JPS6329939B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention comprises an outer tube filled with mercury and a rare gas as a discharge medium, and an inner tube with an electrode enclosed at one end. The present invention relates to a discharge lamp configured to form a path.

Various types of discharge lamps of this type have been proposed with the aim of reducing the size of the discharge lamps. FIG. 1 shows a typical example. That is, a disc-shaped stem 3 with an electrode 6 projecting thereon is provided with an inner tube 5 that is open at both ends so as to enclose the electrode 6 therein, and the stem 3 is further sealed to the outer tube 1. A discharge path regulated in a U-shape by an inner tube 5 is formed in an outer tube 1. Note that 9 is a thin tube for exhaust. Therefore, the light source can be made compact to about half the tube length of a straight tube discharge lamp, and can be made similar in shape to a conventional incandescent light bulb.

However, due to the structure of the discharge lamp described above, the inner tube 5 is fixed to the stem 3, and then the stem 3 and the outer tube 1 are sealed together. In this case, usually the inner tube 5 and the stem 3
Since the glass frit 7 is used for fixing the stem 3 to the outer tube 5, heat causes the frit 7 to soften, causing the inner tube 5 to tilt, impairing the product's marketability. As the water flows out, a gap is created between the stem 3 and the end face of the inner tube 5,
This has the disadvantage that an undesired discharge path is formed between the electrodes 6, resulting in a so-called discharge short-circuit accident. Furthermore, the larger the diameter of the flat stem 3, the more difficult it is to manufacture, so a metal plate that can be welded to glass is used for larger diameter stems.
In this case, there were disadvantages such as an additional step of fixing the thin tube 9 to the stem 3, and in the case of a metal thin tube 9, a large tube sealing and cutting device (not shown) was required.

This invention was made in view of the above drawbacks.
In an outer tube with an inner tube for regulating the discharge path, the inner tube with an electrode sealed at one end is inserted into the inner tube insertion hole formed in the stem, and in this state the inner tube and stem are connected. The abutment area is fixed airtight with the outside, and at least one end of the inner tube is provided with a thin tube that communicates with the outside, so that the inner tube and stem can be easily connected without tilting the inner tube and impairing its marketability. To provide a discharge lamp which can prevent gaps from forming in the parts, prevent discharge short-circuit accidents, do not increase manufacturing steps, and does not require a large-scale capillary sealing and cutting device.

This invention will be explained below based on FIGS. 2 and 3. In the figure, reference numeral 1 denotes a cylindrical outer tube made of light-transmitting glass with an open bottom 2, and a predetermined amount of mercury and a rare gas serving as a discharge medium are sealed inside. 3
is a stem made of disk-shaped glass that can be welded to the outer tube 1, and is sealed to the bottom 2 of the outer tube 1 to make the outer tube 1 an airtight container.In the center, there are two inner tubes. An insertion hole 4 is formed. Reference numeral 5 denotes two straight inner tubes made of transparent glass, each having an electrode 6 hermetically sealed at one end and an open end. The body 51 is fixed to the inner tube insertion hole 4 of the stem 3 with a glass frit 7 so as to be airtight. 8 is this inner tube 5
a phosphor layer 9 formed on the inner surface of each inner tube 5;
A thin glass tube for exhaust gas is sealed together with an electrode 6 at one end, and is formed so that the inside of the outer tube 1 and the outside of the stem 3 can communicate with each other. After passing through the exhaust treatment process, it is fused at a predetermined location. 11 is a starter connected to one of the lead wires 10 led out of the inner tube 5 from each electrode 6, 12 is a current limiting element connected to one of the other lead wires 10, and 13 is the outer tube. The starter 11 is fixed to the bottom of the starter 11 inside the starter 11.
and a cover body 14 that accommodates the current limiting element 12 is fixed to the end of this cover body 13, and the current limiting element 1
2 and the remaining one of the other lead wires 10,
These are caps that are individually conductively connected. Then, when AC power is applied from the base 14, a U-shaped discharge path A is formed inside the outer tube 1, which is bent inside the tip, as the starter 11 operates.

In the discharge lamp configured in this way, the inner tube 5 has the electrode 6 sealed at one end, so that the stem 3
After the stem 3 is sealed to the outer tube 1, the other end of the stem 3 can be inserted from the outside into the inner tube insertion hole 4 and fixed to the stem 3. Therefore, the frit 7 that fixes the inner tube 5 to the stem 3 is not subjected to heat that would cause it to soften after solidification, and the inner tube 5 is reliably supported on the stem 3 in a desired state. Moreover, the electrode 6 is connected to each inner tube 5.
In addition, since they are sealed without using individual frits 7, the possibility of discharge short circuits is greatly reduced. Furthermore, since the thin tube 9 is sealed to the inner tube 5, the inner tube 5
The sealing work is completed at the same time as the inner tube insertion hole 4 is fixed, and the number of manufacturing steps is not increased. Moreover, in this case, since the thin tube 9 can be made of glass regardless of the material of the stem 3, the thin tube sealing and cutting device can also be a simple one that has been commonly used in the past. Further, by providing the thin tubes 9 in each of the two inner tubes 5, it is expected that the exhaust treatment process inside the outer tube 1 can be carried out efficiently.

In the above embodiments, glass was used as the stem material, but the stem material is not limited to this. For example, Kovar metal, iron-nickel-chromium alloy, iron-chromium alloy, etc.
There is nothing to prevent the use of metals that can be welded to glass.

Furthermore, good adhesion can be achieved by selecting an inorganic adhesive such as a low-melting point glass frit mainly made of lead borate or an adhesive mainly made of silicon for fixing the stem 3 and the inner tube 5. This has been confirmed.

Furthermore, the number and shape of the inner tubes 5 do not necessarily have to be two and have a straight shape as in the above embodiment, but two or more inner tubes 5 may also have a shape with some bends. Even if the above embodiment is implemented, the same effect as that of the above embodiment can be expected.

As explained above, the present invention has an inner tube disposed inside the outer tube to regulate the discharge path, the stem is provided with an inner tube insertion hole, and the inner tube is sealed with an electrode at one end. When the tube is inserted into the inner tube insertion hole, it is fixed to the stem so that it is airtight with the outside, and at least one end of the inner tube is provided with a thin tube that communicates with the outside, so the inner tube is tilted and the product is not marketable. This method has the following effects: it improves the damage caused by the capillary tube, it greatly reduces the occurrence of discharge short-circuit accidents, it does not require an increase in the number of manufacturing steps, and it does not require a large-scale capillary sealing and cutting device.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional discharge lamp, FIG. 2 is an exploded perspective view showing an embodiment of the discharge lamp according to the present invention, and FIG. 3 is a sectional view showing the outer bulb and cover body separated. It is. In the figure, 1 is an outer tube, 2 is a bottom, 3 is a stem, 4 is an inner tube insertion hole, 5 is an inner tube, 6 is an electrode, and 9 is a thin tube. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A glass outer tube with an open bottom filled with mercury and a rare gas, a stem sealed to the outer tube so as to close the bottom and forming a plurality of inner tube insertion holes, and the above-mentioned inner tube insertion holes. an inner tube that is inserted into the stem in an airtight manner with the outside, has an electrode sealed at one end, and has a tip open inside the outer tube, and at least one end of the inner tube exposed to the outside of the stem is provided with an A discharge lamp characterized by having a thin tube communicating with the discharge lamp.