JPH07230789A - Bulb, light source and lighting system - Google Patents

Abstract

PURPOSE:To provide a bulb and light source of high quality reducing a crack and chip in a seal part point end, by providing an external lead wire in such a manner that the tips of a harder sealing lead wire and the external lead wire are connected outside a glass-made air-tight vessel. CONSTITUTION:In both ends of a glass tube 3, a sealing lead wire 5 is sealed in seal parts 11. Material of this lead wire 5, applying a copper coating to an iron nickel alloy, is the same to that used in an ordinary bulb product. An external lead wire 13 is welded to a point end of the lead wire 5. The lead wire 13 is constituted of oxygen free copper of prescribed external diameter. In a fluorescent lamp 1, since the lead wire 13 is laid around, its force is transmitted to also the lead wire 5, but it is harder than the lead wire 13, so that even when generated bending stress due to laying around the lead wire 13, the soft lead wire 13 is bent to absorb the stress, as a result to prevent or reduce bending the lead wire 5, and damaging a point of the seal part 11 can be prevented or suppressed, to attain improving reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bulb having an improved structure of a lead wire for sealing and an outer lead wire, a light source including the bulb, and a lighting device having the light source.

[0002]

2. Description of the Related Art Glass tubes such as light sources typified by light bulbs and fluorescent lamps and fluorescent display tubes have filaments, electrodes and other electric parts disposed therein, and the interior thereof is hermetically sealed. Among the lead wires to electrodes and other electric parts, special lead wires for sealing are used in the sealing portion with glass. The special sealing lead wire is made of a material that is well compatible with glass and has a similar coefficient of thermal expansion. Generally, iron-nickel alloy (iron
The basic structure is copper coating on 58% and nickel 42%).

On the other hand, in recent years, downsizing of tubes has been progressing,
As a result of various changes in the sealing structure of the sealing lead wire and the glass tube, a sealing failure that has not been seen up to now has occurred.

For example, in a fluorescent lamp having an outer diameter of 5 mm or less, the flare stem which is normally used cannot be used because the tube diameter is small. Then, for example, in FIG.
A fluorescent lamp 1 having a sealing lead wire sealed therein has been developed by heating the tip of a glass tube without using a flare stem as shown in FIG. In this fluorescent lamp 1, a glass tube 3 constitutes an airtight container, and a small amount of mercury and a rare gas such as argon are sealed inside. At both ends of the glass tube 3, sealing lead wires 5 are sealed at the sealing portions to support the internal electrodes 7. A phosphor coating 9 is formed on the inner surface of the glass tube 3.

The sealing portion 11 heats the glass tube 3 from the outside with a heating burner or the like with the sealing lead wire 5 inserted thereinto, and the molten glass naturally contracts due to surface tension to cause the sealing lead wire. It is formed by utilizing the phenomenon of welding to No. 5. As a result, the tip of the sealing portion 11 has a spindle shape.

Since this fluorescent lamp has a small tube diameter, the base is rarely attached, and the tip of the sealing lead wire is connected to the external lead wire, and this external lead wire is routed to the lighting circuit. It was common to be connected.

[0007]

However, when the external lead wire is routed as described above, the force applied to the external lead wire is applied to the sealing lead wire 5 as it is, and therefore the tip of the sealing portion 11 is formed. However, it became impossible to resist the bending force of the lead wire 5 for sealing, and the phenomenon of chipping or cracking has become common.

Such a defect is not limited to the fluorescent lamp,
It was found that it also appears in other light sources such as light bulbs or fluorescent display tubes.

The present invention is intended to improve the above-mentioned drawbacks of the prior art, and provides a high-quality tube and light source in which cracks and chips at the tip of the sealing portion are reduced, and this high-quality light source is provided. It is an object of the present invention to provide a lighting device having high quality when used.

