JPS6362063B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-pressure mercury vapor discharge lamp having an inner tube that regulates a discharge space so that a predetermined discharge path is formed within the outer bulb.

A discharge lamp of this type is proposed in Japanese Patent Application Laid-open No. 44370/1983. FIG. 1 shows the discharge lamp, in which a pair of electrodes 3 are sealed to a substrate 2 forming the bottom of an outer bulb 1 forming a discharge space, and a phosphor layer 4 is further coated on the inner surface. One end 55 of one leg of the U-shaped inner tube 5 is fixed to the substrate 2 with one electrode 3 contained therein in an airtight manner, and the other end 57 of the U-shaped inner tube 5 is set as an open end 56 and the other electrode 3 is fixed to the substrate 2. Close to 3,
The inner tube 5 forms a substantially U-shaped discharge path. Reference numeral 6 indicates a base, and reference numeral 7 indicates a base.The discharge lamp constructed in this manner provides a discharge lamp in which the outer bulb 1 can be used in an existing incandescent light bulb socket and can be made relatively small without reducing lamp efficiency. It has the advantage of being able to Further, since the inner tube 5 has a simple U-shaped shape, there is an advantage that the inner tube 5 is particularly easy to manufacture.

However, in the discharge lamp with the above configuration,
The inner tube 5 is fixed to the substrate 2 at one end 55 of one leg.
Since the other end 57 is a free end, the fixation of the inner tube 5 is insufficient, and one end 57 of the inner tube 5 is fixed.
There has been a major problem in that the inner tube 5 may break at the fixed portion due to vibrations or shocks applied to the inner tube 5 during the manufacturing process after the lamp 5 is fixed or when the lamp is handled after completion. Further, one end 55 of the inner tube 5 is connected to one electrode 3.
Even when the inner tube 5 is enclosed in an airtight manner and fixed to the substrate 2, the position of the inner tube 5 is not determined and it tends to fall down, which causes a problem that the workability of attaching the inner tube 5 to the substrate 2 is poor.

This invention was made in view of the above-mentioned drawbacks, and includes an inner tube that regulates the discharge space within an outer tube that forms a discharge space, and a pair of electrodes are sealed on a substrate that forms the bottom of the outer tube. Both ends of the inner tube, which regulates the discharge path, are fixed to this substrate with glass frit, and one end of the inner tube is encapsulated in an airtight manner, and the other end without the electrode communicates with the inside of the outer tube. It is an object of the present invention to provide a discharge lamp in which an opening serving as a discharge guide port is formed, the inner tube can be securely fixed, and the inner tube can be easily attached.

An embodiment of the present invention will be described below with reference to FIG. In the figure, 1 is a translucent glass outer tube with a dome-shaped tip and an open bottom, and 2 is a thin metal plate sealed to the outer tube 1 to form the bottom of the outer tube. A substrate 3 is a pair of electrodes sealed to the substrate 2 so as to protrude into the outer tube 1; 5 is a U-shaped glass inner tube with a phosphor layer 4 coated on the inner surface;
5 includes one electrode 3 in an airtight manner and is fixed on the substrate 2 surface with a glass frit 8, and the other end 57 is fixed on the substrate 2 surface with a glass frit 8 so as to be located near the other electrode 3. There is. Furthermore, an opening 56 is formed near the substrate 2 at the other end 58 that does not contain the electrode 6 and looks into one of the electrodes 3. This opening 56 communicates with the inside of the outer tube 1 and serves as a discharge guide port during operation. Furthermore, a predetermined amount of mercury and rare gas are sealed in the space sealed by the outer tube 1 and the substrate 2. A base 6 is fixed to the bottom of the outer tube 1 and houses a ballast and a starting device (none of which are shown) inside.A cap 7 is fixed to the base 6, and can be used as a socket for an incandescent light bulb. It is now possible to embed it.

In the discharge lamp constructed in this way, both ends 55 and 57 of the U-shaped inner tube 5 are fixed to the substrate 2 by the glass frit 8, so the inner tube 5 is so-called "both-end supported" and is extremely firmly fixed. Become something. Therefore, during the manufacturing process after fixing the inner tube 5 to the substrate 2 or when handling the completed lamp, accidents such as breakage of the inner tube 5 due to vibration or impact can be almost eliminated. Moreover, even if the fixation of the inner tube 5, especially at the end on the side containing the electrode 3, is broken, "cantilever support" is possible.
The inner tube 5 is supported in the state of , and falls and the outer tube 1
Although this will not cause an accident such as breaking through the inner tube, "crosstalk discharge" will occur where the discharge path passes through the cracks in the fixed part, and because it is possible to detect discharge abnormalities before the inner tube 5 falls, it is possible to prevent serious accidents. It becomes possible.
Furthermore, when fixing the inner tube 5 to the substrate 2, both ends 55 and 57 of the inner tube 5 can land stably on the substrate 2, making it easy to position the inner tube 5 and temporarily fix it until the glass frit 8 hardens. Therefore, the workability when fixing the inner tube 5 is significantly improved. Note that in this embodiment, it is necessary to provide an opening 56 in advance near the other end 58 of the inner tube 5, but such an opening 56 can be made in a simple manner when manufacturing the inner tube 5. Therefore, this does not pose a major problem in this embodiment. On the other hand, by changing the shape of this opening 56 as needed, the tube voltage and discharge current of the lamp can be controlled without changing the shape or shape of the inner tube 5, making it easy to manufacture lamp models with different watt sizes. There are also new benefits.

