JP2007194046A - Glow starter and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glow starter capable of easily emitting electrons without using a radioactive material, and of reducing a dark-place startup delay time; and to provide its manufacturing method. <P>SOLUTION: This glow starter 1 is provided, in a sealed vessel 2, with a pair of electrodes comprising a movable electrode 3 including a thermally-actuated element 14 and a counter electrode 4 to the movable electrode 3, and a discharge gas. At least one of the pair of electrodes includes electron emission parts 18 and 19 containing iron; the electron emission parts 18 and 19 come into contact with an alkaline metal supply substance 7 containing potassium, and is activated by applying a pulse-like D.C. voltage to the pair of electrodes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lighting tube for starting a fluorescent lamp and a manufacturing method thereof.

  As a general problem related to a discharge tube such as a lighting tube, there is a delay in starting a dark place. For example, when starting a lighting tube that has been built into the device and shielded from ambient light or that has been stored for a long time in a packed state, This is a phenomenon in which the amount of initial electrons supplied due to the effect is small and a considerable amount of time is required until the start of discharge, that is, a phenomenon in which a delay occurs between the time the power switch is turned on and the start.

  Therefore, in the conventional lighting tube, a radioactive substance is enclosed inside so that the lighting tube can be started even in a dark place. Although the amount of radioactive material contained was within the range that complied with laws and regulations, in consideration of the social concern for environmental problems, switching to a lighting tube that does not use radioactive material has been attempted.

For example, a method of shortening the dark start delay time by photoemission combined with a long afterglow paint (see, for example, Patent Document 1), or a cesium compound having a low work function enclosed in a lighting tube, There has been disclosed a lighting tube that does not use a radioactive substance, such as a method of shortening the dark start delay time by discharge (see, for example, Patent Document 2).
JP-A-10-255724 JP 2002-216703 A

  However, the method described in Patent Document 1 has a problem that the start delay in the dark place cannot be sufficiently solved for the lighting tube left in the dark place for a long time. Further, the method described in Patent Document 2 has a problem that the operation reliability is not sufficient, such as the dark place start delay time varies, or the dark place start delay time becomes longer as the number of uses increases.

  The present invention provides a lighting tube that can easily emit electrons without using a radioactive substance, and can shorten a delay time in starting a dark place.

  The lighting tube of the present invention is a lighting tube comprising a movable electrode including a thermally responsive element and a pair of electrodes composed of a counter electrode of the movable electrode, and a discharge gas inside a sealed container, At least one of the pair of electrodes includes an electron emission portion containing iron, and the electron emission portion is in contact with an alkali metal supply material containing potassium, and the pulsed direct current is applied to the pair of electrodes. It is activated by applying a voltage.

  In addition, a method for manufacturing a lighting tube according to the present invention includes a lighting tube including a pair of electrodes including a movable pole including a thermal responsive element and a counter electrode of the movable pole, and a discharge gas. In the manufacturing method, an alkali metal-containing substance containing potassium is disposed in contact with an electron-emitting portion contained in at least one of the pair of electrodes and containing iron, and the pair of electrodes is disposed on the pair of electrodes. By applying a pulsed DC voltage, the electron emission part is heated while discharging the discharge gas to adsorb potassium contained in the alkali metal supply substance to the electron emission part. Features.

  The lighting tube of the present invention can easily emit electrons, and can be started in a short time even if stored in a dark place for a long time.

  Moreover, the manufacturing method of the lighting tube of this invention can manufacture the lighting tube of the said this invention reasonably.

  The lighting tube of the present invention is a lighting tube provided with a pair of electrodes including a movable pole including a thermally responsive element and a counter electrode of the movable pole, and a discharge gas inside a sealed container. At least one of the pair of electrodes includes an electron-emitting portion containing iron, and the electron-emitting portion is in contact with an alkali metal supply material containing potassium, and the pair of electrodes is pulsed. It is activated by applying a DC voltage.

  By adopting such a configuration, it is possible to shorten the dark start delay time without using a radioactive substance. Since this lighting tube includes an electron emission portion activated with a small work function, for example, electrons can be easily emitted even if the lighting tube is stored in a dark place for a long time.

