JP2002260590A - Rare gas discharge lamp and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture a rare gas discharge lamp wherein the breakdown voltage between outer surface electrodes is excellent even if the diameter of a glass bulb is small, in the rare gas discharge lamp where the outer surface electrode which is a main electrode for discharge is provided on the outer surface of a cylindrical glass bulb while the exposed surfaces of the outer surface electrode and the glass bulb are coated with a translucent insulating material. SOLUTION: On the outer surface of a cylindrical glass bulb 3 in which a rare gas 5 is sealed in, outer surface electrodes 7A and 7B which are main electrodes for discharge are provided. Around an exposed parts of the outer surface electrodes 7A and 7B and the glass bulb, a translucent and electrically-insulating slender insulating tape 17A is wound in spiral with a tube axis as a center of winding. Since it is wound in spiral, neither workability nor adhesion to the bulb 3 degrades even if the pipe diameter of the bulb 3 is small. Different from the case of a heat shrinkage tube, in which a clearance between a thinner bulb 3 and a tube before shrinkage decreases, no workability degrades. Compared to a method of coating an insulating varnish, degradation in insulating performance due to air bubbles does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rare gas discharge lamp and a method of manufacturing the same, and more particularly, to a method of producing a dielectric barrier discharge in a gas sealed in a cylindrical glass bulb through a glass bulb on the outer surface of the bulb. Gas discharge lamp having a structure in which a main electrode (external electrode) is provided, and the external electrode and the exposed surface of the glass bulb are covered with a transparent insulating coating, and a method for manufacturing the same.

[0002]

2. Description of the Related Art A gas containing a rare gas such as xenon is sealed in a cylindrical glass bulb having a phosphor film formed on an inner surface thereof, and a discharge is caused to occur in the sealed gas. Fluorescent lamps with a structure that excites a film, converts it to visible light, and extracts it to the outside, generally have a main electrode for discharge inside a glass bulb, such as a hot cathode fluorescent lamp or a cold cathode fluorescent lamp. (Internal electrode type) and an external electrode type having a structure in which a main electrode is provided on the outer surface of a glass bulb, such as a rare gas discharge lamp disclosed in Japanese Patent No. 2969130, for example. The present invention relates to a rare gas discharge lamp of the external electrode type.

FIG. 10 shows a perspective view and a sectional view of an example of a rare gas discharge lamp of an external electrode type. FIG. 10 is based on FIG. 1 and FIG. 2 of the above-mentioned Japanese Patent No. 2969130, and FIG. 10 (a) corresponds to the front view shown in FIG. FIG. 2 (b) corresponds to the sectional view of FIG. In FIG. 10, for convenience of explanation, reference numerals and names different from those used in the above-mentioned publications may be used for reference numerals and names of each part in the drawing.

Referring to FIG. 10, a cylindrical glass bulb 3 is an envelope, and a phosphor film 11 is formed on an inner surface thereof over substantially the entire length in the axial direction of the bulb. In the space inside the glass bulb 3, the rare gas 5 containing xenon gas as a main component is 3.99 × 10 ^{3 to} 13.3 × 10 ^3.
It is sealed at a pressure of about ³ Pa (30 to 100 Torr). On the other hand, a pair of metal electrodes 7A and 7B made of an opaque metal such as aluminum are provided on the outer peripheral surface of the glass bulb 3 so as to face each other with the tube axis interposed therebetween. Each of the two metal electrodes 7A and 7B is a strip-shaped electrode that is long in the tube axis direction.
The books are electrically insulated from each other across the gaps (openings) 13A and 13B. The above two metal electrodes 7A, 7
B is an outer surface electrode as a main electrode for causing a dielectric gas discharge in the rare gas 5. The two outer electrodes 7A and 7B are provided with a light-transmitting insulating coating 15 made of a silicone resin for improving insulation and safety between the two electrodes.

In this rare gas discharge lamp, the electrodes 7A,
When a high frequency and a high voltage such as 30 kHz and 1600 V are applied between 7B, a dielectric barrier discharge is generated inside the glass bulb 3. At that time, the xenon sealed in the glass bulb is excited to generate ultraviolet rays having a wavelength of 172 nm, and the ultraviolet rays excite the phosphor film 11 and are converted into visible light, and the aperture between the electrodes 7A and 7B is opened. Taken out of the department.

The rare gas discharge lamp of this external electrode type has a structural feature that the main electrode for discharge is provided on the outer surface of the glass bulb. Therefore, the electrode is not consumed by ion bombardment due to the discharge. It is more resistant to flashing and has a longer life than a discharge lamp of the system. Also, there is almost no change in the illuminance distribution in the tube axis direction due to blackening of the tube end. Xenon gas is included in the rare gas for discharge, and the rise of the light amount after lighting is sharp,
Since it has the characteristic that the light amount reaches nearly 100% at the same time as the lighting, it has been widely used for document irradiation in OA equipment such as a facsimile, an image scanner or a PPC.

