JP2001006612A - Fluorescent lamp and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp and its manufacturing method capable of sufficiently setting off a part to accommodate mercury amalgam grains and suppressing certainly the movement of grains into a discharge tube. SOLUTION: This fluorescent lamp is composed of a glass tube 1 equipped with phosphor layer 2 on the inner surface, a sealing part 6 to seal the glass tube 1, an accommodation part 8 in communication with the inside of the glass tube 1 and having an inner space isolated from the outside, and mercury amalgam grains 7 accommodated in the accommodation part 8. The sealing part 6 is furnished with a through hole to generate communication from the glass tube 1 to the accommodation part 8, wherein the part of the through hole situated inside the sealing part 6 has at least partially an inside diameter smaller than the diameter of mercury amalgam grains 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp in which a mercury vapor pressure in a discharge tube is adjusted by using amalgam.

[0002]

2. Description of the Related Art In a fluorescent lamp, a fluorescent layer formed on the inner wall of a glass tube is stimulated by ultraviolet rays generated in the tube, and the obtained fluorescent light is used as a light source. As ultraviolet rays, resonance lines of mercury are widely used. Usually, pure mercury is sealed in the glass tube of the fluorescent lamp. In such a fluorescent lamp, the temperature of the coldest part of the lamp is about 40 ° C.
When the temperature around the lamp is about 25 ° C., the mercury vapor pressure in the glass tube becomes a suitable value, and the maximum luminous efficiency is obtained. However, in a compact fluorescent lamp formed of a glass tube having a bent shape such as a U-shape or a plurality of glass tubes connected to each other, the ambient temperature of the lamp tends to increase, so that the lamp temperature tends to increase. There is.

Therefore, a method of arranging mercury amalgam particles in a portion corresponding to the coldest part of a fluorescent lamp so that the mercury vapor pressure in the glass tube is adjusted to an appropriate range even when the temperature of the fluorescent lamp becomes high. Proposed. The mercury amalgam particles are usually arranged in a glass tube provided so as to communicate with a glass tube which is a discharge tube. In this case, the glass tube is provided with means for regulating the position of the mercury amalgam particles and preventing the mercury amalgam particles from moving into the discharge tube. As a structure of a fluorescent lamp provided with such means, for example, as shown in FIG. 7, a sealing portion 12 having a glass tube 14 penetrated through an end portion of a glass tube 10 on which a phosphor layer 11 is formed is provided. Is formed, and this glass capillary 1
A portion protruding outside from the sealing portion 12 of FIG.
(Japanese Utility Model Publication No. 2-16513) has been proposed. In the fluorescent lamp shown in FIG. 7, mercury amalgam particles 13 are held between the sealed end of the glass tube 14 and the narrowed portion 15. Further, as another structure, there has been proposed a structure in which a glass tube is penetrated through a sealing portion of the glass tube, and a blocking member for suppressing movement of amalgam particles is inserted into the glass tube.

[0004]

In recent years, in a compact fluorescent lamp such as a light bulb, a thin glass tube has been used as a discharge tube in accordance with a demand for further miniaturization, and a mercury amalgam particle is contained therein. Also, thinner and shorter glass tubes tend to be used.

In the conventional structure shown in FIG. 7, when a short glass tube is used, the sealing portion 12 of the glass tube 14 is used.
The portion protruding from the mercury amalgam granules 1
It is difficult to form the narrowed portion 15 while securing a sufficient portion for accommodating 3. Further, when a thin glass tube is used, there is a possibility that the glass tube 14 is crushed when the narrowed portion 15 is formed.

Further, in the structure in which the blocking member is inserted into the glass tube, when the glass tube is used as an exhaust pipe in the manufacture of a fluorescent lamp, the blocking member impedes the smooth exhaust, and a fluorescent lamp with poor exhaust occurs. There was a risk of doing.

The present invention has been made to solve such a problem, and it is possible to reliably suppress the movement of the mercury amalgam particles into the glass tube while securing a sufficient portion for accommodating the mercury amalgam particles. An object of the present invention is to provide a fluorescent lamp and a method for manufacturing the same.

