JP6775415B2 - Light source device with short arc type discharge lamp - Google Patents

Description

The present invention relates to a light source device including a short arc type discharge lamp, and relates to a holding structure to the lamp.

In a light source device used in an exposure device, a projector, or the like, a short arc type discharge lamp is fixed along the central axis of a concave reflector. A pair of sealing tubes are integrally formed at both ends of the arc lamp arc lamp, and one sealing tube is inserted through the hollow (cylindrical) neck of the reflector, and the sealing tube and the reflector neck are inserted. The discharge lamp is held (fixed) by the reflector by filling the space between the lamp and the mirror. Since the discharge lamp becomes hot when the lamp is lit, a heat-resistant adhesive (inorganic adhesive, etc.) is used.

If the adhesive leaks to the arc tube side in the process of holding the discharge lamp on the reflecting mirror with an adhesive and the adhesive adheres to the arc tube, the arc tube is damaged when the lamp is lit. In order to prevent this, it is known that an adhesive outflow prevention ring (washer) through which a discharge lamp is inserted is arranged at the arc tube side end of the reflector neck (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-186053

The adhesive filled between the sealing tube and the neck of the reflector may have voids inside when it solidifies, and the larger the space filled with the adhesive, the more likely the voids will be. Moisture easily enters such voids from the outside of the lamp during the manufacturing process and transportation process of the discharge lamp. Impurities (for example, alkali metal ions of the adhesive component) dissolve in the water that has entered, so when the adhesive is heated by lighting the lamp, gas containing impurities (for example, water vapor containing impurities) is released. It goes out of the adhesive through the voids inside the adhesive (for example, it spouts or exudes).

In particular, the adhesive region near the adhesive outflow prevention ring is close to the arc tube of the discharge lamp, and the temperature becomes higher when the lamp is lit. Therefore, if there is a gap in this portion, impurities will flow out to the arc tube side through between the adhesive outflow prevention ring and the sealing tube. As a result, impurities adhere to the arc tube, causing problems such as devitrification of the arc tube.

Therefore, it is required to prevent impurities from leaving to the arc tube side while maintaining the strong holding of the discharge lamp.

The light source device of the present invention includes a short arc type discharge lamp provided with a pair of sealing portions at both ends of the arc tube, and a concave reflecting mirror provided with a tubular neck portion into which one sealing portion is inserted. At the same time, a plurality of annular portions through which one sealing portion is inserted are provided in the neck portion. One sealing portion is adhesively fixed to the inner surface of the neck portion by an adhesive in the neck portion. For example, the adhesive is composed of an inorganic adhesive.

In the present invention, a plurality of annular portions are arranged along the optical axis direction so that an adhesive is interposed between the first annular portion closest to the arc tube side end and the second annular portion adjacent thereto. Has been done. The interposition of the adhesive between the two annular portions limits the space of the adhesive region near the first annular portion, and suppresses the formation of voids that are likely to contain impurities.

On the other hand, between the first annular portion and the second annular portion, the adhesive is interposed from the inner surface of the neck to one of the sealing portions in the radial direction of the sealing portion to ensure the holding of the discharge lamp. Can be a thing.

Considering that the suppression of impurities from going out to the arc tube side and the firm lamp holding are satisfied, the length of the adhesive interposed between the first annular portion and the second annular portion in the optical axis direction is determined. , It is desirable that the length of the first annular portion in the optical axis direction is halved or less.

For example, the plurality of annular portions can be composed of three or more annular portions, and may be arranged so that an adhesive is interposed between the annular portions adjacent to each other. Further, the plurality of annular portions can be configured to have the same shape.

For the plurality of annular portions, it is possible to arrange a plurality of ring-shaped members each having one annular portion. Alternatively, it is also possible to arrange the multi-ring member in which the groove portion is formed in the radial direction and the first annular portion and the second annular portion are provided.

In another method of manufacturing the light source device according to the other aspect of the present invention, the first annular portion is inserted into the neck portion and arranged in contact with the contact portion of the neck portion with the neck portion of the reflector facing in the vertical direction. The adhesive is injected until the first annular portion is filled, the second annular portion is inserted into the neck, and the adhesive is further injected until the second annular portion is filled.

