JP2880340B2 - Low pressure mercury lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small low-pressure mercury lamp used for, for example, a small fluorescent lamp for a backlight of a liquid crystal panel and a germicidal lamp.

[0002]

2. Description of the Related Art Conventionally, as a means for charging mercury into a low-pressure mercury lamp such as a small fluorescent lamp or a germicidal lamp, a liquid free mercury is automatically weighed by a mercury dozer, and this is filled into a valve from an exhaust pipe. I was However, in such a method, the amount of mercury to be filled is small, for example, 10
Precise weighing of mercury in the case of applying the ^-1 to 10 ⁰ mg order and small compact fluorescent lamps is difficult. And
If the amount of mercury is small, the service life will be short, so normally more mercury will be contained than is necessary.However, this excess mercury will cause contamination on the inner surface of the tube, resulting in severe fluctuations in performance and stability. It was inferior.

[0003] Other such circumstances, in recent years, titanium, zirconium, mercury (Ti _a Zr _b Hg _c) is applied to one side as the mercury releasing alloy, zirconium-aluminum (Zr ₃ Al ₂₎ as a getter alloy A plate-shaped mercury-containing getter made of a nickel-plated iron plate adhered to the surface has been developed, by mounting such a mercury-containing getter in a valve, and heating the mercury-containing getter after exhaust sealing of the valve. Mercury filling means for releasing mercury into the bulb is used.

FIG. 4 is an explanatory view showing one end of a low-pressure mercury lamp manufactured by enclosing mercury with the above-mentioned mercury-containing getter. In the figure, reference numeral 1 denotes a bulb, 4 denotes glass beads forming a sealing portion, and 3 denotes a lead rod extending through the sealing portion and extending inward. Reference numeral 5 denotes an electrode composed of a filament 51 and a metal pipe 52. The electrode 5 is disposed at the tip of the lead bar 3 so as to face an electrode (not shown) on the other end. Reference numeral 6 denotes a plate-shaped mercury-containing getter mounted on the lead bar 3 between the electrode 5 and the sealing portion. Decomposition products of the mercury-releasing alloy (titanium and zirconium remaining after mercury release) are applied to one surface 6A of the mercury-containing getter 6, and the getter alloy is applied to the other surface 6B.

[0005]

However, the mercury filling means using a mercury-containing getter has the following problems. In order to mount the mercury-containing getter inside the bulb,
It is necessary to cut the mercury-containing getter into a size corresponding to the valve diameter and attach it to the lead rod by spot welding. However, when the mercury-containing getter is mounted on the lead bar, it is necessary to secure a space for mounting the getter, and the process of mounting the plate-shaped mercury-containing getter on the lead bar is complicated. In particular, in the case of manufacturing a low-pressure mercury lamp having a large amount of mercury to be sealed, the number of attached mercury-containing getters increases, and the space efficiency and the production efficiency decrease significantly. Since the mercury-containing getter has a structure in which a mercury-releasing alloy is adhered to one surface of a nickel-plated iron plate, a sufficient amount of the mercury-releasing alloy cannot be introduced into the bulb, and high-frequency heating is used as a heating means. When mercury is used, the decomposition of mercury is not sufficiently achieved, and eventually the amount of decomposition varies, making it difficult to seal a predetermined amount of mercury in the bulb.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to have excellent space efficiency and to easily introduce a mercury releasing alloy into a valve during manufacturing. Another object of the present invention is to provide a low-pressure mercury lamp in which a predetermined amount of mercury is surely sealed in a bulb with excellent production efficiency.

[0007]

The low-pressure mercury lamp of the present invention comprises:
In a low-pressure mercury lamp in which electrodes are disposed opposite to each end of a pair of lead rods extending inward through sealing portions at both ends of the bulb, each of the electrodes is formed of a metal powder containing a titanium-mercury alloy. Is characterized in that it is a cylindrical shaped electrode formed by heating the powder sintered body to release mercury.

[0008] Further, each of the opposed electrodes is
It is a cylindrical molded electrode containing 5 to 50% by weight of titanium, and is preferably connected to each of the pair of lead rods by caulking.