[0008]

In order to achieve the above object, a first fluorescent lamp according to the present invention comprises a glass tube having a phosphor layer on an inner surface thereof, and a sealing tube formed at an end of the glass tube. Part, a housing part communicating with the inside of the glass tube and having an internal space isolated from the outside, and mercury amalgam particles housed in the housing part, wherein the sealing part has the glass tube and the housing part. Is formed, and at least a part of a portion of the through hole located in the sealing portion has an inner diameter smaller than a particle size of the mercury amalgam granules.

In the fluorescent lamp having such a configuration,
Since the portion that suppresses the movement of the mercury amalgam particles is formed in the sealing portion, regardless of the length of the portion protruding from the sealing portion of the storage portion, while ensuring a sufficient volume of the storage portion, It is possible to suppress movement. Further, since there is no member corresponding to the blocking member, that is, a member other than the mercury amalgam particles, inside the housing portion and the through hole, even when the housing portion and the through hole are used as an exhaust pipe, sufficient exhaust efficiency is obtained. Can be secured.

[0010] In the first fluorescent lamp, it is preferable that at least a part of the accommodating portion is disposed in the sealing portion. According to this preferred example, it is easy to sufficiently secure the volume of the storage section even when the portion of the storage section protruding from the sealing section is short.

Further, a second fluorescent lamp according to the present invention communicates with a glass tube having a phosphor layer on an inner surface, a sealing portion formed at an end of the glass tube, and the inside of the glass tube. And a glass tube having an internal space isolated from the outside, and including a mercury amalgam particles contained in the glass tube, the glass tube has a small diameter portion having an inner diameter smaller than the particle size of the mercury amalgam particles, A large-diameter portion having an inner diameter larger than the particle size of the mercury amalgam granules, the small-diameter portion being disposed in the sealing portion, and the large-diameter portion being more external to the glass tube than the small-diameter portion. Side by side,
It is fused to the glass tube.

In the fluorescent lamp having such a configuration,
Regardless of the length of the portion protruding from the sealing portion of the glass tube, it is possible to suppress the movement of the mercury amalgam particle while ensuring a sufficient volume of the portion for containing the mercury amalgam particle, and Even when used as an exhaust pipe, sufficient exhaust efficiency can be secured.

[0013] In the second fluorescent lamp, it is preferable that at least a part of the large diameter portion is disposed in the sealing portion. According to this preferred example, even if the portion of the glass tube protruding from the sealing portion is short, it is easy to sufficiently secure the volume of the portion accommodating the mercury amalgam particles.

Next, a method for manufacturing a fluorescent lamp according to the present invention is as follows.
Inserting a forming rod having a large-diameter portion and a small-diameter portion having different diameters into a thin glass tube; forming a phosphor layer on the inner wall of the glass tube; and Arranging the glass tube so that the large-diameter portion is located on the outer side of the glass tube with respect to the small-diameter portion, and after sealing the open end of the glass tube, the molding rod is formed from the glass tube. Extracting the mercury amalgam particles in the glass tube, and sealing an open end of the glass tube on the outside of the glass tube, and sealing the open end of the glass tube. In the stopping step, at least a portion of the glass tube into which the small-diameter portion is inserted is fused to the glass tube, and the inside diameter of the glass tube is reduced by the mercury in the portion into which the large-diameter portion is inserted. While maintaining larger than Marugamu grains having a grain size, in the portion where the small diameter portion is fused to the inserted and the glass tube is characterized in that to shrink less than the particle size of the mercury amalgam particles.

[0015] The phrase "comprising a large diameter portion and a small diameter portion having different diameters from each other" means that the forming rod has two portions having different diameters from each other, and the larger diameter portion of the two portions has the larger diameter. The smaller the part and the smaller the diameter, the smaller the diameter.