According to the present invention, in a light source device provided with a short arc type discharge lamp, while firmly holding the discharge lamp, it is possible to suppress a malfunction of the lamp due to an adhesive at the time of lighting.

It is a schematic partial sectional view of the short arc type discharge lamp of this embodiment. It is the schematic sectional drawing which enlarged the vicinity of the through hole of FIG. It is the schematic sectional drawing which enlarged the vicinity of the through hole of FIG. It is a figure which showed the process of adhesively fixing a discharge lamp to a reflector. It is the schematic sectional drawing which enlarged the vicinity of the through hole of the discharge lamp which is 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing a part of the light source device according to the first embodiment.

The light source device 100 includes a short arc type discharge lamp 10 and a reflector 50, and can be used for a projector, an exposure device, and the like.

The short arc type discharge lamp 10 includes a spherical arc tube 12 made of transparent quartz glass, and a pair of electrodes 20 and 30 are arranged to face each other at predetermined distance intervals in the arc tube 12. Quartz glass sealing tubes (sealing portions) 14A and 14B are integrally provided with the arc tube 12 on both sides of the arc tube 12. Mercury, halogen, and a rare gas (for example, argon gas) are sealed in the discharge space 10S in the arc tube 12.

The sealing tube 14B includes an electrode support rod 17B that supports the electrode 30, a lead rod 19B that is connected to an external power source, a metal foil (not shown) that electrically connects the electrode support rod 17B and the lead rod 19B, and the like. Is enclosed. The sealing tube 14A on the opposite side has the same configuration. The lamp outer end of the sealing tube 14B is arranged in the base 11B.

The discharge lamp 10 is an AC lighting lamp to which a predetermined rated power (for example, 100 to 500 W) is supplied, and the polarity (cathode, anode) is alternated by applying an AC voltage to the pair of electrodes 20 and 30. It is replaced with. When a voltage is applied to the pair of electrodes 20 and 30, an arc discharge is generated between the electrodes 20 and 30 and light is radiated to the outside of the arc tube 12. The light emitted from the arc tube 12 is guided in a predetermined direction by the reflector 50.

The reflecting mirror 50 is an elliptical reflecting mirror provided with a reflecting portion (reflector) 70 having a reflecting surface 70S on the concave surface side and a cylindrical neck portion 60. The neck portion 60 is provided so as to project from the central bottom portion of the reflecting portion 70 toward the opposite side of the reflecting surface 70S, and a through hole 62 is provided inside the neck portion 60 along the optical axis (rotation axis) of the reflecting mirror 50. It is formed. The through hole 62 has a small diameter portion 64 on the reflection surface 70S side, and a large diameter portion 61 having a diameter larger than that of the small diameter portion 64 is formed from a boundary portion with the small diameter portion 64 to the rear end surface 50E of the neck portion.

The discharge lamp 10 is arranged coaxially with the reflector 50 in the reflector 50 so that the arc is at the focal position of the reflector 50 when the lamp is lit, and one sealing tube 14B is inserted into the through hole 62 of the neck 60. It is held by the reflector 50 in the state of being. Specifically, the sealing tube 14B is adhesively fixed (fixed) to the inner surface of the through hole 62 by the adhesive 80 in the through hole 62.

In the present embodiment, a plurality of rings (annular portions) 90 are arranged at predetermined positions in the through hole 62 of the neck portion 60 so as to surround the sealing tube 14B. The plurality of rings 90 prevent the adhesive 80 from leaking to the reflecting portion 70 side (light emitting tube 12 side) during the lamp manufacturing process, and impurities are emitted from the inside of the adhesive 80 to the arc tube side while the lamp is lit. Prevent going. This will be described below with reference to FIGS. 2 and 3.

2 and 3 are enlarged cross-sectional views of the vicinity of the through hole 62 of FIG.

The plurality of rings 90 are composed of three rings (annular portions), and here, the first ring (first annular portion) 90A and the second ring (first ring portion) are directed from the arc tube 12 side toward the rear end surface 50E of the neck. It is called 2 ring part) 90B and 3rd ring (3rd ring part) 90C. The first ring 90A, the second ring 90B, and the third ring 90C have the same shape, and the outer diameter and the inner diameter, and the length (thickness) in the axial direction are all the same. Further, each ring is made of a heat-resistant material (for example, a ceramic material).