  It is preferable that potassium supplied from the alkali metal supply substance is adsorbed on the surface of the electron emission portion by application of the voltage. This is because the work function is further reduced in the electron emission portion where potassium is adsorbed, and therefore the dark start delay time can be further shortened.

  The pulsed DC voltage preferably has a pause period. This is because when a high voltage is applied to the lighting tube, the discharge current increases, the temperature of the electrode suddenly rises, and the movable pole moves to short-circuit.

  The electron emission part preferably contains at least one metal selected from iron and an alloy containing iron on the surface in contact with the alkali metal supply material. The work function is further lowered by the adsorption of potassium on the surface of the electron emission portion containing iron.

  The alkali metal supply material is preferably glass containing an alkali metal oxide. In particular, glass containing potassium oxide is preferable. This is because a chemically unstable alkali metal can be handled easily because it is chemically stabilized if it is contained in glass.

  The alkali metal supply material is preferably at least a part of the sealed container. It is because the member of a lighting tube can be reduced.

  In addition, a method for manufacturing a lighting tube according to the present invention includes a lighting tube including a pair of electrodes including a movable pole including a thermal responsive element and a counter electrode of the movable pole, and a discharge gas. It is a manufacturing method. That is, an alkali metal supply material containing potassium is disposed in contact with an electron emission portion contained in at least one of the pair of electrodes and containing iron, and a pulsed direct current is applied to the pair of electrodes. By applying a voltage, the electron emission part is heated while discharging the discharge gas, and the potassium contained in the alkali metal supply material is thermally diffused and adsorbed on the electron emission part for activation. Thus, it is possible to rationally manufacture a lighting tube including an electrode on which potassium is adsorbed.

  Hereinafter, embodiments of a lighting tube and a manufacturing method thereof according to the present invention will be described with reference to the drawings. In addition, since the same site | part has the same component and shape and there exists the same effect, the description may be abbreviate | omitted.

(Embodiment 1)
FIG. 1 is a partial sectional view showing an example of a lighting tube of the present invention.

  The lighting tube 1 of this embodiment includes an electrode (movable electrode) 3, an electrode (counter electrode) 4 paired with the movable electrode 3, and a discharge gas inside a sealed container 2 (container interior 8). And.

  The container 2 is sealed by a valve 6, a flare stem 7 and an exhaust pipe 9. An exhaust pipe 9 used when the discharge gas is sealed in the container interior 8 is connected to the flare stem 7 through the exhaust hole 10 so as to communicate with the container interior 8. One end of the exhaust pipe 9 is bonded to the flare stem 7 through the exhaust hole 10 and the other end is closed. A base 5 is attached so as to cover the end of the container 2 on the side where the electrodes 3 and 4 are sealed, and is electrically connected to the electrodes 3 and 4.

  The electrode 3 includes a bimetal element 14 which is a thermally responsive element and an internal lead wire 13 including an electron emission portion 18 containing iron. The electrode 4 includes an internal lead wire 15 including an electron emission portion 19 containing iron.

  The electron emission portions 18 and 19 are fixed in contact with the flare stem 7 containing potassium. Further, the electron emission portions 18 and 19 are activated by applying a pulsed DC voltage to the electrodes 3 and 4.

  The lighting tube 1 of the present embodiment can shorten the dark start delay time by adopting the above-described configuration. Since the lighting tube 1 includes the electron emitting portions 18 and 19 activated with a small work function, for example, even when the lighting tube 1 is stored in a dark place for a long time, electrons can be easily emitted.

  The material of the flare stem 7 is glass containing potassium, but is not particularly limited as long as the material includes an alkali metal supply substance containing potassium on the surface in contact with the electron emission portions 18 and 19.

  The shape of the flare stem 7 is an umbrella-like shape and has a structure in which the skirt portion is sealed to the end portion on the open side of the valve 6, but is not particularly limited to this shape.

  The material of the bulb 6 is not particularly limited as long as it can withstand the above discharge and heating, but generally glass, resin, or the like may be used.

  The shape of the valve 6 is a substantially cylindrical shape with one end closed, but is not particularly limited to this shape.

  The discharge gas is not particularly limited as long as it is a gas suitable for discharge. In general, one gas selected from helium, neon, argon, and xenon, a mixed gas thereof, or the like may be used. In particular, argon gas or a mixed gas of neon and argon is preferably used.

