JPH0917375A - Electrode, high pressure discharge lamp, lighting device and lighting system - Google Patents

Abstract

PURPOSE: To increase and equalize an applying quantity of emitters, and lengthen the service life of a lamp by arranging coil intervals larger than an average particle diameter of the emitters in a part of outside coils densely wound on the outside of inside coils. CONSTITUTION: In respective electrodes 13 and 14, electrode coils 18 are respectively wound and installed, for example, by inside outside two-layer turns on the outer periphery of electrode shafts 15a and 15b. The electrode coils 18 have inside coils 19 and outside coils 20. The respective inside coils 19 are formed so as to respectively possess emitters 21 between these respective coil pitches 19a. The respective outside coils 20 are brought into close contact with outer peripheral surfaces of the respective inside coils 19, and are densely wound in its shaft direction, and its part is also roughly wound, and coil intervals 22 of intervals 1 larger than an average particle diameter of the emitters 21 are formed. Therefore, the emitters 21 can be easily and reliably applied and possessed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure discharge lamp such as a metal halide lamp, its electrode, a lighting device and a lighting device.

[0002]

2. Description of the Related Art Conventionally, as an electrode of this type of metal halide lamp, an outer peripheral surface of an electrode shaft made of tungsten or the like is used.
It is known that an electrode wire made of tungsten or the like is closely wound in a coil shape in a single layer, and the outer surface of the electrode coil is filled with an emitter (electron emitting substance).

Therefore, the emitter is attached to the outer surface of the electrode coil and the gap between the coils. However, since the emitter attached to the outer surface of the electrode coil is easily removed and the electrode coil is closely wound, the gap between the coils into which the emitter enters is not necessarily formed quantitatively. There are variations in numbers and intervals. For this reason, there are problems that the coating amount of the emitter is not large and there are variations, and thus the lamp life is not long and the life characteristics also vary.

[0004] Therefore, from the conventional practice
The electrode described in Japanese Patent No. 1 has been proposed. As shown in FIG. 5, the electrode 1 has an electrode coil 3 wound around the electrode core body 2 and has a large diameter portion 3a and a small diameter portion 3b. A part of the coil pitch of the large-diameter portion 3a is roughly wound, and the emitter 4 is held inside the coil of the large-diameter portion 3a.

[0005]

However, in such a conventional electrode 1, since the electrode coil 3 is a single layer of tight winding, the outer peripheral surface of the electrode core body 2 and the small diameter portion 3b of the electrode coil 3 are formed. It is in close contact with the peripheral surface, and the emitter 4 is placed between both surfaces.
Cannot intervene. Therefore, the coating amount of the emitter 4 is reduced accordingly, and the lamp life cannot be extended.

Further, although the above publication describes that the emitter 4 is held in the large diameter portion 3a, it is described that the gap between the coarsely wound portions 3c of the large diameter portion 3a is made larger than the average particle diameter of the emitter 4. Since there is not, from the gap of the rough winding portion 3c,
It is not clear whether the emitter 4 can be inserted inside.

In view of the above, the present invention can increase the coating amount of the emitter and make it uniform, and therefore can extend the life of the lamp and make it uniform. And to provide a lighting device.

[0008]

According to a first aspect of the present invention, an electrode shaft is energized; a plurality of layers are wound around the outer periphery of the electrode shaft, and the inner coil is roughly wound while the outer coil is wound. An electrode coil which is closely wound and has a coil interval larger than the average grain size of the emitter in at least a part thereof.

Here, the coarse winding of the inner coil means that the coils are wound in the gap between the adjacent coils at a coil pitch such that the emitter can be interposed, and the tight winding means the average grain size of the emitter. A case where a coil pitch smaller than the diameter is wound. The electrode shaft is the core of the electrode coil to be energized, and the emitter is the electron emitting material.

The invention of claim 2 is the invention of claim 1, further, in the electrode, the electrode coil is a two-layer winding having inner and outer layers.

A third aspect of the present invention is the invention according to the first or second aspect, further, in the electrode, the inner coil has an outer end of the emitter interposed at a coil interval of at least one end thereof closed by an electrode coil. There is.