According to such a manufacturing method, the portion for suppressing the movement of the mercury amalgam particles can be formed simultaneously with the sealing of the glass tube, and the formation position is set in the sealing portion. Further, in the glass thin tube, even after the sealing step, the inside diameter of the portion where the large diameter portion of the molded rod is inserted is larger than that of the mercury amalgam particles, so that it is easy to secure a portion for accommodating the mercury amalgam particles. Therefore, it is possible to manufacture the fluorescent lamp of the present invention without providing a separate step of forming a glass tube. Further, in the step of reducing the inner diameter of the specific portion of the glass thin tube, since the forming rod is inserted into the glass thin tube, it is possible to prevent the inner diameter of the glass thin tube from being reduced more than necessary. Therefore, sufficient exhaust efficiency can be ensured even if a glass tube is used as the exhaust pipe.

In the above manufacturing method, it is preferable that the inside of the glass tube is evacuated using the glass tube as an exhaust tube before the step of disposing mercury amalgam particles in the glass tube. When another member other than the glass tube is used as the exhaust pipe, a glass tube must be used to prevent the release of mercury from the mercury amalgam particle from the time the mercury amalgam particles are put into the glass tube until the exhaust is completed. And it is necessary to cool the glass capillary. However, according to this preferred example, since the glass thin tube is used as the exhaust pipe and the mercury amalgam particles are introduced after the inside of the glass tube is exhausted, the cooling operation as described above is unnecessary.

[0018]

FIG. 1 is a sectional view showing an example of a fluorescent lamp according to a first embodiment of the present invention. In this fluorescent lamp, a glass tube in which three U-shaped molded bulbs 1 are connected so that their internal spaces communicate with each other is used as a discharge tube, and a phosphor layer 2 is formed on the inner surface thereof. Each U-shaped mold valve 1 is sealed by a sealing portion, and a predetermined amount of an inert gas (for example, argon or the like) is sealed therein. At least one
One, and preferably all, U-shaped mold bulbs 1 are provided with glass tubules 8 containing mercury amalgam granules 7. Also, a U-shaped molded valve 1 disposed at both ends
Each has an electrode body composed of a filament electrode 3, a lead wire 4 and a glass bead 5.

FIG. 2 shows the structure of the U-shaped molded bulb constituting the fluorescent lamp of FIG. 1 which is arranged at the end.

The U-shaped molded valve 1 is sealed at both ends by sealing portions. Two lead wires 4 pass through one sealing portion. A filament electrode 3 is provided between the two lead wires 4, and the filament electrode 3 is disposed in the U-shaped molded valve 1. Note that the interval between the lead wires 4 is regulated by the glass beads 5. The other sealing portion 6 is provided with a thin glass tube 8 containing mercury amalgam particles 7.

FIG. 3 shows the structure around the sealing portion 6. A glass tube 8 penetrates through the sealing portion 6.
The glass thin tube 8 is a glass tube having one end opened and the other end closed, and the portion including the closed end is a U-shaped molded valve 1.
And is provided such that the open end is disposed inside the U-shaped mold valve 1.

The glass thin tube 8 has a shape in which a small-diameter portion 8a and a large-diameter portion 8b having different inner diameters are joined, and the mercury amalgam particles 7 are accommodated in the large-diameter portion 8b. That is, the large-diameter portion 8b forms a storage portion for storing the mercury amalgam granules 7, and the small-diameter portion 8a penetrates the large-diameter portion (storage portion) 8b to communicate with the internal space of the U-shaped mold valve 1. It constitutes a hole.

The large diameter portion 8b is provided so that at least a part thereof projects from the sealing portion 6 to the outside of the U-shaped molded valve 1. The inner diameter of the large diameter portion 8b is set to be at least partially larger than the particle size of the mercury amalgam 7 so that the mercury amalgam 7 can be accommodated.

The small diameter portion 8a is a portion serving as a passage for communicating the internal space of the U-shaped molded valve 1 with the internal space of the large diameter portion 8b. The small diameter portion 8a is located on the inner side of the U-shaped molded valve 1 with respect to the large diameter portion 8b, and at least a part thereof is located in the sealing portion 6. Small diameter part 8a
Is set smaller than the particle size of the mercury amalgam 7 at least in part so that the passage of the mercury amalgam 7 can be prevented.

