JPS6116457A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To prevent the damage of a lamp before happens and at the same time, nearly equalize the wall temperature of a straight tube portion, by providing slits at the connecting portion of the tube wall separating a discharge path. CONSTITUTION:A bulb 21 is formed as one body by crushing a glass tube 25 of large diameter by forming metallic mold 26 and 27 separable in two parts. In other words, the molds 26 and 27, in case of being brought face to face with each other, have forming faces 28 and 29 making up the space of the predetermined shape, that is, U-shape, and these forming faces 28 and 29 provide partition walls 30 and 31 respectively between both the straight portions of the U-shape. On putting the glass tube 25, softened uniformly as a whole by heating, in between the metallic molds 26 and 27, and crushing the softened glass tube 25 by both these metallic molds 26 and 27, the facing portions of the tube walls 32a and 32b separating the discharge path in straight tube portions 24a and 24b are connected as one body by a continuous wall 32 formed between the facing faces of the partition walls 30 and 31. The slits 38 are formed as one body, at the time of the molding of the bulb by the metallic molds 26 and 27, by providing protruding portions facing each other on the partition walls 30 and 31 of the metallic molds 26 and 27 respectively, and thereby the small portions of the tube walls 32a and 32b are separated by these slits 38.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a thin light lamp having a U-shaped or meandering discharge path between electrodes.

[Technical background of the invention and its problems]

For example, it can be used as a light source for color image display devices.
The conventional U-shaped fluorescent lamp is made by softening a conventional straight glass tube by heating and winding the softened glass tube around a forming drum to form a U-shape.

However, in such conventional fluorescent lamps, the straight nolas tube is heated and softened and bent, so at the U-shaped bending part, the tube wall on the outside of the bend is stretched and the inside of the bend is stretched. The wall thickness is thinner than that of the conventional one, which poses a problem in terms of valve strength. Moreover, because a forming drum is used to bend the glass tube, there is a gap between the multiple straight tube sections connecting the bent section and both ends.
It is necessary to ensure a gap for the above-mentioned forming drum to be interposed, and (2) the straight pipe parts are spaced apart from each other, making them vulnerable to external horns such as twisting, and the relative distance between the straight pipe parts. In this case, the light output becomes low, which is unfavorable in terms of light distribution characteristics.

For this reason, as shown in Japanese Patent Publication No. 49-47516, for example, the discharge path in the straight tube section is separated by crushing the heated and softened glass tube together with a mold. It is known that the central pipe wall is formed integrally and there is no gap between the straight pipe parts.

However, the U-shaped fluorescent lamp as mentioned above has a smaller tube diameter and has a higher load than the general straight tube type or ring-shaped fluorescent lamp, and the temperature of the fluorescent lamp itself becomes high while it is lit. If the tube walls between the discharge paths are formed integrally as in the above-mentioned prior art, the temperature of the entire fluorescent lamp tends to rise more easily, which significantly limits the output of the fluorescent lamp, and the current U-shaped fluorescent lamp There is a problem that it cannot be replaced with a light lamp.

Furthermore, while the lamp is on, the temperature of the tube wall 2 that separates the straight tube portions 1a and 1b decreases as shown by the broken line in FIG.
The height increases as you get closer to the connecting part of a and 2b, so
The temperature of the pipe wall of the straight pipe portions 1a and Ib is uneven, and therefore thermal strain tends to concentrate at the connecting portion of the pipe walls 2a and 2b, which may cause cracks. [Objective of the Invention] The present invention This was done in response to these circumstances,
Fluorescent light that makes it difficult for thermal distortion to occur on the tube wall that separates the discharge path, prevents damage to the lamp, and evens out the tube wall temperature in the straight tube section, maintaining good light output. The purpose is to provide lamps.

[Summary of the invention]

That is, in order to achieve the above object, the present invention provides a slit in the connecting portion of the tube wall that separates the discharge path, allows the slit to absorb thermal strain, and improves the heat dissipation of the tube wall by the outside air flowing through the slit. It is characterized by being elevated.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

In the figure, 21 is a bulb having a U-shaped discharge path, and this bulb 21 has a U-shaped bent portion 22 and two adjacent ends connecting this bent portion 22 and both end portions 23 and 23. It is provided with straight pipe portions 24a and 24b-. As shown in FIG. 4, such a bulb 21 is a large-diameter glass tube 2.
5 by crushing them with two-part molding molds 26 and 27. That is, the above mold 26.27
molding surfaces 28. which form a predetermined shape, that is, a U-shaped space in this embodiment, when abutted against each other. , 29, and these molding surfaces 28, 29 are provided with a partition wall 30, 31 between the two U-shaped drawing portions. And this mold 26.
A glass tube 25 whose entire surface has been uniformly heated and softened is inserted between the two molds 26 and 27, and when the softened glass tube 25 is crushed by these two molds 26 and 27, the glass tube 25 is molded onto each molding surface 28. 29, it is molded into a shape having two straight pipe parts 24a, 24b on both sides of the U-shaped bent part 22, and the discharge path in the straight pipe parts 24a, 24b is separated by a chilled pipe wall 32a. , 32b are integrally connected by a continuous wall 32 formed between the opposing surfaces of the partition walls 30, 31.

