JPS6329938B2 - - 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. Reference numeral 9 denotes a thin exhaust tube, which can be made compact to about 1/2 the tube length of a straight tube discharge lamp, and can be used as a light source similar in shape to a conventional incandescent light bulb. It is.

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, the stem 3 and the outer tube 1 are generally heated to soften and melt them and then welded together, and the inner tube 5 and the stem 3 are fixed together using an adhesive 7. Therefore, when sealing the stem 3 to the outer tube 5, the adhesive 7 is softened by heat, which causes the inner tube 5 to tilt, impairing its marketability. A gap is formed between the electrodes 6 and the end faces of the electrodes 6, thereby forming an undesirable discharge path between the electrodes 6. There were drawbacks such as causing so-called discharge short-circuit accidents. Furthermore, after the process of fixing the inner tube 5 to the stem 3, the stem 3 must be sealed to the outer tube 1, which has the disadvantage of complicating the work process.

This invention was made in view of the above drawbacks.
In an outer tube with an inner tube that regulates 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, stem, and outer tube are connected. By fixing the tube and stem airtightly with adhesive, the inner tube will not tilt and the product quality will be compromised, and gaps will be prevented from forming between the inner tube and the stem, preventing short-circuit accidents during discharge. The present invention aims to provide a discharge lamp that can simplify the working process.

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, fitted into the opening of the outer tube bottom 2 and fixed in an airtight manner with adhesive 7, and has two inner tube insertion holes 4 formed in the center. ing. Reference numeral 5 denotes two straight inner tubes made of translucent glass, each of which has an electrode 6 hermetically sealed at one end and is open at the other end. Tighten the body 5 to make it airtight.
1 is fixed to the inner tube insertion hole 4 of the stem 3 with an adhesive 7. Reference numeral 8 indicates a phosphor layer formed on the inner surface of the inner tube 5, 9 indicates a thin exhaust tube sealed to the stem 3 so as to communicate with the inside of the outer tube 1, and 11 indicates the connection of the inner tube 5 from each of the electrodes 6. A starter is connected to one of the lead wires 10 led out, 12 is a current limiting element connected to one of the other lead wires 10, and 13 is a current limiting element fixed to the bottom of the outer tube 1 and has the starter 11 inside. 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 12
and the remaining one of the other lead wires 10, each of which is individually conductively connected. When AC power is applied from this base 14, the starter 11
With this operation, a U-shaped discharge path A is formed inside the outer tube 1, which is bent inside the tip.

In the discharge lamp configured in this way, the stem 3 and the outer tube 1 as well as the inner tube insertion hole 4 and the inner tube 5 formed in the stem 3 are each airtightly fixed with an adhesive 7. After the adhesive 7 has hardened, it is unavoidable that the adhesive 7 will be exposed to heat that will cause it to soften. Therefore, the adhesive 7 is prevented from softening or flowing out, so that the inclination of the inner tube 5 and the accident of short circuit due to discharge are prevented. In addition, the stem 3 is provided with an inner tube insertion hole 4, and the inner tube 5 inserted into the inner tube insertion hole 4 is sealed with an electrode 6 at one end, so that it does not protrude from the stem 3 as in the conventional case. In addition to eliminating the work of fixing the inner tube 5 to the electrode 6, the stem 3, the outer tube 1, and the stem 3 can be
It is possible to perform the work of fixing the inner tube 5 and the inner tube 5 at the same time, thereby simplifying the work.

In the above embodiments, glass was used as the stem material, but the stem material is not limited to this. For example, copper 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, by selecting an inorganic adhesive 7 such as a low melting point glass frit mainly made of lead borate for the fixed part between the stem 3 and the outer tube 1, which is relatively susceptible to external forces during the manufacturing process, It has been confirmed that it can sufficiently withstand external forces, does not peel or crack, and maintains a good adhesive state.

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 for regulating the discharge path, and an inner tube insertion hole is provided in the stem provided at the bottom of the outer tube.
Moreover, an electrode is sealed at one end of the inner tube inserted into the inner tube insertion hole, and the stem and outer tube and the inner tube and the inner tube of the stem are respectively fixed with adhesive so as to be airtight with the outside. Therefore, the effects of the inner tube being tilted and the loss of marketability can be improved, short-circuit accidents in discharge can be greatly reduced, and the manufacturing process can be simplified.

[Brief explanation of drawings]

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 7 is an adhesive.
Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A glass outer tube with an open bottom filled with mercury and rare gas, and a plurality of inner tube insertion holes formed in the bottom of the outer tube so as to close the openings. A stem is inserted into the inner tube insertion hole, has an open end inside the outer tube, and has an electrode sealed at the bottom.The stem and the outer tube, and the inner tube insertion hole and the inner tube A discharge lamp characterized by being airtightly fixed with adhesive to form a sealed container. 2. The discharge lamp according to claim 1, wherein the adhesive for bonding at least the stem and the outer bulb is an inorganic adhesive.