At the boundary between the small diameter portion 8a and the large diameter portion 8b, as shown in FIG. 3, the inner diameter changes stepwise, and a step is formed. Further, in the boundary portion, the inner diameter may be continuously changed to form a slope.

As described above, the inner diameters of the small diameter portion 8a and the large diameter portion 8b are set according to the particle size of the mercury amalgam particles 7 contained therein. The following is an example of specific dimensions. The particle size of the mercury amalgam particles 7 is, for example, 2 to 2.
It is 2.5 mm, preferably 2.2 mm. Small diameter part 8a
Has an inner diameter of, for example, 0.5 to 2 mm, preferably 1.2 m
m. The inner diameter of the large diameter portion 8b is, for example, 3.0 to 3.0.
It is 3.5 mm, preferably about 3.1 mm.

The length of the large-diameter portion 8b is
It is not particularly limited as long as it is larger than the particle size of,
For example, it is about 3 to 15 mm, preferably about 3 to 10 mm, and more preferably about 4 mm. In the present embodiment, the length of the large diameter portion 8b corresponds to the length of the portion of the glass tube 8 protruding from the sealing portion 6.

The length of the small diameter portion 8a is appropriately determined according to the total length of the glass tube.
Preferably 4 to 13 mm, more preferably 4 to 10 m
m, most preferably about 6 mm.

FIG. 4 is a partial sectional view showing an example of a fluorescent lamp according to the second embodiment of the present invention. This form
Particularly, it is suitable when a short glass tube is used. 4 and 3, the members corresponding to each other are denoted by the same reference numerals.

In the second embodiment, a thin glass tube 8 having a small diameter portion 8a and a large diameter portion 8b is provided in the sealing portion 6, and the small diameter portion 8a and a part of the large diameter portion 8b are sealed. It is located in the stop 6. That is, in the fluorescent lamp according to the second embodiment, the large-diameter portion 8b that forms the storage portion that stores the mercury amalgam particles 7 has a
It is provided in a state buried inside.

In the present embodiment, since a part of the large diameter portion 8b is buried in the sealing portion 6, the length of the small diameter portion 8a is shorter than that of the first embodiment. The length of the small diameter portion 8a is, for example, 0.5 to 8 mm, preferably 1 to 5 mm, and more preferably 1 to 3 mm. The inner diameter of the small diameter portion 8a can be set in the same manner as in the first embodiment.

Further, since a part of the large diameter portion 8b is embedded in the sealing portion 6, the length of the large diameter portion 8b protruding from the sealing portion 6 is longer than that of the first embodiment. Be shorter. Large diameter part 8
The length of the portion b that protrudes from the sealing portion 6 (that is, the portion that is not embedded in the sealing portion 6) is, for example, 2 to 10 m.
m, preferably 2 to 8 mm, more preferably 2 to 5 mm
It is.

The entire length of the large diameter portion 8b is not particularly limited as long as it is larger than the particle size of the mercury amalgam particles 7, and can be set in the same manner as in the first embodiment.
Further, the inner diameter of the large diameter portion 8b can be set in the same manner as in the first embodiment.

According to the second embodiment, the large diameter portion 8b
By disposing a part of the inside of the sealing part 6, the volume of the part accommodating the mercury amalgam particles can be more sufficiently secured. In addition, compared with the first embodiment, the small diameter portion 8a
Therefore, even when the thin glass tube 8 is used as an exhaust pipe during manufacturing, good exhaust efficiency can be realized.

Next, an example of a method for manufacturing a fluorescent lamp according to the present invention will be described. FIG. 5 is a process chart showing an example of a method for manufacturing the fluorescent lamp shown in FIG.

