JPH1055780A - Fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a fluorescent lamp, burning of metal base or the like generated by abnormal discharge of semi-discharge or the like at an end of service life by applying a substance containing arc extinguishing gas onto an inner introducing line constituting an electrode and a stem glass. SOLUTION: Electrodes are disposed on both tube ends of a glass bulb 1, and a filament 3 is filled with an electron emissive material. Further, an inner introducing line 4 is planted in a stem 6. On the inner introducing line 4 or the stem 6 including the line 4, a substance consisting of an organic solvent and a water-containing silica material and the organic solvent in which nitro cellulose is dissolved in butyl acetate is employed. A binder is maintained to an extent to evaporation by a heat applied in a manufacturing process of this fluorescent lamp. Even if fusion of the inner introducing line is generated in this lamp, water contents in which arc extinguishing gas generation substance applied to a root of the inner introducing gas and the stem is contained in a water-containing silica by brightness temperature is generated, and discharge stops immediately. Thus, damage of the fluorescent lamp and burning of the metal base or the like can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a fluorescent lamp.

[0002]

2. Description of the Related Art In a fluorescent lamp, a fluorescent substance is coated on the inner wall of a glass tube, electrodes connected to a lead wire are arranged on both ends of the glass tube, and a vacuum is applied to the inside of the tube. Gas is enclosed. The electrode is composed of a filament made of tungsten and an electron-emitting substance filled in a gap between the filaments.

[0003] The lead-in wire is generally embedded in an inner lead-in portion for connecting electrodes and a glass portion, and an outer lead-in portion for connecting a sealing portion for keeping the inside of the tube airtight and a base pin. And consists of The lamp is lit in combination with the ballast,
When the electron emitting material on the electrodes provided at both ends of the lamp is exhausted, the lamp is usually turned off and its life is extended.

[0004] However, when the ballast is boosted by the power supply voltage and outputs a high voltage, at the end of the life of the lamp, the energy required to sustain the discharge is large,
An abnormal discharge such as a half-wave discharge was generated, and the lamp itself was damaged by heat generation, or a contact portion with the base or the socket was heated, and although very rarely, burned out.

[0005]

When the electron-emitting material constituting the electrode is exhausted, the fluorescent lamp cannot be continuously lit and has a life. In this case, not all lamps are turned off as they are, but generally the electron-emitting material is consumed or, at the final consumption stage, a hot spot is generated on the tungsten wire constituting the filament to maintain the discharge. And In most cases, the lighting is not turned on after repeating this state.

However, rarely, the discharge continues for a longer time,
After the filament is melted, the discharge from the inner lead wire starts, and the inner lead wire starts to melt in a very short time, and this melting may progress to the stem glass portion in which the inner lead wire is buried. This process has a half-wave discharge or a current waveform close to the half-wave discharge, and has a current or a peak value that is higher than the rated current. Due to this large current, heating occurs in the contact portion between the base pin and the lead wire or in the contact portion between the pin tip and the socket contact piece, and the surrounding plastic and fiber portions generate heat and, very rarely, burn out.

In the process of melting the lead wire, the lead wire softens and hangs down, falls down and comes into contact with the inner wall of the glass tube, causing a phenomenon that the glass portion is damaged, and the stem glass portion is melted and broken. Sometimes. In particular, when the output voltage of the ballast used is high, the rate of occurrence of this phenomenon increases. Recently, electronic ballasts have become widespread, and accidents and phenomena that have impaired the safety of this type of product have been confirmed in fluorescent lamps lit in combination with this ballast.

Conventionally, in order to ensure safety at the end of the life of this type of fluorescent lamp, it is common to install a current fuse or a temperature fuse on the ballast side. It is installed to prevent smoke and ignition from the ballast due to abnormal heat generation during the service life or due to poor production. For this reason, at present, a sufficient protection function is not provided for heat generation and damage of the lamp itself which occurs at the end of the life of the fluorescent lamp.

[0009]

There is an unavoidable occurrence of an abnormal discharge such as a half-wave discharge which occurs at the end of the life of a fluorescent lamp. Even in this case, a problem that may lead to an accident must not occur. Although it is conceivable to provide the ballast with a protection function, it is necessary to provide a function that satisfies both the function to prevent accidents in the ballast itself and the overall safety function including the lamp itself and the lamp and socket. It was difficult.

An object of the present invention is to provide a lamp with a protective function in order to prevent an accident occurring at the end of the life of the lamp. Specifically, the object can be achieved by applying a substance containing an arc-extinguishing gas to a part of the internal introduction line.

The electrodes arranged at both ends of the lamp wear out in substantially the same manner, but some imbalance is inevitable. Therefore, since one of the electrodes is quickly consumed, it is unavoidable that the current becomes a state close to a half wave at the end of life. The consumed electrode generates a hot spot (bright spot) on the filament due to the impact of ions in the plasma generated by absorbing the electric energy supplied from the ballast. Since this temperature is higher than the melting temperature of tungsten, the filament is blown out. At this time, there is a lamp that is not lit and has a life, but the discharge is maintained from the electron emitting substance attached to the internal lead, and at this time, a bright point is formed on nickel or nickel-coated iron wire constituting the internal lead, High temperatures cause melting. In a very short time, all of the internal feed lines are melted, followed by a discharge from the stem glass, which also melts.

