JPH0721987A - Fluorescent lamp - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fluorescent lamp that stabilizes the electron jumping position to prevent flicker during lighting and prevents the life from being shortened due to scattering of the emitter. In a fluorescent lamp in which a filament 4 is installed between a pair of internal lead wires 3, a resistance value R on a connecting side of the internal lead wire 3 with the filament 4 is made higher than a resistance value r of the filament 4. It is characterized by In the internal lead wire, a portion having a high potential is formed, and electrons jump into this portion, so that the anode point does not fluctuate, the lamp current is stabilized, and flicker can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp which prevents a flicker phenomenon during lighting.

[0002]

2. Description of the Related Art Generally, a fluorescent lamp has a fluorescent bulb formed on the inner surface of a glass bulb and filaments sealed at both ends of the bulb, and a predetermined amount of mercury is contained in the bulb. It is configured by enclosing a rare gas such as argon. The filament is formed by molding a tungsten wire into a double coil or a triple coil, and the legs formed at both ends are clamped to the inner lead wires respectively, so that the filament is installed between these inner lead wires. There is.

By the way, when such a fluorescent lamp is turned on, when one of the filaments is in the anode mode, electrons fly into the filament. In general, electrons have the property of flowing into a portion with a short interelectrode distance or a portion with a high potential level.

In the conventional case, the inner lead wire is formed of a wire mainly composed of nickel, and such an inner lead wire has an extremely low electric resistance value and a small resistance difference from tungsten constituting the filament (nickel. Has a specific resistance of 6.9 μΩ · cm, whereas tungsten has a specific resistance of 5.5 μΩ · cm, at 20 ° C.). For this reason, the filament and the internal lead wire have the same potential level during lighting, so that the position where the electrons jump in (anode point) is on the filament or the tip of the internal lead wire (clamp portion). To do. When the anode point moves in this manner, the oscillation of the anode becomes unstable, which makes the lamp voltage waveform during lighting unstable and the lamp current fluctuates. As a result, there is a problem that flicker occurs during lighting.

In order to prevent this, conventionally, as shown in FIG. 6, there has been proposed a fluorescent lamp having a structure in which auxiliary electrodes 20 and 20 extending to the discharge space side are joined to internal lead wires 3 and 3, respectively. In FIG. 6, 1 is a valve and 2 is
Is a stem, 4 is a filament, and 7 is a phosphor coating, which may be the same as those of the embodiments of the present invention, and will be described in detail in the embodiments described later. In the case of such a structure, as described above, electrons have a property of easily jumping into a portion having a short inter-electrode distance, so that an anode point is formed at the tip portion of the auxiliary electrode 20, and thus flying electrons are generated in the auxiliary electrode 20. It jumps into the tip, the anode point is stable, and the anode vibration is also stable, so the lamp lamp current during lighting is stable, and as a result,
There is an advantage that flicker can be prevented.

[0006]

However, in the case of the conventional structure in which the auxiliary electrode 20 is attached, the auxiliary electrodes 20 and 20 are welded to the inner lead wires 3 and 3 so that the heat capacity of the entire electrode increases. However, the filament temperature decreases near the end, and in the cathode mode, the cathode drop voltage rises, and the electron emitting material (emitter) such as barium oxide coated on the filament scatters and the emitter is consumed. There is a problem that it adheres to the bulb earlier and leads to premature blackening, which shortens the lamp life.

The auxiliary electrodes 2 are attached to the inner lead wires 3 and 3.
The structure in which 0 and 20 are additionally provided has a drawback that the manufacturing process such as welding work is increased and the manufacturing cost is increased. The present invention has been made in view of the above circumstances, and an object thereof is to stabilize the generation position of the anode point to prevent flicker during lighting, and also to prevent life reduction due to scattering of the emitter. The aim is to provide a fluorescent lamp that can be used.