The inner diameter of each ring is larger than the outer diameter of the sealing tube 14B so that the sealing tube 14B can be inserted. On the other hand, the outer diameter of each ring is smaller than the diameter of the large diameter portion 61 of the through hole 62 and larger than the diameter of the small diameter portion 64. The first ring 90A is in contact with the abutting surface 63 perpendicular to the optical axis (lamp axis) direction X, which is the boundary between the small diameter portion 64 and the large diameter portion 61.

The first ring 90A, the second ring 90B, and the third ring 90C are arranged side by side at predetermined intervals along the ramp axial direction. Further, the second ring 90B and the third ring 90C are embedded in the adhesive 80. That is, the adhesive 80 is interposed between the first ring 90A and the second ring 90B, and the adhesive is also interposed between the second ring 90B and the third ring 90C.

Further, the adhesive 80 is also interposed between the first ring 90A, the second ring 90B, the third ring 90C, and the inner surface of the through hole 62. The adhesive 80 is interposed between the second ring 90B and the third ring 90C and the sealing tube 14B, and the adhesive 80 is partially interposed between the first ring 90A and the sealing tube 14B. Therefore, the adhesive 80 interposed between the adjacent rings is interposed from the inner surface of the through hole to the sealing pipe 14B, and the periphery of the first ring 90A to the third ring 90C is filled with the adhesive 80.

Here, an inorganic adhesive that has heat resistance and can be firmly adhered and fixed is applied to the adhesive 80. For example, an inorganic adhesive such as alumina or silica is applied to an aqueous solution containing an alkali metal silicate. Those obtained by adding powder and kneading can be used. The adhesive 80 is filled in the through hole 62 of the neck portion 60, and the first ring 90A, the second ring 90B, and the third ring 90C are fixed in place by the adhesive 80, respectively.

The first ring 90A, the second ring 90B, and the third ring 90C arranged in the through hole 62 of the neck portion 60 are leaked from the adhesive 80 to the arc tube side and from the adhesive 80 while the lamp is lit. Prevents impurities from leaving. Hereinafter, it will be described with reference to FIG.

First, the first ring 90A prevents the adhesive 80 from leaking to the arc tube side in the adhesive fixing step described later.

The second ring 90B is arranged outside the first ring 90A in the lamp axial direction by a predetermined length D2. As a result, the lamp axial length of the adhesive range S adjacent to the outside of the first ring 90A in the lamp axial direction can be set to D2. The voids that occur when the adhesive solidifies are more likely to occur as the area filled with the adhesive is larger, and less likely to occur as the area is smaller. Therefore, in consideration of suppressing the formation of voids in the adhesive range S, it is desirable that the length D2 in the lamp axial direction of the adhesive range S be as small as possible, and is preferably 1 mm or less. Further, it is desirable that the lamp axial length D2 of the adhesive range S is 1/2 or less of the axial length D1 of the first ring 90A.

Even if the lamp axial length D2 is 1 mm or less, if the axial length D1 of the first ring 90A is not sufficiently large with respect to the axial length D2, expansion due to solidification of the adhesive 80 in the adhesive range S Cannot be suppressed by the gap between the first ring 90A and the sealing tube 14B. That is, as the adhesive 80 in the adhesive range S solidifies, the adhesive 80 comes out from the gap between the first ring 90A and the sealing tube 14B, so that a gap is likely to occur in the adhesive range S. It ends up.

Therefore, it is preferable that the axial length D2 of the adhesive 80 is 1/2 or less of the axial length D1 of the first ring 90A, and such a structure allows impurities to be abundant during lamp lighting. It is possible to prevent the ring 90A from coming out from the gap between the sealing tube 14B.

On the other hand, in the radial direction of the second ring 90B, the adhesive 80 is interposed between the through hole 62, and the adhesive 80 is also interposed between the second ring 90B and the sealing tube 14B. Therefore, the holding force of the adhesive 80 along the radial direction and the lamp axial direction X does not decrease regardless of the arrangement of the second ring 90B.

