JP2008288129A - Circular illumination lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circular illumination lamp which can be prevented from a contact between a pair of lead wires connected to a filament electrode over a wide range. <P>SOLUTION: This is the circular illumination lamp in which a pair of lead wires 11a, 11b which are connected to a filament electrode 10 arranged at a circular light-emitting tube 1 penetrated through an installed flare 13 at the end part of the circular light-emitting tube 1 and through a flare 13 and the circular fluorescent lamp which are drawn through a wiring space 30 between an installed capillary 12 to outside of the circular light-emitting tube 1, a wiring space 30, by means of narrowed parts 31a to 31d of linear or less of the lead wire, of flare 13, extreme length is approximately lasted for, and is divided into at least two regions is arranged a pair of lead wire 11a, 11b divided on the other side of a pair of lead wire 11a and a pair of the other side region are arranged. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an annular illumination lamp, and more particularly to a technique for preventing a short circuit due to contact between a pair of lead wires connected to a filament electrode.

  A general annular fluorescent lamp is mounted so as to straddle between a pair of stems that are bent so that both ends thereof are bent, a pair of stems that hermetically seals both ends of the ring-like arc tube, and a pair of stems. With a base.

  The annular arc tube has a hollow tubular shape, and a phosphor film is formed on the inner wall surface. The inside of the annular arc tube is decompressed and filled with a rare gas such as argon gas or mercury.

  Each of the pair of stems includes a filament electrode, a pair of lead wires having one end connected to the filament electrode, a thin tube, and a flare.

  The flare is a substantially cylindrical glass member having a bottom surface. The flare is inserted into the end portion of the annular arc tube in such a direction that the bottom surface is disposed inside the annular arc tube, and is thermally welded to the annular arc tube.

  The said thin tube is arrange | positioned inside the flare thermally welded to the edge part of the annular arc tube. Specifically, one end side in the longitudinal direction of the thin tube is arranged inside the flare, and the other end side protrudes from the opening of the flare to the outside of the flare. Here, the opening of the flare means an open end facing the bottom surface. The narrow tube was used as an exhaust tube in the manufacturing process of the annular fluorescent lamp. Specifically, a through-hole is formed in the bottom surface of the flare, and the inside of the annular arc tube communicates with the outside through a thin tube until a certain stage in the manufacturing process of the annular fluorescent lamp. Then, the gas inside the annular arc tube is exhausted through the thin tube, or a rare gas or the like is introduced into the inside. Thereafter, the narrow tube is cut to an appropriate length, and the cut end is heated and melted and sealed. The other end of the thin tube described above that protrudes from the opening of the flare is the end portion on the side sealed in this way.

  Return to the explanation of the stem again. Each of the pair of lead wires is disposed along a longitudinal direction of the thin tube in a gap between the flare and the thin tube disposed inside thereof. Furthermore, one end (hereinafter referred to as “tip”) of each lead wire passes through the bottom surface of the flare and is drawn into the annular arc tube. On the other hand, the other end (hereinafter referred to as “rear end”) of each lead wire is drawn out of the stem from the opening of the flare.

  The filament electrode is disposed inside the annular arc tube and is connected to the tip of each lead wire that passes through the bottom surface of the flare and is drawn into the annular arc tube. In other words, both ends of the filament electrode are supported by the ends of the pair of lead wires. On the other hand, the rear end of the lead wire is connected to a terminal provided on the base. This terminal is a terminal to which a connector for supplying power to the annular fluorescent lamp is connected.

  Here, the base is attached so as to be able to rotate to some extent along the outer periphery of the annular arc tube in order to improve the mountability of the connector. However, as described above, since the rear end of the lead wire is connected to a terminal provided on the base, when the base rotates, tension is applied to the lead wire, and the lead wire is between the stem and the thin tube. Displaces within the gap. At this time, depending on the direction and amount of displacement, the pair of lead wires may contact each other and short-circuit. In particular, the possibility of short-circuiting between the lead wires has increased with the recent reduction in the diameter of the annular fluorescent lamp. That is, as the annular fluorescent lamp is reduced in size, the flare and the narrow tube are also reduced. As a result, the pair of lead wires are close to each other even in the initial state. Therefore, even when the amount of displacement of the lead wires is smaller than that of the conventional case, the pair of lead wires may come into contact with each other.

