JPS60208024A - Manufacture of low pressure mercury discharge lamp - Google Patents

Abstract

PURPOSE:To shorten the time required for aging by encapsulating amalgam while splitting into plural particles into a light emission tube thereby quickening emission of mercury from the amalgam. CONSTITUTION:Amalgam 19 is encapsulated into a light emission tube 8 while splitting into many particles 19'.... Consequently, said particles 19' are dispersed widely into said tube 8 to substantially increase the surface area for the volume of amalgam 19. Since the mercury emission rate from the amalgam 19 under aging is related with the surface area, substantial increase of the surface area of amalgam 19 will cause corresponding increase of mercury. Consequently, mercury is discharged quickly from the amalgam 19 resulting in shortening of time required for aging.

Description

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

[Technical background of the invention and its problems]

In a low-pressure mercury vapor discharge lamp, typically a fluorescent lamp, the tube wall temperature is around 40°C and the mercury vapor pressure is approximately 6
It is designed to have the highest efficiency in converting the supplied power to ultraviolet light when the temperature is 10'ioaHg.
For example, if a fluorescent lamp is housed in a bulb-shaped envelope and turned on, the mercury vapor pressure will exceed the above value as the ambient temperature rises, causing problems such as a decrease in light output. .

When a fluorescent lamp is used under such severe temperature conditions, the mercury vapor pressure inside the fluorescent lamp is controlled within an appropriate range by using amalgam, which has a lower vapor pressure than pure mercury. The method is considered effective.

By the way, this type of amalgam is usually attached to the wall of the stem or the inner surface of the tube wall of the arc tube, but as mentioned above, it can be housed in a light bulb-shaped envelope to replace the existing incandescent light bulb. In fluorescent lamps intended for use, the lighting direction is not uniform, so if the amalgam is fixed in one place, a temperature difference will occur in the amalgam installation area due to thermal convection based on the lighting direction, and the vapor pressure will decrease. There are problems such as the control characteristics varying depending on the lighting direction. Therefore, this amalgam is formed into a single approximately spherical lump,
The present applicant has proposed a method of movably enclosing the arc tube into the arc tube through the capillary tube at the end of the arc tube. In this case, if the amalgam is dispersed in multiple locations within the arc tube, the operating temperature of the amalgam will differ in the multiple locations, which may cause instability in the control of mercury vapor pressure by the amalgam. be.

Therefore, the number of such amalgams during operation is better to be small, and most preferably the mercury vapor pressure of one granular amalgam is controlled.

On the other hand, in the case of fluorescent lamps filled with amalgam, when the lamp is first manufactured, the mercury contained in the amalgam has not yet been released into the arc tube. Aging is performed by raising the temperature to release the mercury in the amalgam.

In this case, the amount of mercury released from the amalgam is largely related to the surface area of the amalgam itself, so if the amalgam is sealed in a single lump in the arc tube as described above, the surface area will be smaller than the volume of the amalgam. Since the amount of mercury is substantially reduced, problems such as the need for time to release mercury occur.

Thus, there is a seemingly contradictory requirement that the amalgam should preferably have a large surface area during aging, while it should preferably have a small and numerically smaller surface area during operation. This requirement is based on the fact that if multiple amalgams are placed in an arc tube so that they can move freely (by gravity), the multiple amalgams will coalesce while the light is on, and the number will decrease even though the amount will not change. The fact discovered by the present inventors has made it possible to satisfy the above requirements.

[Purpose of the invention]

The present invention was made based on these circumstances, and
An object of the present invention is to obtain a method for manufacturing a low-pressure mercury vapor discharge lamp in which amalgam is freely movably sealed in an arc tube, mercury is quickly released from the amalgam, and the time required for aging is shortened. .

[Summary of the invention]

That is, in order to achieve the above object, the method of the present invention divides the amalgam into a plurality of grains and encapsulates them so that the amalgam can move freely inside the arc tube, and the amalgams are mutually separated during lighting, including aging. are fused, and the number is reduced even though the amount does not change.