According to the present invention, a material which generates an arc-extinguishing gas at a high temperature is applied to a part of the inner lead wire or a range including the stem glass part, so that the discharge luminescent spot reaches this part. At this time, a large amount of gas is generated to stop the continuation of discharge. Thus, it is possible to prevent the glass portion from being damaged, and from burning out the plastic and fiber of the base and the socket portion.

[0013]

FIG. 1 is a sectional view of a tube end of a fluorescent lamp used in an embodiment. The outer diameter of the glass bulb 1 is φ2
6.0 mm. Electrodes are arranged at both ends of the tube, and the filament 3 is filled with an electron emitting substance (not shown). The filament 3 is connected to an inner lead wire 4 made of a nickel-coated iron wire having a diameter of 0.6 mm. Further, the inner lead wire 4 is implanted in the stem 6. Further, the lead wire is connected to the external lead wire 8 shown in FIG. An appropriate amount of mercury and a rare gas are sealed in the tube.

A substance 5 containing an arc-extinguishing gas is applied onto the inner lead 4 or the stem 6 containing the inner lead 4. This substance is composed of an organic solvent and a hydrous silica material. As the organic material, nitrocellulose dissolved in butyl acetate is used. The application amount is about 7 mg, and no forced thermal decomposition is performed, and the heat is applied during the manufacturing process of the fluorescent lamp, and the binder is kept to the extent that the binder evaporates.

The lamp having such a configuration was lit in combination with a ballast called a so-called inverter for high-frequency lighting, and detailed experiments on the occurrence of abnormal discharge at the end of life were repeated. In order to improve the experimental accuracy by performing many life tests, an acceleration test was performed. In this case, one of the electrodes of the fluorescent lamp was coated with an electron-emitting substance as designed in a steady state, and the other electrode was coated with only about 1/10 of the designed value in order to promote consumption. . or,
The lighting conditions were lighting in combination with an inverter type ballast having a lighting frequency of 45 kHz, the power supply voltage was set to the rated voltage of 130% V, and the end-of-life phenomenon was accelerated and reproduced by a blinking test of a 3-minute cycle including a light-off time of 1 minute. The reason for this is that with normal lighting, almost no malfunction at the end of life occurs,
This is because it is difficult to confirm. Table 1 shows the results.

[0016]

[Table 1]

According to the results, of the conventional lamps, out of a total of 250 tests for the first and second times, 14 of the lamps in which the internal lead wire was melted occurred. Of these, four led to the inner lead line hanging down, contacting the glass bulb and damaging the lamp, or melting or cracking the stem to damage the lamp. In addition, the heat generated at the contact part due to the abnormal discharge generated in this process (the connection part between the base pin and the external lead-in wire and the contact part between the base pin and the socket contact piece) causes the base,
Only one socket burned out.

On the other hand, in the embodiment according to the present invention, 1
Of the 250 tests, the second and the second, a total of 250 tests with melted inner lead wires were 10 and were not much different from the conventional lamps, but no lamp breakage and no smoke was generated from the base and socket. Was.

In this embodiment, the fluorescent film was not applied to only a part of the electrode portion in the vicinity, and the inside was observed. In the lamp of the present invention, even if melting of the internal feed line occurs, within several tens of seconds, the arc-extinguishing gas generating substance applied to the root of the internal feed line and the stem rises to a luminance temperature that rises to nearly 2000 ° C.
It was confirmed that water contained in the hydrated silica was generated, and the discharge stopped immediately.

[0020]

According to the present invention, by applying a substance containing an arc-extinguishing gas onto the inner lead wire and the stem glass constituting the electrode, an accident at the end of the life of the fluorescent lamp can be prevented. While we have confirmed, there is no alternative to doing this in any other way. For example, at least a part of the internal introduction line may be made of a material that generates a large amount of arc-extinguishing gas at the time of melting, or the thickness of the internal introduction line may be determined using a wire diameter (φ0.4 to From φ0.7),
It is also conceivable to make the discharge from the internal introduction line difficult by making the wire thicker. Further, it is conceivable that an arc-extinguishing gas is put in a glass capsule in advance, and the capsule is destroyed by the heat of the discharge by attaching it to the inner lead wire, thereby generating a gas and stopping the discharge.

As the arc-extinguishing gas used in Examples of the present invention, hydrated silica was used. The hydrated silica used was a material that released about 10% of the total weight of water when heated to about 1000 ° C. During normal use, the area of application of this substance should be approximately 200
Since the temperature is on the order of ° C., no gas is released, and the lamp can continue to operate normally. Material costs are low and accidents can be prevented at low cost.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view of a fluorescent lamp according to an embodiment of the present invention.

FIG. 2 is a front view of the electrode unit of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass bulb, 2 ... Phosphor, 3 ... Filament, 4
... Introduction line, 5 ... Arc-extinguishing gas-containing substance, 6 ... Stem glass, 9 ... Base, 10 ... Base pin.

Claims (1)

[Claims] 1. An electrode is provided at both ends, an appropriate amount of mercury and a rare gas are sealed in a tube, and the electrode is connected to an internal lead-in line and includes the internal lead-in line or the internal lead-in line extending into the tube. A fluorescent lamp, wherein a material containing an arc-extinguishing gas is applied to a stem glass portion.