KR20060124918A - Dual-type external electrode fluorescent lamp and method of manufacturing the same - Google Patents

Abstract

A dual type of external electrode fluorescent lamp and a method for manufacturing the same are provided to reduce the entire length of the external electrode fluorescent lamp, by coupling additive glass tubes with both end portions of an electrodeless fluorescent lamp. A first glass tube(100) has both open end portions(110), and a fluorescent material is coated on the inner wall of the first glass tube. A pair of second glass tubes(200) are coupled with both end portions of the first glass tube. Each of the second glass tubes has an open end portion(210) and a closed end portion. A first diameter(D1) of the first glass tube is smaller than a second distance(D4) of the second glass tube. The first glass tube is communicated with the second glass tubes by coupling both end portions of the first glass tube with the open end portions of the second glass tubes.

Description

Dual type external electrode fluorescent lamp and manufacturing method therefor {DUAL-TYPE EXTERNAL ELECTRODE FLUORESCENT LAMP AND METHOD OF MANUFACTURING THE SAME}

1 is a view schematically showing the structure of a dual type external electrode fluorescent lamp according to an embodiment of the present invention.

FIG. 2 is a view schematically illustrating a bonding structure of a third glass tube and a first glass tube and a manufacturing process thereof provided according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: first glass tube

110: Expanded open end of the first glass tube

200, 300: second glass tube

210: The concave open end of the second glass tube

The present invention relates to an external electrode fluorescent lamp (EEFL) and a method of manufacturing the same, and more particularly, by bonding a separate glass tube having a diameter different from the diameter of the lamp to both ends of the electrodeless fluorescent lamp The present invention relates to a dual type external electrode fluorescent lamp capable of reducing the total length of an electrode fluorescent lamp and the length of an external electrode, and a method of manufacturing the same.

A liquid crystal display is a light emitting flat panel display that itself emits light and does not form an image, and is a light receiving flat panel display that receives light from the outside to form an image, thereby observing an image in a dark place. There is a problem that cannot be done.

In connection with the above problem, a backlight is provided on the back of the liquid crystal display to irradiate light so that the image can be viewed even in a dark place. Typical specifications required for the backlight include high brightness, high efficiency, uniformity of brightness, long life, thinness, low weight, and low cost.

Conventionally, Cold Cathode Fluorescent Lamps (CCFLs) are frequently used as the backlights, but they are operated at high brightness and lifespan of lamps is pointed out as a problem. In this regard, in recent years, an external electrode fluorescent lamp has been widely used as a backlight.

The external electrode fluorescent lamp encapsulates gas in a sealed glass tube and forms electrodes on both ends of the lamp to perform gas discharge operation without exposing the electrode to the gas discharge space, thereby forming plasma in the lamp by the electric field of the external electrode. It is a fluorescent lamp having a structure. The gas discharge phenomenon inside the tube is the same as a normal lamp, but since the glass tube itself acts as a dielectric, the wall charge due to the accumulation of space charges caused by the discharge is added to the external voltage applied to induce the discharge. The gain is generated.

Unlike ordinary fluorescent lamps such as cold-cathode fluorescent lamps, external electrode fluorescent lamps have electrodes outside the lamp and do not generate heat by using an electron emission method by an electric field, and their lamp life is more than five times longer than ordinary fluorescent lamps. It is about 10 times brighter and next generation lighting lamp with more than 5 times energy efficiency compared to cold cathode fluorescent lamps. In addition, the external electrode fluorescent lamp has a number of advantages, such as being able to drive a plurality of tubes by different driving devices, and is widely used in applications requiring high brightness, such as LCD TVs and billboards.

On the other hand, the tube diameter of the lamp is related to the luminance and the light quantity. The smaller the diameter is, the higher the luminance is but the smaller the light emitting area of the fluorescent lamp is, the smaller the light quantity is. On the other hand, the larger the diameter, the smaller the luminance, but the light emitting area is increased, so that it is applied to a lamp for high power having a large amount of light. Particularly, external electrode fluorescent lamps generally use small tubes having small diameters to obtain high luminance, but the amount of light is small, and the luminance decreases when the diameters are increased to compensate for them.