[0009]

Each of the electrodes constituting the low-pressure mercury lamp is a cylindrical molded electrode formed by heating a cylindrical powder sintered body made of a metal powder containing a mercury-releasing alloy (titanium-mercury alloy) to release mercury;
That is, since it is an electrode that also has a mercury emission structure,
Excellent space efficiency. The powder sintered body that becomes a cylindrical molded electrode by releasing mercury is easy to process and manufacture, so that it is possible to improve production efficiency, and by controlling the length and thickness of the powder sintered body Thus, a desired amount of mercury can be reliably obtained. The shape of the powder sintered body is cylindrical, and a larger volume can be secured than a plate-shaped mercury-containing getter. Therefore, a sufficient amount of the mercury-releasing alloy can be introduced into the bulb, and the self-heating property when high-frequency heating is performed is large, so that mercury is easily released. Therefore, even when the required amount of mercury is large, it can be easily handled without deteriorating the space efficiency. Since the titanium-mercury alloy has excellent decomposability and reliably releases mercury upon heating, even a small low-pressure mercury lamp can be filled with a predetermined amount of mercury without variation. Each of the opposing electrodes may contain 5 to 5 titanium.
In the case where the electrode is a cylindrical molded electrode containing 0% by weight, and further contains a refractory metal that does not form an alloy with mercury as another component constituting the cylindrical molded electrode, the electrode has flexibility. Thus, connection with the lead rod by caulking (fixation by external mechanical forcible pressure) can be easily achieved. And the low-pressure mercury lamp in which the cylindrical molded electrode is connected to the lead rod by caulking can introduce the mercury-releasing alloy into the bulb without performing welding at the time of manufacturing, so that the production efficiency is further improved. At the same time, there is no adverse effect on performance due to welding, for example, oxidation caused by instantaneous heating during spot welding.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is an explanatory sectional view showing a low-pressure mercury lamp of the present invention used as a small fluorescent lamp for a backlight of a liquid crystal panel. In the figure, 1 is a bulb made of glass, 3, 3 'are lead rods made of dumet wire, 4,
4 ′ is a glass bead formed on the lead rods 3 and 3 ′, which is sealed at both ends of the bulb 1;
Are cylindrical shaped electrodes which are arranged so as to face each other at the tip of each of the lead rods 3 and 3 '.

Each of the cylindrical shaped electrodes 2 and 2 ′ is formed by heating a cylindrical powder sintered body made of a metal powder containing a mercury releasing alloy (titanium-mercury alloy) and releasing mercury. Also serves as a mercury release structure. Therefore, there is no need to separately provide a space for mounting the mercury emission structure, and the space efficiency is excellent.

Further, mercury is released to form a cylindrical shaped electrode 2,
The powder sintered body of 2 ′ is easy to process and manufacture, so that the production efficiency can be improved, and by controlling the length and thickness of the powder sintered body, a desired amount of sealing can be achieved. Can be obtained reliably.

Here, an example of the specifications of the low-pressure mercury lamp in this embodiment is as follows: the output is 2 W, the total length is 210 mm, the effective luminous length is 190 mm, the tube outer diameter is 4.1 mm, and 2 to 4 mg of mercury is contained in the bulb. It is enclosed.

The cylindrical shaped electrodes 2 and 2 ′ may be titanium electrodes formed by heating a powder sintered body of a titanium-mercury alloy (Ti ₃ Hg) and releasing mercury. A high-melting-point metal having flexibility that does not form an alloy with mercury, such as niobium, tantalum, tungsten, molybdenum, or the like may be contained as a base metal. In particular, when 5 to 50% by weight of titanium is contained and the base metal is contained as another component, the cylindrical shaped electrode 2
2 ′ has flexibility, as shown in FIG.
The connection with the lead rods 3 and 3 'by caulking can be easily achieved. And, the low-pressure mercury lamp in which the cylindrical molded electrode is connected to the lead rod by caulking can introduce the mercury-releasing alloy into the bulb without performing welding at the time of manufacturing, so that the production efficiency is further improved. In addition, the performance is not adversely affected by welding. In addition, when the content ratio of titanium in the cylindrical molded electrode exceeds 50% by weight, it is also possible to connect by welding means as shown in FIG.

