JP2004253360A - Dielectric barrier discharge type low-pressure discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance reliability of long-term lighting by preventing a mercury exhaustion phenomenon in sealing parts at both ends of a tubular glass lamp vessel. <P>SOLUTION: In this dielectric barrier discharge type low-pressure discharge lamp 1, a ball bead sealing part 11 is formed by loading a ball bead 41 in at least one end of the tubular glass vessel 10, that is, the end part of the vessel on the side sealed after evacuating it and filling a filler in it and by thermally fusing it, protrusion of the ball bead into a discharge space at the ball bead sealing part thermally sealed under the atmospheric pressure is minimized, to prevent the mercury exhaust phenomenon at the ball bead sealing part, and to make long-term lighting possible. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a dielectric barrier discharge type low pressure discharge lamp.
[0002]
[Prior art]
2. Description of the Related Art As a so-called dielectric barrier discharge type low-pressure discharge lamp having electrodes on the outer surface of a tubular glass lamp vessel, for example, the one described in Japanese Utility Model Application Laid-Open No. 61-126559 is known.
[0003]
FIG. 5 shows the structure of a dielectric barrier discharge type low-pressure discharge lamp prototyped by the inventors of the present invention with reference to the technology described in this publication. In FIG. 5, reference numeral 5 denotes a low-pressure discharge lamp, and reference numeral 10 denotes a tubular glass lamp vessel. Inside the tubular glass lamp vessel 10, a filler 60 made of a mixed gas of mercury and a rare gas is sealed as a discharge medium. On the inner wall surface of the tubular glass lamp container 10, a phosphor layer 70 is formed as necessary. External electrodes 21 and 26 composed of current conductor layers 31 and 36 are disposed on the outer surfaces of both ends of the tubular glass lamp vessel 10. The current conductor layers 31, 36 of the external electrodes 21, 26 are formed by dipping the ends in an ultrasonic solder bath.
[0004]
In the low-pressure discharge lamp 5 shown in FIG. 5, 13 and 16 are sealing portions at both ends of the tubular glass lamp container 10. In the manufacturing process, one beadless sealing portion 16 heat seals the glass lamp vessel 10 before the glass lamp vessel 10 is evacuated, and the other conventional sealing section 13 evacuates the tubular glass lamp vessel 10, After introducing 60, heat sealing is performed. In the sealing step of the conventional sealing portion 13, since the internal pressure of the glass lamp vessel 10 is lower than the atmospheric pressure, the glass material in a high-temperature and flexible state at the time of sealing is pressed by the external pressure to form a glass lamp. The shape is drawn into the discharge space of the container 10. For this reason, the thickness of the glass of the sealing portion 13 becomes very thin, and there is a problem that the glass is easily broken at this portion.
[0005]
In order to solve this problem, the present inventors have prototyped a dielectric barrier discharge type low-pressure discharge lamp 6 having the structure shown in FIG. In the dielectric barrier discharge type low-pressure discharge lamp 6, in the manufacturing process, the beadless sealing portion 16 at one lamp end is heat-sealed before the glass lamp container 10 is evacuated, and the cylinder at the other lamp end is sealed. As for the bead sealing portion 14, a cylindrical bead 44 obtained by cutting a relatively easily available thin glass rod is inserted up to the position of the cylindrical bead sealing portion 14 of the tubular glass lamp container 10, and in this state, the glass lamp container After evacuating the inside of 10 and introducing the filler 60, the end of the tubular glass lamp vessel 10 is heat sealed so as to cover the cylindrical beads 44.
[0006]
In the dielectric barrier discharge type low-pressure discharge lamp 6 having this structure, since the cylindrical beads 44 are interposed, the glass of the cylindrical bead sealing portion 14 is not sucked into the discharge space, and the structure shown in FIG. Can be manufactured.
[0007]
[Patent Document 1]
Japanese Utility Model Application Laid-Open No. 61-126559 [0008]
[Problems to be solved by the invention]
However, in the latter dielectric-barrier discharge type low-pressure discharge lamp 6, the end of the cylindrical bead 44 of the cylindrical bead sealing portion 14 protrudes into the discharge space of the tubular glass lamp vessel 10, and the glass lamp vessel 10 and this protruding portion It is unavoidable that a gap is formed between them. If there is such a gap, the mercury vapor in the filler 60 stays and accumulates in the gap during the operation of the lamp. Then, as a result, the mercury in the filler 60 is depleted, and only the rare gas is locally generated, and a rare gas discharge occurs. When this rare gas discharge occurs, the temperature of the glass lamp container 10 in contact with the discharge part tends to partially rise, so that the glass may be melted, leading to leakage, and the reliability of lighting for a long time may be reduced. There was a problem of being scarce. In the beadless sealing portion 16 sealed under the atmospheric pressure, since the glass does not protrude into the discharge space, the temperature rise due to the rare gas discharge does not occur.