  The amount of discharge gas enclosed is not particularly limited as long as discharge can be started and can be continued, but the gas pressure inside the container 8 may be several kPa to several hundred kPa, preferably 1 to 10 kPa.

  The material of the internal lead wires 13 and 15 is not particularly limited as long as it contains iron. For example, iron, iron-nickel alloy, or the like can be used.

  It can be said that the electron emission portions 18 and 19 are the surfaces in contact with the flare stem 7 in the internal lead wires 13 and 15, or the peripheral portions including this surface, or the entire internal lead wires 13 and 15. At this time, it is sufficient that at least a part of the surface of the electron emission portions 18 and 19 is in contact with the discharge gas.

  The surface of the flare stem 7 in contact with the electron emission portions 18 and 19, the peripheral portion including the surface, or the entire flare stem 7 can be said to be an alkali metal supply material containing potassium.

  When the pulsed DC voltage is applied under the condition that the electrodes 3 and 4 are not short-circuited, that is, the condition where the bimetal element 14 is not movable, the magnitude of voltage (peak voltage, minimum voltage, etc.), rest period, pulse width It does not specifically limit to etc. The pulsed DC voltage is not particularly limited, and may be a sine wave controlled or a rectangular wave controlled, but a sine wave cut off and controlled (for example, If it is controlled to discharge twice per second), it is preferable because it can be easily controlled. Also, a general AC voltage (for example, 60 Hz, 0.2 kV) boosted by a step-up transformer is preferable because it is inexpensive.

  The pulsed DC voltage is applied, for example, using one of the electrodes 3 and 4 as a cathode, a peak voltage of 0.2 kV to 1.0 kV, a minimum voltage of 0 kV to 0.2 kV, and a pulse repetition period of 0.1 times / second. The electron emission portions 18 and 19 can be activated by applying a DC voltage of 10 to 10 times / second and a pulse width of 0.5 ms (milliseconds) to 10 ms for 0.1 hour to 1.0 hour, respectively. . In particular, a DC voltage having a peak voltage of 0.6 kV to 0.8 kV, a minimum voltage of 0 kV to 0.1 kV, a pulse repetition cycle of 1.0 times / second to 4.0 times / second, and a pulse width of 1.0 ms to 4.0 ms is used. It is preferable to apply.

  When the peak voltage exceeds 1.0 kV, there is a problem in safety such as electric shock, and when it is less than 0.2 kV, discharge may not be started. Moreover, if the peak voltage is 0.6 kV to 0.8 kV, abnormal discharge occurs, for example, when the peak voltage is too high, for example, only the area around the flare stem 7 of the internal lead wires 13 and 15 is locally discharged. Therefore, the electron emission portions 18 and 19 can be activated efficiently, which is more preferable.

  If the pulse width exceeds 10 ms, a large amount of heat is generated and the bimetal element 14 may move. If it is less than 0.5 ms, the energization cycle must be shortened. Loss may occur. Further, when the pulse width is 0.5 ms to 6.0 ms, more preferably 1.0 ms to 4.0 ms, the electron emission portions 18 and 19 are efficiently activated without moving the bimetal element 14. Can do.

  In addition, the pulse shape is such that the energization cycle (light emission cycle) due to the discharge generated between the electrodes is 0.5 times / second to 6 times / second, preferably 1.0 times / second to 4.0 times / second. If the direct current voltage is controlled, the amount of heat generated is small, so that the bimetal element 14 does not move, and the electron emission portions 18 and 19 can be activated efficiently in a shorter time.

  Here, a method for activating the electron emission portions 18 and 19 will be described.

  When a voltage is applied between the electrode 3 and the electrode 4 using the electrode 4 as a cathode in the container inside 8 where the discharge gas is sealed, a discharge occurs between the electrodes. At this time, since impurities in the surface of the electron emission portion 19 are knocked out by ions in the discharge gas accelerated toward the electrode 4 serving as the cathode, the surface of the electron emission portion 19 is cleaned. Moreover, if the said voltage is applied, the flare stem 7 which is an alkali metal supply substance will be heated, and an alkali metal will thermally diffuse. Therefore, alkali metal is adsorbed on the surface of the purified electron emission portion 19 that contacts the flare stem 7, and the work function of the electron emission portion 19 (minimum energy necessary for extracting one electron from the metal) is reduced. To do. Since electrons are easily emitted from the portion having a low work function, the electron emitting portion 19 is activated. Similarly, when a voltage is applied using the electrode 3 as a cathode, the work function of the electron emission portion 18 is lowered and activated.

