JP2668831B2 - Miniature lamp manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a miniature lamp used for, for example, a backlight of a liquid crystal television.

[Conventional technology and its problems]

Recently, small miniature lamps such as flashlights for strobe guns, fluorescent lamps for backlights of LCD televisions, small low-pressure mercury lamps for sterilizing the inside of food packaging containers, and small filament lamps for store lighting have been developed. It has come to be widely used for various purposes.

In the case of these miniature lamps, the thickness of the glass bulb is thin, so the mechanical strength of the welded part is weak, and if a bending stress is applied to the protruding electric conductor or an impact is applied, a minute crack occurs in the welded part, The airtightness may be reduced to cause a slow leak or even damage. In these miniature lamps, an electric conductor connected to an electrode or a filament is hermetically penetrated into a glass sealing body such as glass beads, and the glass sealing body is attached to the end portion of the glass bulb. And heat the end of the glass bulb with a gas burner etc. to weld them together,
It is hermetically sealed. For this reason, there is a problem that a lot of manual work is required in the manufacturing process, which requires time and effort.

[Object of the invention]

Therefore, an object of the present invention is to provide a method for easily manufacturing a miniature lamp which has a high mechanical strength at a welded portion even when the thickness of a glass bulb is thin, and does not cause a slow leak or breakage. Is.

[Configuration of the invention and its operation]

The structure of the present invention is a method for manufacturing a miniature lamp in which a glass sealing body through which an electric conductor connected to an electrode or a filament penetrates is welded to an end portion of a thin glass bulb, One end of the glass bulb is inserted by inserting one end of the glass sealing body and the glass bulb into a bottomed tubular mold in which a recess having a large diameter is formed, and causing the bottomed tubular mold to generate heat. And melting the glass sealing body, and forming the molten portion with an outer diameter larger than the outer diameter of the glass bulb so as to be thick.

That is, one end of the glass sealing body and the glass bulb is inserted into a bottomed cylindrical mold in which a recess having a diameter larger than the outer diameter of the glass bulb is formed and melted by, for example, induction heating. Easy to mechanize and extremely easy to manufacture. Since the outer diameter of the welded portion is larger than the outer diameter of the thin glass bulb and is formed thicker, the miniature lamp manufactured according to the present invention has a stronger mechanical strength at the welded portion and has a protruding portion. Even if a small stress or impact is applied to the electric conductor, the electric conductor does not leak or break.

〔Example〕

The present invention will be specifically described below based on the embodiments shown in the drawings.

FIG. 1 shows a miniature lamp having a rated power consumption of 2 W used as a backlight light source of a liquid crystal television, for example. In Figure 1, the glass bulb 10 has an outer diameter of 6.2 m.
It is a glass tube having a length of 60 mm and a length of 60 mm, and a phosphor (not shown) is applied to an inner surface thereof. And glass bulb
At the ends 10a, 10b of 10, glass sealing bodies 11 made of glass beads are welded, respectively, and a small amount of mercury and an inert gas such as an argon gas having a sealing pressure of about several tens of Torr are sealed therein. .

The ends 10a and 10b of the glass bulb 10 and the glass sealing body 11 are welded in a mold by a manufacturing method described later.
The outer diameter of the welded portion 15 is larger than the outer diameter of the glass bulb 10, and the welded portion 15 is formed thicker than the glass bulb 10. A pair of electric conductors 12 made of a Dumet wire or a nickel wire is hermetically penetrated through the glass sealing body 11, a filament electrode 13 is held by the electric conductors 12, and one electric conductor 12 is made of a mercury alloy. Getter 14 is attached.

The filament constituting the electrode 13 is a single or double coiled wire of a refractory metal such as tungsten or molybdenum, and in any case, is lightweight and has an electron emitter attached thereto, for example. The weight of the part is about 0.1 to 0.3 mg. This is because the heat capacity is reduced by the weight reduction, the temperature is easily raised even if the power consumption is reduced, and the lighting performance is improved. As a material of the electron emitter, an oxide or a carbonate of an alkali metal or an alkaline earth metal, or another material is used.

Next, a method of manufacturing a miniature lamp having such a configuration will be described. In FIG. 2, a bell jar 2 made of quartz is detachably fitted to a cylindrical holding table 1 connected to a pressure reducing device (not shown). . The bell jar 2 has a bottomed tubular shape with one end closed, and is hermetically fitted by the seal 3. Therefore, when the decompressor operates, the pressure inside the bell jar 2 is reduced to about 10 ⁻⁴ Torr. A support rod 4 is erected in the center hole of the holding table 1, and a cylindrical holder 5 is fixed to the tip of the supporting rod 4 and is disposed above the holding table 1. A plurality of exhaust windows 51 are formed on the peripheral wall of the holder 5, and a mold 6 made of a high melting point material such as graphite, molybdenum or silicon nitride is fitted and held in the upper end hole.

