JP2005149798A - Manufacturing method of fluorescent lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a long-size fluorescent lamp for a backlight of a liquid crystal display with a large screen by using straight glass tubes manufactured by a conventional manufacturing equipment. <P>SOLUTION: The manufacturing method of the fluorescent lamp manufactures the U-shaped fluorescent lamp unlike the conventional lamp manufactured by bending a piece of straight glass tube, but by jointing two pieces of straight glass tubes at a jointing part 7. By the above, the U-shaped fluorescent lamp with a length longer than maximum length of the conventional fluorescent lamp by approximately two times or longer, while using the glass straight tube having the same length as that of the conventional lamp. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a fluorescent lamp.

  Conventionally, a direct backlight of a liquid crystal television or a liquid crystal display has a configuration in which a plurality of straight fluorescent lamps are arranged. However, in recent years, in response to demands such as reducing the cost of the backlight, reducing the number of lamps used, and improving the lighting efficiency, the company has shifted to a direct backlight system that uses a U-shaped or U-shaped fluorescent lamp. I am doing. FIG. 10 shows a configuration of a backlight device using a U-shaped fluorescent lamp. The backlight device shown in FIG. 10 includes an inverter 101 as a power source of a fluorescent lamp, an insulating sheet 102, a back frame 103, a reflective sheet 104 for reflecting light, a plurality of U-shaped fluorescent lamps 105, and a plurality of fluorescent lamps. Resin holders 106 and 107 for fixing 105, a diffusion plate 108 for light diffusion, and a front frame 109 are configured.

  However, the U-shaped fluorescent lamp 105 has a problem that the pitch dimension (diameter) is applied to the frame 109 due to the bending pitch, and the effective screen size of the liquid crystal panel is reduced.

  Therefore, more recently, a U-shaped fluorescent lamp tends to be used instead of the U-shaped fluorescent lamp. The U-shaped fluorescent lamp is manufactured by holding a straight glass tube at a position separated by a pair of chucks, and rotating the pair of chucks one by one in a facing direction by a rotation guide groove. Rotating and guiding along an involute curve based on the diameter (circumference) of an imaginary circle with an arc formed by the part to be shaped into a circle as a part of the circumference, and rotating along the rotation guiding groove A first bending step (1) in which the chuck is rotated 45 degrees by a rotating arm via a slider to form an L shape (90 degrees), and the chuck is taken out and conveyed, and is again transferred to a pair of chucks. In the same manner as in the first bending process, the second bending process is performed by rotating the arm 45 degrees by 45 degrees to form a U-shape.

  However, since there is a limit to the length of a straight tube glass tube produced by existing equipment, a conventional fluorescent lamp manufacturing method for manufacturing a U-shaped fluorescent lamp by bending a straight tube glass tube is liquid crystal. There has been a problem that it is impossible to manufacture a U-shaped fluorescent lamp having a large size corresponding to an increase in the size of televisions and liquid crystal displays.

  On the other hand, in order to increase the size of the U-shaped fluorescent lamp, it is necessary to introduce equipment that matches the overall length of the lamp, resulting in an increase in equipment cost, a decrease in yield and operating rate, and an increase in product cost. There was a problem.

  The present invention has been made in view of the technical problems of the conventional fluorescent lamp manufacturing method described above, and has a U-shaped shape with a longer dimension than the conventional one while using a straight tube lamp manufactured with the existing equipment. It is an object of the present invention to provide a fluorescent lamp manufacturing method capable of manufacturing a fluorescent lamp.