In addition, as the length and diameter of the entire lamp become larger, the length of the external electrode is also proportionally longer correspondingly to obtain a constant brightness. However, when the length of the external electrode is increased, the effective light emitting surface is reduced, and when the backlight is used, the external electrode portion is wide, and thus the non-light emitting area where the panel is not emitted is increased, which is a negative factor in terms of lamp efficiency. .

Therefore, although a long length and a correspondingly large diameter are required according to the use of the external electrode fluorescent lamp, the present situation still remains.

Accordingly, an object of the present invention is to provide an external electrode fluorescent lamp which can reduce the length of an external electrode that can serve as a non-light-emitting region as well as obtain the required luminance when a long external electrode fluorescent lamp is required. It is an object to provide a lamp and a method of manufacturing the same.

In order to achieve the above object, the present inventors separately provide a glass tube in which the external electrode is formed, unlike the prior art in which the length of the entire external electrode fluorescent lamp is increased accordingly to the use and thus the length of the external electrode is increased. The present invention was completed by making the diameter of the larger than the diameter of the glass tube body coated with the fluorescent material.

In order to achieve the above object, there is provided a dual type external electrode fluorescent lamp according to an embodiment of the present invention, which is open at both ends, the fluorescent material is coated on the inner wall, the both ends are expanded A first glass tube; One end is closed and the other end is open, and includes a second glass tube of one type closed type having a diameter larger than the diameter of the first glass tube and bonded to both ends of the first glass tube, The second glass tube is joined to communicate with each other through the open end of the expanded first glass tube and the open end of the second glass tube.

Preferably, the open end of the second glass tube bonded to the open end of the first glass tube may be shaft-shaped.

In one embodiment, the diameter of the open end of the expanded first glass tube may be greater than or less than or equal to the diameter of the open end of the concentric second glass tube.

In a preferred embodiment, the fluorescent opening is not coated on the expanded open end of the first glass tube and the inner wall of the second glass tube.

The second glass tube is provided with an external electrode on its surface.

In order to achieve the above object, there is provided a method of manufacturing a dual type external electrode fluorescent lamp according to another aspect of the present invention, (i) both ends are open, the inner wall is coated with a fluorescent material, Providing a first glass tube with an enlarged diameter at the open end, and (ii) a second closed glass tube with one end closed and the other open and having a diameter greater than the diameter of the first glass tube. Is bonded to one of the two open ends of the first glass tube so that the first glass tube and the second glass tube communicate with each other; (iii) both ends are open and have a larger diameter than the first glass tube. And a first glass tube section joined to the other open end of the first glass tube and a second glass tube section connected to the exhaust system, the shaft being narrowed between the glass tube sections. Joining a third glass tube that is formed into a tube to another open end of the first glass tube so that the first glass tube and the third glass tube communicate with each other; and (iv) connecting an exhaust system to the second glass tube section to connect the inside of the glass tube. And evacuating and injecting an inert gas to cut and seal the shaft tube forming portion between the first glass tube section and the second glass tube section.

According to another embodiment of the present invention, there is provided a method of manufacturing a dual type external electrode fluorescent lamp, which comprises: (i) both ends are open, the inner wall is coated with a fluorescent material, and the diameter of the open end is enlarged; Providing a first glass tube, and (ii) a second closed glass tube having one end closed and the other end open and having a diameter larger than that of the first glass tube. Bonding to one of the open ends so that the first glass tube and the second glass tube communicate with each other; (iii) both ends are open and have a larger diameter than the first glass tube; A first glass tube section joined to the open end and a second glass tube section connected to the exhaust system and a third glass tube section between the first and second glass tubes, the tube diameter being between Joining a third glass tube narrowly shaped to the other open end of the first glass tube so that the first glass tube and the third glass tube communicate with each other; (iv) connecting an exhaust system to the second glass tube section; Vacuuming the inside of the glass tube and injecting an inert gas to cut the tube forming portion between the second glass tube section and the third glass tube section; (v) forming the tube between the first glass tube section and the second glass tube section; It is characterized in that it comprises a step of sealing while cutting the portion.

