube 22 before welding and the outer sealing tube 23 before welding.

  Next, a mounting component arranging method will be described with reference to FIG. The mount component 19 holding the inner sealing tube 22 and the outer sealing tube 23 is inserted into the outer sealing tube 21 before welding, and the anode 2 is disposed at a desired position in the discharge space S. The inside of the outer sealing tube (in the discharge space) is in a negative pressure state and heated by a burner or the like to reduce the diameter of the outer sealing tube 21, the inner sealing tube 22 and the outer sealing tube 23 before welding, and The sealing tube 21, the inner sealing tube 22, the outer sealing tube 23, and the mount component 19 are welded. Thus, the double sealing structure can be sealed at a time. Although an example using two types of inner sealing pipes having different outer diameters has been described, two or more types of inner sealing pipes having different outer diameters depending on the required strength can be used. A heavy sealing structure can also be obtained easily.

  Compared with the diameter D1 of the welding end portion on the discharge space side when the conventional thick inner glass tube shown in FIG. 7 is used, when the tapered inner glass tube 36 is used as shown in FIG. Since the diameter D2 of the portion can be reduced, stress concentration on the tapered inner glass tube can be prevented. Since the diameter of the welding end 24 on the discharge space side can be the same as that of the conventional single tube sealing structure, the generation of cracks from the welding end can be reduced. Furthermore, since the end surface of the inner glass tube on the discharge space side can be made small in diameter, the temperature rise at the start of lighting is quickened, and the rise of lighting is quickened.

  As described above, in the first embodiment of the present invention, the sealing part structure of the short arc type discharge lamp is configured by using the tapered internal glass tube having the small diameter portion on the discharge space side to constitute the mount component, and the tapered internal glass tube Since the end portion on the discharge space side of the inner sealing tube is sealed together with the end surface of the large-diameter portion, the reliability is improved and the lighting rise time is shortened.

  In the second embodiment of the present invention, a mount component is configured using a middle-thick internal glass tube having a large-diameter portion formed in the middle portion, and the discharge space of the inner sealing tube is formed on the end surface of the large-diameter inner glass tube. It is the sealing part structure of the short arc type discharge lamp which united the edge part of the side and welded the inside thick inner glass tube and the outer side sealing tube.

  FIG. 5 is a partial cross-sectional view showing a sealing portion structure of a short arc type discharge lamp. In FIG. 5, the inner end portion 16 is an end portion on the discharge space side of the inner sealing tube 10. The outer end portion 17 is an end portion of the inner sealing tube 10 on the fixing ring side. The glass rod 18 is a glass member that structurally connects the lead rod and the electrode support rod 4. The middle thick inner glass tube 136 is an inner glass tube that holds the electrode support rod 4. There is a large-diameter portion (diameter D3) having a mountain-shaped or trapezoidal cross-sectional shape in the axial direction at the intermediate portion between the discharge space side and the inner metal ring side of the middle thick inner glass tube. The large diameter portion is preferably near the center in the axial direction of the internal glass tube. The small diameter portion 137 is a portion where the diameter of the tapered inner glass tube is small. The large diameter portion 138 is a portion where the diameter of the tapered inner glass tube is large. The base diameter portion 140 is a portion of a medium-thick internal glass tube having a diameter D4 that is the same as the diameter of the internal metal ring. In FIG. 5, since the thickness of the metal foil is drawn, the diameter of the base diameter portion appears larger than the diameter of the internal metal ring. However, since the actual metal foil is a thin foil, the diameter of the base diameter portion is the internal diameter. It is approximately equal to the diameter of the metal ring. The large diameter end surface 139 is an end surface of the large diameter portion on the inner metal ring side. The weld end portion 124 is a circumferential end on the discharge space side of the weld portion between the middle thick inner glass tube and the outer sealing tube. A description of the same parts as those in the first embodiment will be omitted.

  FIG. 6 is a cross-sectional view showing a state in which the mount component having the sealing portion structure of the short arc type discharge lamp is inserted into the inner sealing tube. In FIG. 6, the fixing ring 9 is a ring-shaped part for suppressing the axial movement of the outer sealing tube. The inner sealing tube 22 before welding is an inner sealing tube before being welded with a reduced diameter due to heat from a burner or the like, and has an inner diameter that is the same as the outer sealing tube but larger in outer diameter. It is a sealed tube. The outer sealing tube 23 before welding is an outer sealing tube before welding, and is an inner sealing tube having the same inner diameter and a smaller outer diameter as compared with the inner sealing tube. The inner end portion 26 is an end portion on the discharge space side of the inner sealing tube before welding. The outer end 27 is the end opposite to the discharge space of the outer sealing tube before welding. The mount component 19 is a mount component using a middle thick internal glass tube.

  The sealing part structure and manufacturing method of the short arc type discharge lamp in Example 2 of the present invention configured as described above will be described. The mount component will be described with reference to FIG. Using a middle-thick internal glass tube 136, a middle-thick mounting component 119 is produced in the same manner as a conventional one. The manufactured middle-thick mount component 119 is inserted into the inner sealing tube 22 before welding and the outer sealing tube 23 before welding, and the axial movement is stopped by the fixing ring 9.

  As shown in FIG. 5, the inner end portion 26 of the inner sealing tube 22 before welding is brought into contact with the large-diameter end surface 139 of the middle thick inner glass tube 136 and stops. The large-diameter end face 139 functions as a stopper for locking one end of the inner sealing tube 22. The outer end portion 27 of the outer sealing tube 23 before welding is in contact with the fixing ring 9. Therefore, the large-diameter end face 139 and the fixing ring 9 can suppress the axial movement of the inner sealing tube 22 before welding and the outer sealing tube 23 before welding.