  In the method for manufacturing a fluorescent lamp according to the first aspect of the present invention, an electrode is sealed at one end of a straight tubular glass tube, the connection-scheduled part of the glass tube is heated, and air is press-fitted into the connected part. Forming a projection for connecting to the outside, forming the first lamp tube by sealing the other end of the glass tube on which the projection for connection is formed, and straight tubular glass A second electrode is formed by sealing an electrode at one end of the tube, heating the planned connection portion of the glass tube, and press-fitting air into the glass tube, thereby projecting the connection planned portion to the outside and forming a connection protrusion. The lamps are connected to each other by connecting the protrusions for connection of the first lamp tube and the second lamp tube to each other to heat the lamps, Communicate inside the tube And evacuating the inside of both lamp tubes by evacuating from the open ends of the second lamp tubes, and discharging medium and mercury from the open ends of the second lamp tubes to the inside of both lamp tubes. A step of inserting, a step of cutting off an excess portion on the open end side of the second lamp tube at a position where the second lamp has a length equivalent to that of the first lamp, and the second lamp tube. And a step of sealing the cut-off end.

  According to a second aspect of the present invention, in the method of manufacturing a fluorescent lamp according to the first aspect, in the step of forming the connection protrusions on the first lamp tube and the second lamp tube, in addition to the connection protrusions, In the step of forming the projections for separation in the first and second connecting projections for connecting the first lamp tube and the second lamp tube, the projections for separation are connected to each other. is there.

  According to a third aspect of the present invention, there is provided a fluorescent lamp manufacturing method comprising: sealing an electrode at one end of a straight glass tube; heating the portion to be connected of the glass tube; and press-fitting air into the portion to be connected. A first end position lamp tube by sealing the other end of the glass tube on which the connection protrusion is formed, and a straight tube By sealing an electrode to one end of the glass tube, heating the planned connection portion of the glass tube and press-fitting air into the inside, thereby projecting the connection planned portion to the outside to form a connection protrusion A step of creating a second end position lamp tube, and an electrode is sealed at one end of a straight tubular glass tube, and each of the portions to be connected on both sides of the tube wall of the glass tube is heated, and air is injected into the inside thereof. The consolidated planned department Projecting outward to form connecting projections on both sides of the tube wall, and sealing the other end of the glass tube in which the connecting projections are formed to create an intermediate position lamp tube; The connecting protrusions of the first end position lamp tube and the connecting protrusion on one side of the intermediate position lamp tube are abutted and heated to connect the connecting protrusions of the two lamp tubes. The step of connecting the inside, and the connecting protrusions on the other side of the intermediate position lamp tube and the connecting protrusions of the second end position lamp tube are brought into contact with each other to heat the connecting protrusions. Connecting and connecting the insides of the two lamp tubes, and evacuating from the open end of the second end position lamp tube, the first end position lamp tube, the intermediate position lamp tube, and the second end position Exhausting the inside of each lamp tube; Inserting a discharge medium and mercury into each of the first end position lamp tube, the intermediate position lamp tube, and the second end position lamp tube from the open end of the second lamp tube; A step of cutting off an excess portion on the open end side of the lamp tube at a position where the second lamp has a length equivalent to that of the first lamp; and a step of sealing the cut-off end of the second lamp tube; It is what has.

  According to a fourth aspect of the present invention, in the method for manufacturing a fluorescent lamp according to the third aspect, the connecting protrusion is formed on each of the first end position lamp tube, the second end position lamp tube, and the intermediate position lamp tube. A step of forming a separation protrusion in addition to the connection protrusion, and connecting the connection protrusions of the first lamp tube and the intermediate position lamp tube to each other, and the intermediate position lamp tube and the second In the step of connecting the projections for connection with the lamp tube, the projections for separation are connected to each other.

  According to a fifth aspect of the present invention, there is provided a fluorescent lamp manufacturing method according to the fourth aspect, wherein a plurality of the intermediate position lamp tubes are used and the adjacent intermediate position lamp tubes are connected to each other in order to connect the intermediate position lamp tubes to each other. It has the process of connecting the said protrusion part for connection by making the protrusion part for abut | matching and heating, and making the inside of both lamp tubes communicate.