[0010]

According to a first aspect of the present invention, there is provided a tube comprising a glass airtight container, a gas sealed in the airtight container, a sealing lead wire sealed in the glass airtight container, and a sealing member. It is characterized in that it is provided with a lead wire for sealing and an external lead wire whose ends are connected to each other outside the glass airtight container, the lead wire being harder than the lead wire.

The shape of the glass airtight container is not limited to a straight tube shape, a ring shape or the like. Examples of the bulb include a low-pressure mercury vapor discharge lamp typified by a fluorescent lamp, a rare gas fluorescent lamp, a light source such as a light bulb, a fluorescent display tube, and the like. Hard means that it is difficult to bend, and it is hard to bend when the same force is applied.

The tube of claim 2 is a glass airtight container,
A gas sealed in an airtight container, a sealing lead wire sealed in a glass airtight container, and an external lead wire in which the sealing lead wire and the tips are connected to each other outside the glass airtight container,

[Equation 2] It is characterized by having a relationship of. Here, PD is the 0.2% proof stress of the sealing lead wire, RD is the wire diameter (outer diameter) of the sealing lead wire, PO is the 0.2% proof stress of the external lead wire, and RO is the external lead wire diameter. (Outer diameter) is shown. This relational expression indicates that the sealing lead wire is harder than the external lead wire.

A third aspect of the present invention is the tube according to the first or second aspect, wherein the sealing lead wire is a Dumet wire in which a core wire mainly made of iron-nickel alloy is coated with copper.

The term “mainly composed” means that it includes a mixture of additives and the like.

The tube of claim 4 is characterized in that, in claim 1 or 3, the external lead wire is mainly made of oxygen-free copper.

"Oxygen-free copper as a main component" means that impurities can be mixed in.

According to a fifth aspect of the present invention, in the tube according to the first or fourth aspect, the sealing length of the sealing portion of the glass hermetic container for sealing the sealing lead wire is 5 mm or less, and the average sealing width is 5 mm or less. It is characterized in that the tip of the glass flesh at the sealing portion has a spindle shape.

The sealing length of 5 mm or less means that when the sealing length is usually 5 mm or less, when the tip of the sealing portion is cracked,
It means the critical value at which leakage is likely to occur. The average sealing width of 5 mm or less means a critical value that the tip of the sealing portion is easily cracked when the average sealing width is 5 mm or less. Therefore, the sealing length is 5 mm or less, and the average sealing width is 5 m.
When it is m or less, the effect of the present invention can be expected more. The spindle shape means a shape that becomes thinner toward the tip, and because of this shape, the tip is easily cracked.

According to a sixth aspect of the present invention, in the first or fifth aspect, the sealing lead wire has a diameter of 0.5 mm or less.

The diameter of the sealing lead wire being 0.5 mm or less means that if the lead wire has a larger thickness, it is usually difficult for the sealing lead wire to bend. Therefore, the effect of the present invention is 0.5 mm or less. Means that you can expect more.

A light source according to a seventh aspect is characterized by comprising the tube according to the first to sixth aspects.

The tube includes a light source such as a fluorescent lamp or a light bulb, or a fluorescent display tube.

An illuminating device according to an eighth aspect of the present invention is characterized by having a device main body and a light source according to the seventh aspect mounted on the device main body.

When the present invention is applied to a fluorescent lamp for reading an original, the illuminating apparatus includes an original illuminating apparatus incorporating the fluorescent fluorescent lamp and an image forming apparatus incorporating the original illuminating apparatus. Further, when the present invention is applied to a fluorescent lamp for a backlight of a liquid crystal television or the like, it includes a backlight incorporating the fluorescent fluorescent lamp, a liquid crystal display device incorporating the backlight, and the like.

[0025]

In the bulb of claims 1 to 6 and the light source of claim 7, since the sealing lead wire is harder than the external lead wire, the external lead wire bends before the sealing lead wire bends, and thus the sealing lead wire. It is possible to reduce cracks at the tip of the sealing portion due to bending of the wire.

In the tube according to the third aspect of the present invention, the sealing lead wire is made of a Dumet wire which is easily bent, so that the necessity and usefulness of the present invention is high.

