JPS6290829A - Manufacture of electric discharge lamp - Google Patents

Abstract

PURPOSE:To reduce the amount of frit exposed inside of the light emitting tube for increasing the life of an electric discharge lamp and to inhibit the electric discharge of the root of the exhaust tube by sealing the gap between the lower cap of the light emitting tube and the exhaust tube with a frit located outside the light emitting tube. CONSTITUTION:Frits 4a and 4b are molten by heating and molten frits 4a and 4b are filled into gaps 3a and 3b between a light emitting tube 1 and caps 2a and 2b. A frit 7a is molten by heating and the molten frit 7a is filled into a gap 8a between a cap 2a and an introduction conductor 6a. At the same time, a frit 7b is molten and the molten frit 7b is filled into a gap 8b between a cap 2b and an exhaust tube 5b by capillary phenomena. Pulling up the molten frit 7b by capillary phenomena reduces the amount of frit exposed inside of the tube 1 and reduces the loss of Na thereby maintaining the electric and the optical characteristics of the electric discharge lamp and increasing its life. Besides, it prevents the frit 7b from adhering to the root of the tube 5b thereby inhibiting the electric discharge of the root.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method of manufacturing a discharge lamp, such as a high-pressure sodium lamp.

[Technical background of the invention and its problems]

A conventional method for manufacturing a discharge lamp will be explained with reference to FIGS. 4 to 6. FIG. 4 is a diagram showing the state of the arc tube after the frit has been attached in the conventional manufacturing method of a discharge lamp, FIG. 5 is a diagram showing the state of the arc tube after the frit is melted in the manufacturing method, and FIG. The figure is an enlarged view of the lower part of the arc tube in FIG. 5.

First, caps 2a and 2b are attached to arc tube 1. At this time, a frit 4a is formed in the gaps 3a and 3b between the two.
, 4b are attached. Then, an introduction conductor 6a having an electrode 5a at its tip is inserted into a hole provided in the center of the cap 2a.
into the hole also made in the center of the cap 2b,
An exhaust pipe 6b having an electrode 5b at its tip is inserted. At this time, along the gap 8a between the cap 2a and the introduction conductor 6a, a ring-shaped fringe door a is formed on the upper end surface of the cap 2a.
Also, along the gap 8b between the cap 2b and the exhaust pipe 6b, a luminous tube! Kiya inside.

A ring-shaped frif 7b is attached to the upper end surface of the ring 2b.

Next, as described above, the cap 2as2bs introduction conductor 6a
The arc tube 1 with the exhaust pipe 6b attached thereto is fixed in a closed container (not shown) with the exhaust pipe 6b facing downward, as shown in FIG. After the inside of the sealed container is once brought into a vacuum state, it is heated.

Then, the frits 4a and 4b are heated by the heat. melt,
A gap 3a between the arc tube 1 and the caps 'la and 'lb,
3b is filled with the molten frit, and the frits 7a and 7b are melted, and the cap 2a and the introduction conductor 6a
s and gaps 8a, 8 between the cap 2b and the exhaust pipe 6b.
b. As a result, the gaps 3a and 3b and the gaps 8a and 8b are sealed as shown in FIG. can be fixed.

However, the discharge lamp manufactured by the above conventional manufacturing method has the following drawbacks. In the conventional manufacturing method, since the frit 7b filling the gap 8b is attached to the arc tube 1, a large amount of the molten frit door b remains in the lower part of the arc tube 1, as shown in FIG. In this way, if a large amount of the frit is exposed inside the arc tube, sodium
) and the frit, the amount of sodium (Na) il in the arc tube decreases due to chemical reaction and physical diffusion, which changes the electrical and optical characteristics of the discharge lamp and adversely affects its lifespan.

In addition, if there is a frit at the root of the exhaust pipe 6b that also serves as an electrical lead (near the surface of the cap 2b inside the arc tube l), the frit has good emission characteristics due to its components, so Electric discharge (back arc) is likely to occur, and therefore, discharge lamps manufactured using conventional methods have the disadvantage that arc tube cranks are likely to occur.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and provides a method for manufacturing a discharge lamp that has a long life and is less likely to cause discharge from the base of the exhaust pipe by reducing the amount of frit exposed inside the discharge tube. The purpose is to

[Summary of the invention]

To achieve the above object, the present invention provides a gap formed between an arc tube and a cap for sealing both ends of the arc tube when the arc tube is held vertically, and a gap between the cap and the cap. In a method for manufacturing a discharge lamp, a gap formed between the inlet NL body or the exhaust pipe inserted into a hole provided in the center of the discharge lamp is sealed by heating and melting a frit, the arc tube being held vertically. A frit is placed along the gap formed between the cap at the lower end and the introduction conductor or exhaust pipe so as to contact both the outer end surface of the cap and the outer peripheral surface of the introduction conductor or exhaust pipe. After attaching, the frit 7 is heated and melted, and the molten frit 7 is pulled up into the gap using capillary phenomenon, thereby sealing the gap and sealing the cap.
The special feature is that the introduction conductor or the exhaust pipe is firmly fixed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. Figure 1 is a diagram showing the state of the arc tube after the frit has been attached in the method for manufacturing a discharge lamp which is an embodiment of the present invention, and Figure 2 is the state of the arc tube after the frit has been melted in the manufacturing method. FIG. 3 is an enlarged view of the lower part of the arc tube in FIG. 2. Note that in FIGS. 1 to 3, the same parts as in the conventional method for manufacturing a discharge lamp shown in FIGS. 4 to 6 are designated by the same reference numerals to simplify the explanation.