  According to a sixth aspect of the present invention, in the method of manufacturing a fluorescent lamp according to the fifth aspect, in the step of connecting and connecting the projections for connection to each other by heating, the projections for separation are connected in the step of communicating the interiors of both lamp tubes. The parts are brought into contact with each other and connected by heating, and the interval between adjacent lamp tubes is kept constant.

  According to the present invention, instead of producing a U-shaped fluorescent lamp by bending a single straight glass tube as in the prior art, a plurality of the same long straight glass tubes are used, Since the U-shaped fluorescent lamp is manufactured by providing the connecting portions at the predetermined dimensional positions and connecting them to each other, it is approximately 2 from the straightest glass tube of the same size as that of the conventional fluorescent lamp having the maximum size. A U-shaped fluorescent lamp up to twice as long can be produced, and a fluorescent lamp having a length of 3 or more can also be produced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. A method of manufacturing the fluorescent lamp according to the first embodiment of the present invention will be described with reference to FIGS. In the first stage process, a position corresponding to the dimension of the target U-shaped fluorescent lamp is heated and melted by the burner 10 with respect to a long straight tube-shaped glass tube 1 in which a phosphor film is formed. The excess portion 11 is removed and the end portion 2 of the remaining glass tube 1 is closed (steps S1 to S3).

  Next, the connection portion 3 of the glass tube 1 whose one end portion 2 is closed is heated by the burner 10, and a gas 4 such as air is injected from the opening end portion of the other end of the glass tube 1 to be heated and connected. The planned portion 3 is inflated outward by air pressure and protruded to form a perforated connecting protrusion 5 as shown on the left side of FIG. 3 (steps S4 and S5). Further, the first lamp tube 1A is formed by inserting the electrode mount 6 having the light emitting portion electrode into the opening end of the glass tube 1 and heat-sealing (steps S6 and S7).

  Subsequently, the second lamp tube 1B is formed and connected to the first lamp tube 1A by the second stage process shown in FIG. 2 to form a U-shaped fluorescent lamp LP1. That is, using a straight glass tube 1 equivalent to that used in the first stage, the electrode mount 6 is heat-sealed at one end of the glass tube 1, and the connection portion of the glass tube 1 is heated with a burner. A gas such as air is press-fitted into the glass tube 1 from the open end side not sealed by the electrode mount 6 to inflate the heated portion outwardly to form a perforated connecting projection 5. The glass tube 1 for the second lamp tube 1B thus obtained is opposed to the first lamp tube 1A. As shown in the right side of FIG. 10 is heated and pressed to be welded, and the internal spaces of both pipes 1A and 1 are communicated through the welded connecting projections 5 and 5, and further heated to form a large-diameter communicating part 7 ( Steps S8 and S9).

  Next, evacuation is performed from the unoccluded open end of the glass tube 1, and not only the inside of the glass tube 1 but also the inside of the first lamp tube 1 </ b> A communicating with the communication portion 7 is exhausted. After the evacuation step S10, a discharge medium such as mercury and a rare gas is sealed (step S10).

  Thereafter, the position of the glass tube 1 having the same dimensions as the first lamp tube 1A is heated with a burner to remove the surplus portion 11 and close the cut end 2 (step S11). Thereby, the second lamp tube 1B is formed from the glass tube 1, and the manufacture of the U-shaped fluorescent lamp LP1 in which the first and second lamp tubes 1A and 1B communicate with each other at the connecting portion 7 is completed. .

  According to the method for manufacturing a fluorescent lamp of the first embodiment, a U-shaped fluorescent lamp is not produced by bending a single straight glass tube 1 as in the prior art. The two glass tubes 1 are connected to each other by a connecting portion 7 to produce a U-shaped fluorescent lamp. Therefore, a straight tube glass tube having the same size as that of the conventional tube tube is used. A U-shaped fluorescent lamp LP1 up to twice as long can be manufactured.