Since the outer lead wire is mainly made of extremely soft oxygen-free copper, the sealing lead wire is more difficult to bend. Therefore, the bending of the sealing lead wire makes it difficult to bend the sealing lead wire. Cracking can be further reduced.

Since the sealing length of the tube of claim 5 is 5 mm or less, leakage easily occurs when the tip of the sealing portion is cracked, and the average sealing width is 5 mm or less and the tip of the sealing portion has a spindle shape. Fragile. Therefore, in the case of the tube of claim 5, the necessity and usefulness of the present invention are higher.

The tube of claim 6 is easily bent because the diameter of the lead wire for sealing is 0.5 mm or less, and therefore the necessity and usefulness of the present invention is much higher.

The illumination device of claim 7 has the same effects as the tube and the light source of the present invention.

[0031]

Embodiments of the present invention applied to a fluorescent lamp will be described below with reference to the drawings. FIG. 1 is a front view showing a cross section of a part of the fluorescent lamp 1. The fluorescent lamp 1 has an outer diameter of 4 mm, and a glass tube 3 having a wall thickness of 0.50 mm constitutes an airtight container in which a trace amount of mercury and a rare gas such as argon are enclosed. The filling pressure is 13300 Pascal (Pa), which is higher than that of the fluorescent lamp for general lighting.

At both ends of the glass tube 3, a sealing lead wire 5 having an outer diameter of 0.4 mm and a length of 7 mm is sealed in the sealing portion. The material of the lead wire 5 for sealing is an iron-nickel alloy (58% iron, 42% nickel) coated with copper, which is the same as that used for ordinary bulb products.

The sealing lead wire 5 supports the internal electrode 7. The electrode 7 has an outer diameter of 1 mm, a length of 7 mm, and a wall thickness of 0.1 mm.
A getter containing Zr-Al as a main component, which absorbs residual substances after mercury is released from a mercury alloy containing Ti and the like, and Zr-Al that absorbs impure gas released from the mercury alloy at the same time. It is housed. This electrode 7 is sold under the trade name of Gemedes before mercury emission. For example, after the electrode 7 is sealed in the glass tube 3, a high-frequency electric field is applied from the outside of the glass tube 3 to the nickel skin portion of the electrode 7 to generate an eddy current in the nickel skin portion, and resistance heating of this current causes The mercury alloy is decomposed by utilizing self-heating, and mercury is released into the glass tube 3.

A phosphor coating 9 is formed on the inner surface of the glass tube 3. As the fluorescent substance, those used in fluorescent lamps for general lighting can be applied, but since this type of lamp has a high load, it is similar to the so-called three-wavelength type fluorescent lamp among fluorescent lamps for general lighting. It is preferable to use the phosphor of

The sealing portion 11 heats the glass tube 3 from the outside with a heating burner or the like in a state where the sealing lead wire 5 is inserted thereinto, and the molten glass naturally contracts due to the surface tension, and the sealing lead wire. It is formed by utilizing the phenomenon of welding to No. 5. As a result, the tip of the sealing portion 11 has a spindle shape. The sealing length of the sealing portion 11 is 3 mm, and the sealing width is 4 mm on the electrode 7 side, and the average is 2 mm. The distance between the sealing portion 11 of the sealing lead wire 5 and the connecting portion 15 is 1 mm, and the distance between the bottom of the electrode 7 and the sealing portion 11 is 3 mm.

An external lead wire 13 is welded to the tip of the lead wire 5 for sealing. Reference numeral 15 is a connecting portion. The outer lead wire 13 is made of oxygen-free copper having an outer diameter of 0.4 mm.

The fluorescent lamp 1 is used as a light source of a lighting device as shown in FIG. 2, specifically, a backlight. In this case, the main part of the fluorescent lamp 1 is housed inside a shallow box body 17 whose inner surface constitutes a light reflecting surface and whose top surface is open, and a light diffusion plate 19 is arranged in the opening part of the box body 17.
The liquid crystal plate 21 is arranged on the diffusion plate. The sealing portion 11 of the fluorescent lamp 1 is located outside the box body 17, and the external lead wire 13 is routed outside the box body 17 for connecting with an external component such as a power circuit (not shown). It is connected to the connector 23.