First, a straight tubular glass tube is formed into a U-shape by a forming block to produce a U-shaped molded bulb 1 (FIG. 5A). Next, after forming the phosphor layer 2 on the inner surface of the U-shaped molded valve 1 (FIG. 5B), the phosphor layers 2 at both ends of the U-shaped molded valve 1 are removed (FIG. 5).
(C)).

On the other hand, the filament electrode 3 is provided between one ends of the two lead wires 4, and the glass beads 5 are arranged so as to regulate the interval between the lead wires 4, thereby producing an electrode body.

Subsequently, one end of the U-shaped molded valve 1 is sealed with the electrode body inserted. Further, the other end of the U-shaped mold valve 1 is sealed with the glass tube 8 inserted therein to form a sealing portion 6 (FIG. 5D). These sealings are performed by heating the end of the U-shaped molded valve 1 until it is softened, and then sandwiching it with a pincher.

Subsequently, a U-shaped molded valve 1 is provided with two separately prepared U-shaped mold valves so as to correspond to the structure shown in FIG.
Connect with and integrate with a V-shaped mold valve. Further, after evacuating the inside of the U-shaped mold bulb 1 using the glass tube 8 as an exhaust tube, the filament electrode 3 is activated, an inert gas is injected into the discharge space, and the mercury amalgam particles 7 are introduced into the glass tube 8. And the sealing of the glass tube 8 are sequentially performed to obtain a fluorescent lamp according to the present invention (FIG. 5E).

Next, the steps from FIG. 5C to FIG. 5E will be described in more detail with reference to FIG.
FIG. 6 corresponds to the portion shown in FIG.

First, the forming rod 9 is inserted into the glass tube 8. The glass tubule 8 is a straight tubular glass tube that is substantially uniform and has an inner diameter that is larger than the particle size of the mercury amalgam granules to be subsequently stored in the glass tubule 8. The molded rod 9 is a rod having a small diameter portion having a diameter smaller than the particle size of the mercury amalgam particles and a large diameter portion having a diameter larger than the particle size of the mercury amalgam particles. As the forming rod 9, for example, a metal having releasability from glass, such as tungsten, stainless steel, or brass, can be used. The molding rod 9 can be formed, for example, using a mold.

At the open end of the U-shaped molded valve 1, a glass tube 8 into which a molding rod 9 is inserted is arranged (FIG. 6).
(A)). At this time, the glass thin tube 8 is arranged such that the small diameter portion of the molded rod 9 inserted is closer to the inside of the U-shaped mold valve 1 than the large diameter portion.

Subsequently, the open end of the U-shaped mold valve 1 in which the glass tube 8 is disposed is heated and sealed with a pincher (FIG. 6B). The heating temperature is the softening point of the U-shaped mold bulb 1 and the glass capillary 8 (for example, 665 ° C.).
The temperature may be at least 900 ° C to 1250 ° C, preferably 1000 ° C to 1200 ° C.

By this step, the U-shaped mold valve 1
Is formed at the end of the sealing member 6 through which the glass tube 8 penetrates. At the same time, the inner surface of the portion of the glass thin tube 8 penetrating the sealing portion 6 is formed into a shape imitating the stepped forming rod 9. In other words, the small-diameter portion 8a having an inner diameter smaller than the particle size of the mercury amalgam particles to be stored later is formed in the glass thin tube 8, and the U-shaped molded valve 1 is smaller than the small-diameter portion 8a.
A large-diameter portion 8b having an inner diameter larger than the particle size of the mercury amalgam granules 7 is formed in a portion located on the outer side of.

Thereafter, the molding rod 9 is removed from the glass tube 8 (FIG. 6C), and the inside and the outside of the U-shaped molded valve 1 are communicated via the glass tube 8.

Subsequently, after connecting the U-shaped molded valve 1 to two separately prepared U-shaped molded valves, the inside of the U-shaped molded valve 1 is evacuated using the glass thin tube 8 as an exhaust pipe. After activating the filament electrode 3 and injecting the inert gas into the U-shaped mold bulb 1, the mercury amalgam particles 7 are inserted into the glass tube 8.
Thereafter, the end of the glass tube 8 is sealed to obtain a fluorescent lamp (FIG. 6D).