  Next, a method for manufacturing the fluorescent lamp according to the second embodiment of the present invention will be described with reference to FIGS. The manufacturing method of the fluorescent lamp of the second embodiment is different from that of the first embodiment in order to maintain and fix the parallel first and second lamp tubes 1A and 1B. In addition to forming the connecting projections 5 on each of the glass tubes 1, the separating projections 8 are formed and welded together. The manufacturing method of the fluorescent lamp of the second embodiment is as follows.

  As shown in FIG. 4, a straight glass tube 1 having a phosphor film formed on the inner surface is prepared (step S21), and an electrode mount 6 is heat-sealed to one end (lower end in the figure) of the glass tube 1. (Steps S22 and S23).

  In the glass tube 1 to which the electrode mount 6 is sealed at one end, a portion to be formed with the separating protrusion 8 is heated with a burner in the same manner as in the method according to the first embodiment, and the open end (the upper end in the figure) ), A gas such as air is press-fitted into the glass tube 1 to inflate the heated portion outward, thereby forming the separating protrusion 8 (step S24). Subsequently, the connection portion of the glass tube 1 is also heated by the burner in the same manner as in the first embodiment, and a gas such as air is pressed into the glass tube 1 from the open end to expand the heating portion. Then, the connecting protrusion 5 is formed (step S25). After forming the connecting projection 5 and the separating projection 8 in this way, the glass tube 1 is heated and melted at a position that is the length of the lamp for manufacturing purposes to cut off the surplus portion 11 and the melted end 2 is closed. Thus, the first lamp tube 1A is obtained (step S26).

  As shown in FIG. 5, for the glass tube 1 for the second lamp tube 1B, a straight glass tube 1 having a phosphor film formed therein is prepared, and a final scheduled separation portion and a mercury alloy The holding portion is heated to form the narrowed portions 21 and 22, and the glass tube 1 is provided with the intermediate cut portion 23 and the first step cut portion 24 (step S28). Next, the electrode mount 6 is inserted into one end portion (lower end portion in the figure) of the glass tube 1 and heat-welded to seal the electrode mount 6 to one end portion of the glass tube 1 (steps S29 and S30).

  Thus, the glass tube 1 with the electrode mount 6 sealed at one end is heated with a burner in the same manner as in the first embodiment to form the separation projection 8 and from the opening end (the upper end in the figure). A gas such as air is press-fitted into the glass tube 1 to inflate the heated portion outward, thereby forming the separation protrusion 8 (step S31). Subsequently, the connection portion of the glass tube 1 is also heated by the burner in the same manner as in the first embodiment, and a gas such as air is pressed into the glass tube 1 from the open end to expand the heating portion. Then, the connecting protrusion 5 is formed (step S32). Thus, after forming the connecting protrusion 5 and the separating protrusion 8 on the glass tube 1 for the second lamp tube 1B, the first lamp tube 1A and the glass tube 1 are placed opposite to each other, and the connecting protrusion 5, 5 and the separation protrusions 8 and 8 are brought into contact with each other and welded by heating with a burner in the same manner as in the first embodiment. The connecting portion 9 is formed (steps S33 to S35). In this intermediate combined member, the first lamp tube 1A and the glass tube 1 that becomes the second lamp tube 1B are communicated with each other by a communication connecting portion 7.

  Subsequently, a mercury alloy 25 serving as a mercury source and impurity adsorption getter is inserted from the opening end of the glass tube 1 and is received by the narrowed portion 22 (step S36). Thereafter, the glass tube 1 is evacuated from the opening end of the glass tube 1 to make the inside of the glass tube 1 vacuum (step S37). The first-stage separation part 24 is heated by a burner above the position where the mercury alloy 25 is held and blown by a burner, the excess part 27 is cut off, and the fusing end part 28 of the glass tube 1 is closed. The alloy 25 is confined on the glass tube 1 side (step S38).

  Next, the mercury alloy 25 confined in the vacuum glass tube 1 is heated at a high frequency to generate mercury vapor and fill the glass tube 1, and the first lamp tube 1 </ b> A through the communication connecting portion 7. Fill the inside of the side. At the same time, impurities in both tubes 1A, 1 are removed by adsorption by the getter of this mercury alloy 25 (step S39).