[0009]
The present invention has been made in view of such technical problems, and can prevent a mercury depletion phenomenon at a sealing portion at both ends of a tubular glass lamp container, and can guarantee a long-term reliability of a dielectric barrier discharge type. An object is to provide a low-pressure discharge lamp.
[0010]
[Means for Solving the Problems]
The invention according to claim 1 is a dielectric barrier discharge type low-pressure discharge lamp in which external electrodes are provided on the outer periphery of both ends of a tubular glass lamp vessel and a discharge medium is sealed in the tubular glass lamp vessel. One end of the tube of the lamp vessel is heat-sealed, and the other end of the tube is heat-sealed with ball beads, and the end surfaces and the outer peripheral surface of both ends of the tube are covered with the external electrodes.
[0011]
The invention according to claim 2 is a dielectric barrier discharge type low-pressure discharge lamp in which external electrodes are provided on the outer periphery of both ends of a tubular glass lamp vessel and a discharge medium is sealed in the tubular glass lamp vessel. Ball beads are put into both ends of the tube of the lamp vessel and heat-sealed, and the end surfaces and outer peripheral surfaces of both ends of the tube are covered with the external electrodes.
[0012]
In the dielectric barrier discharge type low pressure discharge lamp according to the first and second aspects of the present invention, at least one end of the tubular glass lamp container, that is, the end on the side to be sealed after vacuum evacuation and filling of the filler is heat sealed with ball beads. By doing so, the protrusion of the thermally sealed spherical beads under atmospheric pressure into the discharge space can be reduced, and in the case of a discharge medium containing mercury, the mercury depletion phenomenon at the sealed spherical bead portion can be prevented. Enable lighting for a period.
[0013]
The invention according to claim 3 is the dielectric barrier discharge type low-pressure discharge lamp in which external electrodes are provided on the outer periphery of both ends of the tube of the tubular glass lamp vessel and a discharge medium is sealed in the tubular glass lamp vessel. One of both ends of the tube of the lamp vessel is heat-sealed, and the other end of the tube is heat-sealed by inserting a bullet-shaped bead with the head thereof facing the discharge space, and the end surface and the outer peripheral surface of both ends of the tube Is covered with the external electrode.
[0014]
The invention according to claim 2 is a dielectric barrier discharge type low-pressure discharge lamp in which external electrodes are provided on the outer periphery of both ends of a tubular glass lamp vessel and a discharge medium is sealed in the tubular glass lamp vessel. Shell-type beads are placed at both ends of the tube of the lamp vessel with their heads facing the discharge space side and heat sealed, and the end surfaces and the outer peripheral surfaces of both ends of the tube are covered with the external electrodes.
[0015]
In the dielectric barrier discharge type low-pressure discharge lamp according to the first and second aspects of the present invention, at least one end of the tubular glass lamp vessel, that is, the end on the side to be sealed after vacuum evacuation and filling of the filler, is provided with a bead-shaped bead. By placing it in a position facing the discharge space side and heat sealing, the round head of the shell type beads sealed at atmospheric pressure faces the discharge space side, so that the protrusion into the discharge space is reduced. In the case of a discharge medium containing mercury, it is possible to prevent a mercury depletion phenomenon in a sealed portion of a spherical bead and enable lighting for a long time. In addition, in the case of shell-type beads, they can be smoothly introduced without being caught when introduced into the end of the tubular glass lamp vessel in the heat sealing step, and therefore the product yield in mass production can be improved.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the configuration of a dielectric barrier discharge type low-pressure discharge lamp according to a first embodiment of the present invention. In FIG. 1, reference numerals common to the prototype low-pressure discharge lamps 5 and 6 shown in FIGS. 5 and 6 indicate the same elements.