Next, a production example of the low-pressure mercury lamp according to the present invention will be described. [Production Example 1] 30% by weight of titanium powder having an average particle size of about 250 mesh and 70% by weight of niobium powder as a base metal were mixed.
/ Cm ² to obtain a cylindrical molded body. By leaving this compact in mercury vapor at 800 ° C., the titanium powder in the compact and the mercury vapor were reacted to obtain a powder sintered body containing a titanium-mercury alloy. The obtained powder sintered body was attached by caulking to the tip of a lead rod to which glass beads constituting a sealing portion were attached. Next, one end of the valve is sealed, the inside of the valve is evacuated, argon gas is sealed, and the other end of the valve is sealed. Then, the powder sintered body is heated to 800 to 900 ° C. using a high-frequency heating means. A predetermined amount of mercury was released into the bulb by heating to decompose the titanium-mercury alloy constituting the powder sintered body, thereby producing the low-pressure mercury lamp in the connected state shown in FIG.

[Production Example 2] Titanium powder having an average particle size of about 250 mesh was press-formed at a pressing pressure of 3000 kg / cm ² to obtain a cylindrical molded body. Production Example 1
In the same manner as described above, a powder sintered body composed of a titanium-mercury alloy was obtained by being left in a mercury vapor. The obtained powder sintered body was mounted by spot welding on the tip of a lead rod to which glass beads constituting a sealing portion were mounted. In the same manner as in Production Example 1, the powder sintered body was heated to release a predetermined amount of mercury into the bulb, thereby producing the low-pressure mercury lamp in the connected state shown in FIG.

[0017]

According to the first aspect of the present invention, each of the electrodes constituting the low-pressure mercury lamp is an electrode having a mercury-releasing structure, so that the space efficiency is excellent. Further, since the powder sintered body is easy to process and manufacture, the production efficiency can be improved, and further, by controlling the length and thickness of the powder sintered body, the desired amount of enclosed mercury can be ensured. Obtainable. Therefore, even a small low-pressure mercury lamp is filled with a predetermined amount of mercury without variation, and even when the required amount of mercury is large, it can be easily handled without impairing the space efficiency.

According to the second aspect of the present invention, each of the electrodes constituting the low-pressure mercury lamp has flexibility, and the connection with the lead rod by caulking can be easily achieved. And since it is manufactured by introducing the mercury-releasing alloy into the valve without performing welding, the production efficiency is further improved and the performance due to welding is not adversely affected.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing a low-pressure mercury lamp of the present invention.

FIG. 2 is an explanatory cross-sectional view illustrating an example of a connection state between a cylindrical molded electrode and a lead rod.

FIG. 3 is an explanatory cross-sectional view showing another example of a connection state between a cylindrical molded electrode and a lead rod.

FIG. 4 is an explanatory sectional view showing one end of a conventional low-pressure mercury lamp.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Bulb 2, 2 'Cylindrical molded electrode 3, 3' Lead rod 4, 4 'Glass bead 5 Electrode 6 Mercury containing getter 51 Filament 52 Metal pipe

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-21011 (JP, A) JP-A-4-341747 (JP, A) JP-A-4-314748 (JP, A) 57855 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) H01J 61/067 H01J 61/24

Claims (2)

(57) [Claims] 1. A low-pressure mercury lamp in which electrodes are disposed opposite to respective ends of a pair of lead rods extending inward through sealing portions at both ends of a bulb, wherein each of the electrodes includes a titanium-mercury alloy. A low-pressure mercury lamp characterized in that it is a cylindrical shaped electrode formed by discharging a mercury by heating a cylindrical powder sintered body made of a metal powder. 2. The method according to claim 1, wherein each of the opposed electrodes is a cylindrical molded electrode containing 5 to 50% by weight of titanium, and is connected to each of the pair of lead rods by caulking. 2. The low-pressure mercury lamp according to 1.