[0008]

According to a first aspect of the present invention, in a fluorescent lamp in which a filament is sealed at an end portion of a bulb and the filament is installed between internal lead wires, a resistance value of the internal lead wires is high. Is larger than the resistance value of the filament.

The invention of claim 2 is characterized in that the resistance value of the portion corresponding to the filament length from the end of the filament connecting wire in the internal lead wire is made larger than the resistance value of the filament. According to a third aspect of the present invention, the means for increasing the resistance value of the internal lead wire uses a wire having a higher resistivity than the filament for the internal lead wire.
The invention of claim 4 is characterized in that a substance having a higher resistivity than the internal lead wire is attached to the internal lead wire having a low resistance value. The invention of claim 5 is characterized in that the internal lead wire is configured by connecting two types of wire rods having different resistivities. The invention of claim 6 is characterized in that the sectional area of the internal lead wire is partially reduced. The invention of claim 7 is characterized in that the inner lead wire is covered with an insulator.

[0010]

According to the inventions of claims 1 to 6, since the resistance value of the internal lead wire becomes larger than the resistance value of the filament, a portion having a high potential is formed in the internal lead wire, so that the anode point is The internal lead wire is stably formed at a high potential portion. For this reason, the anode point does not fluctuate and the anode vibration also stabilizes, so the lamp current during lighting is stable and flicker can be prevented.
Moreover, since the electrons fly to the internal lead wire, the filament is not beaten by the electrons, the emitter is prevented from being beaten out, and the life reduction due to the scattering of the emitters can be prevented.

Further, according to the invention of claim 7, since the inner lead wire is covered with the insulator, the anode point is stably formed on the filament, and the anode point does not fluctuate. Vibration is stable, and it is possible to prevent flickering during lighting.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the first embodiment shown in FIGS. FIG. 2 shows the entire straight tube type fluorescent lamp, and reference numeral 1 in the figure is a glass bulb. The flare stem 2 is hermetically joined to the end of the valve 1, so that the end of the valve 1 is flared with the flare stem 2.
Is blocked by. A pair of internal lead wires 3 and 3 are hermetically penetrated through the stem 2. A filament 4 is laid over the inner ends of the inner lead wires 3 and 3. The filament 4 is made of a tungsten wire and is formed into a double coil or a triple coil. The leg portions 5 and 5 at both ends of the filament 4 are held by the hook portions 6 and 6 formed on the internal lead wires 3 and 3.

Although not shown in the filament 4,
An emitter such as barium oxide is applied. Also,
As shown in FIG. 1, a phosphor coating 7 is formed on the inner surface of the bulb 1, and a predetermined amount of mercury and a rare gas such as argon are enclosed in the bulb 1.

Bases 10, 10 are attached to the ends of the valve 1, and a base pin 11 is attached to the bases 10, 10.
... is projected. The outer end portions of the internal lead wires 3 and 3 are connected to the base pins 11 ...

In this embodiment, the wires forming the internal lead wires 3 and 3 are wires having a high resistance, that is, the tungsten forming the filament 4 (specific resistance = 5.5 μΩ · cm, at 20 ° C.). ) And the conventional internal lead wires 3 and 3, which have a larger electric resistance than the nickel (specific resistance = 6.9 μΩ · cm) series wire, such as a nichrome wire (specific resistance = 100 to 109 μΩ).
・ Cm).

Then, such internal lead wires 3, 3
Indicates that the resistance value (total resistance) gradually increases from the tip of the hook portion 6 toward the base end side, but the resistance value R in a region of a predetermined dimension L from the tip end of the hook portion 6 toward the base end side.
(Ω) is set to be larger than the resistance value r (Ω) of the filament 4 (R ≧ r). In this case, the predetermined dimension L from the tip of the hook portion 6 toward the base end side is made to correspond to the erection length FW of the filament 4 (L
= FW).

