JPH0684506A - External electrode discharge lamp and manufacture thereof - Google Patents

Abstract

PURPOSE:To easily form an external electrode on a bulb and enhance an insulation property. CONSTITUTION:In an external electrode discharge lamp wherein a luminous substance is enclosed in a transparent bulb 1, an external electrode 4 is equipped on an outer surface of the bulb 1 and high frequency power is supplied to this external electrode 4 to generate electric discharge in the bulb 1, a transparent insulation resin tube 3 is fitted to the outer surface of the bulb 1 while the external electrode 4 is fixed to the outer surface or inner surface of the resin tube 3. Since the external electrode 4 is fixed to the outer surface of the bulb 1 via the insulation resin tube 3, fitting of the external electrode is easy and an insulation property is secured. Since the resin tube 3 is tightly fitted to the bulb 1 by means of heat shrinkage, peeling-off and falling-off can not be generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external electrode discharge lamp in which an external electrode is provided on the outer surface of a bulb, and high frequency power is supplied to the external electrode to generate a discharge in the bulb to emit light. The manufacturing method is related.

[0002]

2. Description of the Related Art A general fluorescent lamp is constructed by sealing electrodes on both ends of a glass bulb, forming a fluorescent film on the inner surface of the bulb, and enclosing mercury and a rare gas in the bulb. The above electrodes are made of refractory metal,
It is provided so as to project inside the valve.

However, this type of internal electrode fluorescent lamp requires a special electrode in the bulb and a special sealing structure, which increases the number of parts and requires labor to manufacture. Manufacturing cost is high. Moreover, there are many points that influence the lamp life due to the internal electrodes, and there is a problem that the life characteristics are deteriorated.

From the above, for example, JP-A-60-
In Japanese Patent No. 12660, mercury and a rare gas are enclosed inside a glass bulb having a phosphor coating formed on the inner surface, and a pair of outer electrodes are provided on the outer surface of the bulb along the axial direction. An external electrode fluorescent lamp has been proposed in which high-frequency electric power is supplied to the lamp to generate high-frequency discharge in the bulb, and the mercury is ionized and excited to emit light. Since such an external electrode fluorescent lamp does not require an internal electrode, it is possible to solve the above-mentioned various problems caused by providing the internal electrode, and in particular, it is an effective lamp in that the life characteristics are improved. Is.

[0005]

However, since the conventional external electrode fluorescent lamp is constructed by attaching a pair of electrodes directly to the outer surface of the bulb, the resistance of the glass surface is reduced when moisture adheres to the glass surface. There is a problem in that the electrodes fall down and the insulation is broken down, resulting in electrical continuity between the electrodes.

In the conventional external electrode fluorescent lamp, a pair of external electrodes are formed by directly applying silver paste on the outer surface of the bulb. Such external electrodes are formed by applying silver paste in a predetermined width. Since coating must be done in the axial direction, it takes time and effort for coating, and since a step of heating and fixing after this coating is required, a special heating step and a high-temperature heating furnace are required. The equipment cost becomes high, resulting in high cost.

A means for sticking an aluminum foil instead of the silver paste is also conceivable. However, such a sticking structure has a drawback that the adhesive is easily deteriorated by heat and humidity, and thus the aluminum foil is easily peeled off. There is. The formation of such external electrodes often fails, and such defective products cause the entire lamp to be discarded.

The present invention has been made in view of the above circumstances. An object of the present invention is to allow an external electrode to be easily formed outside the bulb, to improve the insulation property, and to prevent manufacturing problems. An object of the present invention is to provide an external electrode discharge lamp that can be reused even if a non-defective product is generated and is less wasteful, and a manufacturing method thereof.

[0009]

In the external electrode discharge lamp of the present invention, a luminescent substance is enclosed in a translucent bulb, an external electrode is provided outside the bulb, and high frequency power is supplied to the external electrode. In an external electrode discharge lamp adapted to generate a discharge in a bulb, a transparent insulating resin tube is attached to an outer surface of the bulb, and an outer electrode is attached to an outer surface or an inner surface of the resin tube. To do.