The structural characteristic of the rare gas discharge lamp of the external electrode type is that a main electrode for discharge is provided on the outer surface of the glass bulb. The insulating coating 15 covering the electrodes 7A and 7B and the glass bulb is a very important component. That is,
First, electrical insulation from the outside must be ensured and safety must be guaranteed. Secondly, in this type of rare gas discharge lamp, the area immediately below the outer electrode is discharged and brightened. Therefore, when the distance between the electrodes is increased and the portion without the outer electrode is widened, the brightness is reduced. Therefore, by providing the insulating coating 15, the withstand voltage between the outer surface electrodes 7A and 7B is increased, and even if the distance between the electrodes is shortened, creeping discharge does not occur, thereby increasing the electrode area and increasing the brightness. Because it can be.

In view of the above, conventionally, various methods have been devised for forming the insulating coating 15. One (conventional example 1)
Is a method using a transparent insulating varnish such as a silicone resin as described in the above-mentioned Japanese Patent No. 2969130, and JP-A-9-134706 describes in paragraph [0006] A method of forming an insulating coating 15 by applying an insulating varnish to the surfaces of the external electrodes 7A and 7B and the boundary between the glass bulb 3 and the external electrode is disclosed.

Another method of forming an insulating coating (conventional example 2) is to use a heat-shrinkable tube. For example, Japanese Patent No. 2783448 discloses that a glass bulb having an outer surface electrode formed thereon is immersed in a silicone resin bath and dried to apply the insulating varnish. It discloses a technique of double coating in which a shrink tube is covered, and the shrink tube is shrunk by heating in an oven to adhere to a base insulating varnish film.

Still another method of forming an insulating coating (conventional example 3)
Is a method of winding a translucent and electrically insulating sheet around the glass bulb 3. For example, as shown in FIG.
In the rare gas discharge lamp disclosed in Japanese Patent No. 134706, a translucent insulating sheet coated with an adhesive on one side is prepared in advance, and outer electrodes 7A and 7B are formed on the glass bulb 3. After that, the above-mentioned insulating sheet 27 is wound around the entirety of the glass bulb 3 around the tube axis in parallel, so that the electrodes 7A and 7B are not exposed on both end faces of the glass bulb.

Japanese Patent No. 3022283 discloses a method in which a pair of strip-shaped electrodes extending in the tube axis direction are formed in advance on one surface of a light-transmitting insulating sheet having substantially the same length as the entire length of the glass bulb 3. Is wound around a glass bulb 3 (only a rare gas is sealed and no outer electrode is provided) around the tube axis so that the outer electrode is placed on the glass bulb. It discloses a method of simultaneously forming and forming an insulating coating thereon.

[0012]

In recent years, the size of various electronic devices has been remarkably reduced, and even in the field of the OA device, which is one of the applications of this type of rare gas discharge lamp, the size of the document reading section and the device are reduced. There is a strong demand for reducing the size of rare gas discharge lamps, which are light sources, in order to reduce the size. Therefore, various attempts have been made to make the rare gas discharge lamp narrower. One of them is to make the outer tube electrode thin by changing the electrode structure.

For example, Japanese Patent Application No. 2001-039111 filed by the assignee of the present invention makes it possible to reduce the diameter of a glass bulb by spirally winding an outer surface electrode around the glass bulb. . Further, Japanese Patent Application Laid-Open No. 5-082
As in the rare gas discharge lamp shown in FIG.
Each outer surface electrode has a ring structure surrounding the outer periphery of the glass bulb (however, only one gap for light extraction is opened), and two such ring structure electrodes are arranged in the tube axis direction. By doing so, the tube diameter of the glass bulb may be reduced. Even the rare gas discharge lamp of the same external electrode type shown in FIGS.
In the case of a rare gas discharge lamp having a structure in which two band-shaped outer electrodes 7A and 7B extending in the tube axis direction are opposed to each other with the tube axis interposed therebetween (hereinafter, sometimes referred to as band electrodes), two band electrodes 7 are provided.
Since the minimum distance (openings 13A and 13B) for electrical insulation and light extraction between the electrodes must be provided between A and 7B, the smaller the tube diameter of the glass bulb 3 is, the smaller the diameter is. , Band-shaped electrodes 7A, 7B vs. openings 13A, 13
The area ratio of B decreases and the luminous efficiency (the ratio of brightness to power consumption) deteriorates.
A discharge lamp having an outer surface electrode having a helical structure (same as the helical electrode) described in JP-A-01-039111;
In the discharge lamp having a ring-shaped outer electrode (the same ring-shaped electrode) disclosed in Japanese Patent Publication No. 1, the distance between the two outer electrodes is determined irrespective of the tube diameter of the glass bulb 3 in extreme terms. Therefore, the glass bulb can be easily made into a thin tube. For example, in a rare gas discharge lamp with a strip-shaped outer electrode,
The minimum tube diameter of the glass bulb from the viewpoint of luminous efficiency is 6m
Although m is the limit, if the outer surface electrode is a spiral or ring-shaped discharge lamp, it can be as thin as 3 mm or less and about 0.8 mm.

