JPH0464130B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a low-pressure mercury vapor discharge lamp in which the mercury vapor pressure inside the tube is controlled using amalgam.

[Technical background of the invention and its problems]

In low-pressure mercury vapor discharge lamps, typically fluorescent lamps, the efficiency of converting supplied electricity into ultraviolet light is highest when the tube wall temperature is around 40°C and the mercury vapor pressure is approximately 6 × 10 ^-3 mmHg. The ambient temperature of the lamp at this time is approximately 20 to 25 degrees Celsius. Therefore, when the ambient temperature significantly exceeds this value, the conversion efficiency of ultraviolet rays deteriorates rapidly.
Problems such as a decrease in optical output arise.

By the way, in recent years, as the output of fluorescent lamps has increased and they have been used in closed lighting equipment, the operating temperature of fluorescent lamps may become higher, and as a result, the ambient temperature of fluorescent lamps may exceed the above values. There are many opportunities for this, and the problem is that the light output and ultraviolet conversion efficiency decrease. On the other hand, as a means to control the mercury vapor pressure in the tube of a fluorescent lamp to an appropriate value, there are two methods: to fill the lamp with a metal such as indium that combines with excess mercury to form an amalgam, or to leave the amalgam itself as is. Encapsulation is already known and has various applications mainly in high-load type fluorescent lamps. It is desirable to install these amalgams and metal bodies for forming amalgams in the low-temperature part of the fluorescent lamp where mercury is likely to condense. It is known that the exhaust pipe of the stem is used as a place to install amalgam.

However, according to the configuration of this prior art,
This requires a spherical cavity at the tip of the exhaust pipe to accommodate and hold the amalgam, or a container and support rod to hold the amalgam, which not only increases the number of parts but also increases the cost of the stem. becomes a complicated and special shape. Therefore, it takes time and effort to manufacture,
This causes inconveniences such as increased costs.

[Purpose of the invention]

The present invention was made based on the above circumstances, and it is possible to use a commonly used stem as it is without requiring a specially shaped stem when storing an amalgam or metal body in an exhaust pipe. The object of the present invention is to provide a method for manufacturing a low-pressure mercury vapor discharge lamp, which can be easily manufactured with a small number of assembly steps, and can reduce costs.

[Summary of the invention]

That is, in the manufacturing method of the present invention, a metal that forms an amalgam by combining with amalgam or mercury in an arc tube bulb is inserted into hollow cylindrical thin tubes that can be inserted at regular intervals into an exhaust pipe provided in a stem. This thin tube is inserted into the exhaust pipe to communicate the amalgam or metal body with the internal space of the arc tube bulb, and in this state, an inert gas, mercury, etc. is introduced into the arc tube bulb through the thin tube. The present invention is characterized in that a filler such as the following is introduced, and then the thin tube and the exhaust pipe are integrally fused and sealed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In the figure, reference numeral 1 denotes a straight arc tube bulb, the inner surface of which is coated with a phosphor coating 2. As shown in FIG. Flare portions 5 of a stem 4 constituting a mount 3 are sealed to both end openings (only one is shown) of the arc tube bulb 1. A pair of lead wires 7, 7 are hermetically sealed through the stem tube 6 of the stem 4.
An electrode 8 is connected between the leading ends of the lead wires 7, 7 located inside the arc tube bulb 1.
Further, this stem tube 6 is provided with an exhaust pipe 10 protruding from one end leading out of the arc tube bulb 1 and the other end opening into an internal space 9 within the arc tube bulb 1. A hollow cylindrical glass capillary tube 11 with both ends open is inserted into the exhaust pipe 10 with a gap 12 between it and the inner peripheral surface of the exhaust pipe 10 . At the same time, a predetermined amount of mercury 16 and an inert gas are filled into the arc tube bulb 1. On the outer surface of the thin tube 11 on the insertion tip side,
A metal body 13 that forms an amalgam by combining with mercury sealed in the arc tube bulb 1 is attached. Examples of the metal body 13 include indium In, bismuth Bi, tin Sn, lead Pb, and mercury.
Hg and an alloy obtained by appropriately mixing these various metals are preferred, and this metal body 13 is located at the opening to the internal space 9 of the exhaust pipe 10. The exhaust pipe 10 and the thin tube 11 are simultaneously and integrally hermetically sealed by heating the exhaust pipe 10 with a burner 14. is fixed to the exhaust pipe 10.

Next, a procedure for manufacturing a fluorescent lamp having such a configuration will be explained. Once the phosphor coating 2 has been applied to the inner surface of the arc tube bulb 1, the mount 3 is inserted into the openings at both ends of the arc tube bulb 1, the electrode 8 is positioned on the bulb axis, and the flare portion 5 is Hermetically seal the openings at both ends. Next, the metal body 13 is attached to the outer surface of the tip of the thin tube 11 in a substantially cylindrical shape, and the thin tube 11 is inserted through the outward opening of the exhaust pipe 10 as shown in FIG. 13 is located at the opening to the internal space 9. In this state, the arc tube bulb 1 is passed through the thin tube 11.
After cleaning the inside and exhausting the flow, a predetermined amount of inert gas and mercury 16 are sealed into the arc tube bulb 1 through the thin tube 11 as shown in FIG. Next, the outwardly leading portion of the exhaust pipe 10 is heated with a burner 14 or the like, and the exhaust pipe 10 and the inner thin tube 11 are simultaneously hermetically sealed by welding. is fixed to the inside of the exhaust pipe 10, and an amalgam-containing fluorescent lamp is completed.