As shown in FIG. 3, the mold 6 has a cylindrical shape with a bottom, a recess 61 is formed, and an exhaust hole 63 is formed in the bottom of the recess 61. An induction coil 7 connected to a high-frequency oscillator (not shown) is arranged on the outer periphery of the bell jar 2 at a position corresponding to the mold 6, and the induction coil 7 induces heat to heat the mold 6 having a high melting point. To do so. A low-frequency oscillator may be used instead of the high-frequency oscillator to generate heat by low-frequency induction heating, or heat may be generated by resistance heating by directly energizing without using the induction coil 7.

Then, as shown in FIG.
The glass sealing body 11 is placed in the center of the concave portion 61 with the electric conductors 12 extending from 11 to the outside inserted into the exhaust holes 63 of the mold 6 respectively. Subsequently, one end 10a of the glass bulb 10 is inserted into the concave portion 61 so as to cover the glass sealing body 11. At this time,
A gap 62 is formed between the outer peripheral surface of the glass bulb 10 and the inner peripheral surface of the recess 61.
However, the size of the gap 62 is the difference between the outer diameter of the welded portion 15 and the outer diameter of the glass bulb 10, and is also the difference in the wall thickness of the welded portion 15 and the glass bulb 10.

Next, a quartz-made bell jar 2 is airtightly fitted to the holding table 1, and a decompressor is operated to decompress the inside of the bell jar 2.
Then, an inert gas such as an argon gas having a pressure of, for example, 760 Torr is introduced into the bell jar 2. Then, the high-frequency oscillator is energized to cause a high-frequency current to flow through the induction coil 7 to cause the mold 6 to generate heat at about 1000 ° C. As a result, the one end 10a of the glass bulb 10 and the glass sealing body 11 melt, but as the glass bulb 10 melts, the glass bulb 10 slightly lowers under its own weight, and the molten glass fills the concave portion 61. That is,
The gap 62 disappears, and the welded portion 15 corresponding to the shape of the concave portion 61 is formed. Next, the glass bulb 1 with one end 10a welded
0 is inverted, and the other end 10b is inserted into the mold 6 with the one end 10a facing upward. Then, after depressurizing the inside of the bell 2 by the same operation, an inert gas such as argon is introduced at a gas pressure designed as a gas pressure for filling the fluorescent lamp, for example, a gas pressure of several tens of torr, and the mold 6 is heated. As a result, the other end 10b and the glass sealing body 11 are also welded to each other to form a welded portion 1 having the same shape.
5 is formed.

In this embodiment, one glass bulb 10 is arranged in the bell jar 2, but if a plurality of glass bulbs are arranged at the same time, the productivity can be further improved. Furthermore, a low-pressure mercury lamp, a flash discharge lamp, or an electrode 13
It is apparent that the welded portion 15 can be formed in a similar shape by this step even in an incandescent lamp to which a filament coil is attached instead.

As described above, according to the present invention, the manufacturing process is easily mechanized, and the manufacturing is simplified. Further, the miniature lamp manufactured according to the present invention has a high mechanical strength because the thickness of the welded portion 15 is large even if the thickness of the glass bulb 10 is small, and the welded portion 15 is small even if a slight vibration or impact is applied. There is no slow leak or damage.

〔The invention's effect〕

As described above, the method of manufacturing a miniature lamp according to the present invention has a glass sealing body through which an electric conductor connected to an electrode or a filament penetrates and one end of a thin glass bulb has a diameter larger than the outer diameter of the glass bulb. It is easy to mechanize the process because it is inserted into a bottomed cylindrical mold with a recess formed with it, and even if the thickness of the glass bulb is thin,
It is extremely easy to manufacture a miniature lamp that can easily increase the thickness of the welded part, and therefore has high mechanical strength and does not leak or break from the welded part even if a little vibration or impact is applied. You can

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a miniature lamp, FIG. 2 is an explanatory view of a manufacturing process of the present invention, and FIG. 3 is an enlarged sectional view of a portion A in FIG. 10: Glass bulb, 11: Glass sealing body 12: Electric conductor, 13: Electrode 14: Getter, 15: Welding part 1: Holder 2, Belger 3: Seal 5, … Holder 6 …… type, 7 …… induction coil

Claims (1)

(57) [Claims] 1. A method for manufacturing a miniature lamp in which a glass sealing body through which an electric conductor connected to an electrode or a filament penetrates is welded to an end of a thin glass bulb, wherein the outer diameter of the glass bulb is larger than the outer diameter of the glass bulb. One end of the glass sealing body and the glass bulb is inserted into a bottomed tubular mold in which a recess having a diameter is formed, and one end of the glass bulb is heated by heating the bottomed tubular mold, and A method for producing a miniature lamp, characterized by melting a glass sealing body and forming the outer diameter of the melted portion larger than the outer diameter of the glass bulb so as to be thick.