  Similar to the first embodiment, when the middle thick inner glass tube 136 is used, the diameter D2 of the welding end can be made as small as that of the conventional single tube sealing structure. Therefore, the concentration of stress on the middle thick inner glass tube can be reduced, and the occurrence of cracks from the weld end can be reduced. Furthermore, since the end face of the inner thick glass tube on the discharge space side can be made smaller in diameter, the temperature rise at the start of lighting becomes faster and the rise of lighting becomes faster.

  Between the outer sealing tube 11 connected to the arc tube 1 and the mount component 119, the inner sealing tube 12 is interposed up to the vicinity of the large-diameter end surface 139 of the middle thick inner glass tube 136. Therefore, in Example 1, the inner end surface of the inner sealing tube and the large-diameter end surface of the tapered inner glass tube were welded, whereas in Example 2, the inner surface of the inner sealing tube and the middle thick inner The circumferential outer surface of the base diameter part of the glass tube is welded. Therefore, compared with Example 1, Example 2 can reliably weld the inner sealing tube and the inner glass tube. Therefore, the risk of rupture due to cracks from the vicinity of the inner metal ring is reduced, and the reliability is improved.

  As described above, in Example 2 of the present invention, the sealing structure of the short arc type discharge lamp has a small diameter portion on the discharge space side, a large diameter portion on the intermediate portion, and a base diameter portion on the internal metal ring side. A thick internal glass tube is used to form the mounting component, and the end of the inner sealing tube on the discharge space side is aligned with the large diameter end surface of the inner thick inner glass tube. Therefore, the reliability of the double sealing structure can be improved and the lighting start-up characteristics can be improved. Furthermore, since the inner sealing tube and the inner glass tube can be reliably welded, the reliability against rupture can be improved.

  The short arc discharge lamp sealing portion structure of the present invention is optimal as a short arc discharge lamp sealing portion structure used in the field of manufacturing semiconductors and liquid crystals.

It is a whole sectional view showing the sealing part structure of the short arc type discharge lamp in Example 1 of the present invention. It is a fragmentary sectional view which shows the sealing part structure of the short arc type discharge lamp in Example 1 of this invention. It is sectional drawing which shows the state which inserted the mounting components of the sealing part structure of the short arc type discharge lamp in Example 1 of this invention in the inner side sealing tube. It is sectional drawing which shows the state which inserted the mounting components of the sealing part structure of the short arc type discharge lamp in Example 1 of this invention in the outer side sealing tube, and has arrange | positioned in the desired position. It is a fragmentary sectional view which shows the sealing part structure of the short arc type discharge lamp in Example 2 of this invention. It is sectional drawing which shows the state which inserted the mounting components of the sealing part structure of the short arc type discharge lamp in Example 2 of this invention in the inner side sealing tube. It is sectional drawing which shows the structure of the short arc type discharge lamp which has the conventional double sealing structure. It is an expanded sectional view of the sealing part of the short arc type discharge lamp which has the conventional double sealing structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting tube 2 Anode 3 Cathode 4 Electrode support rod 5 Lead rod 6 Internal glass tube 7 External glass tube 8 Metal foil 9 Fixing ring
10 Inner sealing tube
11 Outer sealing tube
12 Internal sealing tube
13 External sealing tube
14 Internal metal ring
15 External glass tube
16 Internal end
17 External end
18 Glass rod
19 Mounting parts
20 Inner sealed tube before welding
21 Outer sealing tube before welding
22 Internal sealed tube before welding
23 External sealed tube before welding
24 Weld end
25 External metal ring
26 Internal end
27 External end
36 Tapered inner glass tube
37 Tapered inner glass tube small diameter part
38 Tapered inner glass tube large diameter
39 Large diameter end face
119 Mounting parts
124 Weld end
136 inner thick glass tube
137 Small diameter part
138 Large diameter part
139 Large diameter end face
140 Base diameter
224 Weld end
236 thick internal glass tube
237 Small diameter part
238 Large diameter part
239 Slope

Claims (4)

A glass arc tube, a glass outer sealing tube connected to the arc tube, an inner sealing tube coaxially welded inside the outer sealing tube, and sealed in the arc tube A pair of electrodes, a metal electrode support rod for supporting the electrode, an internal metal ring electrically connected to the electrode, a lead rod for supplying power to the electrode, and an electric power to the lead rod Externally connected metal ring, a plurality of metal foils electrically connected to the internal metal ring and the external metal ring, an external glass tube for supporting the lead bar, the lead bar and the internal part A short-arc type discharge lamp having a double sealed structure comprising a metal ring, an outer metal ring, a glass rod for supporting the electrode support rod and the metal foil, and an inner glass tube for supporting the electrode support rod. In the sealing part structure, Internal glass tube, said has a large diameter portion having a larger diameter than the inner metal ring, said to have a small diameter portion having a smaller diameter than the large diameter portion to the light emitting tube side, the welding of the discharge space side of the inner glass tube An inner diameter of the outer sealing tube at the end is smaller than the large diameter portion . 2. The short arc lamp sealing portion structure according to claim 1, wherein the large-diameter portion is a portion extending from a portion in contact with the internal metal ring to the small-diameter portion. 2. The short arc lamp seal according to claim 1, wherein the inner glass tube has a base diameter portion having an outer diameter substantially equal to the inner metal ring in a portion in contact with the inner metal ring from the large diameter portion. Stop structure. The short arc lamp sealing part structure according to claim 3, wherein an axial section of the large diameter part has a mountain shape.

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