Thus, by devising the structure of the outer surface electrode, the tube diameter of the glass bulb 3 can be reduced. However, when viewed from the viewpoint of the insulating coating 15 which is an important component of the rare gas discharge lamp, the above-described conventional example 1
It is difficult to apply any of the insulating coating forming methods of (1) to (3) to a rare gas discharge lamp having a thin tube. That is, in the method of applying a light-transmitting insulating varnish (conventional example 1), a great deal of time is required from application to drying, and fine bubbles generated in the drying stage lower the insulating property, resulting in a sufficient insulating property. Performance may not be obtained.

On the other hand, in the case of the method using a heat-shrinkable tube (conventional example 2), the shrinkage of the heat-shrinkable tube is generally 30%.
Therefore, as the tube diameter of the glass bulb 3 becomes smaller, the clearance between the tube before shrinking and the glass bulb becomes smaller, and the workability is significantly reduced.

In the method of winding a light-transmitting insulating sheet in parallel with the tube axis (conventional example 3), the insulating material is not applied to a thin glass bulb, regardless of the diameter of the glass bulb. Not only is the work extremely difficult due to the elastic repulsion of the conductive sheet, but also the adhesion to the valve is significantly reduced, and the insulation may be impaired.

Accordingly, the present invention provides an external electrode for causing a dielectric barrier discharge in a gas filled in the bulb through the glass bulb on the outer surface of the cylindrical glass bulb, and exposing the external electrode and the glass bulb. An object of the present invention is to provide a rare gas discharge lamp having a structure in which a surface is provided with a light-transmitting insulating coating, and which has a good withstand voltage between outer electrodes even when the tube diameter of the glass bulb is small. I do.

It is another object of the present invention to provide a method for easily manufacturing the above-mentioned external electrode type rare gas discharge lamp having a good withstand voltage.

[0019]

According to the rare gas discharge lamp of the present invention, at least two or more external electrodes for generating a dielectric barrier discharge are provided on the outer surface of a cylindrical glass bulb filled with a gas containing a rare gas. In the rare gas discharge lamp having the structure provided with, the outer surface electrode and the exposed portion of the glass bulb are covered with a spiral, translucent and electrically insulating insulating tape having a tube axis as a center of winding. It is characterized by.

In the rare gas discharge lamp described above, at least a phosphor film is formed on an inner wall of a cylindrical glass bulb, and a sealing gas containing a rare gas is sealed in an internal space. A step of forming at least two or more outer electrodes for causing a dielectric barrier discharge in the sealing gas through the glass bulb, and a glass bulb including the outer electrodes, a translucent and electrically insulating insulating tape. Is spirally wound around the tube axis as the center of winding.

Alternatively, a process of forming at least a phosphor film on the inner wall of a cylindrical glass bulb and enclosing a gas containing a rare gas in an internal space, and a process of forming one surface of a transparent and electrically insulating insulating tape. A step of previously forming at least two or more conductor layers running parallel to the longitudinal direction, and winding the insulating tape having the conductor layer around the glass bulb in a spiral around a tube axis. And mounting the rare gas discharge lamp.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings using some examples.

(Embodiment 1) FIG. 1 shows a side view of a rare gas discharge lamp according to Embodiment 1 of the present invention and a cross-sectional view taken along a line A1-A1. By comparing FIG. 1 with FIG. 10 and FIG. 11, the rare gas discharge lamp 1 according to the first embodiment has a cylindrical glass bulb 3 having a phosphor film 11 formed on the inner surface and a glass bulb 3 inside the glass bulb. The sealed rare gas 5 and two main electrodes (external electrodes) 7 formed in a strip shape on the outer surface of the glass bulb.
A and 7B are the same as the conventional rare gas discharge lamp, but the structure of the insulating coating is different. That is, in this embodiment, the insulating coating is made of a light-transmitting and electrically insulating insulating tape 17 helically wound around the glass bulb 3 and the electrodes 7A and 7B in the tube axis direction. The insulating tape 17A is made of a material having good translucency and excellent insulating properties and heat resistance, such as polyethylene terephthalate.