Further, according to the manufacturing method of the present invention, a light-emitting substance is enclosed in a light-transmitting bulb, and an external electrode is provided on the inner or outer surface of a light-transmitting insulating resin tube into which the bulb can be inserted. The valve is inserted into the tube, and the resin tube is heated to reduce the diameter of the resin tube and adhere it to the outer surface of the valve, whereby the external electrode is attached to the valve.

[0011]

According to the external electrode discharge lamp of the present invention, since the external electrode is attached to the outer surface of the bulb through the insulating resin tube, the external electrode can be easily attached and the external electrode can be mounted on the outer surface of the insulating resin tube. When the external electrode is attached to the inner surface of the insulating resin tube, the surface resistance of the insulating resin tube does not drop as much as the surface resistance of glass even if moisture adheres to the inner surface of the insulating resin tube. Is
It is possible to prevent water from adhering to the periphery of the electrode,
Further, it is possible to ensure insulation without directly touching it from the outside.

Further, if the external electrode becomes defective in the manufacturing process, the insulating resin tube may be peeled off and discarded together with the external electrode. In this case, it is not necessary to discard the valve, and there is little waste.

Further, according to the manufacturing method of the present invention, the external electrode is formed on the outer surface or the inner surface of the resin tube in advance, and the resin tube is attached to the valve by heat shrinking. Becomes easier,
There is no risk of peeling or falling off.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the first embodiment shown in FIGS. In the figure, reference numeral 1 denotes a straight tube type glass bulb, in which a phosphor coating 2 is formed in advance, and a predetermined amount of mercury and a rare gas such as argon are sealed inside. . Both ends of such a valve 1 are hermetically closed.

A transparent insulating resin tube 3 is adhered to the outer surface of the valve 1. This resin tube 3
Is made of polyethylene or a heat-shrinkable tube mainly made of polyethylene, and has a pair of external electrodes 4 and 4 attached to its outer surface. The external electrodes 4 and 4 are made of, for example, a vapor-deposited film of aluminum, and are formed on the outer surface of the resin tube 3 so as to be separated from each other in the circumferential direction and extend in the axial direction to form a strip shape.

The external electrodes 4 and 4 are connected to a high frequency lighting circuit 5, and high frequency power of, for example, 4 kV and 30 kHz is supplied from the high frequency lighting circuit 5.

A method of manufacturing the above external electrode fluorescent lamp will be described with reference to FIG. That is, the bulb 1 is made of, for example, a soft glass tube having an outer diameter of 10 mm and a length of 150 mm, a phosphor coating 2 made of a calcium halophosphate phosphor or the like is formed on the inner surface, and mercury and argon are internally formed. A noble gas like the above is enclosed and both ends are sealed.

On the other hand, the resin tube 3 is made of polyethylene having an outer diameter of, for example, 120%, that is, 12 mm larger than the outer diameter of the valve 1, and a pair of outer electrodes 4 and 4 are attached to the outer surface thereof. The pair of external electrodes 4 and 4 are formed in advance on the resin tube 3 by aluminum vapor deposition, and have a width of 5 m.
It has a band shape of m and a film thickness of 50 μm.

The above-mentioned valve 1 is attached to the resin tube 3 having such a constitution, and this is heated at 100 ° C. for 1 minute, for example.
Then, the resin tube 3 is thermally contracted, so that the resin tube 3 comes into close contact with the outer surface of the valve 1. As a result, the external electrodes 4 and 4 are also attached to the outer surface of the valve 1 via the resin tube 3.

The external electrode fluorescent lamp having the above-mentioned structure is provided with a high-frequency lighting circuit 5 and 4 k from the external electrodes 4 and 4.
When a high frequency electric power of V and 30 kHz is supplied, a discharge due to a high frequency electric field is generated in the bulb 1. This discharge ionizes and excites mercury atoms to emit ultraviolet rays, and the ultraviolet rays are converted into visible light by the phosphor coating 2. Thus, this visible light is emitted to the outside through the bulb 1.

