JPH06283102A - Manufacture of low-pressure mercury vapor discharge lamp - Google Patents

Abstract

PURPOSE:To accurately seal a necessary quantity of mercury by feeding and sealing a powdery mercury alloy in the glass tube of a discharge lamp, heating the glass tube, and emitting mercury from the alloy in the glass tube. CONSTITUTION:A glass tube 1 coated with phosphors 2 and fixed with an electrode 3 is heated, exhausted, and decompressed, then a prescribed quantity of a powdery mercury alloy having the average grain size of about 0.1mm is guided into the tube 1 from an exhaust pipe via the pressure of the inactive gas such as Ar gas. The sealed mercury alloy is accumulated on the tube wall at the bottom section of the tube 1. The inside of the tube 1 is decompressed, then Ar gas is sealed, and the exhaust pipe is sealed. The whole tube 1 is heated at the melting point or above of the mercury alloy. The mercury alloy is made the liquid phase state, and a prescribed quantity of mercury is emitted and diffused in the tube 1. A base 6 is stuck to complete a discharge lamp. A prescribed quantity of mercury can be accurately sealed, and the quantity of mercury used can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a low pressure mercury vapor discharge lamp, and more particularly to a method of manufacturing a low pressure mercury vapor discharge lamp capable of reducing the amount of mercury enclosed in the discharge lamp.

[0002]

2. Description of the Related Art From the viewpoint of environmental protection, there is an increasing need to reduce the amount of mercury supplied to discharge lamps.

The prior art is a method of dropping liquid mercury from an exhaust pipe at the time of manufacturing a fluorescent lamp or a method of enclosing it as a titanium mercury alloy as described in "Writing Handbook" (Ohm Co., 1987, p. 134). Alternatively, a method in which mercury is encapsulated and introduced into a lamp, and a method of using an amalgam of mercury is used for a lamp operating at a high temperature in order to prevent a decrease in luminous efficiency at a high temperature.

Further, as a method of enclosing mercury in the case of using a horizontal type exhaust machine for exhausting a lamp in a horizontal state, a groove is formed as described in, for example, JP-A-56-145632. A method is used in which the shaft is brought into contact with the end of the lamp exhaust pipe and the mercury dropped in the groove is introduced into the lamp by the pressure of the argon gas.
Regarding the average particle size of the powder, for example, “Powder Theory and Application” (Maruzen Co., Ltd., 1962, p. 83) describes a method of calculating the average particle size in consideration of the shape and particle size distribution of the powder. Have been described.

[0005]

In the conventional low-pressure mercury vapor discharge lamp described above, the method of enclosing mercury in the lamp is as follows.
In the case of using the method of sealing 0 mg to 20 mg of liquid mercury through the exhaust pipe, a horizontal exhaust machine is used, in which the lamp is evacuated in a horizontal state in order to supply mercury during the lamp exhaust process. In this case, when mercury is introduced into the lamp by the pressure of the inert gas, at least a part of it adheres to the shaft or the exhaust pipe for introducing the mercury, and all of the mercury to be enclosed is enclosed in the lamp. It is difficult to effectively encapsulate it inside.

Therefore, in order to supply a necessary amount of mercury into the lamp, a mercury dispenser in which a Ti-Hg alloy is coated on a metal plate is installed in the electrode part of the lamp and the mercury is released by high-frequency heating from the outside. Alternatively, a method of encapsulating mercury in a capsule-shaped glass, fixing the capsule to a ring-shaped nickel plate, installing it on the electrode part of the lamp, and heating the microwave to destroy the capsule and introduce the mercury into the lamp Is used.

However, both of these methods have high material costs,
Moreover, the structure is complicated, so that it is difficult to manufacture, and a heating device for discharging mercury is required.

Further, in the method using amalgam containing mercury, bismuth and indium as the main components, the purpose is to control the mercury vapor pressure so that the lamp efficiency is maximized in a fluorescent lamp having a high tube wall temperature. Therefore, the amalgam must be stored in the coldest part of the lamp, for example, in the exhaust pipe. Therefore, there is a problem that the structure and the manufacturing process become complicated.

Further, in the method of enclosing the metal body forming mercury and amalgam in the lamp, it may be exposed to a higher temperature than the method of housing the amalgam in the exhaust pipe, so that the effect of suppressing the mercury vapor pressure is reduced. At the same time, there was a problem that the amalgam made in the tube was free to move in the glass tube, causing peeling of the fluorescent film, and the presence of relatively large particles significantly impaired the commercial value in appearance. . That is, if the fluorescent film in the glass tube is peeled off to the extent that it can be visually recognized, the appearance of the discharge lamp as a product may be poor and the commercial value may be reduced. Further, since the presence of this amalgam can be visually observed from the outside of the discharge lamp as a shadow when the discharge lamp is turned on, the commercial value may be similarly reduced.