Referring to FIG. 2 showing a process of manufacturing the rare gas discharge lamp according to the present embodiment, the rare gas discharge lamp shown in FIG. 1 is manufactured as follows. First, as shown in FIG. 2A, a phosphor film 11 is formed on the inner wall of a glass bulb 3 by a conventionally known method, and a rare gas 5 containing xenon gas as a main component.
Is sealed at a predetermined pressure, and two strip electrodes 7A and 7B are formed on the outer surface of the glass bulb. Then, power supply terminals 19A and 19B for electrical connection with the outside are connected to the electrodes 7A and 7B. An arc tube 21A is manufactured by fixing to each end. For convenience of explanation, the outer electrodes 7A, 7
Regardless of the presence or absence of B and the presence or absence of the power supply terminals 19A and 19B, the state before the insulating coating is applied is referred to as an arc tube.

On the other hand, as shown in FIG. 2B, a strip-shaped insulating tape 17A having an elongated parallelogram shape is prepared. The insulating tape 17A is made of polyethylene terephthalate, and is translucent and electrically insulating. A translucent pressure-sensitive adhesive or adhesive (hereinafter, referred to as a viscous / adhesive) is applied to one surface in advance. When the thickness of the tape is too small, the insulation performance against the outside is reduced. When the thickness is too large, the elastic rebound increases, and the adhesion to the arc tube and the workability are reduced.
The thickness is preferably about 00 μm. This insulating tape 1
In 7A, the short sides at both ends are cut obliquely to the longitudinal direction in advance according to the pitch of the tape winding.
It is easy to wind around the arc tube 21A.

After arranging one end of the glass bulb 3 and one end of the insulating tape 17A in parallel, FIG.
As shown in (c), the insulating tape 17A is spirally wound in the tube axis direction of the glass bulb 3. The winding may be performed by fixing the arc tube 21A and winding the tape 17A, or conversely, by fixing the tape 17A and rolling the arc tube on the tape 17A. It does not matter, but it is preferable that the ends of the loops are wound slightly overlapping (indicated by the symbol D in FIG. 1A) so that no gap is opened between the adjacent loops.

The overlapping width D of the insulating tape 17A (FIG. 1)
See (a). (Indicated by D) is preferably as wide as possible in order to ensure the purpose of insulation, but if it is too large, the transmittance of light extracted from the discharge tube is reduced. The workability is better when the tape width (similarly denoted by the symbol W) is smaller. However, when the tape width is too narrow, not only the number of windings increases but also the number of manufacturing steps increases, but also the ratio of the overlap width D to the tape width W increases. As a result, the transmittance of the extracted light decreases, and the function as a discharge lamp is impaired. On the other hand, if the tape width W is too wide, it is difficult to form a spiral, and workability is reduced. According to the inventor's knowledge, the width W
When a tape having an overlap width D of 1 to 4 mm was wound around a tape having a length of 3 to 15 mm, good results were obtained in all of the workability, insulation, and brightness.

In this embodiment, since an electrically insulating tape is used for coating the electrodes 7A and 7B, the insulating performance due to bubbles and the like is lower than that of the conventional example 1 (a method of applying an insulating varnish such as a silicone resin). There is no instability. Also,
Since the elongate insulating tape 17A is spirally wound around the glass bulb 3, even when the diameter of the glass bulb becomes small, the glass bulb and the shrinkage caused by the conventional example 2 (method using a heat-shrinkable tube) are used. There is no decrease in workability due to a decrease in clearance with the previous tube. In extreme terms, in the present embodiment, the workability is independent of the tube diameter of the glass bulb 3, and the glass bulb of the glass bulb can be made any thinner. Also, the tape width of the insulating tape 17A can be appropriately determined regardless of the tube diameter.

On the other hand, even in a method of winding a sheet-like insulator, the insulating sheet described in the above-mentioned Japanese Patent Application Laid-Open No. 9-134706 or Japanese Patent No. 3022283 is wound in parallel with the tube axis. In the method (conventional example 3), as the tube diameter of the glass bulb 3 becomes thinner, the circumference of the bulb becomes shorter in proportion to the diameter, so that the length of the insulating sheet in the circumference direction becomes inevitably shorter. As a result, when the tube diameter of the glass bulb 3 becomes thin, a narrow insulating sheet having the same width as the circumference of the bulb and the same length as the length of the bulb is wound in parallel with the tube axis. And workability deteriorates. In addition, due to the elastic rebound of the insulating sheet, the adhesion between the glass bulb and the insulating sheet is deteriorated, and the insulating property is reduced. Such a phenomenon becomes more remarkable as the tube diameter of the glass bulb becomes thinner and longer. On the other hand, in the present embodiment, no matter how small the tube diameter of the glass bulb or how long the length, the decrease in workability due to the cause as in the conventional example 3 also causes the deterioration of the insulation property. Nor.