In the case of such a lamp, even after 3000 hours of lighting, the resin tube 3 is not peeled or wrinkled, the external electrodes 4 and 4 are not dropped or the film is not broken, and the dielectric breakdown is not caused. I was not able to admit. Therefore, it was confirmed that the life characteristics were significantly improved.

In the case of the external electrode fluorescent lamp as described above, since no special internal electrode is required in the bulb 1, parts for the internal electrode and sealing work can be omitted, and the number of parts and work man-hours are greatly increased. Therefore, it is possible to reduce the cost, reduce the cost, and prevent the life characteristics due to the internal electrodes, for example, the blackening of the bulb. Since the pair of electrodes 4 and 4 provided outside the bulb 1 are provided on the outer surface of the resin tube 3, good insulation is maintained.

That is, when the external electrode is directly provided on the outer surface of the bulb as in the prior art, there is a concern that moisture adheres to lower the surface electric resistance of the glass and cause electrical conduction. Even if moisture adheres, the resistance does not drop as much as the surface electric resistance of the glass, so that the insulation between the pair of electrodes 4 can be secured.

In such a fluorescent lamp, the external electrodes 4 and 4 are formed on the resin tube 3 in advance, and the resin tube 3 is brought into close contact with the outer surface of the bulb 1 by thermal contraction, whereby the outer surface of the bulb 1 is made. Since the external electrodes 4 and 4 can be fixed to the bulb 1, the work of forming the external electrodes 4 and 4 on the bulb 1 is extremely easy. Further, the external electrodes 4 and 4 can be formed on the resin tube 3 by vapor deposition means, and the width and thickness of the electrode film can be formed with high accuracy, which is particularly effective in preventing peeling.

Further, when the external electrodes 4, 4 are formed on the outer surface of the resin tube 3, or the resin tube 3 is formed.
When the electrodes 4 and 4 and the resin tube 3 are wrinkled or broken when they are adhered to the valve 1, the resin tube 3 is peeled from the valve 1 and the electrode 4 is removed. 4 and the resin tube 3 may be discarded, and in this case, the valve 1 can be reused, which reduces waste.

In the above embodiment, the case of the external electrode type fluorescent lamp has been described, but the present invention is not limited to this, and may be applied to an external electrode type variable color fluorescent lamp. That is, the lamp structure of the external electrode type variable color fluorescent lamp is
The description of the structure is omitted because it may be similar to the case shown in FIGS. 1 and 2, but the difference from the case of FIG. 1 is that the bulb 1 is filled with mercury and neon Ne gas, and the sine to be applied is By changing the high frequency of the wave, it is possible to mainly use neon light emission and mercury light emission.
That is, for example, when high frequency power of a sinusoidal wave of about 40 kHz is supplied from the high frequency lighting circuit 5 to the external electrodes 4 and 4, creeping discharge of negative glow occurs, and in this case, mainly neon emits reddish emission. Present. In addition, the external electrode 4,
When a high frequency power of about 13.6 MHz is supplied to No. 4, arc discharge occurs, and mercury is mainly emitted by the positive column, and in this case, a bluish light is emitted.
Therefore, in the case of such a lamp, different emission colors can be selectively changed with one lamp. Also in such a lamp, if the structure of the external electrodes as shown in FIGS. 1 to 3 is adopted, the same operational effect as that of the first embodiment can be obtained.

In this case, the luminescent substance to be sealed is not limited to neon and mercury, and any combination of these substances is acceptable as long as the substance emits light by negative glow and the substance emits light by the positive column.

Further, the present invention may be a second embodiment as shown in FIGS. 4 and 5. The second embodiment is a case of a pulse lighting type rare gas discharge lamp in which a rare gas of several tens to several hundreds Torr, for example, xenon gas is enclosed in the bulb 1, and this lamp has a high frequency DC pulse lighting circuit. From 20, a high frequency DC pulse of, for example, 4 kV and 30 kHz is applied. The external electrode is attached to the valve by the same structure as that shown in FIGS. 1 to 3, but in the case of this embodiment, one of the pair of external electrodes is the negative electrode 4a,
The other becomes the anode 4b. In the case of this embodiment, a positively charged metal oxide 25 such as alumina Al ₂ O ₃ or Agnesia MgO is attached to the inner surface of the bulb 1 facing the negative electrode 4a.

