Lamp sealing method

Abstract

To provide a structure for sealing a lamp, which hardly causes damage to a luminous tube and which hardly causes illuminance unevenness.SOLUTION: A structure for sealing a lamp 10, which comprises a luminous tube 12 having an airtight internal space 24 and at least one sealing part 22, is constituted as follows: the sealing part 22 is provided with a communication hole 26 for communicating the internal space 24 with the outside; and a chip part 28 for closing the communication hole 26 is formed at the outside end of the communication hole 26.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sealing structure for a lamp, a lamp, and a sealing method for a lamp. [Background technology]

[0002] Conventionally, gas-filled lamps that have been widely used have an enclosed space formed inside an arc tube (glass container) by sealing both ends or one end of the arc tube using a pinch seal method.

[0003] Examples of gas-filled lamps include halogen lamps used for heating, metal halide lamps used for lighting, ultraviolet lamps for ultraviolet cleaning, and discharge lamps. (Note that Patent Document 1 discloses an example of a "gas discharge lamp.")

[0004] For example, in the case of a conventional discharge lamp 1 shown in Fig. 17, a pair of mount parts 2 are inserted and both ends of the arc tube 3 are sealed by a pinch seal method, and then an impurity removal process such as heat treatment is performed, and the air is exhausted through an exhaust pipe 5 that has been attached to the arc tube 3 in advance so as to communicate with the internal space 4, as shown in Fig. 18. Thereafter, the necessary filling material is placed in the internal space 4, the internal space 4 is put into a negative pressure state, and the exhaust pipe 5 is heated and melted to seal the internal space 4 and the exhaust pipe 5 is removed, thereby completing the discharge lamp 1.

[0005] In addition, in the case of discharge lamps, which utilize the light emitted by mercury by generating a discharge between a pair of electrodes in the internal space of the arc tube, or which utilize the light emitted by a luminous metal, or in the case of lamps in which a halide is enclosed in the internal space to prevent the inner surface of the arc tube from blackening during operation, it is necessary to place the necessary filling material into the internal space before evacuating it through the exhaust pipe. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2000-306547 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the case of conventional gas-filled lamps 1, as shown in Fig. 17, after the internal space 4 is sealed, a "tip portion 6", which is a trace of airtight processing, is formed on the surface of the arc tube 3 facing the internal space 4. This tip portion 6 is the weakest in terms of strength because it is the location where stress generated in the arc tube 3 is concentrated, and when the lamp 1 is turned on, the temperature rises to about 700°C to 900°C, which causes structural destruction of the quartz glass (SiO2) that is the material of the arc tube 3, resulting in the problem that the arc tube 3 is susceptible to breakage from the tip portion 6.

[0008] Furthermore, depending on the type of lamp 1, when tip portion 6 is exposed to ultraviolet light with a wavelength of 200 nm or less, the progress of structural destruction of the quartz glass becomes more pronounced.

[0009] Furthermore, since the chip portion 6 is located in a position facing the internal space 4 in which light-emitting portions such as electrodes are provided, the light emitted from the lamp 1 is blocked by the chip portion 6, resulting in uneven illuminance on the object illuminated by the lamp 1.

[0010] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a lamp sealing structure, a lamp, and a lamp sealing method that are less likely to cause damage to the light-emitting tube and are less likely to cause uneven illuminance. [Means for solving the problem]

[0013] According to another aspect of the present invention, A lamp is provided that includes any of the sealing structures described above.

[0014] The present invention one According to the situation, A method for sealing a lamp, comprising the steps of: sealing at least one end of an arc tube to form an airtight internal space within the arc tube, the method comprising the steps of: when forming a sealed portion in the light-emitting tube by pinching and sealing the end portion, a communication hole that communicates the internal space with the outside is formed in the end portion in the width direction of the sealed portion, an exhaust pipe is attached to an outer end of the communication hole, and exhaust is exhausted from the internal space and an enclosed material is enclosed in the internal space through the exhaust pipe; The base of the exhaust pipe is heated and melted to form a tip portion that closes the communication hole. A method for sealing a lamp is provided. Effect of the Invention

[0016] According to the lamp sealing structure and sealing method of the present invention, the tip portion that seals and closes the internal space of the arc tube is formed at the outer end of the sealing portion, spaced apart from the internal space. Since the outer end of the sealing portion is at a relatively low temperature (e.g., 300°C or lower) even when the lamp is emitting light, it is possible to reduce the possibility that structural destruction of the quartz glass will progress during lamp light emission, causing the arc tube to break from the tip portion.