According to this structure, one of the pair of internal lead wires 3 and 3 on one electrode side is always connected to the power source side during lighting of the lamp. When this electrode is in the anode mode, it is connected to the anode, that is, a current flows in the direction of the arrow in FIG.
In this case, the internal lead wire 3 has a resistance value of the filament 4
Since it is larger than the filament 4, a portion having a higher potential than the filament 4 is generated. That is, in the electrode, A shown in FIG.
The voltages at points B, C, and C are different, but in the conventional case A
Although the difference in voltage drop between points B, C, and C is small, the resistance value R of the internal lead wire 3 is increased in the present embodiment.
With respect to the voltage VO at the point, a voltage drop of VO-iR (where i is the lamp current) at the point B and a voltage VO-i (R + r) at the point C occurs, and the potential becomes high at the point A of the internal lead wire 3.

Therefore, in the case of the anode mode, the anode point is generated at the high potential location of the internal lead wire 3. That is, FIG.
As shown in, the probability that an anode point will occur in the internal lead wire 3 increases as the resistance value of the internal lead wire 3 increases, and the resistance value R of the internal lead wire 3 exceeds the resistance value r of the filament 4. Then, the probability of jumping into the internal lead wire 3 of electrons becomes 100%. Therefore, the anode point where the electrons jump does not change, the anode vibration is stable, the lamp voltage does not change during lighting, and the lamp current is stable, and flicker can be prevented.

Further, since the anode point is always formed on the internal lead wire 3, electrons are prevented from jumping into the filament 4, and the emitter coated on the filament 4 is prevented from being hit by the electron. Therefore, early depletion and early blackening due to scattering of the emitter are prevented, and the lamp life can be extended.

Moreover, in the case of the above embodiment, since the wire material of the internal lead wire 3 is only selectively changed, there is no increase in the number of parts and no change in the manufacturing process is required.
There is no need to worry about soaring manufacturing costs.

Table 1 below shows a straight tube type white fluorescent lamp FL.
20SS ・ W / 18 (rated lamp power 18W, tube diameter 28
mm, tube length 580 mm), the test results of examining the degree of blackening and the occurrence of flicker are shown.

[0022]

[Table 1]

From the results in Table 1 above, in the case of the conventional lamp without the auxiliary anode, flicker occurs regardless of the lighting time, and in the case of the conventional lamp with the auxiliary anode, blackening occurs early. As can be seen, in the case of the lamp having the embodiment structure according to the present invention, it is confirmed that both the blackening and the flicker are improved even when the lamp is lit for a long time.

As shown in FIG. 4, if the internal lead wire 3 is provided with a portion having a resistance value larger than the resistance value r of the filament 4 somewhere in the internal lead wire 3, the anode point will surely become the internal lead wire. Occurs (probability 100%). However, the resistance value R
If a portion having a resistance value larger than the resistance value r is formed on the base end side of the internal lead wire 3, electrons have the property of jumping into a portion having a short inter-electrode distance, so that the inter-electrode distance becomes long and the anode point becomes the internal lead. The probability of occurring on the line is reduced. Further, when electrons jump into the base end portion of the inner lead wire 3, the stem 2 is thermally damaged due to the temperature rise. From this, the position where the resistance value R (Ω) is larger than the resistance value r is from the tip end of the hook portion 6 toward the base end side.
It is desirable to set it at a position shorter than (L≤FW).

The present invention is not limited to the above-mentioned first embodiment. That is, the present invention uses the internal lead wire
In addition, since it suffices to provide a portion where the resistance value R is larger than the resistance value r of the filament 4, a wire having a large resistance such as a nichrome wire or the like is used as the internal lead wire 3.
A material 30 having a higher resistivity than that of the inner lead wire 3 may be attached to the inner lead wire 3, as in the second embodiment shown in FIG. By doing so, the resistance of the portion to which the substance 30 having a high resistivity is attached becomes high, so that a potential difference can be generated.