In a preferred embodiment, the open end of the second glass tube bonded to one open end of the first glass tube and the open end of the first glass tube section of the third glass tube bonded to the other open end of the first glass tube are shaft-shaped. Can be.

In one embodiment of the invention, the diameter of the open end of the condensed second glass tube and the diameter of the open end of the first glass tube section may be smaller or larger than or equal to the diameter of the open end of the expanded first glass tube. You may.

In a preferred embodiment, the method may further include forming an external electrode on the surface of the second glass tube and the surface of the first glass tube section.

In one embodiment of the invention, the first glass tube, the second glass tube, and the open end of the smaller diameter glass tube open end are inserted into the larger diameter glass tube open end and then heated by heating. Open ends can be joined.

In one embodiment, the two open ends are joined by heating with the open end of the second glass tube facing one open end of the first glass tube, and the first open tube section and the other open end of the first glass tube are joined. The two open ends can be joined oppositely.

According to another embodiment of the present invention, a method of manufacturing a dual type external electrode fluorescent lamp is provided, which method comprises: (i) both ends are open, the inner wall is coated with a fluorescent material, and the diameter of the open end is enlarged; Providing a first glass tube, wherein (ii) a second closed glass tube of one end type is closed and the other end is open and has a diameter larger than that of the first glass tube. Bonding to one open end of the two open ends so that the first glass tube and the second glass tube communicate with each other; (iii) a third glass tube having both ends open and having a larger diameter than the first glass tube; Bonding to the other open end of the first glass tube so that the first glass tube and the third glass tube communicate with each other, (iv) dividing the third glass tube into two or more glass tube sections, and Forming a narrower diameter between the sections; and (v) connecting the glass tube section opposite to the glass tube section of the glass tube section of the third glass tube, which is joined to the open end of the first glass tube, with the exhaust system to connect the inside of the glass tube. After evacuating and injecting discharge gas, cutting and removing the glass tube section connected to the exhaust system by cutting the forming mold.

According to a preferred embodiment, in step (iv), the first glass tube section is joined to the other open end of the first glass tube, and the second glass tube section connected to the exhaust system and between these glass tube sections. It may be divided into a third glass tube section, it may include forming a narrowing diameter between the glass tube sections.

In one preferred embodiment of the present invention, step (v) comprises connecting the exhaust system to the second glass tube section to evacuate the inside of the glass tube and injecting discharge gas, followed by the second glass tube section and the third glass tube section. Cutting the shaft tube forming portion between the second glass tube section and sealing the first glass tube section while cutting the shaft tube forming portion between the first glass tube section and the third glass tube section.

The objects, features and advantages of the present invention described above will be more clearly understood through the following detailed description of preferred embodiments of the present invention with reference to the accompanying drawings.

In the following description with reference to the accompanying drawings, in the manufacture of an external electrode fluorescent lamp, a description of the manufacturing process, operations that can be commonly performed, and the configuration or operation of a known device, which are already known in the art, Omit. In addition, although the characteristic configuration of the present invention has been described and illustrated as being applied to an external electrode fluorescent lamp, it will be readily understood by those skilled in the art that the present invention can also be applied to neon signs using glass lamps that are not coated with a fluorescent material.

1 is a view schematically showing the structure of a dual type external electrode fluorescent lamp according to an embodiment of the present invention. Specifically, FIG. 1 (a) shows a state in which the first glass tube 100 and the second glass tube 200 are separated, and FIG. 2 (b) shows a state in which the two glass tubes 100 and 200 are coupled. Shows. (C) and (d) of FIG. 1 show a state in which a second glass tube having a diameter different from that of the open end 210 of the second glass tube 200 shown in (a) of FIG. 1 is combined with the first glass tube. . 1, only a part of the left side of the dual type external electrode fluorescent lamp of the present invention is shown.

