JPH06111775A - Low pressure discharge lamp - Google Patents

Abstract

PURPOSE:To release a proper amount of mercury from a mercury releasing body into a thin bulb and prevent a phosphor film, etc., from contamination caused by the released mercury attaching directly to the tube inner wall. CONSTITUTION:Mercury releasing bodies 15a, 15b are accommodated in sleeves 13a, 13b made of a conductive material and installed in a thin glass bulb 12 of a fluorescent lamp 11. Each mercury releasing body 15a, 15b has a tube 16 made of a conductive material, which is filled with a mercury alloy 17 and a getter 18. Sintered electrodes 14a, 14b are set in the foremost parts of the sleeves 13a, 13b and secured by caulking, The major diameter tips 17a, 17b of a pair of leads 16a, 16b are inserted in the open terminations of the sleeves 13a, 13b and secured by caulking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-pressure discharge lamp such as a small-diameter fluorescent lamp suitable for a light source of a liquid crystal display or the like, and more particularly to a low-pressure discharge lamp having an improved structure in which an appropriate amount of mercury is enclosed in a bulb.

[0002]

2. Description of the Related Art Conventionally, as an example of a small-sized cold cathode fluorescent lamp of this type, as shown in a partially enlarged vertical sectional view of FIG. 4, there is a chipless type without an exhaust pipe (chip). . Since the glass bulb 2 of the fluorescent lamp 1 has a small diameter, there is not enough space for forming an exhaust pipe at one end thereof, and the fluorescent lamp 1 is omitted and formed in a chipless type. For this reason, the inside of the bulb 1 cannot be evacuated through the exhaust pipe, and thereafter, mercury cannot be enclosed in the exhaust pipe.

Therefore, in this type of fluorescent lamp 1, a mercury emitter 5 is fixed in a bulb 2 in the middle of a lead wire 4 connected to a pair of electrodes (only one side is shown in FIG. 4) 3.

The mercury emitter 5 is, for example, as shown in FIG. 5, a substrate 5 in which the outer surface of an iron flat plate is plated with nickel, for example.
A mercury alloy 5b such as a Ti-Hg alloy is pressure-bonded to one surface of a, and a getter 5c made of a Zr-Al alloy is pressure-bonded to the other surface. Therefore, after the mercury emitter 5 is sealed in the bulb 2 and evacuated, the bulb 2
By irradiating the substrate 5a with high-frequency electromagnetic waves from the outside of the substrate to heat the mercury alloy 5b, mercury can be released into the bulb 2.

Further, when the mercury is released, the impure gas is released into the bulb 2, so that the impure gas is taken by the getter 5.
It can be absorbed and stored by c.

FIG. 6 and FIG. 7 show another mercury-emitting body 6, which is obtained by plating the outer surface of an iron dish-shaped body 6a with nickel or the like, and filling the inside with a mercury alloy 6b and a getter 6c. And has substantially the same function as the mercury emitter 5.

[0007]

However, in the conventional mercury emitters 5 and 6 as described above, when the length in the width direction is longer than the inner diameter in the bulb 2, the bulb 2
In addition to the fact that the mercury emitter 5 shown in FIG. 5 cannot be inserted into the inside, and the amount of mercury alloy that can be pressure-bonded to the substrate 5a is small, there is a problem that the amount of mercury sealed in the bulb 2 is less than a predetermined amount. .

Furthermore, the mercury emitter 6 shown in FIG.
Due to the heating of the main body 6a, there is a problem that mercury inside thereof is vaporized and becomes high-pressure gas and is ejected from the gap or the small hole and adheres to the inner wall of the bulb 2 to contaminate the phosphor film. In particular, since it is difficult to control the direction of the spouting point, there is a problem that mercury stains the phosphor at an unexpected location. In addition, since the mercury emitters 5 and 6 are fixed by spot welding or the like in the middle of the thin lead wire 4, mercury is easily released from the mercury alloys 5b and 6b to the outside of the bulb by heating during the welding. In addition, there is a problem in that, if it is attempted to prevent this emission, the adhesion is not sufficient, and the mercury emitters 5 and 6 are likely to fall off from the lead wire 4.