FIG. 3 shows another embodiment different from the above embodiment. That is, one electrode 3 is provided with one U-shaped inner tube 5, the other electrode 3 is similarly provided with a U-shaped inner tube 5, and both ends 5 of each inner tube 5 are provided with a U-shaped inner tube 5.
5 and 57 are fixed on the substrate 2 with a glass frit 8 in the same manner as in the above embodiment, and an opening 56 is formed near the other end 58 of each inner tube 5 that does not have the electrode 3. 56 are arranged to face each other closely.

In the discharge lamp of this embodiment, a pair of electrodes 3
The discharge between the respective inner tubes 5 and the opening 5 of the inner tube 5
Two continuous substantially U-shaped discharge paths are formed via 6. Therefore, a longer discharge path length can be obtained without changing the shape of the outer bulb 1, and a compact lamp with high light output can be obtained. In addition, since the openings 56 of the respective inner tubes 5 are close to each other near the substrate 2, the distance between the openings 56 can be shortened, and therefore the positive column-shaped portion that simply connects the discharges can be shortened. More favorable effects can be obtained in terms of light output. Furthermore, it also has the effect of making it difficult to see the blue light emitted from the sunlight column.

FIG. 4 shows yet another embodiment.
In FIG. 4, a part of one end 57 of the inner tube 5 on the side not having the electrode 3 is made into a cutout opening 56, and the remaining part is fixed onto the substrate 2 with a glass frit 8. Even with such a configuration, the same effect as the embodiment shown in FIG. 2 can be obtained.

Furthermore, the fixation between the one end 57 of the inner tube 5 on the side that does not have an electrode and the substrate 2 does not require as much airtightness as the fixation between the one end 55 of the inner tube 5 on the side containing the electrode 3 and the substrate 2. Partial adhesion is also fine. On the other hand, board 2
The materials used are not limited to thin metal plates, but also include glass materials,
You are free to choose any material such as ceramic material. Furthermore, a thin layer of phosphor, titanium oxide, or silicon oxide may be provided on the inner surface of the outer tube 1 or the inner surface of the substrate 2. When a thin layer is provided on the inner surface of the outer tube, it has the effect of reducing the glare of the inner tube, and when a thin layer is provided on the inner surface of the substrate 2, it has the effect of reducing light absorption loss on the inner surface of the substrate 2. There is also.

As explained above, the present invention includes an outer tube that defines a discharge space and an inner tube that regulates the discharge space. Both ends of the inner tube are fixed to the substrate with glass frit, one end is encapsulated in an airtight manner, and the other end without the electrode is provided with an opening that communicates with the inside of the outer tube and serves as a discharge guide port. Because of this, the inner tube is fixed at two locations on both ends of the inner tube, making it extremely strong. Moreover, since the fixed part of the inner tube is broken when only the electrode side end is fixed, it is possible to detect an abnormality in the fixed part by the discharge abnormality before the inner tube falls, making it possible to prevent accidents. can. Furthermore, when fixing the inner tube to the substrate, both ends of the inner tube are in contact with the substrate, making positioning and temporary fixing easier. Therefore, it is possible to provide a low-pressure mercury vapor discharge lamp that has high manufacturing yield and reliability, and can improve manufacturing workability.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing a conventional low-pressure mercury vapor discharge lamp, FIG. 2 is a partially cutaway perspective view showing an embodiment of the low-pressure mercury vapor discharge lamp according to the present invention,
4 through 4 are partially cutaway perspective views of other embodiments of the present invention. In the figures, 1 is an outer tube, 2 is a substrate, 3 is an electrode, 5 is an inner tube, 8 is a glass frit, and 56 is an opening. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A glass outer tube with a closed end and an open bottom, a substrate hermetically sealed to the outer tube so as to close the bottom of the outer tube, and a pair sealed to the substrate so as to protrude into the outer tube. One end of the electrode encloses one of the electrodes in an airtight manner and is fixed on the substrate surface with a glass frit, and the other end is provided with an opening that becomes a discharge guide hole during operation, and the end surface is attached to the substrate surface. 1. A low-pressure mercury vapor discharge lamp, characterized in that it comprises at least one inner tube fixed on its surface with a glass frit.