As shown in the figure, the dual type external electrode fluorescent lamp according to an embodiment of the present invention consists of a first glass tube 100 and a second glass tube 200 are bonded to each other, the second glass tube 200 The external electrode (not shown) is formed on the surface of), and the discharge gas is contained in the glass tube.

The end 110 of the first glass tube is open, and the inner wall of the glass tube is coated with a fluorescent material except for the end portion. In addition, as shown in the figure, the diameter D2 of the open end 110 is larger than the diameter D1 of the glass tube body.

One end of the second glass tube 200 is closed, and the other end thereof is formed to have an open structure. The second glass tube 200 is joined to the open end 110 of the first glass tube through the open end 210. On the other hand, as shown in the figure, the diameter (D4) of the second glass tube has a diameter larger than the diameter (D1) of the first glass tube, according to a preferred embodiment of the present invention the open end 210 is 1 The tube may be shaped for easy bonding with the open end 110 of the glass tube.

The diameter D3 of the shaft-shaped open end 210 may be smaller than the diameter D2 of the open end 110 of the first glass tube 100 (see FIG. 1A), or may be larger (FIG. 1 (c)) or may be the same (see (d) of FIG. 1).

The dual type external electrode fluorescent lamp having the structure as described above provides the second glass tube 200 in which the external electrode is formed separately from the first glass tube 100, and provides the diameter D4 of the diameter of the first glass tube. By making it larger than (D1), when an external electrode fluorescent lamp with a long length is required according to the use, it is possible to secure an area for obtaining a desired luminance without having to lengthen the external electrode correspondingly, so that The light emitting area can be reduced.

Hereinafter, the method of manufacturing the dual type external electrode fluorescent lamp having the configuration as described above will be described in detail.

1. Bonding of the first glass tube 100 and the second glass tube 200

First, as shown in FIG. 1A, a first glass tube 100 for preparing an external electrode fluorescent lamp is prepared, and a fluorescent material is formed on the inner surface of the glass tube according to a process commonly performed in a general fluorescent lamp manufacturing process. It is coated, and both ends 110 are open. It is preferable that the diameters of the both ends are expanded to be larger than the diameter of the glass tube body portion coated with the fluorescent material. This will be described in more detail below.

On the other hand, as shown in the drawings, according to one preferred embodiment of the present invention, the inner wall of the first glass tube 100 is not coated with a fluorescent material as a whole, the open end of the second glass tube 200 later A portion of both ends 110 to be bonded to 210 is not coated with a fluorescent material. That is, if the fluorescent material is coated at the time of bonding the glass tube, the bonding operation may be disturbed due to the fluorescent material, so it is preferable not to coat the fluorescent material at the bonding portion of the glass tube.

Next, the second glass tube 200 to be bonded to the first glass tube 100 is prepared. As shown in the figure, it can be seen that the diameter D4 of the second glass tube 200 is larger than the diameter D1 of the first glass tube 100. That is, depending on the application, a long external electrode fluorescent lamp may be required. When the length and / or diameter of the lamp are increased, the length of the external electrode is also proportionally large to obtain a constant luminance. However, when the length of the external electrode becomes longer, the effective light emitting surface is reduced and the non-light emitting area is increased as a whole of the lamp, thereby decreasing its efficiency.

The present invention does not manufacture an external electrode fluorescent lamp in the form of a single glass tube, but separately prepares and bonds the glass tube on which the external electrode is formed and the glass tube coated with the fluorescent material, and the diameter of the glass tube on which the external electrode is formed. To solve the problems of the prior art by making the larger than the diameter of the glass tube coated with a fluorescent material.