  After the mercury filling step, the constricted portion 21 is heated with a burner, and the intermediate portion is cut off, the planned portion 23 is melted from the glass tube 1, and the melted end portion 2 of the glass tube 1 is closed so that the second lamp tube 1B is closed. At the same time, a U-shaped fluorescent lamp LP2 in which the first lamp tube 1A and the second lamp tube 1B are connected in a U-shape is completed (steps S40 and S41).

  6A and 6B are enlarged cross-sectional views of the communication connecting portion 7 and the separating connecting portion 9 in the U-shaped fluorescent lamp LP2. The interiors of the first and second lamp tubes 1A and 1B communicate with each other on the side of the connecting portion 7 for communication, but the inside of the tubes are welded to each other on the side of the connecting portion 9 for separation, although the tube walls are welded together. Absent.

  In the fluorescent lamp manufacturing method of the second embodiment described above, in addition to the same effects as those of the first embodiment, the first lamp tube 1A and the second lamp tube 1B are connected to the connecting portion 7 for communication. The first and second lamp tubes 1A and 1B are fixed at the connecting portion 9 for separation at a position opposite to the connecting portion 7 for communication. A U-shaped fluorescent lamp LP2 having a structure held at an interval can be manufactured, and a fluorescent lamp having a strong structure can be manufactured.

  Next, the manufacturing method of the fluorescent lamp of the 3rd Embodiment of this invention is demonstrated using FIGS. As shown in FIG. 9, the third embodiment is characterized in that a fluorescent lamp LP3 in which a plurality of three or more lamp tubes are connected is manufactured. The process of forming the first lamp tube 1A on one side is the same as that of the first embodiment. The process of forming the second lamp tube 1B on the other side is the same as that of the first embodiment.

  In the present embodiment, an intermediate position lamp tube 1C as shown in FIG. 7 is formed and connected to the first lamp tube 1A, the second lamp tube 1B, and the intermediate position lamp tubes. In the following, in the process of manufacturing a fluorescent lamp LP3 having a configuration in which three lamp tubes of the first lamp tube 1A, the intermediate position lamp tube 1C, and the second lamp tube 1B as shown in FIG. 9 are connected, A process of forming the intermediate position lamp tube 1C and a connection process of the first lamp tube 1A and the intermediate position lamp 1C will be described.

  The process of forming the intermediate position lamp tube 1C is as follows. As shown in FIG. 7, the first lamp tube in the first embodiment is used for a long straight tube glass tube 1 in which a phosphor film is formed as in the other tube tubes. The position corresponding to the dimension of the target U-shaped fluorescent lamp is heated and melted by the burner 10 to remove the surplus portion 11 and close the end 2 of the remaining glass tube 1 (step). S1-S3).

  Next, the connection planned part 3 of the glass tube 1 whose one end 2 is closed is heated by the burner 10, and a gas 4 such as air is injected from the opening at the other end of the glass tube 1 and heated. The portion 3 is inflated outward by air pressure and protruded to form a connecting protrusion 5 (steps S4 and S5). Then, it heated with the burner 10 with respect to the connection plan part 3 on the opposite side to the protrusion part 5 for a previous connection, and injected the gas 4 like air from the opening part of the other end of the glass tube 1, and was heated. The to-be-connected portion 3 is inflated outward by air pressure and protruded to form a connecting protrusion 5 (step S5 ′).

  Furthermore, the intermediate position lamp tube 1C is formed by inserting the electrode mount 6 having the light emitting portion electrode into the opening of the glass tube 1 and heat-sealing (steps S6 and S7).