In the case of such a pulse lighting type rare gas discharge lamp, the brightness becomes 1.4 times higher than that of the sinusoidal high frequency lighting type shown in FIG. 1 even if the applied voltage and frequency are the same. There are advantages. This is because when the xenon rare gas discharge lamp is lit by a high frequency DC pulse, the positive column in the bulb 1 diffuses, and the proportion of ultraviolet rays emitted in the positive column absorbed by the positive column decreases. It is considered that this increased amount of ultraviolet light reaches the phosphor, and the visible light increases. However, in this case, the diffusion of the positive column is small on the negative electrode 4a side, and such a contracted portion tends to shake each time a pulse is applied. As a result, there is a phenomenon that flicker occurs on the negative electrode 4a side.

Therefore, as shown in FIG. 5, if the positively charged metal oxide 25 is provided in the bulb 1 facing the negative electrode 4a, the ions of the plasma generated by the discharge and the positive ions are positively charged. Since the charged metal oxides 25 repel each other and suppress the surface bonding, the negative electrode 4a
On the side, the contraction of the positive column is prevented. Therefore, the shaking of the contracted portion is eliminated, and as a result, the flicker on the negative electrode 4a side can be prevented. Even in such a lamp, if the structure of the external electrodes as shown in FIGS. 1 to 3 is adopted, the insulating property is improved and waste in the manufacture of the lamp can be eliminated.

In each of the above embodiments, the case where the external electrodes 4 and 4 are formed on the outer surface of the resin tube 3 has been described, but the present invention is not limited to this, and the external electrodes 4 and 4 are formed on the resin tube 3. It may be formed on the inner surface. That is, in the case of the embodiment shown in FIGS. 6 and 7, the external electrodes 40, 40 are formed on the inner surface of the resin tube 3 in advance, and the resin tube 3 is put on a valve (not shown here) and the resin When the tube 3 is heated and contracted, the pair of external electrodes 40, 40 comes into contact with the outer surface of the bulb, and the outer side thereof is covered with the resin tube 3. In order to form the external electrodes 40, 40 on the inner surface of the resin tube 3, as shown in FIG. 7, the external electrodes 40, 40 are formed on one surface of the resin sheet 30 so as to be spaced apart from each other by a method such as vapor deposition. The resin sheet 30 may be rolled into a tube.

In the case of such a structure, since moisture does not adhere to the outer surface of the valve and the inner surface of the resin tube 3 and the insulation resistance does not decrease, the insulation failure of the external electrodes 40 does not occur. Further, since the external electrodes 40, 40 are covered with the resin tube 3, the external electrodes 4, 40 are not touched by a conductor or human hands, and the safety is improved.

Furthermore, in each of the above-described embodiments, the case where two external electrodes are formed is explained, but it is possible to implement even when one electrode is an internal electrode and the other electrode is an external electrode. Therefore, the external electrodes are not restricted to the case of a pair.

As an example in which the external electrodes are not a pair, a spiral electrode as shown in FIG. 8 can be considered. That is, in this type of lamp, a spiral (coil-shaped) electrode 60 is provided on the outer surface of the bulb 50, and when high-frequency power is applied to the spiral electrode 60, a high-frequency magnetic field is generated in the bulb 50. Plasma discharge occurs in the bulb, and the enclosed substance discharges and emits light. In such a case, the spiral electrode 60 is formed on the resin tube 70 by a method such as a vapor deposition method, and when the resin tube 70 is covered with the valve 50 and heat-shrinked, the resin tube 70 adheres to the valve 50, A spiral electrode 60 can be formed on the bulb 50.