The invention of claim 4 is the invention of any one of claims 1 to 3, further, in the electrode, the wire diameter of the electrode coil is 0.04 to 0.06 mm.

A fifth aspect of the present invention is the invention according to any one of the first to fourth aspects, further, in the electrode, the outer coil has a coil interval of 0.05 ± 0.01 mm.

A sixth aspect of the present invention is the invention according to any one of the first to fifth aspects, further, in the electrode, the emitter is Sc ₂ O ₃ , Ca ₂ O ₃ , or at least one of these. It is a mixture containing.

The invention according to claim 7 is the invention according to any one of claims 1 to 6, further comprising: an electrode; an airtight container in which the two electrodes are opposed to each other; And a discharge medium to be enclosed.

The invention of claim 8 is the invention of claim 7, further comprising: a high-pressure discharge lamp; a lighting circuit for supplying electric power to the high-pressure discharge lamp to illuminate it stably.

The invention of claim 9 is the invention of claim 7, further comprising: a high-pressure discharge lamp; and an instrument main body for housing the high-pressure discharge lamp.

[0018]

According to each of the first to sixth aspects of the present invention, the inlet of the emitter is formed by providing a coil interval larger than the average grain size of the emitter in a part of the outer coil closely wound outside the inner coil. Therefore, by simply applying the emitter to the outer surface of the outer coil, the emitter is inserted inward from the inlet of the large coil gap of the outer coil and introduced into each coil gap of the inner coil inside. And can intervene.

As a result, the emitter can be easily and reliably interposed between the coils of the inner coil.

Further, since the inner coil wound around the outer circumference of the electrode shaft is roughly wound, the emitter can be interposed in each gap between these coils. For this reason, the coating amount of the emitter can be quantitatively increased, and the coating amount can be equalized. Therefore, it is possible to prolong and even out the lamp life.

According to the third aspect of the present invention, since at least the outer end of the inner coil with the emitter interposed is closed by the electrode coil, the emitter falls off from the outer end of the electrode coil, which reduces the lamp life, which shortens the lamp life. Can be effectively prevented.

A high pressure discharge lamp according to claim 7,
Since the lighting device described above and the lighting device according to claim 9 include the electrode according to any one of claims 1 to 6, they have the same operation and effect as the electrode.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 4, the same or corresponding parts are designated by the same reference numerals.

FIG. 2 is a partial longitudinal sectional view of the first embodiment in which the present invention is applied to a metal halide lamp which is a kind of high pressure discharge lamp. In this figure, the metal halide lamp 11 is made of, for example, a straight tubular quartz glass tube. The bulb 12 is filled with an appropriate amount of mercury, a rare gas such as argon (Ar), xenon (Xe), krypton (Kr), and neon (Ne), and a metal halide that is a light emitting metal. Examples of the metal halide include Tl-Na-I
n, Sc-Na-Th, Dy-Tl and the like.

In the bulb 12, a pair of electrodes 13,
14 is airtightly incorporated. The electrodes 13 and 14 are connected to the molybdenum foils 16a and 16 via the electrode shafts 15a and 15b.
b and the outer lead wires 17a and 17b are sequentially connected, and power is supplied through the pair of outer lead wires 17a and 17b.

The electrode shafts 15a, 15b and parts of the outer lead wires 17a, 17b and the molybdenum foil 1
6a and 16b as a whole are a pair of sealing ends 12 of the valve 12.
It is airtightly embedded in a and 12b. These sealing end portions 12a and 12b are hermetically sealed by pinching the both axial ends of the bulb 12 in the diametrical direction, and the molybdenum foils 16a and 16b have a coefficient of thermal expansion similar to that of glass. End portions 12a, 12b due to thermal expansion of
We are trying to prevent cracking. The bulb 12 may be made of translucent ceramics.

As shown in FIG. 1, each of the electrodes 13 and 14 is made of a straight rod made of tungsten or thoriated tungsten (doped tungsten) and has a shaft diameter of, for example, 0.07 ± 0.01 mm. Similarly, an electrode coil 18 made of tungsten or the like is wound around the outer periphery of the coil in a two-layer winding, for example.