  Next, the process of connecting the intermediate position lamp tube 1C to the first lamp tube 1A will be described with reference to FIG. Note that this connecting step is similarly applied to the connection between the intermediate position lamp tubes 1C. In the connection between the first lamp tube 1A formed in the process shown in FIG. 1 and the intermediate position lamp tube 1C formed in the process shown in FIG. 7, the first lamp tube 1A and the intermediate position lamp tube 1C are connected to each other. The portions of the connecting projections 5 and 5 of both pipes are heated by the burner 10 and pressed to be welded, and the internal spaces of both tubes 1A and 1C are passed through these welded connecting projections 5 and 5. Communicate (steps S8 ', S9'). Further, by heating the burner 10, the connecting protrusions 5 and 5 are made to have a large diameter to form a connecting part 7 for communication, and the pipes 1A and 1C are connected (steps S51 and S52).

  When the triple fluorescent lamp LP3 is manufactured, the glass tube 1 for the second lamp tube 1B is then attached to the unconnected connecting projection 5 of the intermediate position lamp tube 1C as shown in FIG. 2 in the first embodiment. The three fluorescent lamps LP3 shown in FIG. 9 are manufactured by connecting them in substantially the same manner as shown in FIG.

  According to the method for manufacturing a fluorescent lamp of the third embodiment, a U-shaped fluorescent lamp is not produced by bending a single straight glass tube 1 as in the prior art. The three fluorescent tubes LP3 are connected to each other at the connecting portion 7 to produce a triple fluorescent lamp LP3. Therefore, even from a straight tube glass tube of the same size, it is almost twice as large as the conventional maximum size fluorescent lamp. A triple fluorescent lamp up to a long length can be produced.

  Note that four or more fluorescent lamps can be manufactured in the same manner as in the third embodiment by connecting the necessary number of intermediate position lamp tubes 1C to each other by the process shown in FIG.

  In addition, in the fluorescent lamp according to the second embodiment, the separation protrusion 8 is provided at the end opposite to the connection protrusion 5, and the separation protrusion 8 is connected together with the connection of the connection protrusion 5. The manufacturing method can also be applied to three or more U-shaped fluorescent lamps. In that case, by applying the process of the third embodiment, the first lamp tube 1A is formed by a process substantially similar to the process shown in FIG. 4 and connected to both ends of the glass tube 1 near both ends. The intermediate position lamp tube 1C is formed by forming the protrusion 5 for separation and the protrusion 8 for separation, and this is formed between the first lamp tube 1A and the second lamp tube 1B as shown in FIG. One or more are connected by substantially the same process as in the above embodiment. The final intermediate position lamp tube 1C and the second lamp tube 1B are connected in substantially the same manner as the connection step of the second embodiment shown in FIG.

  As a result, in the third embodiment, the strength of supporting both ends of each lamp tube by the connecting portion 7 and the connecting portion 9 for separation as in the fluorescent lamp manufacturing method of the second embodiment. It is possible to produce a fluorescent lamp with

Explanatory drawing 1 of the 1st Embodiment of this invention. Explanatory drawing 2 of the 1st Embodiment of this invention. Explanatory drawing of the connection process of the protrusion parts for connection in the said 1st Embodiment. Explanatory drawing 1 of the 2nd Embodiment of this invention. Explanatory drawing 2 of the form of said embodiment. The expanded sectional view of the connection part for a communication in the fluorescent lamp produced in 2nd Embodiment, and the connection part for separation | spacing. Explanatory drawing 1 of the 3rd Embodiment of this invention. Explanatory drawing 2 of the 3rd Embodiment of this invention. The top view of the fluorescent lamp produced in the 3rd Embodiment of this invention. The disassembled perspective view of the conventional backlight apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass tube 1A 1st lamp tube 1B 2nd lamp tube 1C Intermediate position lamp tube 5 Connection protrusion part 6 Electrode mount 7 Connection part 8 Separation protrusion part 9 Separation connection part

Claims (6)