In the rare gas discharge lamp according to the first embodiment, a high-frequency power supply circuit is connected between the pair of outer electrodes 7A and 7B, and a frequency of, for example, 10 k to 10 mm is applied between the two electrodes 7A and 7B.
The lighting is performed by applying a high frequency voltage of 100 kHz, voltage: 1000 to 2000 V _0-P . As the high frequency voltage, a half wave can be used in addition to a general sine wave.
Further, a rectangular wave, a square wave, or a pulse wave may be used. As for the frequency of the voltage, the light quantity of the discharge lamp increases with an increase in the frequency of the applied voltage. In this case, although the optimum frequency of the applied voltage varies depending on the characteristics of the target discharge lamp, the discharge becomes unstable and flickers when the frequency is lower than 10 kHz. Does not increase so much with the increase of the luminous efficiency, and the luminous efficiency tends to decrease. Therefore, the frequency of the applied voltage is 10 to 100 kHz.
A range of about z is desirable.

In the first embodiment, the glass bulb 3 is a cylindrical bulb having a uniform tube diameter and a uniform cross section over its entire length, and has a space inside. The material is lead glass, borosilicate glass, or the like. However, the shape of the glass bulb is not limited to the above example. It may have a cylindrical shape whose thickness changes in the tube axis direction or a shape whose cross-sectional shape changes. The cross section is not necessarily circular, and may be, for example, an elliptical shape.
Various thicknesses are conceivable, and any thickness can be adopted according to required conditions.

As the material of the glass bulb 3, lead glass or borosilicate glass is used, but it is not necessarily limited to these. It is preferable that the glass bulb itself does not generate heat due to the applied high-frequency voltage and that the volume resistivity does not change even if the glass temperature changes, and that the glass bulb is stable.
If the material has a volume resistivity of 1 × 10 ⁹ Ω · cm or more, stable discharge can be obtained even if the tube wall temperature of the glass bulb 3 rises.

A rare gas 5 containing xenon gas as a main component is sealed in the glass bulb 3, but this sealed gas does not contain a vapor of a metal such as mercury. Since the phosphor film 11 is not affected by metal ions such as mercury, deterioration of the film is reduced and the life is significantly prolonged. The total pressure of the rare gas 5 may be set to a predetermined pressure within a range in which discharge occurs. However, if the partial pressure of the xenon gas is too high, the discharge starting voltage increases. Is reduced, the partial pressure of xenon gas is increased to 1.33 × 10 ³
It is desirable that the pressure be in the range of 39.9 × 10 ³ Pa (10-300 Torr). Incidentally, the filling gas is not limited to this embodiment. Any kind of gas may be used as long as it is a gas that generates ultraviolet rays by electric discharge. However, the wavelength 147 generated by the discharge of xenon gas is mainly
Since ultraviolet rays of 172 nm and 172 nm are suitable for exciting many phosphors, it is desirable that the sealing gas 5 contains at least xenon gas.

The phosphor film 11 is made of a material which emits light of multiple wavelengths in response to ultraviolet rays generated by a rare gas, such as a rare earth phosphor or a halophosphate phosphor.

The outer electrodes 7A and 7B are made of an opaque metal material such as copper, silver or aluminum. The metal outer electrode can be formed using a metal foil. In addition, it can be formed by using a sputtering method, or by printing and sintering a conductive paste. In addition to the opaque metal, ITO (Indium TinOx)
A light-transmitting conductive material such as ide) or Nesa may be used for the outer surface electrode. When a translucent conductive material is used, the sheet resistance of the transparent electrodes 7A and 7B is set to 10
It is desirable to be kΩ / □ or less. The resistivity of the translucent conductive material is higher than the resistivity of the metal, and may vary depending on the manufacturing conditions and the like. However, if the sheet resistance of the transparent electrode is less than this value, the overall resistance of the electrodes 7A and 7B is reduced. If the value is high or the resistance is locally high,
By forming a conductive film such as a silver paste or a metal foil in contact with the transparent electrode and making it electrically parallel, the resistance value of the entire outer surface electrode is suppressed to a level that does not hinder stable discharge. Can be.