[Embodiments of the invention]

Below is an example of the present invention. - Explanation will be given based on drawings applied to a bulb-shaped lighting device.

First, to explain the structure of this lighting device, 1 in Figure 1.
is a cover made of synthetic resin, and a cap 2 is attached to the top of one end of the cover 1. The opening at the other end of the cover 1 is covered with a substantially spherical globe 3, and the cover 1 and the globe 3 constitute an envelope 4 that approximates a ball-shaped incandescent light bulb.

Inside the envelope 4 are a fluorescent lamp 5 that is typical of a low-pressure mercury vapor discharge lamp, a lighting tube 6 as a starting element for the fluorescent lamp 5, and a choke coil type ballast 7 as a discharge stabilizing element. It is housed integrally. The luminous tube 8 of the fluorescent run f5 is made by bending a straight glass pulp into a substantially U-shape at the center between both ends 9.9, and between the first bent part 10 and both ends 9. A pair of second
A curved portion 11.11 is formed, and both end portions 9, 9 and the curved portion 1o are adjacent to each other and positioned in the same direction. A phosphor coating 12 is coated on the inner surface of the arc tube 8, and flare portions 14 of a mount 13 are sealed to both ends 9, respectively, as shown in FIG. . Internal lead wires 16.16 are sealed in the stem tube 15 connected to the flared portion 14), and a filament 17 as an electrode is connected between these lead wires 16.16. Further, the thin tube 18 led out from the stem tube 15 of each mount 13 is opened at the tip of the stem tube 15 close to the filament 17. 'fl
Through IB, the interior of the arc tube 8 is evacuated and a predetermined amount of inert gas is filled.

The fluorescent lamp 5 is housed in the envelope 4 with both end portions 9.9 and the first curved portion 10 facing the base 2, and the filament 17 is turned on. The tube 6 is of course connected to the cap 2 via a ballast 7.

By the way, the fluorescent lamp "j" 5 has an amalgam 19 to control the mercury vapor pressure inside the tube during steady lighting.The manufacturing procedure of this fluorescent lamp 5 will be explained below.

First, in the arc tube 8 before bending, a phosphor wave 1112 is applied to the inner surface of the glass pulp which has a round straight tube shape, and a filament is attached to the openings at both ends of the glass pulp (only one is shown). The flare portion 14 of the mount 13 on which the assembly of the tube 17 and the thin tube 18 has been completed is sealed.

Subsequently, the bulb is bent into a bending process. In this process, the first part of the glass pulp that is to be bent in the middle in the longitudinal direction is heated and softened (using a burner, etc.), and in this state is bent into a substantially U-shape. In particular, a first bend 10 is formed. Next, the second curved portion between the both end portions 9, 9 of the glass gourd and the first curved portion 10 is similarly heated and softened, and in this state, it is bent in a direction substantially perpendicular to the plane containing the above-mentioned U-shape. By bending it into a substantially U-shape, a pair of second curved bottom portions 11.11 are formed. By bending twice in this manner, a generally saddle-shaped arc tube 8 is formed.

Next, one of the capillary tubes 18 led out from the arc tube 8 is sealed in advance, preferably melt-sealed (chipped), and the other capillary tube 18 is connected to an exhaust device.
The inside of the arc tube 8 is evacuated. During this evacuation, the arc tube 8 is heated as a whole to discharge impurities contained in the arc tube 8, mount 13, filament, 17, etc. Incidentally, when exhausting the inside of the arc tube 8, not only one-side exhaust but also double-sided exhaust using both thin tubes 18 and 18f may be used.