In the fluorescent lamp 1, since the external lead wire 13 is drawn around, the force is also transmitted to the sealing lead wire 5, but since the sealing lead wire 5 is harder than the external lead wire 13, Even if bending stress is generated due to the routing of the external lead wire 13, the soft external lead wire 13 bends and absorbs the stress, and as a result, bending of the sealing lead wire 5 can be prevented or reduced, and damage to the tip of the sealing portion 11 can be prevented. It can be prevented or suppressed, and reliability can be improved.

In order to obtain such an effect, the outer lead wire 13 is made softer than the sealing lead wire 5, for example, if the same material is used, the diameter of the outer lead wire 13 is set to the sealing lead wire 5. It is necessary to make the outer lead wire 13 thinner and softer than the sealing lead wire 5 if the wire diameter is the same. If this is expressed by an equation,

[Equation 3] It becomes a relationship. Here, PD is the 0.2% proof stress of the sealing lead wire 11, RD is the wire diameter (outer diameter) of the sealing lead wire 5, PO is the 0.2% proof stress of the external lead wire 11, and RO is the external lead wire. 11 represents the wire diameter (outer diameter). 0.2% proof stress means (defines) the stress that causes 0.2% permanent set.

As the material of the sealing lead wire 5, it is almost impossible to use other than the Dumet wire due to the compatibility with glass and the restriction of expansion coefficient, and there is not much room for changing the material. In addition to the oxygen-free copper of the example,
For example, the surface of the wire made of these materials may be coated with nickel to prevent corrosion.

The sealing length of the sealing portion 11 is not limited to 5 mm or less, but if it exceeds 5 mm, the possibility of leakage even if the tip of the sealing portion 11 is cracked decreases. The present invention is more effective when the sealing length is 5 mm or less. Similarly, the average sealing width is not limited to 5 mm or less, but if the average sealing width is 5 mm or less, the possibility that the tip of the sealing portion 11 is cracked and leaks significantly decreases. Is more effective than the case of exceeding 5 mm. Further, similarly, the present invention is not limited to the one in which the tip of the glass fillet of the sealing portion 11 has a spindle shape, but the sealing portion 1 has a spindle shape.
1 The tip of the present invention is easily cracked, and the usefulness of the present invention is higher than that of the one having no spindle shape. The diameter of the lead wire for sealing is also 0.
Although it is not limited to 5 mm or less, when it is 0.5 mm or less, the sealing lead wire is easily bent, and therefore, the usefulness of the present invention is higher than that of the lead wire of more than 0.5 mm.

In the above embodiment, the fluorescent lamp and the backlight using this fluorescent lamp are explained, but the phosphor coating 12 is not essential, for example, the mercury emission line of 254 nm.
It may be an ultraviolet lamp that directly uses the light, or an ultraviolet processing device as the lighting device. In this case, the transparent airtight container does not allow ultraviolet rays to pass through it with ordinary soft glass, so it is necessary to use quartz glass or the like to transmit the ultraviolet rays. Further, the discharge gas is not limited to mercury, and may be a xenon gas discharge lamp.

Further, as in the above embodiment, the electrodes at both ends have a spindle-shaped sealing structure, and therefore the external lead wires of the present invention are not limited to being connected to both sealing lead wires. However, only one side may satisfy the requirements of the present invention. For example, as shown in FIG. 3, one electrode 7 is installed at one end in the glass tube 3, this electrode 7 has the same sealing structure as in the first embodiment, and the other electrode 25 is made of glass. It may be attached to the outer wall of the pipe 3. The electrode 7 is a lead wire 5 for sealing similar to that of the first embodiment.
And the tip ends of the sealing lead wire 5 and the external lead wire 13 are spot-welded to each other. The material of the lead wire 5 for sealing and the outer lead wire 13, the wire diameter, the size of the sealing portion 11,
The shape and the like are the same as those in the first embodiment.