[0017]
In the dielectric barrier discharge type low-pressure discharge lamp 1 shown in FIG. 1, reference numeral 41 denotes a spherical bead, which is manufactured by further molding a cylindrical bead cut out from a thin glass rod. However, the method for producing the spherical beads 41 is not limited, and a glass bulb having an appropriate diameter can be selected and used according to the size of the tubular glass lamp container 10.
[0018]
In the manufacturing process of the dielectric barrier discharge type low-pressure discharge lamp 1 of the present embodiment, the beadless sealing portion 16 at one lamp end is heat-sealed before the glass lamp container 10 is evacuated, and the other lamp is sealed. With regard to the ball bead sealing portion 11 at the end, the ball bead 41 is inserted up to the position of the ball bead sealing portion 11 of the tubular glass lamp vessel 10, and in this state, the inside of the glass lamp vessel 10 is evacuated and the filler 60 is filled. Is introduced, the end of the tubular glass lamp vessel 10 is heat sealed so as to cover the spherical beads 41.
[0019]
In this embodiment, the spherical beads 41 are used instead of the cylindrical beads 44 used in the prototype low-pressure discharge lamp 6 shown in FIG. 6, so that the sealing portion 11 can be prevented from protruding into the discharge space. For this reason, in the dielectric barrier discharge type low-pressure discharge lamp 1 of the present embodiment, the cylindrical beads 44 and the tubular glass lamp 10 at the time of lamp lighting as generated when sealing with the cylindrical beads 44 are used. The occurrence of local rare gas discharge due to the depletion of mercury in the gap can be prevented, and the occurrence of the problem that the glass melts due to the temperature rise due to the rare gas discharge and leads to leakage can be prevented.
[0020]
Next, a dielectric barrier discharge type low-pressure discharge lamp 2 according to a second embodiment of the present invention will be described with reference to FIG. The second embodiment is characterized in that the spherical beads 41, 46 are inserted into both ends of the tubular glass lamp vessel 10, and the beads 11 and 17 are formed by heat sealing. In FIG. 2, components common to those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals.
[0021]
In the manufacture of the dielectric barrier discharge type low-pressure discharge lamp 2 of the present embodiment, the spherical bead sealing portion 17 at one end of the lamp inserts the spherical beads 46 into the glass tube before the glass lamp container 10 is evacuated. After heat sealing, the ball bead 41 is inserted into the ball bead sealing portion 11 of the other lamp end up to the position of the ball bead sealing portion 11 of the tubular glass lamp vessel 10, and in this state, the inside of the glass lamp vessel 10 is Is evacuated and the filler 60 is introduced, and then the end of the tubular glass lamp container 10 is heat-sealed so as to cover the spherical beads 41.
[0022]
In the dielectric barrier discharge type low-pressure discharge lamp 2 of the second embodiment, similarly to the first embodiment, a lamp which is generated when the lamp is sealed with the cylindrical beads 44 is used. The occurrence of local rare gas discharge due to mercury depletion in the gap between the cylindrical beads 44 and the tubular glass lamp 10 at the time of lighting can be prevented, and the temperature rise due to the rare gas discharge melts the glass and causes a problem that leads to leakage. Occurrence can be prevented.
[0023]
Next, a dielectric barrier discharge type low-pressure discharge lamp according to a third embodiment of the present invention will be described with reference to FIG. In FIG. 3, the same reference numerals as those of the dielectric barrier discharge type low-pressure discharge lamps 1 and 2 of the first and second embodiments shown in FIGS. 1 and 2 indicate the same elements.
[0024]
In the dielectric barrier discharge type low-pressure discharge lamp 3 shown in FIG. 3, reference numeral 41A denotes bullet-shaped beads, which are produced by further molding cylindrical beads cut out from a thin glass rod. However, the manufacturing method of the bullet-shaped beads 41A is not limited, and an appropriate diameter is selected and used according to the size of the tubular glass lamp container 10.
[0025]
In the manufacturing process of the dielectric barrier discharge type low-pressure discharge lamp 3 of the present embodiment, the beadless sealing portion 16 at one lamp end is heat-sealed before the glass lamp container 10 is evacuated, and the other lamp is sealed. With regard to the shell-shaped bead sealing portion 11A at the end, the shell-shaped bead 41A is inserted to the position of the shell-shaped bead sealing portion 11A of the tubular glass lamp container 10 with the head thereof facing the discharge space, and in this state. After evacuating the inside of the glass lamp container 10 and introducing the filler 60, the end of the tubular glass lamp container 10 is heat-sealed so as to cover the bullet-shaped beads 41.