According to such a fluorescent lamp, the exhaust pipe 10
Since the amalgam-forming metal body 13 is located at the opening into the arc tube bulb 1, if the mercury vapor pressure exceeds the appropriate value as the ambient temperature of the fluorescent lamp increases, the metal body combines with excess mercury in the arc tube bulb 1 and takes it in, thus preventing the mercury vapor pressure from increasing and keeping the ultraviolet ray conversion efficiency at a high level at all times, increasing the light output. can be maintained high.

However, if the manufacturing method described above is adopted,
When housing the metal body 13 in the exhaust pipe 10, the metal body 13 is attached to the outer peripheral surface of the thin tube 11 that can be inserted into the exhaust pipe 10, and this thin tube 11 is inserted into the exhaust pipe 1.
0, these exhaust pipe 10 and thin tube 11
Since it is only necessary to fuse and seal them at the same time, there is no need to prepare a specially shaped stem or exhaust pipe as in the conventional case, and the commonly used stem 4 can be used as is.

Furthermore, since the evacuation and filling of the inert gas and mercury 16 in the arc tube bulb 1 can be performed through the thin tube 11, the evacuation and filling work is no different from that when using the exhaust pipe 10, and moreover, the exhaust pipe 10 can be sealed. Since the thin tube 11 and the metal body 13 are fixed at the same time, a special process for fixing the thin tube 11 and the metal body 13 is not necessary. Therefore, since the number of man-hours required is small, manufacturing and assembling can be easily performed, and the stem 4 can be used as is, and costs can be reduced.

It should be noted that the present invention is not limited to the embodiments described above; for example, as shown in FIG. , an example is shown in which a main metal body 22 for controlling the mercury vapor pressure during stable lighting is provided at a location spaced apart from the auxiliary metal body 21 in the axial direction. In this case, the thin tube 11 has its insertion tip protruded into the arc tube bulb 1 so that the auxiliary metal body 21 is located near the electrode 8, and the main metal body 22 is located in the exhaust pipe 10. Both are opposed to a through hole 23 formed on the side surface of the stem tube 6. And in this example as well,
After inserting into the thin tube 11 and the exhaust pipe 10, the exhaust pipe 1
The thin tube 11, the main metal body 21, and the auxiliary metal body 22 are fixed by fusing and sealing at the same time.

Further, in the above embodiment, the interior of the arc tube bulb is evacuated through the thin tube, but the interior of the arc tube bulb may be evacuated through the original exhaust tube, for example, before the thin tube is inserted.

Further, instead of the metal body for forming the amalgam, the amalgam itself may be attached to the capillary, and in this case, it is not necessary to enclose mercury.

Furthermore, the amalgam or the metal body forming the amalgam may be attached not only to the outer surface of the capillary, but also to the inner surface, for example, in a ring shape, as long as it does not block the capillary.

〔Effect of the invention〕

According to the method of the present invention described in detail above, when storing an amalgam or a metal body for forming an amalgam in the exhaust pipe of a stem, the amalgam or metal body is attached to a thin tube, and this thin tube is inserted into the exhaust pipe. In this case, we filled the arc tube bulb with inert gas and mercury if necessary through the thin tube, and then melted and sealed the exhaust tube and the thin tube at the same time. There is no need to prepare an exhaust pipe or exhaust pipe, and a commonly used stem can be used as is. In addition, the work of filling mercury or inert gas into the valve can be done through a thin tube, so there is no difference from using an exhaust pipe, and by sealing the exhaust tube, it is possible to fix the thin tube, amalgam, or metal object. Since this is done at the same time, there is no need for a special process for fixing these thin tubes, etc. Therefore, there is an advantage that manufacturing and assembly can be easily performed and costs can be reduced.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, FIG. 1 is a cross-sectional view, FIGS. 2 and 3 are process explanatory diagrams showing the order of manufacturing steps, and FIG. 4 is another embodiment of the present invention. It is a sectional view showing an example. 1... Arc tube bulb, 3... Mount, 4...
Stem, 9... Internal space, 10... Exhaust pipe, 11
...tubule, 13,21,22...metal body (amalgam), 16...mercury.

Claims (1)

[Scope of Claims] 1. An amalgam for controlling the mercury vapor pressure in the arc tube bulb or a combination of mercury in the arc tube bulb with a stem having an exhaust pipe sealed at the end thereof. In a method for manufacturing a low-pressure mercury vapor discharge lamp in which a metal body forming an amalgam is enclosed, the amalgam or metal body is attached to a hollow cylindrical thin tube, the thin tube is inserted into the exhaust pipe, and the amalgam or metal body is sealed. is communicated with the internal space of the arc tube bulb, and then a predetermined filling material is introduced into the arc tube bulb through the thin tube, and then the thin tube and the exhaust tube are integrally fused and sealed. A method for manufacturing a low-pressure mercury vapor discharge lamp characterized by: