JP2014075293A - Fluorescent lamp and lighting deice using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp having an extremely long lighting life, by suppressing the consumption rate of an emitter which is consumed as the lighting time elapses.SOLUTION: In a fluorescent lamp provided with a phosphor layer on the inner surface of a glass bulb, filled with mercury or a mercury compound and a rare gas, and including an electrode where a tungsten coil filament holding an emitter, i.e., an electron emitting substance, at both ends of the glass bulb is supported by an inner lead wire, a metal or an alloy is used in the inner lead wire, and the electrode structure uses an inner lead wire satisfying a relation 80<κ<450, where κ(W mK) is the thermal conductivity of the inner lead wire.

Description

  The present invention relates to a fluorescent lamp provided with an electrode having an extremely long lighting life.

  In general, it is known that the lighting life of a fluorescent lamp is long in proportion to the amount of electron-emitting material (emitter) held by the tungsten coil filament. For this emitter, a complex oxide (BaO, SrO, CaO) of an alkaline earth metal or an alloy is often used. When the lamp is lit, the emitter is peeled off, dropped off, evaporated, and consumed as the lighting time elapses. When the emitter is consumed until the lamp cannot be lit, the lamp has a lighting life. In order to extend the operating life of this fluorescent lamp, various multi-coil filaments that increase the amount of emitter have been designed and used. Furthermore, the coil weight of the multi-coil filament is set to Mc (mg) in order to prevent the emitter from peeling and dropping due to external factors such as vibration during lamp manufacture and vibration / impact during transportation, and to obtain a life extension effect. A structure of a filament and an emitter is disclosed in which the emitter weight is Me (mg) and the ratio of Me / Mc is kept within a certain range to prevent peeling and dropping (Patent Document 1).

JP-A-10-255718

  However, in Patent Document 1, the ratio of the coil weight Mc (mg) to the emitter weight Me (mg) of the multi-coil filament, and the configuration of the filament and emitter that keep Me / Mc within a certain range reduces the peeling and dropping of the emitter. However, no consideration is given to the thermal evaporation of the emitter. That is, even if the ratio of Me / Mc falls within a certain range, the thermal evaporation of the emitter does not decrease, and as a result, the lighting life may be shortened.

  The present invention has been made based on such circumstances, and the object thereof is to use a metal or an alloy having a high thermal conductivity for the inner lead wire supporting the tungsten coil filament holding the emitter, thereby By increasing the heat transfer amount of heat conduction from the tungsten coil filament to the inner lead wire, lowering the maximum temperature (bright spot temperature) of the emitter, thereby reducing the thermal evaporation of the emitter and suppressing the consumption rate of the emitter Another object of the present invention is to provide a fluorescent lamp having a very long lighting life and a lighting device using the fluorescent lamp.

In the present invention, a phosphor layer is provided on the inner surface of a glass bulb, mercury or a mercury compound and a rare gas are sealed inside, and a tungsten coil filament holding an emitter which is an electron radioactive substance at both ends of the glass bulb is provided with an inner layer. In a fluorescent lamp having an electrode supported by a lead wire, a metal or an alloy is used for the inner lead wire, and the thermal conductivity of the inner lead wire is κ (W · m ⁻¹ · K ⁻¹ ). In this case, 80 <κ <450.

  A fluorescent lamp having a very long lighting life and a fluorescent lamp lighting device using the fluorescent lamp can be provided.

The front and partial sectional view showing the fluorescent lamp which is an embodiment of the present invention The expanded perspective view which shows the tungsten coil filament and emitter which are embodiment of this invention The expanded perspective view which shows the tungsten coil filament which is embodiment of this invention The figure which shows the relationship between the evaporation rate of the emitter of the fluorescent lamp which is embodiment of this invention, and the bright spot temperature of an emitter The figure which shows the name and dimension of each part of embodiment of this invention and the triple coil of a prior art example

  Hereinafter, fluorescent lamps according to embodiments of the present invention will be described with reference to the drawings.

  The present inventors have investigated in detail the state of consumption of the emitter held by the tungsten coil filament and analyzed the consumption mechanism of the emitter. As a result, the consumption rate of the emitter is closely related to the material of the inner lead wire and its thermal conductivity. I found that there is a relationship.

That is, in order to solve the problem of providing a fluorescent lamp having a very long lighting life and a lighting device using the fluorescent lamp, the invention according to claim 1 is provided with a phosphor layer on the inner surface of a glass bulb, In a fluorescent lamp comprising an electrode in which mercury or a mercury compound and a rare gas are sealed inside and a tungsten coil filament holding an emitter that is an electron-emitting substance is supported at both ends of the glass bulb by an inner lead wire, When metal or an alloy is used for the inner lead wire and the thermal conductivity of the inner lead wire is κ (W · m ⁻¹ · K ⁻¹ ), 80 <κ <450. is there.

  According to the first aspect of the present invention, the thermal conductivity of the inner lead wire increases, so that when the lamp is lit, the conduction of heat conduction from the tungsten coil filament holding the emitter to the inner lead wire. The amount of heat increases, the emitter bright spot temperature can be lowered, and the thermal evaporation of the emitter can be reduced. Therefore, it is possible to create a fluorescent lamp having an electrode having a much longer lighting life than conventional ones.

  According to a second aspect of the present invention, in the first aspect, the inner lead is plated with a metal having a high thermal emissivity.

  According to the invention of claim 2, when the lamp is lit, the heat transfer amount of the heat radiation from the inner lead wire also increases, and the heat transfer amount of the heat conduction from the tungsten coil filament to the inner lead wire becomes more and more. Increases, it becomes possible to lower the bright spot temperature of the emitter, and to reduce the thermal evaporation of the emitter.

  The invention according to claim 3 is a lighting device using the fluorescent lamp according to claim 1 or 2 as a light source.

  According to the third aspect of the present invention, it is possible to provide a lighting device that uses a fluorescent lamp having an extremely long lighting life as a light source.

  FIG. 1 is a front and partial cross-sectional view showing a straight tube 32W (FHF 32) of a fluorescent lamp dedicated for high-frequency lighting according to the present embodiment. A phosphor layer 2 is provided on the inner surface of the glass bulb 1, and mercury or a mercury compound and a rare gas (not shown) are sealed therein. At both ends of the glass bulb 1, a triple coil tungsten coil filament 3 holding an emitter 4, which is an electron radioactive substance, is crimped by two inner lead wires 5, and the tungsten coil filament 3 is supported between the lead wires 5. An electrode 6 is provided. The two inner lead wires 5 are connected to the two base pins 7 by caulking, and power is supplied to the tungsten coil filament 3 from the outside through the base pins 7. When the lamp is lit, the tungsten coil filament 3 holding the emitter 4 is supplied with power through the base pin 7 and a voltage for starting discharge is applied between the electrodes 6. The fluorescent lamp is lit.

The present inventors investigated in detail the state of consumption of the emitter held by the tungsten coil filament from the initial state to the state of consumption as the lighting time elapses, and analyzed the emitter consumption mechanism. It has been found that the consumption rate is closely related to the material of the inner lead wire and its thermal conductivity. That is, when the thermal conductivity of the inner lead wire is κ (W · m ⁻¹ · K ⁻¹ ),
80 <κ <450
It has been found that if a satisfactory metal or alloy is used for the inner lead wire, the thermal evaporation of the emitter is reduced and the consumption rate of the emitter can be suppressed.

  As a result of calculating the heat transfer amount of the heat conduction from the tungsten coil filament holding the emitter to the inner lead wire, in this range, the bright spot temperature of the emitter is lowered by the heat conduction from the tungsten coil through the inner lead wire, and the emitter It has been found that thermal evaporation is reduced and emitter consumption is slowed down. Specific examples are described below. In the present invention, for example, a triple coil having the dimensions shown in FIG. 5 is used, copper is used for the inner lead wire, and the thermal conductivity of the inner lead wire is increased.

  FIG. 2 shows the state of the emitter held by the tungsten coil filament.

  FIG. 5 shows the names and dimensions of each part of the triple coil according to the present embodiment and the conventional example, with reference to FIG. 1, FIG. 2 and FIG.

  The high-frequency lighting-only fluorescent lamp FHF32 of this embodiment is approximately 62,200 hours high at the rated output (at a lamp current of 255 mA) due to the relationship between the lamp lighting time and the change in the mass of the emitter held by the tungsten coil filament. An average life of about 48,000 hours was obtained at the time of output (when the lamp current was 425 mA). On the other hand, the conventional high frequency lighting type fluorescent lamp FHF32 has an average life of about 24,700 hours at rated output (at a lamp current of 255 mA) and about 24,500 hours at high output (at a lamp current of 425 mA). In this embodiment, it can be seen that although the weight of the emitter is almost the same as that of the conventional example, the life is significantly extended by this embodiment.

Nickel-plated iron is used for the inner lead wire of the conventional example, and the thermal conductivity κ (W · m ⁻¹ · K ⁻¹ ) is 73. Copper is used for the inner lead wire of this embodiment, and the thermal conductivity κ (W · m ⁻¹ · K ⁻¹ ) is 403. Therefore, in the range of 80 <κ <450, when the lamp is lit, the amount of heat conduction from the tungsten coil filament holding the emitter to the inner lead wire increases, and the bright spot temperature of the emitter is lowered. Is possible. In the range where κ is 80 or less, the amount of heat conduction from the tungsten coil filament holding the emitter to the inner lead wire is the same as before, and the bright spot temperature of the emitter cannot be lowered. It is not possible to obtain an electrode with On the other hand, when κ is in the range of 450 or more, it becomes extremely difficult to find a material having κ of 450 or more in a general metal or alloy, and the cost becomes high to use.

FIG. 4 shows the relationship between the evaporation rate of the emitter and the bright spot temperature of the emitter of the high-frequency lighting-only fluorescent lamp FHF32 of this embodiment and the conventional high-frequency lighting-only fluorescent lamp FHF32. The emitter evaporation rate rises exponentially with respect to the emitter bright spot temperature. The bright spot temperature of the emitter of the present invention was about 989 to 1010 ° C., and the evaporation rate of the emitter at this time was about 2.5 to 4.5 μg / mm ² · h. On the other hand, the bright spot temperature of the conventional emitter was about 1013 to 1030 ° C., and the evaporation rate of the emitter at this time was about 4.9 to 7.8 μg / mm ² · h.

  Therefore, it can be seen that the bright spot temperature of the emitter of this embodiment is about 3 to 41 ° C. lower than the conventional example, and the evaporation rate of the emitter is suppressed to 32 to 92% of the conventional example.

  According to the above-described embodiment, it is possible to reduce the thermal evaporation of the emitter, suppress the consumption rate of the emitter, and obtain a fluorescent lamp having an electrode having a very long lighting life.

  As described above, since a fluorescent lamp having an electrode with an extremely long lighting life and a fluorescent lamp lighting device using this fluorescent lamp as a light source can be obtained, labor savings by reducing the number of lamp replacements, and cost savings due to a maintenance effect can be achieved. It leads to reduction and resource saving, and can contribute to global environment protection by reducing waste.

DESCRIPTION OF SYMBOLS 1 ... Glass bulb 2 ... Phosphor layer 3 ... Tungsten coil filament 4 ... Emitter 5 ... Inner lead wire 6 ... Electrode 7 ... Cap pin

Claims (3)

A phosphor layer is provided on the inner surface of the glass bulb, and mercury or a mercury compound and a rare gas are sealed inside, and a tungsten coil filament holding an emitter, which is an electron radioactive substance, at both ends of the glass bulb is supported by the inner lead wire. In the fluorescent lamp equipped with the electrode,
Fluorescence, wherein metal or alloy is used for the inner lead wire, and the thermal conductivity of the inner lead wire is κ (W · m ⁻¹ · K ⁻¹ ), and 80 <κ <450. lamp.   The fluorescent lamp according to claim 1, wherein the inner lead wire is metal-plated.   A fluorescent lamp lighting device using the fluorescent lamp according to claim 1 as a light source.