Further, as in the third embodiment shown in FIG.
A substance having a high resistance value, for example, a resistance element 40 may be connected to the internal lead wire 3. Further, as in the fourth embodiment shown in FIG. 7, a portion 50 having a small cross-sectional area may be provided in a part of the internal lead wire 3. Further, although not shown, one in which two kinds of wire materials having different resistivities are joined to the inner lead wire 3 may be used.

The inner lead wire 3 may be coated or adhered with an insulating material. In this case, electrons start to fly into the filament 4, the anode point does not fluctuate, the anode vibration stabilizes, and the lamp voltage does not fluctuate during lighting, so the lamp current stabilizes and flicker can be prevented. it can. Further, the fluorescent lamp of the present invention is not limited to the straight tube type lamp, but can be applied to fluorescent lamps having various shapes such as a ring shape, a U shape, a W shape, and a saddle shape.

[0028]

As described above, according to the present invention as set forth in claims 1 to 6, since the resistance value of the internal lead wire is larger than the resistance value of the filament, a portion having a high potential is formed in the internal lead wire. As a result, the anode point is always stably formed on the internal lead wire. Therefore, the fluctuation of the anode point is prevented, and the vibration of the anode is stabilized, so that the lamp current during lighting is stabilized, and thus the flicker can be prevented. Moreover, since the electrons surely fly to the internal lead wire and do not flow into the filament, the emitter is prevented from being knocked out by the electron, and the exhaustion and blackening due to the scattering of the emitter are prevented, so that the life characteristics are improved. There are advantages.

Further, according to the invention of claim 7, since the inner lead wire is covered with the insulator, the anode point can be stably formed on the filament, and the anode point does not fluctuate. Vibration is stable, and it is possible to prevent flickering during lighting.

[Brief description of drawings]

FIG. 1 is a sectional view of an end portion of a fluorescent lamp according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the entire fluorescent lamp of the same embodiment.

FIG. 3 is a characteristic diagram showing an electrode drop at each point of the electrode.

FIG. 4 is a characteristic diagram showing a resistance value of an internal lead wire and a probability of electron jumping.

FIG. 5 is a front view of a filament and an internal lead wire according to a second embodiment of the present invention.

FIG. 6 is a front view of a filament and an internal lead wire according to a third embodiment of the present invention.

FIG. 7 is a front view of a filament and an internal lead wire according to a fourth embodiment of the present invention.

FIG. 8 is a sectional view of an end portion of a conventional fluorescent lamp.

[Explanation of symbols]

1 ... Valve 2 ... Stem 3 ...
Internal lead wire 4 ... Filament

Claims (7)

[Claims] 1. A filament is sealed at the end of the bulb,
A fluorescent lamp in which the filament is installed between internal lead wires, wherein the resistance value of the internal lead wire is larger than the resistance value of the filament. 2. A filament is sealed at the end of the bulb,
This filament is a fluorescent lamp constructed by being installed between internal lead wires, wherein the resistance value of a portion corresponding to the filament length from the end of the filament connecting wire in the internal lead wire is made larger than the resistance value of the filament. Fluorescent lamp. 3. The means for increasing the resistance value of the internal lead wire, wherein a wire having a higher resistivity than the filament is used for the internal lead wire.
Fluorescent lamp described in. 4. A filament is sealed at the end of the bulb,
In the fluorescent lamp in which the filament is installed between the inner lead wires, the fluorescent lamp is characterized in that a substance having a higher resistivity than the inner lead wire is attached to the inner lead wire having a low resistance value. 5. A filament is sealed at the end of the bulb,
A fluorescent lamp in which the filament is installed between internal lead wires. The internal lead wire is configured by connecting two kinds of wire materials having different resistivities. 6. A filament is sealed at the end of the bulb,
A fluorescent lamp in which the filament is installed between internal lead wires, wherein the cross-sectional area of the internal lead wire is partially reduced. 7. A filament is sealed at the end of the bulb,
A fluorescent lamp in which the filament is installed between inner lead wires, wherein the inner lead wires are covered with an insulator.