(Embodiment 2) Next, another method (embodiment 2) for manufacturing the rare gas discharge lamp shown in FIG. 1 will be described.
Referring to FIG. 3 showing a process of manufacturing the rare gas discharge lamp of the second embodiment, the second embodiment differs from the first embodiment in the manner of attaching power supply terminals 19A and 19B for electrical connection to the outside. ing. That is, in this embodiment, first, an arc tube 21B having no power supply terminal as shown in FIG. 3A is manufactured by a conventionally known method. Meanwhile, separately from this, FIG.
(B) As shown in FIG.
An elongated parallelogram-shaped insulating tape 17B provided with A and 19B in advance is prepared. In order to obtain reliable conduction and fixation between the power supply terminals 19A, 19B and the electrodes 7A, 7B on the arc tube side, the portions of the terminals 19A, 19B that are in contact with the electrodes 7A, 7B are made of, for example, a conductive adhesive. It is desirable to apply a suitable substance in advance.

Then, the outer electrode 7A on the side of the arc tube 21B,
7B and the power supply terminals 19A and 19B on the side of the insulating tape 17B, the insulating tape 17B is attached to the glass bulb 3.
And spirally wound on the electrodes 7A and 7B. Thereby, simultaneously with the formation of the insulating coating of the electrodes, the outer electrodes 7A,
Since the attachment of the power supply terminals 19A and 19B to 7B is completed, productivity can be improved.

(Embodiment 3) FIG. 4 shows a side view of a rare gas discharge lamp according to Embodiment 3. Referring to FIG. 4, the rare gas discharge lamp shown in FIG. 4 has a structure in which outer electrodes 7 </ b> C and 7 </ b> D are spirally wound in the tube axis direction of glass bulb 3. Is different. In order to manufacture the rare gas discharge lamp according to the third embodiment, first, a conventionally known method shown in FIG.
An arc tube 21A having a structure in which feed terminals 19A and 19B are provided on spiral outer electrodes 7C and 7D as shown in FIG. On the other hand, separately, an elongated parallelogram-shaped insulating tape 17A as shown in FIG. 5 (b) is prepared, and spirally wound around the arc tube 21A to form the outer electrode 7A.
C, 7D is coated with an insulating material.

As described above, when the outer electrode has such a helical structure, the tube diameter of the glass bulb 3 can be reduced in the first and second embodiments.
2, the minimum tube diameter of a discharge lamp using a band-shaped outer surface electrode, which was limited to about 6 mm, can be reduced to about 3 mm or less. According to the present embodiment, by forming the insulating tape into an elongated parallelogram and spirally wrapping it around the glass bulb 3, it is possible to form an insulating coating with good insulation even on the thinner glass bulb as described above.
It can be easily formed.

In this embodiment, the insulating tape 17A (having no power supply terminal) is wound around the arc tube 21B provided with the power supply terminals 19A and 19B as shown in FIG. As in the second embodiment (see FIG. 3C), only the outer electrodes 7A and 7B are formed on the arc tube 21B, while the power supply terminals 19 are formed on the insulating tape 17B in advance.
A and 19B may be provided, and the insulating tape 17B with the power supply terminal may be spirally wound.

(Embodiment 4) This embodiment is an example showing another method for manufacturing the rare gas discharge lamp having the spiral outer surface electrode shown in FIG. Referring to FIG. 6 showing the manufacturing process of this embodiment,
First, the arc tube 23 is manufactured. The luminous tube 23 has a fluorescent film formed on the inner surface of the glass bulb 3 and is filled with a rare gas containing xenon gas as a main component. The glass bulb 3 has no outer electrode.

On the other hand, apart from the arc tube 23, a translucent insulating tape 1 having an elongated parallelogram shape as shown in FIG.
Prepare 7C. This insulating tape 17C is provided with a viscous / adhesive layer (not shown) on one surface, and two electrodes 25A, 25A on the surface on which the viscous / adhesive layer is formed.
25B are formed in advance. These two electrodes 25
A and 25B are elongated parallelogram-shaped insulating tapes 17C.
Running parallel to the edge of the tape, in the longitudinal direction.

In this embodiment, the above-mentioned electrodes 25A, 25B
Is spirally wound around the arc tube 23. Thus, the formation of the outer electrodes 7A and 7B on the outer wall of the glass bulb 3 and the formation of the insulating coating can be performed at the same time, so that the productivity can be improved.