Therefore, the present invention has been made in consideration of such circumstances, and an object thereof is to prevent mercury emitted from a mercury emitter into the bulb from directly adhering to the inner wall of the bulb and contaminating it. Another object of the present invention is to provide a low-pressure discharge lamp that is capable of sealing an appropriate amount of mercury in a bulb and preventing the mercury emitter from falling off.

[0010]

The present invention is configured as follows to solve the above problems.

The invention according to claim 1 of the present application (hereinafter, referred to as the first
In a low-pressure discharge lamp having an electrode built in a bulb and connected to a lead wire, a mercury alloy that releases mercury by heating is filled in a conductor container to form a mercury emitter. Further, the mercury emitter is housed in a sleeve and enclosed in the bulb.

Further, in the invention according to claim 2 of the present application (hereinafter referred to as the second invention), the mercury emitter is filled with a mercury alloy and a getter for storing an impure gas in the container. Characterize.

Further, in the invention according to claim 3 of the present application (hereinafter referred to as the third invention), the sleeve is formed of a conductor, is connected to the lead wire, and fixes the built-in mercury emitter. Characterized by this.

The invention according to claim 4 of the present application (hereinafter, referred to as the fourth
The invention) is characterized in that the sleeve has a sintered electrode built therein.

[0015]

[Action]

<First to Fourth Inventions> When a conductor container of a mercury emitter is irradiated with high-frequency electromagnetic waves from the outer peripheral surface of the bulb, the conductor container is subjected to high-frequency induction heating to heat the mercury alloy therein.

For this reason, it is prevented that mercury is gasified from the mercury alloy and once released into the sleeve, then released into the valve, and the mercury is released directly into the valve and adheres to the inner wall of the tube to contaminate it. can do.

In the second aspect of the invention, the impure gas released at the same time when mercury is released from the mercury emitter into the bulb can be absorbed by the getter. Stability can be prevented.

Further, according to the third aspect of the invention, since the sleeve is connected to the lead wire, when the lamp voltage is applied to the lead wire, the sleeve operates as a cold cathode to enhance the rise of the luminous flux at the time of starting. You can

According to the fourth aspect of the invention, since it is not fixed by welding, Hg will not be released during manufacturing.

<Fifth Invention> When a lamp voltage is applied to the lead wire, the sleeve acts as a cold cathode, and
After the sintered electrode reaches a predetermined operating temperature, it acts as a hot cathode and the lamp current increases, so that the speed of light can be increased.

[0021]

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

FIG. 2 is a partially cutaway front view of an embodiment including the first to fourth inventions of the present application. In FIG. 2, a fluorescent lamp 11 which is a low pressure discharge lamp is made of, for example, a glass thin bulb 12.
Is configured as a chipless type without an exhaust pipe, and a phosphor film is almost entirely deposited on the inner peripheral surface of the bulb 12. In the valve 12, a pair of left and right, for example, N
The cylindrical sleeves 13a and 13b made of a conductor such as i are incorporated.

Each of the sleeves 13a and 13b has, for example, an inner diameter of 1.1 mm and a length of 7 mm, and inside each tip thereof, for example, the sintered electrodes 14a and 14 having an outer diameter of 1 mm and a length of 3 mm.
b, or an electrode impregnated with an electron emitting substance is built in, respectively, and the sleeves 13a, 13b are fixed by caulking the sleeves 13a, 13b at the intermediate portion in the axial direction so as to reduce the diameter.
It is electrically connected.

For the sintered electrodes 14a and 14b, first, for example, a porous metal body having a porosity of 70% or more is formed with a compounding ratio of 75% or more of tungsten and 25% or less of niobium. Emitter on body (electron emitting material)
Is impregnated with one or more components.