An object of the present invention is to discharge a low-pressure mercury vapor which can reduce the amount of mercury used, without significantly increasing the manufacturing cost thereof, as compared with the method of manufacturing a mercury discharge type discharge lamp. A method of manufacturing an electric lamp is provided.
Another object of the present invention is to provide a method for manufacturing a low-pressure mercury vapor discharge lamp that does not impair the appearance of the discharge lamp even if the amount of mercury used is reduced.

[0011]

The above object is to supply a powdery mercury alloy into a glass tube forming a part of a low-pressure mercury vapor discharge lamp, and to seal the glass tube supplied with the mercury alloy. Then, the mercury is released from the alloy in the glass tube by heating the sealed glass tube, which is achieved by using a method for manufacturing a low-pressure mercury vapor discharge lamp.

[0012]

Since the mercury alloy is in powder form (a mercury alloy is used as powder), for example, pressure may be applied to the alloy and supplied from outside the glass tube into the glass tube. By doing so, it is possible to prevent the alloy from substantially adhering to the middle of the exhaust pipe connected to the glass pipe during the supply of the alloy. Therefore, the required amount of mercury can be accurately filled in the low-pressure mercury vapor discharge lamp. That is, if the amount of the mercury alloy supplied in advance is measured and then supplied into the glass tube, a substantially minimum amount of the mercury alloy can be supplied into the glass tube.

If such a method is used, mercury (alloy)
Can be introduced into the glass tube from the exhaust tube. Therefore, the structure of the discharge lamp is not complicated and the method of manufacturing the discharge lamp is not significantly complicated, as compared with the conventional method of manufacturing the low-pressure mercury vapor discharge lamp of the mercury dropping method.

The average particle diameter of the powdery particles, that is, the particles constituting the powdery mercury alloy is 0.01 mm or more and 0.2 or more.
It is desirable that it is less than or equal to mm. The average particle size of the alloy is 0.
This is because when the thickness exceeds 2 mm, there is an empirical rule that when the completed discharge lamp is turned on, the alloy particles that are powders can be clearly seen from the outside of the glass tube. If the alloy particles are visible, the commercial value of the discharge lamp as a product may be impaired in appearance. Further, the remaining alloy from which mercury has been released by heating is in a state where it can move freely inside the discharge lamp. However, the average particle size is 0.2
If a mercury alloy of mm or less is used, even if the particles collide with the fluorescent film in the glass tube, the film baldness of the fluorescent film does not occur. Therefore, the discharge lamp does not significantly impair the commercial value of the appearance.

The use of an alloy having an average particle size of less than 0.01 mm causes a significant increase in the cost of manufacturing a discharge lamp. It is generally extremely difficult to produce a fine powder having an average particle size of less than 0.01 mm. Forcibly producing such a powder causes a significant increase in its production cost, resulting in an increase in the production cost of the discharge lamp.

However, since the appearance of the product does not matter so much depending on the use of the discharge lamp, there is no problem even if the present invention is carried out by using a mercury alloy powder having an average particle size of more than 0.2 mm. Sometimes it doesn't. In addition, it may be necessary to carry out the present invention using a powder of a mercury alloy having an average particle diameter of less than 0.01 mm, for other needs than to keep the cost low. Therefore, it is not a decisive obstacle to carry out the present invention using such a fine mercury alloy powder.

Further, in order to release a necessary and sufficient amount of mercury into the glass tube of the discharge lamp by heating the mercury alloy, it is preferable to use a metal having a melting point of 500 ° C. or less as a constituent of the mercury alloy. desirable. When a mercury alloy made of a metal having a melting point of more than 500 ° C. is used in the production method of the present invention, when the glass tube is heated to release mercury from the alloy in the glass tube, the heating amount of the glass tube must be considerably increased. The amount of mercury required for discharge cannot be released from the alloy. Then, if such heating is performed, the glass tube constituting the low-pressure mercury vapor discharge lamp made of soft glass is deformed by the heat and troubles such as cracks occur.

Further, since heating of the mercury alloy can be easily performed from the outside of the glass tube by a heater or the like, there is an advantage that a complicated device such as a high frequency heating device is not required.