  The lighting tube thus obtained can be started in a short time because the initial electron supply amount of the electrodes 3 and 4 is increased when starting the lighting tube, and the dark start delay time is increased. Can also be shortened.

  In general, even if a DC voltage, for example, a constant voltage is continuously applied to the lighting tube, the bimetal element 14 contacts the internal lead wire 15 before the alkali metal is sufficiently adsorbed to the electron emission portions 18 and 19. As a result, the electrodes are short-circuited and the discharge is stopped, so that the electron emission portions 18 and 19 are not activated. Further, even when an AC voltage is applied, the electrodes are similarly short-circuited, so that the electron emission portions 18 and 19 are not activated. However, the electron emission portions 18 and 19 can be activated in a short time by applying a pulsed DC voltage.

  Here, operation | movement of the lighting tube 1 at the time of making a fluorescent lamp (not shown) light using the lighting tube 1 is demonstrated.

  When a predetermined voltage is applied to the electrodes 3 and 4 of the lighting tube 1, glow discharge occurs between the electrodes. Due to the heat of the glow discharge, the bimetal element 14 is deformed, that is, the electrode 3 is moved and contacts the electrode 4. A short-circuit current flows to preheat the filament electrode (not shown) of the fluorescent lamp. When the electrodes 3 and 4 are in contact with each other, a short-circuit current flows and glow discharge stops. However, if a short-circuit current flows, the bimetal element 14 is gradually cooled, so that the original shape is deformed, that is, the electrode 3 moves, moves away from the electrode 4, and the short-circuit current also stops. At that time, a pulse voltage is generated, a discharge is generated in the fluorescent lamp, and the fluorescent lamp is turned on.

  That is, the electron emission portions 18 and 19 according to the present invention can emit a large amount of initial electrons for causing the lighting tube 1 to start glow discharge.

  In the lighting tube 1 of the present embodiment, it is preferable that potassium supplied from the flare stem 7 by the application of the voltage is adsorbed on the surfaces of the electron emission portions 18 and 19. This is because the work functions of the electrodes 3 and 4 are further reduced in the electron emission portions 18 and 19 where potassium is adsorbed.

  In the lighting tube 1 of the present embodiment, the pulsed DC voltage applied to the electrodes 3 and 4 preferably has a rest period. This is because when a high voltage is applied to the lighting tube 1, the temperature of the movable electrode 3 immediately rises, and the bimetal element 14 moves and short-circuits.

  In the lighting tube 1 of the present embodiment, the electron emission portions 18 and 19 preferably contain at least one metal selected from iron and an alloy containing iron on the surface in contact with the flare stem 7. This is because the work functions of the electron emission portions 18 and 19 are further lowered on the surface of the electron emission portion containing iron.

In the lighting tube 1 of the present embodiment, the flare stem 7 is preferably a glass containing an alkali metal oxide, and particularly preferably a glass containing potassium oxide. Since chemically unstable alkali metals are chemically stabilized if contained in the glass, handling becomes easy. In addition, the alkali metal supplied from the glass exists as ions in this glass. In particular, potassium is diffused on the surface when a pulsed DC voltage is applied and adsorbs on the surface of the iron-based metal. This is because it has the property of easily forming an electron emission portion having an excellent electron emission capability. The glass also has an effect of being excellent in adhesion with an electrode that is a metal. The glass may be any glass generally used for a discharge tube. For example, K ₂ O, SiO ₂ , Na ₂ O, Li ₂ O, Al ₂ O ₃ , Fe ₂ O _{3 and the} like may be used in appropriate combination. Good. In particular, glass containing 1 to 20% by weight of potassium is preferable.

  In the lighting tube 1 of this embodiment, it is preferable that the alkali metal supply substance constitutes at least a part of the sealed container. It is because the member of a lighting tube can be reduced.

  In the present embodiment, a fixed pole is used as the counter electrode 4, but a movable pole may be used. That is, one of the pair of electrodes may be a movable pole or both may be a movable pole.

