JPS59196534A - Manufacture of fluorescent lamp - Google Patents

Abstract

PURPOSE:To prevent the damage of base metal and the blackening of a tube wall by exhausting the inner part of a bulb, decomposing and activating an electron emission material, and sealing the base metal for forming amalgam in the bulb. CONSTITUTION:A mount system with a filament electrode in which an electron emission material is mounted on both ends of a tubular bulb with a phosphor coat on the inner surface is sealed, heated, and exhausted, and a filament is turned on and then the electron emission material is decomposed and activated. Mercury is sealed in the bulb and the filament is turned on again and flow discharge is generated between both ends of the filament. The electron emission material of the filament end is decomposed and activated by the heat and emitted cracked gas is exhausted. Then the fine particles of the base metal that should form amalgam are entered in the bulb. While or after amalgam is formed, an exhaust tube is sealed by filling the inner part of the bulb with start gas, such as argon.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a so-called amalgam-containing fluorescent lamp in which the vapor pressure of mercury is adjusted by amalgam.

[Technical background of the invention and its problems]

When a fluorescent lamp is lit in a high-temperature atmosphere, the mercury vapor pressure inside the lamp increases, the discharge characteristics change, and the luminous efficiency decreases. Therefore, as a countermeasure to this problem, it is known to amalgamate mercury to adjust the vapor pressure of mercury so that high efficiency can be obtained even in a high-temperature atmosphere.

Therefore, there are two methods for producing an amalgam-containing fluorescent lamp: a method in which mercury and a base metal for amalgam formation are reacted in advance and amalgam is supplied into the bulb, and a method in which mercury and the base metal are separately sealed in the bulb. A common method is to form an amalgam within the valve.

Although the method of separately sealing mercury and base metal has various advantages, on the other hand, the base metal is oxidized and worn out inside the bulb, and oxides adhere to the inner surface of the bulb wall, causing blackening. There are drawbacks to becoming

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a fluorescent lamp, which prevents oxidation of the base metal sealed in the bulb and eliminates the risk of wear and tear of the base metal and blackening of the tube wall.

[Summary of the invention]

The inside of the valve is evacuated and the electron radioactive material is decomposed and activated.
Thereafter, the base metal for amalgam formation is sealed inside the bulb, thereby preventing the base metal from being oxidized by residual air in the bulb or decomposition gas of the electron radioactive substance.

[Embodiments of the invention]

The details of the invention are illustrated by the following examples.

First, a mount stem having a filament electrode coated with an electron-emitting substance is sealed to both ends of a tubular bulb whose inner surface is coated with a phosphor, and this is bent into a curved tube shape, for example, a saddle shape. Next, the valve is heated to release the adsorbed gas while exhausting the gas. Next, the filament is heated while being evacuated to decompose and activate the attached electron radioactive substance, and the released decomposed gas is discharged. This process is called primary lyramp. Then, mercury is sealed inside the bulb. Then, the filament is energized again while being evacuated, causing a glow discharge between both ends of the filament, and the heat decomposes and activates the electron radioactive material at the end of the filament, and the released decomposed gas is discharged. This process is called secondary lamping. Next, fine grains of a base metal to form an amalgam, such as an alloy of 62 mol % bismuth, 19 mol % indium, and 19 mol % tin, are introduced into the bulb. If the surface temperature of the bulb at this time is maintained at 100 to 200°C, the base metal will start reacting with mercury at the same time as the injection, forming an amalgam.

and during or after amalgam formation.

The amalgam fluorescent lamp is completed by filling the bulb with a starting gas such as argon and sealing the exhaust pipe. Then, it is sent to the next process such as aging and capping.

In this way, in this example, the base metal is sealed after the secondary lamp is completed, so there is no residual air or decomposition gas of the electron radioactive material inside the bulb at the time of filling, and after filling 1. The decomposition gas mentioned above is not generated. Therefore, almost the entire amount of the encapsulated base metal is not oxidized and can be used for amalgam formation, and there is no blackening of the tube wall due to the base metal oxide.

3. Next, when the base metal is encapsulated at various stages of the illustrated steps in addition to the above-mentioned examples, the amount of the base metal (including metal and amalgam) that is free from blackening of the tube wall and oxidation of the base metal , ) were investigated, and the relative values of light output were also measured.

The results are shown in the table below. In addition, in this test, the base metal was the above-mentioned bismuth-indium-tin alloy 40~50m
g, and 6 to 10 mg of mercury was used.

In this way, if the base metal is introduced into the bulb after the second lighting or after filling with the starting gas, the base metal will hardly be oxidized, there will be almost no blackening of the tube wall, and furthermore, the light output will be good.

4- In the above-mentioned embodiment, the entire amount of mercury was filled at once between the primary lighting lamp and the secondary lighting lamp, but in the present invention, the mercury was filled in at once after the primary lighting and after the secondary lighting. It may be enclosed in two parts. moreover,
In the present invention, mercury may be sealed in the form of an intermetallic compound, and after the exhaust pipe is sealed, the mercury may be released to form an amalgam. In this case as well, if the base metal is introduced after the second lyramp is completed, the above-mentioned embodiment can be achieved. Similarly, it is possible to prevent wear and tear on the base metal, eliminate blackening of the tube wall, and improve optical output.

Furthermore, the present invention can be applied to cases where the primary light lamp and the secondary light lamp cannot be distinguished in terms of time. Also,
In the present invention, the base metal for amalgam formation is not limited to the above-mentioned embodiments, but can be applied to other alloys or single metals that are likely to be oxidized.

The present invention is applicable not only to the above-mentioned curved tube fluorescent lamp but also to straight tube fluorescent lamps.

〔Effect of the invention〕

The method for manufacturing a fluorescent lamp of the present invention is to separately fill mercury forming an amalgam and a base metal to form an amalgam inside the bulb, and the inside of the bulb is evacuated to decompose and activate the electron radioactive substance. Since the base metal is later filled into the bulb, the base metal is not oxidized by the residual air inside the bulb or the decomposition gas of the electron radioactive substance, so there is almost no depletion of the base metal, and the tube wall is blackened by the oxide. The light output is also good.

[Brief explanation of drawings]

The figure is a process diagram of an embodiment of the method for manufacturing a fluorescent lamp of the present invention. Agent Patent Attorney Inoue - Male 7 = Continuation of page 1 (7 Inventors Atsushi Sato 201-1 Funakoshi-cho 1, Yokosuka City 209-1, Yokosuka Factory, Kyoshibaura Electric Co., Ltd.)

Claims (1)

[Claims] A method for manufacturing a fluorescent lamp, in which mercury and an amalgam-forming base metal are separately sealed in a bulb formed by sealing a pair of filaments coated with an electron radioactive substance at both ends, and an amalgam is formed in the bulb. A method for manufacturing a fluorescent lamp, wherein the base metal is sealed after evacuating the inside of the bulb and decomposing and activating the electron radioactive substance.