(Embodiment 5) FIG. 7 shows a side view of a rare gas discharge lamp according to Embodiment 5 and a cross-sectional view taken along line A2-A2. Referring to FIG. 7, the rare gas discharge lamp according to the present embodiment has a structure of outer electrodes 7E and 7F and a power supply terminal 19A,
The method of taking out 19 is different from those of the first to fourth embodiments. In this embodiment, two outer electrodes 7E and 7F
Are ring-shaped each surrounding the glass bulb 3 (however, an opening 13 for taking out light is opened), and are arranged in the tube axis direction at an interval d for insulation. In this manner, the electrodes 7E and 7E are formed in the same manner as in the rare gas discharge lamp having the spiral outer surface electrode according to the third embodiment (see FIG. 4).
Since the distance d between F can be determined regardless of the diameter of the glass bulb 3, the bulb 3 can be made thinner. Further, since the power supply terminals 19A and 19B are taken out one by one from both ends of the glass bulb 3, it is more suitable for a thinner tube than when two power supply terminals are taken out simultaneously in one direction.

Referring to FIG. 8 showing the manufacturing process of this embodiment, in order to manufacture the rare gas discharge lamp shown in FIG. 7, first, the power supply terminals 19 are respectively connected to the ring-shaped outer electrodes 7E and 7F.
A light emitting tube 21A provided with A and 19B (FIG. 8A) is manufactured. In addition, separately from this, as shown in FIG.
An elongated parallelogram insulating tape 17A is prepared. Then, the insulating tape 17A is helically wound around the glass bulb 3 to insulate the outer electrodes 7A and 7B and the exposed portions of the glass bulb 3.

(Embodiment 6) The rare gas discharge lamp having the structure shown in FIG. 7 can be manufactured by another method (Embodiment 6) described below. That is, referring to FIG. 9 showing the manufacturing method of the sixth embodiment, first, as shown in FIG. 9A, the arc tube 2 having only the outer electrodes 7E and 7F (having no power supply terminals).
Fabricate 1B. Separately, as shown in FIG. 9B, an insulating tape 17B having feed terminals 19A and 19B on both short sides of an elongated parallelogram-shaped translucent insulating tape is prepared. Then, the insulating tape 17B with the power supply terminal is spirally wound around the arc tube 21B on which the outer surface electrode is formed. This allows the power supply terminals 19A and 19B to be attached to the outer electrodes 7E and 7F simultaneously with the formation of the insulating coating.

In the above embodiments, an example was described in which a tape made of polyethylene terephthalate was used as the insulating tape, but the tape material is not limited to this.
Any material can be used as long as it has good translucency, high insulating properties, and heat resistance. As for the shape, for example, as shown in FIG. 2 (b), a parallelogram-shaped insulating tape in which short sides at both ends are cut obliquely in advance with respect to the longitudinal direction was used, but the shape of the insulating tape is not always required. Not limited to this. Using a rectangular strip tape (both ends are not cut diagonally), the insulating tape protruding from both ends of the glass bulb 3 at the beginning or end of winding of the arc tube is cut off later. It may be.

Further, in the above embodiments, an example is described in which the adhesive tape has an adhesive / adhesive layer formed on one surface thereof. However, since the insulating tape is wound spirally while being stacked, When flexibility is sufficient, a tacky / adhesive is not particularly required. However, in consideration of the ease of tape winding work, long-term reliability after winding, and the like, it is preferable to provide a tacky / adhesive.

In each of the embodiments, the phosphor film 11 is formed over the entire inner surface of the glass bulb. However, as in the conventional rare gas discharge lamp shown in FIG. Opening 13 on the light extraction side of 11
The portion corresponding to A may be peeled off in parallel with the tube axis to form a so-called aperture. Further, a light reflection layer may be provided between the glass bulb and the phosphor layer. As is clear from the above description, the present invention shows the same operation and effect regardless of the internal structure of the glass bulb.

[0050]

As described above, according to the present invention,
On the outer surface of the cylindrical glass bulb, an outer electrode for causing a dielectric barrier discharge in the gas inside the bulb via the glass bulb is provided, and the outer electrode and the exposed surface of the glass bulb are transparent insulating coatings. In the rare gas discharge lamp having the structure described above, it is possible to easily manufacture a rare gas discharge lamp having a good withstand voltage between outer electrodes even when the tube diameter of the glass bulb is small.

[Brief description of the drawings]

FIG. 1 is a side view and a sectional view of a rare gas discharge lamp according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a method of manufacturing the rare gas discharge lamp according to the first embodiment.

FIG. 3 is a diagram illustrating a method for manufacturing a rare gas discharge lamp according to a second embodiment.

FIG. 4 is a side view of a rare gas discharge lamp according to a third embodiment.

FIG. 5 is a diagram illustrating a method for manufacturing a rare gas discharge lamp according to a third embodiment.

FIG. 6 is a diagram illustrating a method for manufacturing a rare gas discharge lamp according to a fourth embodiment.