A phosphor coating (not shown) is applied to the inner surface of the bulb 21 molded in this manner, and the straight pipe portion 24 is coated with a phosphor coating (not shown).
At the open ends of a and 24b, there is a filament as an electrode, respectively. -34, 34 are sealed. This filament 3
4.34, a general stem may be used, but in the case of this embodiment, the straight pipe portions 24a and 24b are used.
Arrival is accomplished by binge-sealing the open end of the pipe. That is, the open ends of the straight pipe portions 24a and 24b are flattened and sealed, and the pair of lead wires 36 and 36 connected to the filament 34 are hermetically sealed through the sealing portion 35. Filament 3 above
4 are present in the straight pipe portions 24a and 24b. Note that the exhaust inside the valve 21 and the filling of inert gas are performed through an exhaust pipe 37 branched and connected to the top of the bent portion 22, and then the exhaust pipe 37 is hermetically sealed by fusing.

In such a valve 21, the pipe wall 32
A slit 38 is formed in the continuous wall 33 that connects the opposing portions of the tubes 24a and 3211 along the tube axis direction of the straight tube portions 24a and 241). It is well located. 38 is the partition wall 30. of the mold 26.27.
31 are provided with convex portions (not shown) that abut against each other, so that they are integrally formed during molding with these molds 26 and 27, and this slit 38 allows the tube wall 3
Parts 2a and 32b are separated to form a space between them through which outside air flows.

According to the fluorescent lamp of this embodiment, the straight pipe portion 2
4a, 24b (D pipe walls 32a, 32b Since the slit 38 is opened in the continuous wall 33 that fully connects the pipe walls 32a, 32b, a part of the pipe walls 32a, 32b is separated, and therefore, the pipe walls 32a, 32b are separated while the lamp is lit. The strain that occurs in the connecting part of is absorbed by the slit 38,
It becomes difficult for distortion to concentrate on this connection part. Therefore, the occurrence of cracks can be prevented, and the chance of the valve 21 breaking is reduced.

In addition, since the outside air flows through the slit 38, the straight pipe portions 24a and 24b
As is clear from the temperature distribution shown by the broken line in FIG. 3, it is recognized that the surface temperature of the pipe becomes lower as it gets closer to the connecting portion of the pipe walls 32a and 32b, making it possible to make the surface temperature uniform. However, by providing the slit 38, the surface temperature of the entire fluorescent lamp decreases.
Since the low-temperature region on the side is further expanded compared to the conventional case, the cooling effect of the valve 21 is enhanced. Therefore, in addition to being more convenient in suppressing the above-mentioned distortion, it is possible to suppress the increase in the mercury vapor pressure inside the tube, stabilize various electrical characteristics, and maintain good optical output. Become.

Particularly in the case of this embodiment, since the slit 38 is located at a position biased toward the filament 34, which becomes hot during lamp lighting, the above-mentioned distortion can be absorbed in the portion where the amount of distortion is large. In addition, since the highest temperature area is cooled, it is convenient for lowering the surface temperature of the bulb 21, which greatly contributes to optimizing the light output.

Note that the fluorescent lamp according to the present invention is not limited to the shape of the above-mentioned embodiment; for example, as in the bulb 41 shown in FIG. It is also possible to implement the same method by providing the bending portion 43 and making the discharge path meander.

Further, the number of slits mentioned above can be changed as appropriate depending on the length of the straight pipe section, the lamp output, etc.
As shown by the imaginary line in the figure, the slit 38 is inserted into the straight pipe section 24.
A, 24b may be provided in plural numbers at intervals in the tube axis direction.

(Effects of the Invention) According to the present invention described in detail above, since the slit is provided in the connecting portion of the tube wall that separates the discharge path, the slit can absorb the distortion that occurs in the connecting portion of the tube wall while the lamp is lit. can. Therefore, strain is less likely to concentrate on this connecting portion, and cracks can be prevented from occurring, thereby reducing damage to the valve.

In addition, since outside air flows through the slit, the surface temperature of the straight pipe section in the part where the slit is provided becomes lower as it approaches the connecting part of the pipe wall, making it possible to equalize the surface humidity. Furthermore, by providing this slit, the surface temperature of the entire fluorescent lamp is lowered, and the low-temperature region is further expanded compared to the conventional lamp, so that the bulb cooling effect is enhanced. Therefore, in addition to being more convenient in suppressing the above-mentioned distortion, it is possible to suppress the increase in the mercury vapor pressure inside the tube, stabilize various electrical characteristics, and maintain good optical output. There are some advantages.

[Brief explanation of the drawing]

1 to 5 show one embodiment of the present invention, FIG.
Figure 3 is a front view showing the temperature distribution on the bulb surface; Figure 4 is a perspective view showing the fluorescent lamp manufacturing process; Figure 5 is a cross-sectional view taken during molding with a mold. , FIG. 6 is a front view showing another embodiment of the present invention, and FIG. 7 is a front view showing another embodiment of the present invention.
FIG. 22...Bending portion, 23...Both ends, 24a, 2
4b...straight pipe part, 32a, 32b...pipe wall, 3
4... Electrode (filament), 38... Slit. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 3 Figure 2 Figure 4 Figure 5

Claims (3)

[Claims] (1) It has at least one bent part between both ends to which the electrode is sealed, and has a plurality of adjacent straight pipe parts connecting these both ends and the bent part, and each of the above-mentioned A fluorescent lamp in which tube walls separating discharge paths in a straight tube section are integrally connected, characterized in that a slit is provided in the connecting portion of the tube walls separating the discharge paths. (2) The slit is provided at the end of the straight pipe section that is biased toward the electrode side.
Fluorescent lamps listed in ). (3) A plurality of the slits are provided along the axial direction of the straight pipe portion.
Fluorescent lamps listed in ).