Specifically, the diameter D4 of the second glass tube 200 in which the external electrode is formed is prepared to be larger than the diameter D1 of the first glass tube 100 to secure an area of the external electrode portion required according to the application. That is, in a single external electrode fluorescent lamp as in the prior art, as the length increases, the glass tube of the external electrode forming portion of the same diameter is also lengthened, so as not to secure desired luminance or the like, and the glass tube 100 coated with the fluorescent material. Separately, the second glass tube 200 having a larger diameter than the glass tube is prepared to form an external electrode, thereby securing an area for obtaining a desired luminance.

As shown, one end of the second glass tube 200 is closed and the other end is open. According to a preferred embodiment of the present invention, the open end 210 is the open end 110 of the first glass tube. Its diameter is reduced in size for joining with.

Subsequently, the first glass tube 100 and the second glass tube 200 are joined to each other, and the open ends 110 and 210 of the two glass tubes are brought into contact with each other, and then the two ends are joined using torch heating or the like.

According to the present invention, in joining the two glass tubes, the two glass tubes can be melted and joined by using a torch while being rotated while being fixed using a predetermined holder (not shown). By joining the two glass tubes in this way, the warping of the glass tube to the depression of the glass tube at the joint portion can be effectively prevented.

In performing the bonding as described above, it is preferable that the diameter of the open end 110 of the coated glass tube, that is, the first glass tube 100, be expanded to be larger than the diameter of the first glass tube. That is, as shown in FIG. 1, the diameter D2 of the open end 110 is expanded to be larger than the diameter D1 of the first glass tube. When joining the glass tubes 100 and 200, the glass tubes tend to retract due to high heat. If, due to the high heat, the diameter D2 of the open end 110 is smaller than the diameter D1 of the first glass tube 100, a difference in luminance of the lamp occurs and the electrical resistance increases, and Appearance deteriorates. In view of these points, it is preferable that the open end 110 of the first glass tube 100 has its diameter D2 larger than the diameter D1 of the first glass tube.

On the other hand, according to a preferred embodiment of the present invention, in order to facilitate the bonding of the two glass tubes, the diameter of the open end (110, 210) is processed to be different from each other. At this time, the diameter D1 of the open end 110 of the first glass tube may be larger than the diameter D3 of the open end 210 of the second glass tube ((a) of FIG. 1), and may be made smaller. (FIG. 1C). In addition, according to another embodiment of the present invention, the diameters D2 and D3 of the open ends may be made the same (see FIG. 1D). However, without any molding of the open end 210 of the second glass tube, only the open end 110 of the first glass tube 100 can be processed to perform the bonding process with the second glass tube 200. It should be noted that That is, according to the embodiment, if the diameter (D4) of the second glass tube 200 is not significantly larger than the diameter (D1) of the first glass tube, simply by processing only the open end 110 of the first glass tube to the second The joining process can also be carried out by inserting or facing the glass tube.

After preparing the first and second glass tubes through the above process, a process of joining the two glass tubes is performed. As shown in FIGS. 1A and 1C, the diameters of the open ends of the two glass tubes are different from each other. In the case, after inserting the open end of the small diameter into the open end of the large diameter, the two open ends are joined by torch heating (see FIG. 1B), and as shown in FIG. 1D. If the two open ends have the same diameter, the two ends are joined together and then the two ends are joined by torch heating.

2. Bonding of the first glass tube 100 and the third glass tube 300

After completing the process of bonding the second glass tube 200 to one open end 110 of the first glass tube 100 through the series of processes, the other end of the first glass tube 100 Perform the bonding process. In this bonding process, an additional process is performed unlike the bonding process described above. That is, in manufacturing an external electrode fluorescent lamp, a process such as evacuating the inside of the lamp and injecting an inert gas (discharge gas) should be performed.

According to the present invention, a third glass tube of a novel structure is provided to more easily perform this essential process and the bonding process of the separate glass tube according to the present invention. In the following description, the part which overlaps with respect to the structure of the 1st and 2nd glass tube mentioned above abbreviate | omits the description.