Therefore, Patent Document 1 proposes a method of fixing the lead wire by injecting an insulating resin into the gap between the flare where the lead wire is disposed and the thin tube. Further, Patent Document 2 proposes a method of regulating the displacement of the lead wire by partially deforming a part of the flare in the longitudinal direction and bringing the flare close to the thin tube.
JP 2002-110098 A JP 2006-19045 A

  The methods proposed by Patent Document 1 and Patent Document 2 have the following problems. That is, in the method described in Patent Document 1, it is necessary to inject an insulator such as an insulating resin into the gap between the flare and the thin tube. However, the gap is narrow in the first place, and tends to become narrower as the annular fluorescent lamp becomes narrower. It is difficult to accurately fill the narrow gap with a predetermined amount of insulating resin or the like, and there is a high possibility of reducing the yield. In addition, the cost of insulating resin and the cost increase due to the addition of the step of filling the insulating resin cannot be ignored.

  In the method described in Patent Document 2, a part of the flare in the longitudinal direction is partially deformed. However, the lead wire is arranged over the entire longitudinal direction of the flare. Therefore, in the method proposed by Patent Document 2, even if the lead wire overlaps with the flare and the contact of the lead wire in the vicinity of the portion where the flare is deformed can be prevented, It is not possible to sufficiently prevent contact at the part.

  The present invention has been made in view of the above problems, and an object thereof is to prevent contact between a pair of lead wires connected to a filament electrode as widely as possible.

  In the annular fluorescent lamp of the present invention, a pair of lead wires connected to the filament electrode arranged in the annular arc tube penetrates the flare provided at the end of the annular arc tube, and the flare and the inside thereof are inserted. It is drawn out of the annular arc tube through a wiring space between the provided thin tubes. In addition, the wiring space is divided into at least two regions over substantially the entire length of the flare by a constriction portion that is less than or equal to the linear shape of the lead wire, and one of the pair of lead wires is arranged in one of the divided regions. The other of the pair of lead wires is arranged in the other divided area.

  It is preferable that the narrowed portion is formed by bringing at least two locations on the outer peripheral surface of the thin tube facing the inner peripheral surface of the flare close to the inner peripheral surface over substantially the entire length of the flare. In this case, it is preferable that the cross-sectional shape of the thin tube is an ellipse, and the narrowed portion is formed between two vertices in the major axis direction of the thin tube cross-section and the inner peripheral surface of the flare facing the vertices. Alternatively, it is preferable that the narrow tube is provided with at least two convex portions protruding in a direction close to the inner peripheral surface of the flare, and the narrowed portion is formed between the convex portions and the inner peripheral surface of the flare. .

  According to the present invention, contact between a pair of lead wires connected to a filament electrode can be prevented over a wide range.

  Hereinafter, an example of an embodiment of an annular illumination lamp of the present invention will be described with reference to FIGS. FIG. 1 is a plan view showing the appearance of the annular fluorescent lamp of this embodiment. FIG. 2 is an enlarged perspective view showing a structure in the vicinity of the base 3 shown in FIG. FIG. 3 is an enlarged plan view showing a structure of a stem constituting the annular fluorescent lamp of the present embodiment. 4 is a cross-sectional view taken along the line AA in FIG.

  As shown in the above figures, the annular illumination lamp of the present embodiment includes a ring-shaped arc tube 1 that is bent so that both ends thereof are opposed to each other, and a pair of air-tight seals at both ends of the ring-shaped arc tube 1 A stem 2 and a base 3 attached between the pair of stems 2 are provided.

  As shown in FIG. 1, the annular arc tube 1 is a hollow tube, and a phosphor film (not shown) is formed on the inner wall surface. The inside of the annular arc tube 1 is decompressed and filled with a rare gas such as an argon gas or mercury.

  As shown mainly in FIG. 3, each of the pair of stems 2 includes a filament electrode 10, a pair of lead wires 11 a and 11 b having one end connected to the filament electrode 10, a narrow tube 12, and a flare 13. ing.

  The flare 13 is a substantially cylindrical glass member having a bottom surface 20. The flare 13 is inserted into the end portion of the annular arc tube 1 in such a direction that the bottom surface 20 is disposed inside the annular arc tube 1 (FIG. 1), and is thermally welded to the annular arc tube 1.

  As shown mainly in FIG. 3, the thin tube 12 is disposed inside a flare 13 that is heat-welded to the end of the annular arc tube 1 (FIG. 1). Specifically, one end side in the longitudinal direction of the thin tube 12 is arranged inside the flare 13, and the other end side protrudes from the opening 21 of the flare 13 to the outside of the flare 13. Here, the opening 21 of the flare 13 means an open end facing the bottom surface 20. Since the narrow tube 12 has been used as an exhaust pipe in the manufacturing process and its utilization form has already been described, the description thereof is omitted here.