Further, the third ring 90C prevents impurities contained in the voids generated on the rear end surface 50E side of the neck (end surface side of the sealing tube) from the third ring 90C from moving to the arc tube side, that is, the adhesive range S. .. By making the filling area of the adhesive 80 on the rear end surface 50E side of the neck larger than that of the third ring 90C, the reflector 50 can hold the discharge lamp 10 more firmly, but the large filling area creates a gap. It is easy to occur. However, by arranging the third ring 90C, the path for connecting the adhesives 80 on both sides of the third ring 90C in the lamp axial direction becomes smaller, and impurities in the voids on the rear end surface 50E side of the neck than the third ring 90C become the first. It can be prevented from moving to the arc tube side of the 3 ring 90C. Further, as in the case of the second ring 90B, since the adhesive 80 is interposed between the large diameter portion 61 and the sealing tube 14B, the holding force of the adhesive 80 can be firmly maintained.

Further, the lamp axial length D4 between the second ring 90B and the third ring 90C is also set to the lamp axial length of the adhesive range S in the same manner as D2, so that the second ring 90B and the third ring are formed. It is possible to suppress the formation of a gap between the 90C and the 90C.

Further, stress in the radial direction of the lamp is applied to the sealing tube 14B due to thermal expansion of the first ring 90A, the second ring 90B, and the third ring 90C due to the lighting of the lamp, but the first ring 90A, the second ring 90B, and the first ring 90B have stress. Since the three rings 90C have the same shape, there is no extreme difference in the stress applied to the sealing tube 14B, and it is possible to prevent cracks from occurring due to the stress difference.

It is desirable that the radial distance distance D3 between the first ring 90A and the sealing tube 14B be as small as possible in consideration of preventing impurities from flowing out to the arc tube side along the vicinity of the sealing tube 14B. .. However, it is also necessary to prevent the stress due to the thermal expansion from being excessively applied to the sealing tube 14B. Therefore, it is desirable that the radial distance interval D3 is 20% or more and 70% or less of the radial thickness D5 of the first ring 90A. The second ring 90B and the third ring 90C can be similarly defined.

By arranging the plurality of rings 90 in this way, it is possible to prevent a gap from being generated in the adhesive range S adjacent to the outside of the first ring 90A in the lamp axial direction, and to prevent the adhesive 80 on the rear end surface 50E side of the neck. It is possible to prevent impurities from moving to the adhesive range S from the generated voids, and while maintaining strong retention of the reflector on the discharge lamp, impurities are more reliably discharged from the adhesive 80 to the arc tube side. It can be prevented from going.

Next, the process of adhering and fixing the discharge lamp 10 to the reflector 50 will be described.

FIG. 4 is a diagram showing a process of adhesively fixing the discharge lamp 10 to the reflector 50.

The reflector 50 is arranged so that the rear end surface 50E of the neck is vertically above. The sealing tube 14B of the discharge lamp 10 is inserted into the through hole 62 of the neck 60 from the concave side of the reflector 50, and the position of the discharge lamp is adjusted with respect to the reflector 50 so as to have a predetermined positional relationship. After adjusting the position, the first ring 90A is passed through the sealing pipe 14B from the vertically upper side and arranged in the through hole 62. As described above, since the outer diameter of the first ring 90A is larger than the diameter of the small diameter portion 64, the first ring 90A passes through the sealing tube 14B and comes into contact with the abutting surface 63 to stop. After arranging the first ring 90A, the adhesive 80 is injected into the through hole 62. At this time, the adhesive 80 is injected so that the first ring 90A is filled with a predetermined depth (see FIG. 4A).

Next, the second ring 90B is passed through the sealing pipe 14B from the vertically upper side in the same manner as the first ring 90A. Since the adhesive 80 is viscous, it rests near the surface 80K of the adhesive first injected. As a result, the second ring 90B does not come into contact with the first ring 90A and is separated from the first ring 90A at a predetermined interval via the adhesive 80. After inserting the second ring 90B, the adhesive 80 is injected so that the second ring 90B is filled with a predetermined depth (see FIG. 4B).