[0017] In addition, since the chip portion formed at the outer end of the sealing portion is not easily hit by the light radiated from the internal space of the light-emitting tube, the structural destruction of the quartz glass does not progress noticeably even when ultraviolet rays with wavelengths of 200 nm or less are emitted depending on the type of lamp.

[0018] Furthermore, since the light emitted from the internal space of the light-emitting tube is less likely to hit the tip portion, the light rays emitted from the lamp are blocked by the tip portion, reducing the possibility of uneven illuminance occurring on the object illuminated by the lamp. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing a lamp 10 to which the present invention is applied. [Diagram 2] FIG. [Diagram 3]1A to 1C are diagrams showing a manufacturing procedure for a lamp 10 to which the present invention is applied. [Figure 4] 1A to 1C are diagrams showing a manufacturing procedure for a lamp 10 to which the present invention is applied. [Diagram 5] 1A to 1C are diagrams showing a manufacturing procedure for a lamp 10 to which the present invention is applied. [Figure 6] 2A and 2B are diagrams showing how the end of the arc tube 12 is pinch sealed in the manufacturing process of the lamp 10. [Figure 7] 2A and 2B are diagrams showing how the end of the arc tube 12 is pinch sealed in the manufacturing process of the lamp 10. [Figure 8] 1A to 1C are diagrams showing a manufacturing procedure for a lamp 10 to which the present invention is applied. [Figure 9] FIG. 1 is a diagram showing a lamp 10 according to a first modified example. [Figure 10] FIG. BB line end view. [Figure 11] 1A to 1C are diagrams illustrating a manufacturing procedure for the lamp 10 according to the first modified example. [Figure 12] 11 is a diagram showing how the end of the arc tube 12 is pinch-sealed in the manufacturing procedure for the lamp 10 according to the first modified example. FIG. [Figure 13] 11 is a diagram showing how the end of the arc tube 12 is pinch-sealed in the manufacturing procedure for the lamp 10 according to the first modified example. FIG. [Figure 14] FIG. 13 is a diagram showing a lamp 10 according to a second modified example. [Figure 15] FIG. 13 is a diagram showing a lamp 10 according to a second modified example. [Figure 16] FIG. 1 is a diagram showing a halogen lamp to which the present invention is applied. [Figure 17] FIG. 1 shows a conventional gas-filled lamp 1. [Figure 18] 1A to 1C are diagrams illustrating a manufacturing procedure for a conventional gas-filled lamp 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] (Structure of Lamp 10) The structure of a lamp 10 according to an example to which the present invention is applied will be described with reference to Figures 1 and 2. The lamp 10 is a discharge lamp, and is generally composed of an arc tube 12, a pair of electrodes 14, a pair of foils 16, and a pair of lead rods 18.

[0021] The light emitting tube 12 is made of, for example, quartz glass, and has a light emitting section 20 and a pair of sealing sections 22 extending from the light emitting section 20. An internal space 24 sealed by the pair of sealing sections 22 is formed within the light emitting section 20.

[0022] Furthermore, a predetermined amount of mercury 25 and a halogen (iodine, bromine, or a mixture of iodine and bromine) is enclosed in the internal space 24 of the light emitting section 20.

[0023] The pair of electrodes 14 are generally rod-shaped members made of tungsten, and are disposed in the internal space 24 with one end of each facing each other. The other end of each electrode 14 is electrically connected to one end of each of the molybdenum foils 16 embedded in each of the sealing portions 22.

[0024] Furthermore, the pair of lead rods 18 are generally rod-shaped members made of molybdenum, and one end of each is electrically connected to the other end of each foil 16. The other ends of each of the pair of lead rods 18 extend from each sealing portion 22 to the outside.

[0025] Regarding the structure of the sealing portion 22, one sealing portion 22 is provided with a communication hole 26 that connects the internal space 24 of the light emitting tube 12 with the outside.

[0026] Further, a tip portion 28 that closes the communication hole 26 is formed at the outer end of the communication hole 26, i.e., the outer end of the sealing portion 22 in which the communication hole 26 is formed. This tip portion 28 makes the communication hole 26 and the internal space 24 airtight from the outside.

[0027] (Lamp 10 manufacturing procedure) Next, a manufacturing procedure for the above-mentioned lamp 10 will be described. First, the arc tube 12 is prepared before sealing, as shown in Fig. 3. The electrodes 14 and the lead rods 18 are attached to the foil 16 by means of welding or the like to form a pair of mounts 30.