  As shown mainly in FIG. 3, each of the pair of lead wires 11a and 11b is disposed along the longitudinal direction of the thin tube 12 in the gap between the flare 13 and the thin tube 12 disposed on the inside thereof. Yes. In the present invention, the gap between the flare 13 where the pair of lead wires 11a and 11b are arranged and the thin tube 12 is referred to as “wiring space”. One end (hereinafter referred to as “tip”) of each of the lead wires 11 a and 11 b arranged in the wiring space 30 shown in the drawing passes through the bottom surface 20 of the flare 13 and is drawn into the annular arc tube 1. (See FIG. 2). On the other hand, the other end (hereinafter referred to as “rear end”) of each lead wire is drawn out of the flare 13 from the opening 21 of the flare 13.

  As shown in FIG. 2, the filament electrode 10 is disposed inside the annular arc tube 1 and passes through the bottom surface 20 (FIG. 3) of the flare 13 and is drawn into the annular arc tube 1. , 11b. In other words, both ends of the filament electrode 10 are supported by the tips of the pair of lead wires 11a and 11b. On the other hand, the rear ends of the lead wires 11 a and 11 b are connected to terminals (not shown) provided on the base 3. This terminal is a terminal to which a connector for supplying power to the annular fluorescent lamp is connected. Here, as described above, the base 3 is attached so as to be able to turn to some extent along the outer periphery of the annular arc tube 1 in order to improve the mountability of the connector.

  The above is the basic configuration of the annular fluorescent lamp of this embodiment. Next, the stem 2 which is a feature of the annular fluorescent lamp of the present invention will be described in more detail with reference mainly to FIG. 4 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIG. 4, the flare 13 constituting the stem 2 has a substantially circular cross-sectional shape. On the other hand, the thin tube 12 inserted inside the flare 13 has a substantially elliptical cross-sectional shape. The flare is set so that the distance L between the two vertices 12a in the major axis direction of the thin tube section and the inner peripheral surface 13a of the flare 13 facing the vertices 12a is equal to or smaller than the wire diameter of the lead wires 11a and 11b. The inner diameter of 13 and the outer diameter (long axis) of the thin tube 12 are set. That is, in the wiring space 30, two constricted portions 31 a and 31 b that are not larger than the wire diameters of the lead wires 11 a and 11 b and cannot pass through the lead wires 11 a and 11 b are provided over substantially the entire length of the flare 13. ing. In other words, the wiring space 30 shown in FIG. 4 is divided into a first region 30a on the left side of the drawing and a second region 30b on the right side of the drawing over the entire length of the flare 13, and one lead wire is formed in the first region 30a. 11a is arranged, and the other lead wire 11b is arranged in the second region 30b.

  Therefore, as shown in FIG. 5, even if the lead wires 11a and 11b connected to the terminals of the base 3 are displaced in the wiring space 30 with the rotation of the base 3 (FIG. 1), the first The lead wire 11a arranged in the region 30a cannot move to the second region 31b beyond the constricted portion 31b. Further, the lead wire 11b arranged in the second region 31b cannot move to the first region 30a beyond the narrowed portion 31a. FIG. 5 shows a case where the lead wires 11a and 11b shown in FIG. 4 are displaced counterclockwise. However, the same applies when the base 3 is rotated in the reverse direction and the lead wires 11a and 11b are displaced clockwise. That is, the lead wire 11a disposed in the first region 30a cannot move to the second region 31b beyond the constricted portion 31a, and the lead wire 11b disposed in the second region 30b It is not possible to move to the first area 30a beyond 31b. In short, the lead wires 11a and 11b do not contact each other and cause a short circuit. Moreover, the two narrowed portions 31 a and 31 b are provided over substantially the entire length of the flare 13. Therefore, in the region where the lead wires 11a and 11b overlap with the flare 13, the contact of the lead wires 11a and 11b is reliably prevented. In this example, the region where the lead wires 11a and 11b overlap with the flare 13 covers most of the lead wires 11a and 11b (see FIG. 3). Therefore, contact with each other is substantially prevented over the entire length of the lead wires 11a and 11b.

  FIG. 4 shows an example in which two narrowed portions 31 a and 31 b are provided in the wiring space 30 by making the cross-sectional shape of the narrow tube 12 elliptical. However, the cross-sectional shape of the thin tube 12 is not limited to an elliptical shape as long as a narrowed portion that at least bisects the space 30 is provided in the wiring space 30.

  FIG. 6 is a cross-sectional view showing a modification of the cross-sectional shape of the thin tube 12. The cross section of the narrow tube 12 shown in FIG. 6 has a shape in which two apex portions in the short axis direction of the cross section of the thin tube 12 shown in FIG.