Further, in the present invention, since a powdery mercury alloy whose material cost is low is used, in comparison with the conventional method for manufacturing a low pressure mercury vapor discharge lamp for reducing the amount of mercury used, a low pressure mercury vapor discharge is used. It is possible to minimize the cost increase associated with the manufacture of electric lights. The mercury alloy used in the present invention refers to an alloy of mercury and a certain metal (for example, a metal having at least one of tin, lead and zinc). The mercury content of this alloy is 30% by weight or more and 60% or more.
% Or less is desirable.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a discharge lamp which is an embodiment of the present invention.

FIG. 2 is a diagram showing a method of manufacturing a straight tube low-pressure mercury vapor discharge lamp according to this embodiment.

After coating the phosphor 2 (FIG. 2 (b)) on the inner surface of the glass tube 1 (FIG. 2 (a)) made vertical, the glass tube was made horizontal, baked and baked to fix the electrode 3. A mount (Fig. 2 (c)) is attached to both ends of the glass tube (Fig. 2).
(D)). Then, the glass tube is heated to about 400 ° C. to exhaust gas generated when decomposing the electrode material and impure gas generated from the glass and the phosphor.

Then, about 20 mg of a powdery mercury alloy having an average particle diameter of about 0.1 mm is weighed, and the alloy is introduced into the glass tube through an exhaust pipe by the pressure of an inert gas such as pressurized argon gas. (FIG. 2 (e)). By making the structure in which the inert gas enters through one exhaust pipe and exits through the other exhaust pipe, substantially all of the mercury alloy powder is enclosed in the discharge lamp. Further, since the enclosed mercury alloy is deposited on the tube wall at the bottom of the glass tube of the discharge lamp, the alloy is not substantially discharged from the exhaust pipe on the other side.

Next, after the inside of the glass tube is sufficiently decompressed, argon gas 4 is sealed in the glass tube and the exhaust tube is sealed (FIG. 2 (f)).

After that, the entire glass tube of the discharge lamp is heated at a temperature equal to or higher than the melting point of the mercury alloy (FIG. 2 (g)). As a result, the alloy becomes in a liquid state, and a predetermined amount of mercury is released from the alloy and diffuses as it is into the discharge lamp.

After that, the base 6 is adhered to complete a discharge lamp (FIG. 2 (h)).

The alloy after the mercury is released can move freely inside the discharge lamp even after the discharge lamp is completed, but since the size is as small as 0.1 mm, the film baldness of the phosphor and the particles of the mercury alloy exist. Does not impair the product value in appearance.

Further, a straight tube type low pressure mercury vapor discharge lamp using a vertical exhaust machine, a ring type low pressure mercury vapor discharge lamp, a compact type low pressure mercury vapor discharge lamp, a light bulb type low pressure mercury vapor discharge lamp, and a U-shaped low pressure mercury vapor discharge lamp. Even in other low-pressure mercury vapor discharge lamps such as electric lamps, the mercury alloy is powdered and sealed in the discharge lamp.
Of course, the same effect can be obtained by heating the alloy at a temperature equal to or higher than the melting point of the alloy to bring the alloy into a liquid phase state and releasing a predetermined amount of mercury into the glass tube.

[0030]

According to the present invention, in comparison with the method of manufacturing a mercury-excision-type discharge lamp, low-pressure mercury capable of reducing the amount of mercury used without significantly increasing the manufacturing cost thereof. A method for manufacturing a vapor discharge lamp can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a low pressure mercury vapor discharge lamp according to the present invention.

FIG. 2 is a diagram showing a method of manufacturing a straight tube low-pressure mercury vapor discharge lamp according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass tube, 2 ... Phosphor, 3 ... Electrode, 4 ... Argon gas, 5 ... Mercury alloy, 6 ... Base, 7 ... Metal after mercury is released, 8 ... Heater.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Takahashi 888 Fujibashi, Ome-shi, Tokyo Hitachi, Ltd. Living Equipment Division

Claims (4)

[Claims] 1. A glass tube which comprises powdery mercury alloy supplied into a glass tube forming a part of a low-pressure mercury vapor discharge lamp, the glass tube supplied with the mercury alloy is sealed, and the glass tube is sealed. A method of manufacturing a low-pressure mercury vapor discharge lamp, characterized in that mercury is released from the alloy in the glass tube by heating the glass tube. 2. The method of manufacturing a low pressure mercury vapor discharge lamp according to claim 1, wherein the mercury alloy is melted in a liquid phase state by the heating. 3. The method for manufacturing a low-pressure mercury vapor discharge lamp according to claim 1, wherein the entire glass tube is heated during the heating. 4. The method of manufacturing a low-pressure mercury vapor discharge lamp according to claim 1, wherein the mercury alloy particles which are powders have an average particle diameter of 0.01 mm or more and 0.2 mm or less. .