The other electrode 25 is obtained by applying a conductive glass paste to the outer wall of the glass tube 3 in a strip shape and then firing it. An external electrode lead wire 27 is soldered to one end of the external electrode 25.

Even if there is only one such internal electrode or the external lead wire 13 is routed, the external lead wire 13 is softer than the sealing lead wire 5, so the external lead wire 1
3 bends and absorbs stress, and as a result, the tip of the sealing portion 11 is not cracked, and high reliability can be maintained.

The present invention is not limited to the discharge lamp, but can be applied to, for example, a small light bulb, a fluorescent display tube, or the like. The illumination device may be, for example, a document illumination device or a display device.

[0047]

According to the inventions of claims 1 to 7, cracks at the tip of the sealing portion due to bending of the sealing lead wire can be reduced,
A highly reliable bulb or light source can be provided.

According to the third aspect of the present invention, it is possible to provide a highly reliable bulb or light source even if the sealing lead wire is composed of a flexible Dumet wire.

According to the invention of claim 4, since the outer lead wire is mainly made of extremely soft oxygen-free copper, the lead wire for sealing is more difficult to bend, and therefore a highly reliable tube or light source is provided. it can.

According to the invention of claim 5, the sealing length is 5 mm.
Even if the tip of the sealing portion, which has an average sealing width of 5 mm or less and a spindle shape, is extremely fragile and easily leaks, a highly reliable bulb or light source can be provided.

According to the sixth aspect of the present invention, even when the sealing lead wire has a diameter of 0.5 mm or less and the tip of the sealing portion is extremely fragile and easily leaks, a highly reliable bulb or A light source can be provided.

According to the invention of claim 7, it is possible to provide an illuminating device having the same effects as those of the bulb and the light source of the present invention.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a fluorescent lamp according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view conceptual diagram of a backlight equipped with the fluorescent lamp of the first embodiment.

FIG. 3 is a partially cutaway front view showing a fluorescent lamp of another embodiment of the present invention.

FIG. 4 is a front view showing a conventional fluorescent lamp partially broken away.

[Explanation of symbols]

1 ... Fluorescent lamp, 3 ... Glass tube, 5 ... Lead wire for sealing,
7 ... Electrode 11 ... Sealing part, 13 ... External lead wire, 25 ... External electrode

Claims (8)

[Claims] 1. A glass airtight container; a gas sealed in the airtight container; a sealing lead wire sealed in the glass airtight container; harder than the sealing lead wire, outside the glass airtight container. A bulb comprising: a sealing lead wire; and an external lead wire whose ends are connected to each other. 2. An airtight container made of glass; a gas sealed in the airtight container; a lead wire for sealing sealed in the airtight container made of glass; And an external lead wire connected thereto; A tube characterized by having the following relationship. Where PD is the 0.2% yield strength of the sealing lead wire, RD is the diameter of the sealing lead wire (outer diameter), PO is the 0.2% yield strength of the outer lead wire, RO is the outer diameter of the outer lead wire. Represents 3. The tube according to claim 1, wherein the lead wire for sealing is a Dumet wire in which a core wire mainly made of iron-nickel alloy is coated with copper. 4. The tube according to claim 1, wherein the outer lead wire is mainly made of oxygen-free copper. 5. The sealing portion of a glass airtight container for sealing lead wires for sealing has a sealing length of 5 mm or less and an average sealing width of 5 m.
5. The tube according to any one of claims 1 to 4, wherein the tip of the glass fillet in the sealing portion has a spindle shape when the length is m or less. 6. The tube according to claim 1, wherein the diameter of the lead wire for sealing is 0.5 mm or less. 7. A light source comprising the tube according to any one of claims 1 to 6. 8. A lighting device comprising: a device body; and the light source according to claim 7 mounted on the device body.