In such a lamp as well, the spiral electrode 60 can be easily formed on the outer surface of the bulb 50 by the above-mentioned means, and the decrease in the electric resistance of the resin is small even if moisture adheres. It is possible to maintain good insulation.

In a lamp using such a spiral electrode 60, if high frequency power is supplied to this electrode, the air around the bulb 50 may cause corona discharge, but on the inner surface of the resin tube 70. When the spiral electrode 60 is formed, since the spiral electrode 60 is covered with the resin tube 70, corona discharge can be prevented, and also from this point of view, the insulating property is improved. Further, the present invention is not limited to the straight tube type discharge lamp, and can be applied to a bulb having a flat cross section and a bent type discharge lamp such as a ring shape and a U shape. The external electrodes 4, 4a, 4b are not limited to the aluminum vapor deposition film, and may be a vapor deposition film of copper or the like, or a coating film.

[0037]

As described above, according to the external electrode discharge lamp of the present invention, since the external electrode is attached to the outer surface of the bulb through the insulating resin tube, the external electrode can be easily attached and the external electrode can be easily attached. When the electrode is attached to the outer surface of the insulating resin tube, the surface resistance of the insulating resin tube does not drop as much as the surface resistance of glass even if moisture adheres, so the insulation is maintained, and the external electrode has an insulating resin tube. If it is attached to the inner surface of the electrode, it prevents moisture from adhering to the periphery of the electrode and does not come into direct contact with the outside.
Good insulation can be ensured.

Further, if the external electrode becomes defective in the manufacturing process, the insulating resin tube may be peeled off and discarded together with the external electrode. In this case, it is not necessary to discard the valve, and there is little waste.

Further, according to the manufacturing method of the present invention, the external electrode is formed on the outer surface or the inner surface of the resin tube in advance, and the resin tube is attached to the valve by thermal contraction. Becomes easier,
It is possible to prevent peeling, falling off, and wrinkles.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a straight tube type external electrode fluorescent lamp showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG. 1 in the embodiment.

FIG. 3 shows a method for manufacturing a straight tube external electrode fluorescent lamp in the same embodiment, (A) is a perspective view before assembly,
(B) is a perspective view after assembly.

FIG. 4 is a sectional view showing a pulse lighting type straight tube type external electrode rare gas discharge lamp showing a second embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along line VV of FIG. 4 in the example.

FIG. 6 is a configuration diagram of a resin tube and external electrodes showing a third embodiment of the present invention.

FIG. 7 is a diagram showing a method of forming the resin tube of the same example.

FIG. 8 is an exploded perspective view showing a fourth embodiment of the present invention in which a spiral electrode is formed on a bulb.

[Explanation of symbols]

1 ... Bulb 2 ... Fluorescent film 3 ... Resin tube 4, 4a, 4b ...
Electrode 5 ... High frequency lighting circuit 20 ... High frequency pulse lighting circuit 25 ... Metal oxide 40 ... External electrode 60 ... Helical electrode

Claims (4)

[Claims] 1. An external electrode discharge device in which a luminescent substance is enclosed in a translucent bulb, an external electrode is provided outside the bulb, and high-frequency power is supplied to the external electrode to generate a discharge in the bulb. In an electric lamp, a translucent insulating resin tube is attached to the outer surface of the bulb,
An external electrode discharge lamp characterized in that an external electrode is attached to the outer surface or the inner surface of this resin tube. 2. The external electrode discharge lamp according to claim 1, wherein the external electrode comprises a pair of electrodes spaced apart from each other. 3. The external electrode discharge lamp according to claim 1, wherein the external electrode is formed of a vapor deposition film of aluminum or copper. 4. A light-transmissive bulb is filled with a luminescent substance, and an external electrode is provided on the inner or outer surface of a translucent insulating resin tube into which the bulb can be inserted, and the bulb is inserted into the resin tube. A method for manufacturing an external electrode discharge lamp, characterized in that the resin tube is reduced in diameter by heating the resin tube and attached to the outer surface of the bulb, whereby the external electrode is attached to the bulb.