First, the caps 2a and 2b are attached to the arc tube l. At this time, frits 4a14b are attached to the gaps 3a and 3b.

Then, caps 2a and 2b are placed on both ends of the arc tube 1, and an introduction member 6a having an electrode 5a at its tip is inserted into a hole provided in the center of the cap 2a. An exhaust pipe 6b having an electrode 5b at its tip is inserted into the hole. At this time, a ring-shaped frit 7a is attached to the upper end surface of the cap 2a along the gap 8a between the cap 2a and the introduction conductor 6a, and
A ring-shaped pudding 7b is attached along the gap 8b between the cap 2b and the exhaust pipe 6b so as to contact both the lower end surface of the cap 2b and the outer peripheral surface of the exhaust pipe.

Next, as described above, the cap 2az2bs introduction conductor 6a
The arc tube 1 with the exhaust pipe 6b attached thereto is fixed in a closed container (not shown) with the exhaust pipe 6b facing downward, as shown in FIG. After the inside of the sealed container is once brought into a vacuum state, it is heated.

Then, the frits 4a and 4b are melted by the heat, and the gaps 3a and 3b between the arc tube 1 and the caps 2a and 2b are filled with the melted frits, and the frit 7a is melted, and the cap 2a and the introduction conductor are 6a and the gap 8a between
is filled with a molten frit, and at the same time the frit 7b is melted, and the molten frit 7b is pulled up into the gap 8b between the cap 2b and the exhaust pipe 5b by capillary action. As a result, as shown in FIG.
and the gaps 8a and 8b are sealed, and the arc tube 1 and the cap 2a are sealed.
, arc tube 1 and cap 2b, cap 2a and introducing conductor 6
a, the cap 2b, and the exhaust pipe 6b can be fixed together.

Here, the molten frit 7b in the air gap 8b is pulled up by capillary action, so the discharge lamp manufactured by this example is different from the discharge lamp manufactured by the conventional method, as shown in FIG. The number of frits exposed within the arc tube can be significantly reduced. Therefore, according to this embodiment, it is possible to significantly reduce the decrease in the amount of sodium (Na) due to the chemical reaction and physical diffusion between the frit and sodium (Na), so that the electrical and optical It is possible to manufacture a discharge lamp that maintains its characteristics for a long time and has a long life. Furthermore, according to this embodiment, since no frit is attached to the base of the exhaust pipe that also serves as an electrical lead, it is possible to manufacture a discharge lamp in which discharge from the base of the exhaust pipe is less likely to occur.

Further, the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention. For example, in this example, the arc tube was held and heated so that the exhaust pipe was on the bottom side, but the present invention also includes a case where the arc tube was held and heated so that the introduction conductor was on the bottom side. .

〔Effect of the invention〕

As explained above, according to the present invention, the gap between the cap at the bottom of the arc tube and the introduction conductor or the exhaust pipe is sealed by the frit attached to the outside of the arc tube, so the amount of frit exposed inside the arc tube is sealed. It is possible to provide a method for manufacturing a discharge lamp that reduces the amount of damage, has a long life, and is less likely to cause discharge from the base of the exhaust pipe.

[Brief explanation of drawings]

Figure 1 shows the state of the arc tube after the frit has been attached in the manufacturing method of the discharge tube, which is an embodiment of the present invention, and Figure 2 shows the state of the arc tube after the frit has been melted in the manufacturing method. 3 is an enlarged view of the lower part of the arc tube in FIG. 2; FIG. 4 is a diagram showing the state of the arc tube after adding a frit in the conventional method of manufacturing a discharge lamp; 5
6 is an enlarged view of the lower part of the arc tube in FIG. 5. FIG. 6 is an enlarged view of the lower part of the arc tube in FIG. 5. 1... Arc tube, 2a/2b... Cap, 3a-3
b・8a-8b---Gap, 4a・4b・1a・7b・
... Frit, 5a/5b...Rh, 6a...Four conductors, 6b...Exhaust pipe.

Claims (1)

[Claims] When the arc tube is held vertically, there is a gap formed between the arc tube and a cap for sealing both ends of the arc tube, and an introduction conductor inserted into the hole provided in the center of the cap and the cap. In a method of manufacturing a discharge lamp in which a gap formed between the discharge tube and the exhaust pipe is sealed by heating and melting a frit, the cap at the lower end of the discharge tube held vertically and the introduction conductor or the exhaust After attaching a frit so as to contact both the outer end surface of the cap and the outer peripheral surface of the introduction conductor or exhaust pipe along the gap formed between the cap and the pipe, heating and melting the frit,
A method for manufacturing a discharge lamp, characterized in that the gap is sealed by pulling up a molten frit into the gap using capillarity, thereby fixing the cap and the introduction conductor or the exhaust pipe.