When the evacuation of the arc tube 8 is completed in this way, an inert gas is filled into the arc tube 8 through the evacuation device and the thin tube 18 on the exhaust side, and a predetermined amount of amalgam 19 is filled using the evacuation device. Enclose. The amalgam 19 of this example is indium (In) bis-qx (Bi)
A mixture of tin (Sn), lead (pb), and an alloy obtained by mixing these various metals in appropriate proportions with mercury (Hg) is used. And this amalgam 19 is the fourth
As shown in the figure, it is not a single lump, but is divided into many fine particles 19'... and sealed in the arc tube 8. Like arc tube 8
It is designed to be dispersed within the

After this, if both capillary tubes 18, 18 are sealed and cut using the sealing burner built into the exhaust system,
The entire arc tube 8 is heated to a certain temperature using, for example, a heat-retaining heater, and a knee song is performed in which the temperature of the amalgam 19 sealed earlier is raised and the mercury in the amalgam 19 is released into the arc tube 8.

According to this method of manufacturing the fluorescent lamp 5, the amalgam 19 is divided into a large number of granules 19' and sealed in the arc tube 8, so that after the encapsulation, these granules 19'... '... are widely dispersed within the arc tube 8), the surface area of the amalgam 19 increases substantially relative to its capacity.

Therefore, the rate of mercury released from the amalgam 19 during aging is related to its surface area, so as the surface area of the amalgam 19 increases substantially as described above, the amount of mercury released increases accordingly. As a result, mercury is quickly released from the amalgam 19, which has the advantage of shortening the time required for aging. During lighting, multiple amalgams, including the kneesong, melt due to the heat influence of the filament 17 and others, and fuse together at the lowest part of the arc tube 8, and the number of amalgam particles decreases and the particle size increases. . In other words, since the number of amalgam locations is reduced, the operating temperature of the amalgam becomes more stable, which eliminates the conventional drawback of unstable mercury vapor pressure, making it possible to properly control mercury vapor pressure. .

In the above-described embodiment, the amalgam granules were sealed inside the arc tube through the thin tube extending from the stem. The granular material may be encapsulated through this thin tube.

In addition, the amalgam is not limited to being movably sealed in the arc tube, but may also be held in a thin tube connected to the arc tube. A mercury getter may be installed to improve the rise characteristics by emitting mercury.

Furthermore, the low-pressure mercury vapor discharge lamp according to the present invention is not limited to one that is housed in a bulb-shaped envelope and used for lighting, but can also be used externally, such as a high-output straight or curved fluorescent lamp. It can be similarly applied as a light source for a copying machine that is exposed to the side and lit up, or as a light source for a copier that flashes many times.

〔Effect of the invention〕

According to the method of the present invention detailed above, since a large number of granular amalgams are present in the arc tube during aging, the surface area of the amalgam increases substantially relative to its volume. Therefore, as this surface area increases, the amount of mercury released from the amalgam during aging also increases, so mercury is released quickly, which shortens the time required for knee song, contributing to improved manufacturing efficiency. . On the other hand, during lighting, including aging, multiple granular amalgam particles fuse with each other and their number decreases, which has the advantage of stabilizing the operating temperature of the amalgam and making it possible to properly control mercury vapor pressure. .

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a sectional view of the entire lighting device, Fig. 2 is a partially sectional perspective view of a fluorescent lamp, Fig. 3 is a sectional view of the end of the arc tube, and Fig. 3 is a sectional view of the end of the arc tube. FIG. 4 is a sectional view showing the amalgam encapsulation process. 8... Arc tube, 19... Amalgam, 19'-...
Granules. Applicant's representative Patent attorney Takehiko Suzue Figure 3 Figure 4 Figure 12 1'/

Claims (1)

[Claims] In a low-pressure mercury vapor discharge lamp in which the mercury vapor pressure in the arc tube is controlled by an amalgam that can be moved to the bottom of the arc tube by gravity, when the amalgam is sealed in the arc tube, the amalgam is A method for manufacturing a low-pressure mercury vapor discharge lamp, characterized in that the lamp is divided into particles and sealed.