[0026]
In the present embodiment, instead of the cylindrical beads 44 used in the prototype low-pressure discharge lamp 6 shown in FIG. 11A can be prevented from protruding into the discharge space. For this reason, in the dielectric barrier discharge type low-pressure discharge lamp 3 of the present embodiment, the cylindrical beads 44 and the tubular glass lamp 10 at the time of lamp lighting as generated when sealing with the cylindrical beads 44 are used. The occurrence of local rare gas discharge due to the depletion of mercury in the gap can be prevented, and the occurrence of the problem that the glass melts due to the temperature rise due to the rare gas discharge and leads to leakage can be prevented.
[0027]
Further, in the case of the spherical beads 41 as in the first embodiment, it is not technically easy to form a complete spherical shape with a small diameter, and it is attempted to make the spherical shape by a simple work from the viewpoint of manufacturing cost. It tends to be distorted, and if it is distorted, it may be difficult to introduce it to a predetermined position because it is caught in the middle of the process of being inserted into the glass tube and being introduced to the end of the tubular glass lamp vessel 10. However, when the shell type beads 41A are used instead of the spherical beads 41 as in the present embodiment, the shell type beads 41A formed into a shell type by polishing one end of a short cylinder taken out from the cylindrical glass are used as the head. Can be smoothly introduced into a predetermined position by introducing into the end of the tubular glass lamp vessel 10 in a posture facing the discharge space side. Therefore, in the dielectric barrier discharge type low-pressure discharge lamp 3 of the present embodiment, the product yield can be improved.
[0028]
Next, a dielectric barrier discharge type low-pressure discharge lamp 4 according to a fourth embodiment of the present invention will be described with reference to FIG. The fourth embodiment is characterized in that shell-shaped beads 41A and 46A are inserted into both ends of a tubular glass lamp container 10, and the shells 11A and 17A are formed by heat sealing. . In FIG. 4, elements common to those of the third embodiment shown in FIG. 3 are denoted by the same reference numerals.
[0029]
In the manufacture of the dielectric barrier discharge type low-pressure discharge lamp 4 of the present embodiment, the bullet-shaped bead sealing portion 17A at one of the lamp ends has the bullet-shaped bead 46A before the glass lamp container 10 is evacuated to vacuum. Is placed in a glass tube in a posture facing the discharge space side, and heat sealed. The shell type beads sealing portion 11A at the other end of the lamp is sealed with shell type beads 41A by the shell type beads of the tubular glass lamp container 10. In this state, the inside of the glass lamp vessel 10 is evacuated, the filler 60 is introduced, and then the shell-shaped beads 41A are covered. The end of the tubular glass lamp vessel 10 is heat sealed.
[0030]
Also in the dielectric barrier discharge type low-pressure discharge lamp 4 of the fourth embodiment, similar to the third embodiment, the low-pressure discharge lamp 4 may be generated when sealing with the cylindrical beads 44 in the related art. The occurrence of local rare gas discharge due to mercury depletion in the gap between the cylindrical beads 44 and the tubular glass lamp 10 when the lamp is turned on can be prevented, and the temperature rise due to the rare gas discharge melts the glass and leads to leakage. Can be prevented.
[0031]
In addition, similarly to the third embodiment, the product yield in manufacturing can be improved.
[0032]
In the present invention, as in the above-described first to fourth embodiments, the filler 60 filling the tubular glass lamp container 10 as a discharge medium may be mercury-free.
[0033]
【Example】
Prototypes having the configuration shown in FIG. 1, the embodiment 1 shown in FIG. 1, the configuration shown in FIG. 3, and the configuration shown in FIG. 6 were manufactured, and the results of lighting tests will be described.
[0034]
[Example 1]
<Tubular glass lamp container>
Material: borosilicate glass.
[0035]
Dimensions: outer diameter 2.6 mm, inner diameter 2.0 mm, total length 379 mm.
[0036]
<External electrode>
Current conductor layer: Ultrasonic solder layer.
[0037]
External electrode length: 17 mm.
[0038]
<Phosphor layer>
Material: three-wavelength phosphor. Thickness: 20 μm.
[0039]
<Filler>
Filled gas: mixed gas of neon and argon (composition ratio: neon / argon = 90 mol% / 10 mol%).
[0040]
Sealing pressure: 8 kPa.