An electrode is sealed to one end of a straight tubular glass tube, and a connection projection portion is formed by projecting the connection planned portion to the outside by heating the connection planned portion of the glass tube and injecting air into the inside. A step of creating a first lamp tube by sealing the other end of the glass tube on which the connecting protrusion is formed;
An electrode is sealed at one end of a straight tubular glass tube, and a connection projection portion is formed by projecting the connection planned portion to the outside by heating the connection planned portion of the glass tube and press-fitting air therein. Creating the second lamp tube by:
Connecting the connecting protrusions by contacting and heating the connecting protrusions of the first lamp tube and the second lamp tube, and communicating the interiors of both lamp tubes;
Evacuating the interior of both lamp tubes by evacuating from the open ends of the second lamp tubes;
Inserting a discharge medium and mercury into the inside of both lamp tubes from the open ends of the second lamp tubes;
Cutting off the surplus portion on the open end side of the second lamp tube at a position where the second lamp has the same length as the first lamp;
And a step of sealing the cut end of the second lamp tube. In the step of forming the connecting protrusion on each of the first lamp tube and the second lamp tube, a separating protrusion is formed in addition to the connecting protrusion,
2. The method of manufacturing a fluorescent lamp according to claim 1, wherein in the step of connecting the connecting protrusions of the first lamp tube and the second lamp tube, the separating protrusions are connected to each other. . An electrode is sealed to one end of a straight tubular glass tube, and a connection projection portion is formed by projecting the connection planned portion to the outside by heating the connection planned portion of the glass tube and injecting air into the inside. A step of creating a first end position lamp tube by sealing the other end of the glass tube on which the connecting protrusion is formed;
An electrode is sealed at one end of a straight tubular glass tube, and a connection projection portion is formed by projecting the connection planned portion to the outside by heating the connection planned portion of the glass tube and press-fitting air therein. Thereby creating a second end position lamp tube;
An electrode is sealed to one end of a straight tubular glass tube, and each of the planned connection portions on both sides of the tube wall of the glass tube is heated, and air is pressed into the inside thereof to project the connection planned portion to the outside. Forming intermediate position lamp tubes by forming projecting portions on both sides of the tube wall and sealing the other end of the glass tube on which the connecting projecting portions are formed;
The connecting protrusions of the first end position lamp tube and the connecting protrusion on one side of the intermediate position lamp tube are abutted and heated to connect the connecting protrusions of the two lamp tubes. A process of communicating inside;
The connecting protrusions are connected to each other by heating the connecting protrusions on the other side of the intermediate position lamp tube and the connecting protrusions of the second end position lamp tube against each other and heating. A process of communicating inside;
Evacuating from the open end of the second end position lamp tube to evacuate the interior of each of the first end position lamp tube, the intermediate position lamp tube, and the second end position lamp tube;
Inserting a discharge medium and mercury from the open end of the second lamp tube into each of the first end position lamp tube, the intermediate position lamp tube, and the second end position lamp tube;
Cutting off the surplus portion on the open end side of the second lamp tube at a position where the second lamp has the same length as the first lamp;
And a step of sealing the cut end of the second lamp tube. In the step of forming the connecting protrusion on each of the first end position lamp tube, the second end position lamp tube, and the intermediate position lamp tube, a separating protrusion is formed in addition to the connecting protrusion,
In each of the step of connecting the connecting protrusions of the first lamp tube and the intermediate position lamp tube and the step of connecting the connecting protrusions of the intermediate position lamp tube and the second lamp tube, The method of manufacturing a fluorescent lamp according to claim 3, wherein the separation protrusions are connected to each other.   In order to connect the intermediate position lamp tubes to each other by using a plurality of the intermediate position lamp tubes, the connecting protrusions of the adjacent intermediate position lamp tubes face each other by heating each other. The method for manufacturing a fluorescent lamp according to claim 4, further comprising a step of connecting the two lamp tubes to each other. In the step of connecting the projections for connection to each other and heating them to connect the interiors of both lamp tubes, the projections for separation are connected to each other by heating them against each other, 6. The method of manufacturing a fluorescent lamp according to claim 5, wherein the interval is kept constant.

Images