(1) Structure of Third Glass Tube 300

As shown in FIG. 2, a third glass tube 300 of any length is provided to join the other open end of the first glass tube 100 with a separate glass tube. Unlike the second glass tube 200, the third glass tube 300 is composed of glass tube sections 320, 330, and 340 that can be cut into various parts, and both ends are open.

Specifically, the third glass tube 300 is composed of two or more glass tube sections, the third glass tube 300 consisting of the first, second and third glass tube sections 320, 330, 340 is shown in FIG. ) Is shown. The first glass tube section 320 is substantially shaped into a structure corresponding to the second glass tube 200 and is a glass tube section bonded to the open end of the first glass tube 100. The third glass tube section 340 serves as an exhaust pipe used to exhaust the inside of the external electrode fluorescent lamp, which will be described in detail below.

According to a preferred embodiment of the present invention, the open end 310 of the third glass tube 300 is also reduced in diameter for bonding to the first glass tube 100, and the bonding of the second glass tube 200 Likewise, it is joined with the open end of the first glass tube 100 through the open end 310.

On the other hand, as is clearly shown in the figure, between the respective glass tube sections is continuous through the formed portions 322, 332 to narrow the tube diameter. Thus, in providing the final external electrode fluorescent lamp, it is only necessary to cut the forming molding portion 322 using a torch or the like (see FIG. 2B).

(2) Bonding of the first glass tube 100 and the third glass tube 300

Similarly to the bonding of the second glass tube 200, the third glass tube 300 is bonded to the other open end of the first glass tube 100 through the open end 310.

Next, the inside of the glass tube is evacuated through the third glass tube section 340 connected to the exhaust system (not shown), and a process such as inert gas injection is performed. When the series of processes is completed, the operation of dividing each glass tube section is performed. In order to prevent air from flowing through the third glass tube section 340, in order to maintain high purity of the discharge gas, the laminated glass tube ( 100, 200 and 300 should be isolated from the exhaust system as well as the interior from the outside as soon as possible. According to the present invention, as described above, there are forming parts 322 and 332 between the glass tube sections, so that this separation operation can be performed quickly. That is, when all the exhaust work or the like is completed, the forming molded part 332 is cut out using the torch to cut off the inside of the glass tube from the outside. In addition, since the second glass tube section 330 is provided, the first glass tube section 320 in which the external electrode is formed can be performed with the finishing sealing as clean as possible with time margin. That is, the finishing sealing operation is performed on the forming molded part 322 to complete the bonding process of the third glass tube 300 and the first glass tube 100 (see FIG. 2B).

After completing the bonding process of the second glass tube 200 and the third glass tube 300 to the first glass tube 100 through this series of processes, the surface of the second glass tube 200 and the first glass tube section 320 When the external electrode is formed on the external electrode, the fluorescent lamp of the external electrode is completed. In this case, it should be noted that after forming the external electrode in the second glass tube and the first glass tube section 320 in advance, the above-described series of bonding processes may be performed.

In the above, specific preferred embodiment of this invention was shown and described. However, the present invention is not limited to the specific embodiments shown in the above-described embodiments and drawings, and those skilled in the art without departing from the gist of the present invention as defined in the following claims. It should be understood that anyone can carry out various modifications and modifications.

As described above, according to the present invention, even when a long external electrode fluorescent lamp is required depending on the use, a separate second glass tube in which the external electrode is formed without having to lengthen the length of the external electrode to obtain a desired bend. It is possible to ensure a desired external electrode area by providing a larger diameter of the glass tube than the diameter of the glass tube coated with the fluorescent material. Therefore, in the long external electrode fluorescent lamp, the non-light emitting area due to the external electrode can be reduced.