The sleeves 13a and 13b correspond to the respective sintered electrodes 1.
A pair of left and right mercury emitters 15 are provided behind the 4a and 14b.
a, 15b are respectively built in, and the respective sleeves 14a, 14b are caulked so as to reduce the diameter at the axially intermediate portions thereof so that the respective mercury emitters 15a, 15b are attached to the respective sleeves 13.
It is fixed in a and 13b.

Each of the mercury emitters 15a and 15b is filled with Ti-Hg in a tube 16 which is a cylindrical container made of a conductor such as Ni.
A powder of a mercury alloy 17 that releases mercury by heating an alloy or the like and a powder of a getter 18 such as a Zr-Al alloy that absorbs and stores the impure gas in the bulb 12 are filled.

Further, each sleeve 14a, 14b has its opening end portion (the right end portion in FIG. 1) reduced in diameter to the outer circumference of the large-diameter tip portions 17a, 17b of a pair of lead wires 16a, 16b made of, for example, Dumet wire. It is fixed by crimping so that the lamp voltage is applied to the pair of lead wires 16a and 16b.

When the mercury is sealed in the bulb 12 after the bulb 12 is evacuated, when the mercury emitters 15a and 15b are irradiated from the outer peripheral surface of the bulb 12, for example, the respective tubes 16 of the mercury are ejected. By locally high-frequency induction heating, the mercury alloy 17 inside is heated and the mercury is gasified and once released into the sleeves 13a and 13b, and then released into the valve 12, and an appropriate amount of mercury is released into the valve 12. Enclosed inside.

At this time, the impure gas released into the valve 12 is occluded by the getter 18.

Next, the operation of this embodiment will be described.

When a predetermined lamp voltage is applied to the pair of lead wires 16a, 16b, the pair of sintered electrodes 14a, 14b.
The pair of sleeves 1 until the
3a, 13b and the pair of sintered electrodes 14a, 14b act as cold cathodes to generate glow.

The glow is converged in the tip portions of the sleeves 13a and 13b to increase the ion density, and the electrode temperature quickly reaches a predetermined operating temperature and rises quickly. For this reason, the rising of the luminous flux becomes faster.

When the pair of sintered electrodes 14a and 14b reach a predetermined electrode temperature, they operate as a hot cathode, and a positive column is formed between the two sintered electrodes 14a and 14b. This positive column excites the phosphor film on the inner peripheral surface of the bulb 12 to emit light and light up.

Therefore, according to this embodiment, the tube 1
Since the powder of the mercury alloy 17 and the getter 18 is filled in the tube 6, these can be filled in the tube 16 in a sufficient amount. Therefore, mercury can be filled in the bulb 12 in a necessary and sufficient amount, and the impure gas in the bulb 12 can be sufficiently absorbed.

After the mercury emitters 15a and 15b are enclosed in the bulb 12, the mercury emitters 15a and 15b are sealed.
Since only the gas can be locally heated by the high frequency induction heating, the work of enclosing mercury in the bulb 12 can be simplified.

Further, the mercury released during heating of the mercury emitters 15a, 15b is first of all the sleeves 13a, 13
Since it is discharged into b, it is possible to prevent mercury from being directly discharged into the bulb 12 and adhering to and contaminating the inner peripheral surface thereof.

Furthermore, each of the mercury emitters 15a, 15b
Since they are housed in the sleeves 13a and 13b and fixed by caulking, it is possible to prevent the mercury emitters 15a and 15b from falling out of the sleeves 13a and 13b, and also to weld them by welding as in the conventional example. Mercury emitter 15a,
Since 15b is not fixed on the thin lead wires 16a, 16b, the mercury emitters 15a, 15b are not heated by the heating during welding.
It is possible to prevent mercury from being emitted from b to the outside of the bulb 12.