In the above description, a compact fluorescent lamp using a glass tube in which a plurality of U-shaped molded bulbs are integrated as a discharge tube has been described as an example, but the present invention is not limited to this. is not. For example, the present invention can be applied to fluorescent lamps of any shape, such as a straight tube fluorescent lamp and a double U-shaped fluorescent lamp.

[0048]

As described above, according to the fluorescent lamp of the present invention, the glass tube provided with the phosphor layer on the inner surface, the sealing portion formed in the glass tube, and the inside of the glass tube. An accommodating portion having an internal space that is in communication with and isolated from the outside;
And mercury amalgam granules contained in the container,
A through-hole for communicating the glass tube with the housing portion is formed in the sealing portion, and at least a part of a portion of the through-hole located in the sealing portion is formed of the mercury amalgam. Since it has an inner diameter smaller than the diameter, it is possible to suppress the movement of the mercury amalgam particles into the glass tube while ensuring a sufficient volume of a portion in which the mercury amalgam particles are accommodated.

[Brief description of the drawings]

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

FIG. 2 is a partially cutaway front view in which a part of the fluorescent lamp of FIG. 1 is enlarged.

FIG. 3 is an enlarged front sectional view showing a structure of a portion of the fluorescent lamp of FIG. 1 in which mercury amalgam particles are stored.

FIG. 4 is an enlarged front sectional view showing a structure of a portion of a fluorescent lamp according to a second embodiment of the present invention in which mercury amalgam particles are stored.

FIG. 5 is a diagram illustrating a method for manufacturing a fluorescent lamp according to the present invention.

FIG. 6 is a view for explaining a process from FIG. 5C to FIG. 5E around a portion of the fluorescent lamp in which mercury amalgam particles are stored;

FIG. 7 is an enlarged front sectional view showing the structure of a portion of a conventional fluorescent lamp in which mercury amalgam particles are stored.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 10 U-shaped mold valve 2, 11 Phosphor layer 3 Filament electrode 4 Lead wire 5 Glass bead 6, 12 Sealing part 7, 13 Mercury amalgam particle 8, 14 Glass tube 9 Metal rod 15 Drawing part

 ──────────────────────────────────────────────────の Continuing on the front page (72) Nobuyuki Tsubakihara, Inventor No. 1-1, Komachi, Takatsuki-shi, Osaka Matsushita Electronics Co., Ltd. F-term (reference) 5C015 UU04 5C043 AA20 CC09 CD10 DD01 DD08 EA03 EB18 EC01

Claims (21)