Claims (25)

A first glass tube whose both ends are open, a fluorescent material is coated on the inner wall, and both ends thereof are expanded; One end is closed and the other end is open and has a diameter larger than the diameter of the first glass tube, and the second glass tube of one end type is joined to both ends of the first glass tube. And the first glass tube and the second glass tube are joined to communicate with each other through the open end of the expanded first glass tube and the open end of the second glass tube. The dual type external electrode fluorescent lamp according to claim 1, wherein the open end of the second glass tube joined to the open end of the first glass tube is shaft-shaped. The dual type external electrode fluorescent lamp of claim 2, wherein a diameter of the open end of the expanded first glass tube is larger than a diameter of the open end of the concentric second glass tube. The dual type external electrode fluorescent lamp of claim 2, wherein a diameter of the open end of the expanded first glass tube is smaller than a diameter of the open end of the concentric second glass tube. The dual type external electrode fluorescent lamp of claim 2, wherein the diameter of the open end of the expanded first glass tube and the diameter of the open end of the condensed second glass tube are the same. 6. The dual type external electrode fluorescent lamp according to any one of claims 1 to 5, wherein the expanded open end of the first glass tube and the inner wall of the second glass tube are not coated with a fluorescent material. The dual type external electrode fluorescent lamp according to any one of claims 1 to 5, wherein the second glass tube has an external electrode formed on its surface. (i) providing a first glass tube whose both ends are open, the inner wall is coated with a fluorescent material, and the diameter of said open end is enlarged, (ii) one end closed second glass tube having a diameter larger than the diameter of the first glass tube is closed at one end and opened at the other end of one of the two open ends of the first glass tube. Allowing the first glass tube and the second glass tube to communicate with each other; (iii) both ends are open, have a larger diameter than the first glass tube, and include a first glass tube section joined to the other open end of the first glass tube and a second glass tube section connected to the exhaust system; Joining the third glass tube, which is formed in a narrow tube diameter, between the glass tube sections to another open end of the first glass tube so that the first glass tube and the third glass tube communicate with each other; (iv) connecting the exhaust system to the second glass tube section to evacuate the inside of the glass tube and inject discharge gas, and then cut and seal the shaft tube forming portion between the first glass tube section and the second glass tube section; Method for producing a dual type external electrode fluorescent lamp comprising a. (i) providing a first glass tube whose both ends are open, the inner wall is coated with a fluorescent material, and the diameter of said open end is enlarged, (ii) one end closed second glass tube having a diameter larger than the diameter of the first glass tube is closed at one end and opened at the other end of one of the two open ends of the first glass tube. Allowing the first glass tube and the second glass tube to communicate with each other; (iii) a second glass tube section and a first and a second open end, each having a larger diameter than the first glass tube, the first glass tube section joined to the other open end of the first glass tube and connected to the exhaust system; A third glass tube comprising a third glass tube section between the two glass tubes, and between the glass tube sections, a third glass tube, which is formed in a narrow tube diameter, to another open end of the first glass tube, so that the first glass tube and the third glass tube communicate with each other. To make sure that (iv) connecting the exhaust system to the second glass tube section to evacuate the inside of the glass tube and inject discharge gas, and then cut away the shaft tube forming portion between the second glass tube section and the third glass tube section; (v) sealing while cutting the shaft tube forming portion between the first glass tube section and the second glass tube section; Method for producing a dual type external electrode fluorescent lamp comprising a. The open end of the second glass tube bonded to one open end of the first glass tube, and the open end of the first glass tube section of the third glass tube bonded to the other open end of the first glass tube. A method of manufacturing a dual type external electrode fluorescent lamp, characterized in that the tube is molded. The dual type external electrode fluorescent lamp according to claim 10, wherein the diameter of the open end of the condensed second glass tube and the diameter of the open end of the first glass tube section are smaller than the diameter of the open end of the expanded first glass tube. Method of preparation. The dual type external electrode fluorescent lamp according to claim 10, wherein the diameter of the open end of the condensed second glass tube and the diameter of the open end of the first glass tube section are larger than the diameter of the open end of the expanded first glass tube. Method of preparation. The dual type external electrode fluorescent lamp according to claim 10, wherein the diameter of the open end of the condensed second glass tube and the diameter of the open end of the first glass tube section are the same as the diameter of the open end of the expanded first glass tube. Method of preparation. 