Then, the third ring 90C is passed through the sealing pipe 14B from the vertically upper side in the same manner as the second ring 90B, and the adhesive 80 is injected, so that the third ring 90C becomes the second ring in the same manner as the second ring 90B. It does not come into contact with the 90B, and is separated from the 90B at a predetermined interval via the adhesive 80. (See FIG. 4 (C)). Further, before the adhesive 80 is cured (solidified), the mouthpiece 11B is attached to the sealing tube 14B so that a part thereof is immersed in the adhesive 80 (FIG. 4 (D)). By such a bonding step, the discharge lamp 10 is bonded and fixed to the reflecting mirror 50.

In the first embodiment, three annular portions are arranged by three rings, but four or more annular portions may be arranged by four or more rings.

Next, the light source device according to the second embodiment will be described with reference to FIG. In the second embodiment, a ring having a plurality of annular portions is applied. The other configurations are the same as those in the first embodiment.

FIG. 5 is a schematic partial cross-sectional view showing an enlarged ring in the second embodiment.

The plurality of rings 190 include a multi-ring 191 and a ring (annular portion) 192. The multi-ring 191 has two annular portions 191A and 191B, and a groove portion 191C along the lamp radial direction is formed between them, and the two annular portions 191A and 191B are partially connected to each other. The groove portion 191C is filled with the adhesive 80, and the adhesive 80 is interposed between the annular portions 191A and 191B in the lamp axial direction. Further, the adhesive 80 is also interposed between the multi-ring 191 and the ring 192 in the lamp axial direction. Thereby, regardless of the injection of the adhesive 80 in the adhesive fixing step, the lamp axial length distance interval between the annular portions 191A and 191B can be easily determined.

Even with such a configuration, the same strength can be maintained and impurities can be suppressed from leaving to the arc tube side. The groove may be formed from the outside in the radial direction toward the optical axis direction. Further, it may be formed along a part in the circumferential direction.

In the second embodiment, the three annular portions are arranged by one multi-ring having two annular portions and one ring, but only one multi-ring having three annular portions may be used. Furthermore, a plurality of multilinks may be used.

10 Discharge lamp 14B Sealing tube (sealing part)
20, 30 Electrodes 50 Reflector 60 Neck 80 Adhesive 90 Multiple rings (multiple annular parts)
90A 1st ring (1st ring part)
90B 2nd ring (2nd ring part)
90C 3rd ring (3rd ring part)

Claims (8)

A short arc type discharge lamp with a pair of sealing parts on both ends of the arc tube,
A concave reflector with a tubular neck into which one of the sealing parts is inserted,
In the neck portion, a plurality of annular portions through which the one sealing portion is inserted are provided.
One of the sealing portions is adhesively fixed to the inner surface of the neck portion by an adhesive in the neck portion.
The plurality of annular portions are arranged along the optical axis direction so that an adhesive is interposed between at least the first annular portion closest to the arc tube side end and the second annular portion adjacent thereto. A light source device characterized by that. The first aspect of the present invention is characterized in that an adhesive is interposed between the first annular portion and the second annular portion in the radial direction of the sealing portion from the inner surface of the neck portion to the one sealing portion. The light source device described. The feature is that the optical axis length of the adhesive interposed between the first annular portion and the second annular portion is ½ or less of the optical axis length of the first annular portion. The light source device according to claim 1 or 2. The plurality of annular portions according to any one of claims 1 to 3, wherein the plurality of annular portions are composed of three or more annular portions and are arranged so that an adhesive is interposed between the annular portions adjacent to each other. The light source device described. The light source device according to any one of claims 1 to 4, wherein the plurality of annular portions have the same shape. The light source device according to any one of claims 1 to 5, wherein a multi-ring member having a groove portion formed in the radial direction and provided with the first annular portion and the second annular portion is arranged. .. The light source device according to any one of claims 1 to 6, wherein the adhesive is an inorganic adhesive. With the neck of the reflector facing vertically, the first annular portion was inserted into the neck and placed in contact with the contacting portion of the neck.
The adhesive is injected until the first annular portion is filled.
The second annular portion is inserted into the neck portion,
A method for manufacturing a light source device, which comprises further injecting the adhesive until the second annular portion is filled.