The electrode coil 18 is, for example, 0.04 to 0.0.
It has an inner coil 19 having a wire diameter of 6 mm and closely wound around the outer peripheral surfaces of the electrode shafts 15a and 15b, and further has an outer coil 20 wound around the outer peripheral surface of the inner coil 19.

Each inner coil 19 has a respective electrode shaft 15a, 15
It is closely attached to the outer peripheral surface of b and its axial direction is, for example, 0.05
The coil 21 is roughly wound with a coil pitch of ± 0.01 mm, and an emitter 21 is held between the coil pitches 19a. Of these coil pitch intervals 19a, those located at both ends in the axial direction have their outer end sides closed by the electrode coils 18, and prevent the emitter 21 from falling out of the outer end coil pitch intervals 19a. It is like this. The emitter 21 is made of scandium oxide Sc ₂ O ₃ or calcium oxide Ca ₂ O ₃ , or a mixture containing at least one of these.

Each outer coil 20 is closely attached to the outer peripheral surface of each inner coil 19 and is wound tightly in the axial direction thereof. μm average particle size (maximum particle size:
Spacing l larger than 03 mm) (eg 0.05 ± 0.0
The coil spacing 22 is 1 mm).

Therefore, by simply coating the outer peripheral surface of the outer coil 20 with the emitter 21,
Since 1 can be introduced from each coil interval 22 into each coil interval 19a of the inner coil 19 to be interposed, the emitter 21 can be applied and retained easily and reliably.

Moreover, the emitters 21 are quantitatively interposed between the coils 19a of the inner coil 19 which are wound at a predetermined coarse winding pitch, and the emitter 21 is also provided at the coil spacing 22 of the outer coil 20. Since the holding amount can be increased, the holding amount of the emitter 21 can be increased and the holding amount can be equalized.

Therefore, it is possible to prolong the life of the lamp and reduce the variation of the longevity to make it uniform.

Further, among the coil pitch intervals 19a of the inner coil 19, those located at both ends in the axial direction have their outer end sides closed by the electrode coils 18, so that the coil pitch intervals 19a on the outer end side. It is possible to prevent the emitter 21 from falling off and shortening the life.

FIG. 3 is a front view of an example of a double-tube type metal halide lamp 31 according to the second embodiment of the present invention. This rutal halide lamp 31 uses the metal halide lamp 11 shown in FIG. It is housed in a translucent outer tube 32 made of glass or the like. That is, the double-tube high-pressure sodium lamp 31 is the outer tube 3 made of hard glass.
A bulging portion is formed at the center of 2, and a small diameter top portion 32a and a neck portion 32b are integrally connected to the upper and lower portions thereof to form a so-called BT shape. There is a cap 3 at the end of the neck 32b.
3 is attached to hold the inside of the outer tube 32 in vacuum.

The arc tube 11 housed in the outer tube 22 has its upper and lower sealing end portions 12a and 12b held by a pair of upper and lower holders 34a and 34b, and these holders 34a and 34b are inside the outer tube 32. , Supported by the support wire 35. The support wire 35 is formed of a conductive wire such as stainless steel in the shape of a square frame. The upper part is locked in the top part 32a of the outer tube 32 via the elastic piece 35a, and the lower part is a stem. Three
6 is welded to one sealing line 37a.

One outer lead wire 17a led out from the upper end of the arc tube 11 in FIG. 3 is electrically and mechanically connected to the support wire 35 through an upper conductive holder 29a which also serves as an upper conductive wire 38. Has been done. The other outer lead wire 17b led out from the lower end of the arc tube 2
Is the other sealing wire 3 that is sealed to the stem 27 via the resistor 39.
It is electrically connected to 7b. These sealing lines 37a,
37b is the inner surface of the shell 33a of the base 23 and the eyelet 3
It is connected to the inner bottom surface of 3b.

A wire mesh (not shown) may be wound around the outer surface of the arc tube 2 in order to prevent cracking. In addition, 40 is a getter.

FIG. 4 is an overall configuration diagram showing an example of an illuminating device 41 according to the third embodiment of the present invention.
1 has a reflecting surface 42a on the inner surface of the luminaire main body 42 and has a housing structure in which the lower surface or one side surface is opened, and a front glass 43 may be provided in the lower surface opening. A socket 44 is attached to, for example, a side wall of the lighting fixture main body 42, and the base 34 of the double-tube type metal halide lamp 31 shown in FIG. 3 is screwed into the socket 44 and attached to the lighting fixture main body 42.