[Claims] 1. A housing having a glass tube having a phosphor layer on an inner surface, a sealing portion formed at an end of the glass tube, and an internal space communicating with the inside of the glass tube and isolated from the outside. And a mercury amalgam particle housed in the housing part, a through-hole for communicating the glass tube with the housing part is formed in the sealing part, and the sealing of the through-hole is performed. A fluorescent lamp characterized in that at least a part of a portion located in the part has an inner diameter smaller than a particle diameter of the mercury amalgam granules. 2. The fluorescent lamp according to claim 1, wherein at least a part of the housing section is disposed in the sealing section. 3. The fluorescent lamp according to claim 1, wherein a length of a portion of the housing portion protruding from the sealing portion to the outside of the glass tube is 2 to 15 mm. 4. The fluorescent lamp according to claim 1, wherein an inner diameter of the housing is 3 to 3.5 mm. 5. An inner diameter of a portion of the through hole having an inner diameter smaller than a particle diameter of the mercury amalgam granules is 0.5 to 2
The fluorescent lamp according to any one of claims 1 to 4, wherein the distance is in mm. 6. The length of a portion of the through hole having an inner diameter smaller than the particle size of the mercury amalgam granules is 0.5 to 1
The fluorescent lamp according to any one of claims 1 to 5, which is 5 mm. 7. A glass having an inner surface provided with a phosphor layer, a sealing portion formed at an end of the glass tube, and an inner space communicating with the inside of the glass tube and isolated from the outside. A thin tube, including a mercury amalgam particle contained in the glass tube, wherein the glass tube has a small diameter portion having an inner diameter smaller than the particle size of the mercury amalgam particle, and a particle diameter larger than the particle size of the mercury amalgam particle. A large-diameter portion having an inner diameter, the small-diameter portion is disposed in the sealing portion,
A fluorescent lamp, wherein the large-diameter portion is fused to the glass tube such that the large-diameter portion is disposed outside the glass tube with respect to the small-diameter portion. 8. The fluorescent lamp according to claim 7, wherein at least a part of the large diameter portion is disposed inside the sealing portion. 9. The length of a portion of the glass tube protruding from the sealing portion to the outside of the glass tube is 2 to 15 mm.
The fluorescent lamp according to claim 7 or 8, wherein 10. The inner diameter of the large diameter portion is 3 to 3.5 mm.
The fluorescent lamp according to any one of claims 7 to 9, wherein 11. The small diameter portion has an inner diameter of 0.5 to 2 mm.
The fluorescent lamp according to any one of claims 7 to 10, wherein 12. The length of the small diameter portion is 0.5 to 15 m.
The fluorescent lamp according to any one of claims 7 to 11, which is m. 13. A step of forming a phosphor layer on an inner wall of a glass tube, a step of inserting a forming rod having a large diameter portion and a small diameter portion having different diameters from each other into a glass tube, and the large diameter portion of the forming rod. Disposing the glass tube at the open end of the glass tube so that the glass tube is located on the outer side of the glass tube with respect to the small-diameter portion; and sealing the glass tube after sealing the open end of the glass tube. Extracting the shaping rod from the glass tube, arranging mercury amalgam granules in the glass tube, and sealing the open end of the glass tube on the outside of the glass tube. In the step of sealing the open end, at least a portion of the glass tube into which the small-diameter portion is inserted is fused to the glass tube, and an inner diameter of the glass tube is set at a portion where the large-diameter portion is inserted. Is characterized in that, at a portion where the small diameter portion is inserted and fused to the glass tube, the particle size is reduced to be smaller than the particle size of the mercury amalgam particles, while maintaining the particle size larger than the particle size of the mercury amalgam particles. Method for manufacturing fluorescent lamps. 14. The method according to claim 13, wherein the inside of the glass tube is evacuated using the glass tube as an exhaust tube before the step of disposing mercury amalgam particles in the glass tube. 15. The method according to claim 13, wherein in the step of sealing the open end of the glass tube, at least a part of a portion of the thin glass tube into which the large diameter portion is inserted is fused to the glass tube. The method for producing the fluorescent lamp according to the above. 16. The molding rod according to claim 13, wherein the molding rod is a metal.
15. The method for manufacturing a fluorescent lamp according to any one of the above items 15. 17. The method according to claim 17, wherein the forming rod is at least one selected from the group consisting of tungsten, stainless steel and brass.
The method for manufacturing a fluorescent lamp according to claim 16, wherein the metal is a kind of metal. 18. The glass capillary according to claim 13, wherein the inside diameter of the portion into which the large diameter portion is inserted is 3 to 3.5 mm.
18. The method for manufacturing a fluorescent lamp according to any one of claims 17 to 17. 19. The inner diameter of a portion of the thin glass tube into which the small diameter portion is inserted and which is fused to the glass tube is set to 0.1.
The method for manufacturing a fluorescent lamp according to any one of claims 13 to 18, wherein the thickness is 5 to 2 mm. 20. The length of a portion of the glass thin tube into which the small-diameter portion is inserted and which is fused to the glass tube is set to 0.
The method for manufacturing a fluorescent lamp according to any one of claims 13 to 19, wherein the thickness is 5 to 15 mm. 21. A length of a portion of the glass thin tube projecting outward from a sealed end of the glass tube is 2 to 1;
The method for manufacturing a fluorescent lamp according to any one of claims 13 to 20, wherein the distance is 5 mm.