[0041]
Mercury: 3 mg enclosed amount.
[0042]
<Beads for sealing>
Sphere beads.
[0043]
[Example 2]
The specifications of the tubular glass lamp container, the external electrode, the phosphor layer, and the filler are the same as in the first embodiment. And shell-shaped beads were used as beads for sealing.
[0044]
[Comparative example]
The configuration is the same as that of the embodiment except that one end of the glass lamp container is sealed using cylindrical beads as sealing beads.
[0045]
When each of the dielectric barrier discharge type low-pressure discharge lamps of Examples 1 and 2 of the present invention and the comparative example was lit for 5000 hours at a lamp current of 5 mA, no glass melting occurred. While noble gas discharge occurred in the gap between the cylindrical beads and the tubular glass lamp vessel in Example 1, such a phenomenon did not occur in Examples 1 and 2 of the present invention.
[0046]
【The invention's effect】
As described above, according to the present invention, by sealing spherical beads or bullet-shaped beads to the bead sealing portion at the lamp end of the tubular glass lamp container, the size of the end of the bead projecting into the discharge space is reduced. The size of the discharge lamp can be reduced, and the mercury depletion phenomenon at the bead sealing portion can be prevented.
[0047]
In addition, in the present invention, by using bullet-shaped beads for the beads to be sealed, the step of introducing the beads into the end of the tubular glass lamp container for sealing can be performed smoothly, and the product yield can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first embodiment of the present invention in a lamp axial direction.
FIG. 2 is a sectional view in a lamp axis direction according to a second embodiment of the present invention.
FIG. 3 is a sectional view in a lamp axial direction of a third embodiment of the present invention.
FIG. 4 is a sectional view in a lamp axis direction of a fourth embodiment of the present invention.
FIG. 5 is a cross-sectional view in the lamp axis direction of a prototype manufactured by the present inventors.
FIG. 6 is a cross-sectional view in the lamp axis direction of another prototype manufactured by the present inventors.
[Explanation of symbols]
1-4 Dielectric barrier discharge type low pressure discharge lamp 10 Tubular glass lamp vessel 11 Ball bead sealing portion 11A Shell type bead sealing portion 17 Ball bead sealing portion 17A Shell type bead sealing portion 21, 26 External electrodes 31, 36 Current conductor layers 41, 46 Ball beads 41A, 46A Shell type beads 60 Filler 70 Phosphor layer

Claims (4)

An external electrode is disposed on the outer periphery of both ends of the tube of the tubular glass lamp vessel, and a dielectric barrier discharge type low pressure discharge lamp in which a discharge medium is sealed in the tubular glass lamp vessel,
One of the two ends of the tube of the tubular glass lamp vessel is heat-sealed, and the other end of the tube is heat-sealed with ball beads in between,
A dielectric-barrier discharge type low-pressure discharge lamp comprising an end face and an outer peripheral face at both ends of the tube covered by the external electrode. An external electrode is disposed on the outer periphery of both ends of the tube of the tubular glass lamp vessel, and a dielectric barrier discharge type low pressure discharge lamp in which a discharge medium is sealed in the tubular glass lamp vessel,
Putting spherical beads on both ends of the tube of the tubular glass lamp container and heat sealing,
A dielectric-barrier discharge type low-pressure discharge lamp comprising an end face and an outer peripheral face at both ends of the tube covered by the external electrode. An external electrode is disposed on the outer periphery of both ends of the tube of the tubular glass lamp vessel, and a dielectric barrier discharge type low pressure discharge lamp in which a discharge medium is sealed in the tubular glass lamp vessel,
One of the two ends of the tube of the tubular glass lamp vessel is heat sealed, and the other end of the tube is heat sealed with a bullet-shaped bead placed in a position where the head faces the discharge space side,
A dielectric-barrier discharge type low-pressure discharge lamp comprising an end face and an outer peripheral face at both ends of the tube covered by the external electrode. An external electrode is disposed on the outer periphery of both ends of the tube of the tubular glass lamp vessel, and a dielectric barrier discharge type low pressure discharge lamp in which a discharge medium is sealed in the tubular glass lamp vessel,
Shell-shaped beads are placed at both ends of the tubular glass lamp vessel in a manner that their heads face the discharge space side, and heat sealed,
A dielectric-barrier discharge type low-pressure discharge lamp comprising an end face and an outer peripheral face at both ends of the tube covered by the external electrode.

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