  So far, the example in which the wiring space 30 is divided into two regions by two narrowed portions has been described. However, the wiring space may be divided into three or more regions. FIG. 7 shows an example in which the wiring space is divided into four regions. In the example shown in FIG. 7, four constrictions are provided in the wiring space. Specifically, these narrowed portions are provided as follows.

  In the thin tube 12 in FIG. 7, four convex portions are provided on the outer peripheral surface at equal intervals along the circumferential direction. Each convex part 12a-12d has an arc-shaped outer surface, and constrictions 31a-31d are formed between the inner peripheral surface 13a of the flare 13. Specifically, each interval is set so that the distance between the apex of the outer surface of each convex portion 12a to 12d and the inner peripheral surface 13a of the flare 13 facing the apex is equal to or less than the wire diameter of the lead wires 11a and 11b. The heights of the convex portions 12a to 12d are set.

  As described above, as a result of forming the four convex portions 12a to 12d (constriction portions 31a to 31d) on the outer peripheral surface of the thin tube 12, the wiring space 30 shown in FIG. 7 is divided into four regions 30a to 30d. ing. And the lead wire 11a is arrange | positioned in the 1st area | region 30a between the convex parts 12a and 12b (constriction part 31a and 31d), and can be displaced only in this 1st area | region 30a. On the other hand, the lead wire 11b is disposed in the second region 30b between the convex portions 12c and 12d (constriction portions 31b and 31c), and can be displaced only within the region 30b. In other words, the lead wire 11a cannot move to the adjacent third region 30c or fourth region 30d beyond the narrowed portion 31a or the narrowed portion 31d. Further, the lead wire 11b cannot move to the adjacent third region 30c or fourth region 30d beyond the narrowed portion 31b or the narrowed portion 31c. Therefore, a short circuit between the lead wires 11a and 11b is reliably prevented. Further, in the examples shown in FIGS. 3 and 6, there is only one constricted portion interposed between the lead wires 11a and 11b. However, in the example shown in FIG. 7, two lead wires 11a and 11b are provided between the lead wires 11a and 11b. There is a stenosis. Therefore, a short circuit due to contact between the lead wires 11a and 11b can be prevented more reliably.

It is a top view which shows the external appearance part of the ring-shaped fluorescent lamp of this embodiment. FIG. 2 is an enlarged perspective view showing a structure in the vicinity of a base 3 shown in FIG. 1. It is an enlarged plan view which shows the structure of the stem which comprises the cyclic | annular tendency lamp of this embodiment. It is AA sectional drawing of FIG. FIG. 5 is a diagram showing a state in which a lead wire is displaced with the rotation of the base in FIG. 4. It is the figure which showed the other Example. It is the figure which showed the other Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ring-shaped arc tube 2 Stem 3 Base 10 Filament electrode 11a Lead wire 11b Lead wire 12 Narrow tube 12a Convex part 12b Convex part 12c Convex part 12d Convex part 13 Flare 13a Inner peripheral surface 20 Bottom face 21 Opening part 30 Wiring space 30a 1st area 30b 2nd area | region 30c 3rd area | region 30d 4th area | region 31a Narrow part 31b Narrow part 31c Narrow part 31d Narrow part

Claims (4)

A pair of lead wires connected to the filament electrode arranged in the annular arc tube penetrates the flare provided at the end of the annular arc tube, and between the flare and the narrow tube provided inside thereof. In the annular fluorescent lamp drawn out of the annular arc tube through the wiring space,
The wiring space is divided into at least two regions over substantially the entire length of the flare by the constricted portion of the lead wire or less, and one of the pair of lead wires is disposed in one of the divided regions. The annular fluorescent lamp, wherein the other of the pair of lead wires is disposed in the other region formed.   The narrowed portion is formed by bringing at least two locations on the outer peripheral surface of the thin tube facing the inner peripheral surface of the flare close to the inner peripheral surface over substantially the entire length of the flare. The ring-shaped fluorescent lamp according to claim 1.   The narrow tube has an elliptical cross-sectional shape, and the narrowed portion is formed between two vertices in the major axis direction of the thin tube cross section and the inner peripheral surface of the flare facing the vertex. The ring-shaped fluorescent lamp according to claim 1 or 2.   The narrow tube is provided with at least two convex portions protruding in a direction approaching the inner peripheral surface of the flare, and the narrowed portion is formed between the convex portions and the inner peripheral surface of the flare. The ring-shaped fluorescent lamp according to claim 1 or 2, characterized in that

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