The socket 44 is connected to a commercial power supply 46 via a lighting circuit 45 including a ballast that is attached to the luminaire main body 42 or is installed outside the luminaire main body 42. The metal halide lamp 31 may be replaced with a high pressure sodium lamp.

[0041]

As described above, claims 1 to 6
In each invention, since the inlet of the emitter is formed by providing a coil gap larger than the average grain size of the emitter in a part of the outer coil closely wound outside the inner coil, the outer surface of the outer coil is formed. It is possible to insert the emitter inward from the entrance of the outer coil having a large coil spacing, and further introduce it into each inner coil spacing of the inner coil to intervene by simply applying the emitter.

As a result, the emitter can be easily and reliably interposed between the coils of the inner coil.

Further, since the inner coil wound around the outer periphery of the electrode shaft is roughly wound, the emitter can be interposed in each gap between these coils. For this reason, the coating amount of the emitter can be quantitatively increased, and the coating amount can be equalized. Therefore, it is possible to prolong and even out the lamp life.

According to the third aspect of the invention, since at least the outer end of the inner coil with the emitter interposed is closed by the electrode coil, the emitter falls off from the outer end of the electrode coil.
It is possible to effectively prevent the reduction of the lamp life and the shortening of the lamp life.

A high pressure discharge lamp according to claim 7, claim 8
Since the lighting device described above and the lighting device according to claim 9 include the electrode according to any one of claims 1 to 6, the same operational effect as this electrode can be obtained.

[Brief description of the drawings]

FIG. 1 is an enlarged vertical sectional view of a main part of each electrode shown in FIG.

FIG. 2 is a partial vertical sectional view of the first embodiment of the high-pressure discharge lamp according to the present invention.

FIG. 3 is a front view of a second embodiment of the high pressure discharge lamp according to the present invention.

FIG. 4 is an overall configuration diagram of an embodiment of a lighting device and a lighting device according to the present invention.

FIG. 5 is a vertical cross-sectional view of a conventional electrode.

[Explanation of symbols]

 11 Metal Halide Lamp 12 Bulbs 12a, 12b Pair of Sealed Ends 13, 14 Pair of Electrodes 15a, 15b Pair of Electrode Shades 18 Electrode Coil 19 Inner Coil 19a Inner Coil Interval 20 Outer Coil 21 Emitter 22 Rough Winding 31 Double Tube type metal halide lamp 32 Outer tube 35 Support wires 37a, 37b A pair of sealing wires

Claims (9)

[Claims] 1. An energized electrode shaft; a plurality of layers wound around the outer periphery of the electrode shaft, the inner coil of which is coarsely wound while the outer coil of which is closely wound, and at least a part of which is wound. And an electrode coil having a coil interval larger than the average particle size of the emitter. 2. The electrode according to claim 1, wherein the electrode coil has two layers of inner and outer layers. 3. The electrode according to claim 1 or 2, wherein the inner coil has an outer end of an emitter interposed at least at a coil interval of one end thereof closed by an electrode coil. 4. The electrode according to any one of claims 1 to 3, wherein the wire diameter of the electrode coil is 0.04 to 0.06 mm. 5. The electrode according to any one of claims 1 to 4, wherein the outer coil has a coil interval of 0.05 ± 0.01 mm. 6. The electrode according to claim 1, wherein the emitter is Sc ₂ O ₃ , Ca ₂ O ₃ , or a mixture containing at least one of these. 7. An electrode according to any one of claims 1 to 6, an airtight container containing the two electrodes facing each other, and a discharge medium sealed in the airtight container. High-pressure discharge lamp characterized by having 8. A lighting device comprising: the high-pressure discharge lamp according to claim 7; and a lighting circuit for supplying electric power to the high-pressure discharge lamp to stably light the lamp. 9. A lighting device comprising: the high-pressure discharge lamp according to claim 7; and a fixture main body for housing the high-pressure discharge lamp.