10. The method of claim 8 or 9, comprising forming an external electrode on the surface of the second glass tube and on the surface of the first glass tube section. The method according to claim 11, wherein the glass tube open end of the smaller diameter of the open ends of the first glass tube, the second glass tube and the first glass tube section is inserted into the glass tube open end of the larger diameter, and then the two open ends are joined by heating. Method for producing a dual type external electrode fluorescent lamp, characterized in that. The method according to claim 12, wherein the glass tube open end of the smaller diameter of the open ends of the first glass tube, the second glass tube and the first glass tube section is inserted into the glass tube open end of the larger diameter, and then the two open ends are joined by heating. A method of manufacturing a dual type external electrode fluorescent lamp, characterized in that. The method according to claim 13, wherein the two open ends are joined by heating while facing the open end of the second glass tube with one open end of the first glass tube, and facing the first glass tube section and the other open end of the first glass tube. A method of manufacturing a dual type external electrode fluorescent lamp, comprising joining two open ends. (i) providing a first glass tube whose both ends are open, the inner wall is coated with a fluorescent material, and the diameter of said open end is enlarged, (ii) one end closed second glass tube having a diameter larger than the diameter of the first glass tube is closed at one end and opened at the other end of one of the two open ends of the first glass tube. Allowing the first glass tube and the second glass tube to communicate with each other; (iii) joining a third glass tube having both ends open and having a diameter larger than the first glass tube to the other open end of the first glass tube so that the first glass tube and the third glass tube communicate with each other; (iv) dividing the third glass tube into two or more glass tube sections, and forming a narrow tube diameter between the glass tube sections; (v) connecting the glass tube section opposite to the glass tube section of the glass tube section of the third glass tube, which is joined to the open end of the first glass tube, with the exhaust system to evacuate the inside of the glass tube and inject discharge gas; Cutting and removing the glass tube section connected to the forming mold Method for producing a dual type external electrode fluorescent lamp comprising a. 19. The method according to claim 18, wherein in (iv), the first glass tube section is joined to the other open end of the first glass tube, and the second glass tube section connected to the exhaust system and between the glass tube sections. A method for manufacturing a dual type external electrode fluorescent lamp comprising: dividing into three glass tube sections, and forming a narrow tube diameter between the glass tube sections. 20. The method of claim 19, wherein the step (v) connects the exhaust system to the second glass tube section to evacuate the inside of the glass tube and inject discharge gas to cut the shaft tube forming portion between the second glass tube section and the third glass tube section. Removing the second glass tube section, and then sealing the first glass tube section while cutting the shaft tube forming portion between the first glass tube section and the third glass tube section. . The open end of the second glass tube bonded to one open end of the first glass tube, and the open end of the third glass tube bonded to the other open end of the first glass tube are formed in the form of a shaft. Method for producing a dual type external electrode fluorescent lamp. 22. The dual type external electrode fluorescent lamp of claim 21, wherein the diameter of the open end of the condensed second glass tube and the diameter of the open end of the third glass tube are smaller than the diameter of the open end of the expanded first glass tube. Method of preparation. 22. The dual type external electrode fluorescent lamp of claim 21, wherein the diameter of the open end of the condensed second glass tube and the diameter of the open end of the third glass tube are larger than the diameter of the open end of the expanded first glass tube. Manufacturing method. 22. The dual type external electrode fluorescent lamp of claim 21, wherein the diameter of the open end of the condensed second glass tube and the diameter of the open end of the third glass tube are the same as the diameter of the open end of the expanded first glass tube. Manufacturing method. 25. The dual type of any one of claims 19 to 24 comprising forming external electrodes on the surface of the glass tube section of the third glass tube bonded to the surface of the second glass tube and the other open end of the first glass tube. Method for producing an external electrode fluorescent lamp.

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