[0028] Thereafter, the mount part 30 is inserted into the end of the arc tube 12 from the electrode 14, and while the mount part 30 is held in a predetermined position, one end of the arc tube 12 (the end where the mount part 30 is inserted) is pinch sealed to seal it. As a result, one of the sealing parts 22 is formed, as shown in FIG. 4.

[0029] Next, the other mount portion 30 is inserted into the other end of the arc tube 12, and the other end is pinch-sealed. As a result, an internal space 24 is formed in the approximate center of the arc tube 12. At this time, the other end of the arc tube 12 is sealed so as to form a communication hole 26 that communicates the internal space 24 of the arc tube 12 with the outside, rather than being completely sealed, as shown in FIG. 5. This can be achieved, for example, by using a pinch member 50 having a recess 54 formed in a part of a pressing surface 52 that presses and seals the end of the arc tube 12, as shown in FIG. 6 and FIG. 7. Of course, the sealing portion 22 having the communication hole 26 may be formed first, or a pair of sealing portions 22 may be formed almost simultaneously.

[0030] The communication hole 26 may be formed anywhere in the width direction of the sealing portion 22 (the radial direction of the arc tube 12 (= the up-down direction in Fig. 2)), but is preferably formed at the end of the sealing portion 22 in the width direction (the end of the arc tube 12 in the radial direction) as shown in Fig. 2. The reason for this is that since the end of the sealing portion 22 in the width direction is a portion where it is difficult to make it airtight due to the wall thickness of the arc tube 12, it is relatively easy to form the communication hole 26, and furthermore, if the communication hole 26 is formed closer to the center of the sealing portion 22 in the width direction, it becomes even more difficult to make the end of the sealing portion 22 in the width direction airtight.

[0031] After the communication hole 26 is formed, as shown in FIG. 8, a pipe-shaped exhaust tube 60 is attached to the outer end of the communication hole 26 (the end of the sealing portion 22 of the light emitting tube 12) by means of welding or the like.

[0032] Then, through this exhaust pipe 60, the internal space 24 of the arc tube 12 is evacuated and a fill material is filled into the internal space 24. As described above, the fill material may be mercury 25 and a halogen (iodine, bromine, or a mixture of iodine and bromine). Of course, an appropriate fill material is selected depending on the type of lamp 10.

[0033] 1, the base of the exhaust pipe 60 is heated and melted to form a tip portion 28 that closes the communication hole 26. This tip portion 28 is formed at the outer end of the communication hole 26, that is, the outer end of the sealing portion 22 in which the communication hole 26 is formed. This makes the communication hole 26 and the internal space 24 airtight from the outside, and the lamp 10 is completed.

[0034] When a predetermined high voltage is applied to a pair of lead rods 18 provided on the lamp 10, the glow discharge that begins between a pair of electrodes 14 arranged in the internal space 24 of the light-emitting section 20 transitions to an arc discharge, and light (mainly ultraviolet light) is emitted by mercury 25 that is evaporated and excited by this arc.

[0035] (Features of Lamp 10) According to the sealing structure and sealing method of lamp 10 to which the present invention is applied, tip portion 28 that seals and closes internal space 24 of the arc tube 12 is formed at the outer end of sealing portion 22, spaced apart from internal space 24. Since the outer end of sealing portion 22 is relatively cold (e.g., 300°C or lower) even when lamp 10 is emitting light, it is possible to reduce the possibility that structural destruction of the quartz glass will progress during light emission by the lamp 10, causing damage to the arc tube 12 from tip portion 28.

[0036] Furthermore, since the tip portion 28 formed at the outer end of the sealing portion 22 is not easily hit by the light radiated from the internal space 24 of the light-emitting tube 12, the structural destruction of the quartz glass does not progress noticeably even when ultraviolet rays with wavelengths of 200 nm or less are emitted depending on the type of lamp 10.

[0037] Furthermore, since the light emitted from the internal space 24 of the light-emitting tube 12 is unlikely to hit the tip portion 28, the light rays emitted from the lamp 10 are blocked by the tip portion 28, which reduces the possibility of uneven illuminance occurring on the object illuminated by the lamp 10.

[0038] (Variation 1) In the lamp 10 according to the embodiment described above, the communication hole 26 is formed in at least one of the sealing portions 22, and the exhaust pipe 60 is connected to the outer end of the communication hole 26. Alternatively, as shown in Figures 9 and 10, the exhaust pipe 60 may be embedded in at least one of the sealing portions 22. In this case, it is preferable to use quartz glass, the same as the light emitting tube 12, as the material for the exhaust pipe 60.