FIG. 7 is a diagram illustrating a side view of a rare gas discharge lamp according to a fifth embodiment.

FIG. 8 is a diagram illustrating a method for manufacturing a rare gas discharge lamp according to a fifth embodiment.

FIG. 9 is a view illustrating a method for manufacturing a rare gas discharge lamp according to Embodiment 6.

FIG. 10 is a side view of an example of a rare gas discharge lamp of an external electrode type according to a conventional technique, and a cross-sectional view taken along a plane perpendicular to a tube axis.

FIG. 11 is a view showing a method of manufacturing an example of a conventional external electrode type rare gas discharge lamp.

[Explanation of symbols]

 Reference Signs List 1 rare gas discharge lamp 3 glass bulb 5 rare gas 7A, 7B electrode 11 phosphor film 13 opening 13A, 13B opening 15 insulating coating 17, 17A, 17B, 17C insulating tape 19A, 19B power supply terminal 21A, 21B arc tube 23 light emission Tube 25A, 25B Electrode 27 Insulating sheet

Claims (11)

[Claims] 1. A rare gas discharge lamp having a structure in which at least two or more external electrodes for generating a dielectric barrier discharge are provided on an external surface of a cylindrical glass bulb filled with a gas containing a rare gas. A rare gas discharge lamp, wherein an exposed portion of an electrode and a glass bulb is covered with a helical, translucent, electrically insulating insulating tape centered on a tube axis. 2. The rare gas discharge lamp according to claim 1, wherein the insulating tape is adhered to the outer electrode and the glass bulb. 3. A cylindrical glass bulb; a phosphor film formed on an inner wall of the glass bulb; a sealed gas containing a rare gas sealed in a space inside the glass bulb; A transparent electrode covering at least two or more external electrodes provided on the outer surface of the glass bulb for causing a dielectric barrier discharge in the sealed gas through the glass bulb, and at least a glass bulb exposed portion between the external electrodes and the external electrode. An optical and electrically insulating insulating tape, an insulating tape spirally wound around a glass bulb around a tube axis, between the outer electrode and the glass bulb and the insulating tape. A rare gas discharge lamp including an insulating layer interposed therebetween and an adhesive layer for bonding the outer electrode and the glass bulb. 4. The external electrode is connected to the glass bulb.
The rare gas discharge lamp according to any one of claims 1 to 3, wherein the rare gas discharge lamp has a structure wound spirally around a tube axis as a center of winding. 5. The power supply terminal according to claim 1, wherein the insulating tape is provided with a power supply terminal for electrically connecting the rare gas discharge lamp to the external electrode for supplying electric power from outside. The rare gas discharge lamp according to any one of the above. 6. A process in which at least a phosphor film is formed on an inner wall of a cylindrical glass bulb, and a sealed gas containing a rare gas is sealed in an inner space; and an outer surface of the glass bulb is formed through the glass bulb. A step of forming at least two or more outer electrodes for causing a dielectric barrier discharge in the sealing gas; and winding a tube shaft around a glass bulb containing the outer electrodes with a translucent and electrically insulating insulating tape. And a process of spirally winding around the center of the noble gas discharge lamp. 7. A process of forming at least a phosphor film on an inner wall of a cylindrical glass bulb and enclosing a gas containing a rare gas in an inner space, and one surface of a translucent and electrically insulating insulating tape. A step of previously forming at least two or more conductor layers that run parallel to the longitudinal direction; and winding the insulating tape having the conductor layer around the glass bulb in a spiral around a tube axis. Mounting the rare gas discharge lamp. 8. An insulating tape having a structure in which a power supply terminal for receiving power supply from the outside is provided in advance at least at one of a winding start and a winding end of the insulating tape. A method for manufacturing a rare gas discharge lamp according to claim 7. 9. An insulating tape having a structure in which an adhesive layer is previously formed on one surface of the insulating tape, and the surface on which the adhesive layer is formed is wound around the outer electrode and the glass bulb. The method for manufacturing a rare gas discharge lamp according to any one of claims 6 to 8, wherein: 10. The rare gas discharge lamp according to claim 1, wherein a minimum width of the insulating tape is 3 mm, and a minimum width of the insulating tape is 3 mm.
The method for manufacturing a rare gas discharge lamp according to claim 6, wherein the insulating tape is used. 11. The insulating tape is 1 mm or more and 4 mm
The rare gas discharge lamp or the insulating tape according to any one of claims 1 to 5, and the insulating tape is wound with an overlap of 1 mm or more and 4 mm or less. The method for manufacturing a rare gas discharge lamp according to any one of claims 6 to 9 and 10, wherein: