JP2005190782A - Manufacturing method of discharge tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge tube which is superior in optical irradiation efficiency, does not possibly generate leakage at the jointing portion, and can be manufactured easily and efficiently. <P>SOLUTION: One side end 2 of a flat glass tube 1 is sealed and the other side end 3 is connected to a ventilation part 4 made of a small diameter glass tube. The glass tube portion corresponding to the desired length of the discharge tube is heated by a burner 5 and while exhausting the air inside the glass tube, a neck portion 6 is formed in the glass tube. After evacuating air from the glass tube by the ventilation part, a discharge gas is filled and the ventilation part is sealed. By heating and melting and cutting the neck portion, a plurality of glass tubes are obtained. An external electrode is arranged at the position mutually opposed to on the outer circumference of each glass tube cut off. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a discharge tube used in various light-emitting devices, and in particular, a discharge tube that is excellent in production efficiency and has a long life by adopting a flat cylindrical shape instead of a conventional cylindrical shape or box shape. It is about the method.

Many conventional discharge tubes have a structure in which a metal electrode or the like is disposed in the tube, and this metal is scattered over time, which is a cause of shortening the life of the discharge tube. Conventionally, many cylindrical round tubes exist as the shape of the discharge tube. Recently, a thin discharge tube taking advantage of space saving has been used as a backlight of a liquid crystal display. As shown in FIG. 6, the glass spacer 13 is disposed on the periphery between the rear glass 11 and the front glass 12 coated with a phosphor to provide a discharge space gap of about 3 to 5 mm, and the rear glass. 11, the front glass 12 and the glass spacer 13 are welded at a high temperature with a glass frit. Next, a thin exhaust glass tube 14 is connected to a part of the glass spacer 13 and sealed with a glass frit. In the box-shaped glass container 15 formed as described above, after the air in the box-shaped glass container 15 is exhausted from the exhaust glass tube 14, a predetermined discharge gas is supplied into the box-shaped glass container 15 through the exhaust glass tube 14. The exhaust glass tube 14 is then sealed. Then, by applying a high frequency voltage to an appropriate internal electrode or external electrode provided in the box-shaped glass container 15, the discharge gas and / or mercury vapor is excited to generate ultraviolet rays, and the ultraviolet rays excite the phosphor. As a result, light emission from visible light to ultraviolet light was generated. The discharge tube composed of the box-shaped glass container 15 was superior in light irradiation efficiency as compared with the conventional round tube.
JP 7-296774 A

  However, in the above-described conventional box-shaped glass container, it has a high production cost due to a large number of production steps and a large number of man-hours compared to a round tube. There is a fear that the life of the discharge tube may be shortened by peeling off the seal and causing leakage. Further, when quartz glass is used as the material of the container, a high temperature of about 2000 ° C. is required to weld it, and the processing is extremely difficult.

  Accordingly, in the present invention, in order to solve the above-described problems, a method of manufacturing a discharge tube that is excellent in light irradiation efficiency, has a long life without causing a leak, and can be easily and efficiently produced is provided. With the goal.

  In order to achieve the above object, the discharge tube of the present invention seals one end of the glass tube and forms a ventilation portion at the other end, and heats the glass tube portion according to the desired length of the discharge tube. Forming a constricted portion in the glass tube while exhausting the air in the glass tube, sealing the vent portion by evacuating the inside of the glass tube and then enclosing a discharge gas and / or mercury vapor, the constricted portion It is characterized by comprising a step of obtaining a plurality of glass tubes by heating and melting and cutting an outer electrode, and a step of disposing external electrodes at opposing positions on the outer peripheral surface of the glass tube.

  Further, the glass tube is characterized by having a flat shape.

  According to the method for manufacturing a discharge tube of the present invention, a step of sealing one end of a glass tube and forming a ventilation portion at the other end, and heating the glass tube portion according to the desired length of the discharge tube A step of forming a constricted portion in the glass tube while exhausting air in the tube, a step of sealing the vent portion by filling a discharge gas and / or mercury vapor after evacuating the inside of the glass tube, and heating the constricted portion Manufacturing a plurality of discharge tubes at a time by comprising a step of obtaining a plurality of glass tubes by melting and cutting, and a step of disposing external electrodes at opposing positions on the outer peripheral surface of the glass tubes. In addition to being excellent in production efficiency, it is possible to obtain a long-life discharge tube that does not cause a leak at the joint by welding and sealing one type of glass to form a tube.

  1 to 5 show the discharge tube manufacturing method of the present invention step by step. First, an appropriate length shown in FIG. 1, for example, several to several tens of desired discharge tube lengths. A flat glass tube 1 having a length is prepared (in this embodiment, the length is about four of the desired discharge tube length). Both ends of the glass tube 1 are opened in the same manner as a normal cylindrical glass tube, but one end 2 is heated and melted and sealed as shown in the first processing step of FIG. The end 3 is also heated and melted, and an intake / exhaust vent 4 made of a small-diameter glass tube is connected to the approximate center of the rotating shaft.

  Next, as in the second processing step shown in FIG. 3, while supporting one end 2 and the other end 3 of the glass tube 1 and rotating it, a burner is placed on the glass tube 1 portion corresponding to the desired length of the discharge tube. Heat with 5 flames. Then, the air inside the glass tube 1 is exhausted to some extent through the ventilation part 4 to reduce the inside, and at the same time, both ends of the glass tube 1 are pulled and urged. Thereby, the part of the glass tube 1 heated with the flame of the burner 5 will be dented while extending, and the constricted part 6 of a certain amount will arise.

  Then, in the glass tube 1 in this state, the inside of the glass tube 1 is brought into a substantially vacuum state through the ventilation portion 4, and then a discharge gas such as xenon and / or mercury vapor is sealed, and an appropriate portion of the ventilation portion 4 is heated and melted and sealed. Stop.

  Next, as in the third processing step shown in FIG. 4, the glass tube 1 is rotated, the flame of the burner 5 is applied to the constricted portion 6, the mixture is heated, melted, and sealed. Four sealed glass tubes are obtained at a time. In addition to the sealing method using the gas burner, an appropriate method such as a method of heating and melting the constricted portion by using a carbon heating device can be used. Then, as shown in FIG. 5, the external electrode 7 is disposed at a position opposite to the outer peripheral surface of the cut sealing glass tube, whereby the flat discharge tube 8 of the present invention is completed, and the power source is connected to the external electrode 7. When connected to, it discharges and lights up. Further, a phosphor may be deposited on the inner surface or the outer surface of the glass tube, and the flat discharge tube may be excited by ultraviolet rays emitted to emit visible light or the like.

  In the above-described embodiment, the case where four discharge tubes are formed at a time has been described. Of course, the present invention is not limited to this. Any number of discharge tubes can be used at one time by using a long glass tube. A discharge tube can be created.

It is a perspective view which shows the glass tube in the manufacturing method of the discharge tube of this invention. It is a perspective view which shows the 1st process process in the manufacturing method of the discharge tube of this invention. It is a perspective view which shows the 2nd process process in the manufacturing method of the discharge tube of this invention. It is a perspective view which shows the 3rd process process in the manufacturing method of the discharge tube of this invention. It is a perspective view which shows the discharge tube by the manufacturing method of this invention. It is a disassembled perspective view which shows the conventional discharge tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass tube 2 One end 3 The other end 4 Ventilation part 5 Burner 6 Constriction part 7 External electrode 8 Flat discharge tube

Claims (2)

  Sealing one end of the glass tube and forming a vent at the other end, constricting the glass tube while heating the glass tube part according to the desired length of the discharge tube and exhausting the air in the glass tube A step of forming a vacuum inside the glass tube, sealing a discharge gas and / or mercury vapor and sealing the vent, and heating and melting the constricted portion to cut a plurality of glass tubes A method for producing a discharge tube, comprising the steps of: obtaining an external electrode at a position opposite to the outer peripheral surface of the glass tube.   2. The method of manufacturing a discharge tube according to claim 1, wherein the glass tube has a flat shape.

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