[0039] Regarding the lamp 10 according to the first modified example, the description of the lamp 10 according to the embodiment described above will be used for the same configurations, and only the different configurations will be described.

[0040] An exhaust pipe 60 that connects the internal space 24 of the light-emitting tube 12 to the outside is embedded in at least one sealing portion 22 in the lamp 10 of variant example 1, and a tip portion that blocks the exhaust pipe 60 is formed at the outer end of the exhaust pipe 60 (i.e., the outer end of the sealing portion 22).

[0041] Next, a description will be given of a manufacturing procedure for the lamp 10 according to Modification 1. In the description of this manufacturing procedure, the same procedures as those of the lamp 10 according to the above-described embodiment will be referred to, and only different procedures will be described.

[0042] When forming at least one sealing portion 22, the mount portion 30 and the exhaust pipe 60 are inserted into the end of the light emitting tube 12, and the end is pinch sealed, as shown in Figures 11 to 13. This brings the internal space 24 of the light emitting tube 12 into communication with the outside via the exhaust pipe 60 embedded in the sealing portion 22.

[0043] Thereafter, the internal space 24 of the arc tube 12 is evacuated through the exhaust pipe 60, and the internal space 24 is filled with a fill material. As described above, the fill material may be mercury 25 or a halogen (iodine, bromine, or a mixture of iodine and bromine). Of course, an appropriate fill material is selected depending on the type of lamp 10.

[0044] Finally, exhaust pipe 60 is heated and melted at the position of the outer end of sealing portion 22 to form tip portion 28 that closes exhaust pipe 60. This makes exhaust pipe 60 and internal space 24 airtight from the outside, and lamp 10 is completed (see FIGS. 9 and 10).

[0045] (Variation 2) Furthermore, in the case of the lamp 10 according to the embodiment described above (lamp 10 having the communication hole 26), after the manufacture of the lamp 10 is completed, the communication hole 26 may be further heated from the outside to close the communication hole 26. This makes it possible to prevent the filler (e.g., mercury or halide) of the lamp 10 from collecting inside the communication hole 26, which has a relatively low temperature, which would reduce the amount of light emitted by the lamp 10 or inhibit the halogen cycle.

[0046] The communication hole 26 may be blocked entirely (see FIG. 14), or only the end of the communication hole 26 that is closer to the internal space 24 of the arc tube 12 may be blocked (see FIG. 15).

[0047] (Variation 3) In the above embodiment, a case has been described in which the lamp 10 is configured as a discharge lamp, but the lamp 10 is not limited to a discharge lamp, and may be a halogen lamp as shown in Fig. 16, a single-electrode dielectric barrier discharge lamp, or an electrodeless discharge lamp. Furthermore, it may be a dielectric barrier discharge lamp. In other words, the present invention can be applied to any lamp that has at least one sealing part and seals a gas in a sealed internal space, regardless of whether it has electrodes or not.

[0048] In this way, it is sufficient that the lamp 10 is formed with at least one sealing portion 22, or conversely, the communication hole 26 and the tip portion 28 may be formed in both of the pair of sealing portions 22, or the exhaust pipe 60 may be embedded and the tip portion 28 may be formed. In addition, the mount portion 30 (electrodes 14, foil 16, and lead rod 18) is not an essential component.

[0049] Furthermore, the shape of the arc tube 12 (particularly the light emitting portion 20) is not limited to a perfectly circular cross section as in the above-described embodiment, but may be, for example, an elliptical cross section or a rectangular cross section.

[0050] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0051] 10...lamp, 12...light emitting tube, 14...electrode, 16...foil, 18...lead rod, 20...light emitting portion, 22...sealing portion, 24...internal space, 25...mercury, 26...communicating hole, 28...chip portion, 30...mounting portion 50: pinch member, 52: pressing surface, 54: recess 60…Exhaust pipe

Claims

[Claim 1] 1. A method for sealing a lamp, comprising the steps of: sealing at least one end of an arc tube to form an airtight internal space within the arc tube, the method comprising the steps of: when forming a sealed portion in the light-emitting tube by pinching and sealing the end portion, a communication hole that communicates the internal space with the outside is formed in the end portion in the width direction of the sealed portion, an exhaust pipe is attached to an outer end of the communication hole, and exhaust is exhausted from the internal space and an enclosed material is enclosed in the internal space through the exhaust pipe; The base of the exhaust pipe is heated and melted to form a tip portion that closes the communication hole. How the lamp is sealed.

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