In the above embodiment, each sleeve 13a,
The case where the respective sintered electrodes 14a and 14b, the mercury emitters 15a and 15b, and the lead wires 16a and 16b are fixed by caulking 13b has been described, but the present invention is not limited to this and, for example, FIG. Sintered electrode 1 as shown
4a, 14b are connected to each sleeve 13a, 13b by a short inner lead wire 20, while each sleeve 13
On the inner peripheral surface of the open ends (right end in FIG. 3) of a and 13b, the tip of the outer lead wire 21 made of, for example, Dumet wire having a substantially uniform wire diameter is fixed and mechanically and electrically connected. May be. Further, the present invention provides a lamp in which one electrode is built in the bulb 12 and an external electrode is attached to the outer peripheral surface of the bulb 12 along the axial direction so that the internal electrode and the external electrode discharge. Can also be applied.

Further, the exhaust pipe is used only for exhaust in the exhaust process, but since the exhaust pipe diameter is small, it is possible to use a mercury-releasing alloy for Hg sealing without using the exhaust pipe in order to prevent Hg from clogging in the middle. .

[0040]

As described above, according to the first to fourth inventions of the present application, since the mercury emitter is housed in the sleeve and enclosed in the bulb, when the mercury emitter is heated, the mercury released therefrom is not emitted. Since it is once released into the sleeve and then released into the bulb, it is possible to prevent mercury emitted from the mercury emitter from directly adhering to the inner peripheral surface of the bulb and contaminating it.

Further, in the second invention of the present application, since the impure gas in the valve can be occluded by the getter, it is possible to prevent the efficiency from being lowered and the discharge to be unstable due to the impure gas. Further, in the third invention of the present application, since the sleeve is connected to the lead wire, when the lamp voltage is applied to the lead wire, the sleeve can operate as a cold cathode.

Furthermore, according to the fourth invention of the present application, when a lamp voltage is applied to the lead wire, the sleeve acts as a cold cathode at the time of starting, and after the temperature of the sintered electrode is raised to the operating temperature, this is a hot cathode. , And it is possible to increase the lamp current and increase the brightness.

[Brief description of drawings]

FIG. 1 is an enlarged vertical sectional view of a main part of FIG.

FIG. 2 is a partially cutaway front view of a low-pressure discharge lamp (fluorescent lamp) including the first to fourth inventions of the present application.

FIG. 3 is a longitudinal sectional view of a main part of another embodiment of the present invention.

FIG. 4 is a partial vertical cross-sectional view of a conventional fluorescent lamp.

5 is a cross-sectional view of the mercury emitter shown in FIG.

FIG. 6 is a partially enlarged vertical sectional view of another fluorescent lamp.

7 is a front view of the mercury emitter shown in FIG.

[Explanation of symbols]

 11 Fluorescent lamp 12 Bulbs 13a, 13b Sleeves 14a, 14b Sintered electrodes 15a, 15b Mercury emitter 16 Tubes 16a, 16b Lead wire 17 Mercury alloy 18 Getter 20 Inner lead wire

Claims (5)

[Claims] 1. A low pressure discharge lamp having an electrode built in a bulb and connected to a lead wire, wherein a mercury alloy that releases mercury by heating is filled in a conductor container to form a mercury emitter. Further, the mercury discharge body is housed in a sleeve and enclosed in the bulb, and a low pressure discharge lamp is provided. 2. The low-pressure discharge lamp according to claim 1, wherein the mercury emitter is filled with a getter which stores an impure gas together with a mercury alloy in the container. 3. The low-pressure discharge lamp according to claim 1, wherein the sleeve is formed of a conductor, is connected to the lead wire, and fixes the mercury emitter contained therein. 4. The low-pressure discharge lamp according to claim 1, wherein the mercury-emitter, together with the container, is caulked to the sleeve. 5. The low-pressure discharge lamp according to claim 1, wherein the sleeve has a sintered electrode built therein.