  In the present embodiment, the electron emission portions 18 and 19 are provided in at least a part of the internal lead wires 13 and 15 that are a metal containing iron, but are electrically connected to the electrode inside the container 8 and supplied with an alkali metal. There is no particular limitation as long as it is in contact with the substance. For example, a part of the surface of another metal material that is most suitable as an electrode is covered with iron, or the surface of a lead wire that is a metal containing iron is covered with another metal, and the part is peeled off to expose the iron You may provide an electron emission part in the made part. Moreover, you may provide an electron emission part only in one electrode. Note that the alkali metal supply substance can be activated without being in contact with the electron emission portions 18 and 19, but if it is in contact, potassium supplied from the alkali metal supply substance is easily adsorbed.

  In this embodiment, the flare stem 7 is used in combination as an alkali metal supply material. However, the alkali metal supply material is particularly limited to this shape as long as it contains potassium and is in contact with the electron emission portions 18 and 19. is not. For example, a member other than the flare stem that is brought into contact with the electron emission portion on the internal lead wire (or on the bimetal element) may be used.

(Embodiment 2)
FIG. 2 is a diagram illustrating an example of a method for manufacturing a stem portion of a lighting tube according to the present invention.

  In the lighting tube manufacturing method of the present embodiment, first, as shown in FIG. 2A, the internal lead wires 13 and 15 are inserted into the small opening 16 a of the flare glass 16, and the narrow tube 17 is inserted into the opening 16 b of the flare glass 16. Next, as shown in FIG. 2B, the internal lead wires 13 and 15 and the thin tube 17 are fixed to the upper portion (the small opening 16 a side) of the flare glass 16 to obtain the stem portion 20.

  Next, as shown in FIG. 1, the bimetal element 14 is connected to the end of the internal lead wire 13 on the side not fixed to the flare glass 16. Further, the stem portion 20 and the valve 6 are hermetically adhered to form a container 2 composed of the flare stem 7 (flared glass 16 in FIG. 2), the exhaust pipe 9 (narrow tube 17 in FIG. 2), and the valve 6. To do. The air inside the container 2 is exhausted from the exhaust pipe 9, a discharge gas is blown in, the end of the exhaust pipe 9 is sealed, and the container 2 is sealed. An electrode (movable electrode) 3 composed of an internal lead wire 13 and a bimetal element 14, an electrode (counter electrode) 4 composed of an internal lead wire 15, and a base 5 electrically connected to each other are attached to the container 2.

  Finally, a pulsed DC voltage is applied to the electrodes 3 and 4 to activate the electron emission portions 18 and 19 to complete the lighting tube 1.

  The flare glass 16 is shaped like an umbrella, for example, and may include an opening 16b corresponding to the hem of the umbrella and two small openings 16a at the top of the umbrella.

  External lead wires 11 and 12 are conductively connected to the internal lead wires 13 and 15. Further, the internal lead wire 15 may be longer than the internal lead wire 13.

  When the internal lead wires 13 and 15 are inserted into the small opening 16a, the external lead wires 11 and 12 may be arranged so as to go out from the inner surface side of the flare glass 16 through the opening 16b.

  When the internal lead wires 13 and 15 and the thin tube 17 are fixed to the flare stem 7, the upper portion (the small opening 16a side) of the flare glass 16 is crushed while being heated from the outside, for example, and the internal lead wires 13 and 15 are crushed. The narrow tube 17 may be sealed on the flare glass 16. By crushing the upper part of the flare glass 16 from the outside, the internal lead wires 13 and 15 and the thin tube 17 can be adhered to the flare glass 16. When crushing, air is blown from the end of the thin tube 17 outside the flare glass 16 into the inner end of the flare glass 16, and a part of the side surface of the flare glass 16 is softened. The exhaust hole 10 may be formed by blowing off with air. By the exhaust hole 10, the thin tube 17 can be adhered to the flare glass 16 without closing the tube port.

  In the airtight contact between the stem portion 20 and the bulb 6, for example, the bottomed substantially cylindrical edge portion of the bulb 6 and the opening 16b of the flare glass 16 may be heated and brought into close contact. At this time, the electrode 3 composed of the internal lead wire 13 and the bimetal element 14 and the electrode 4 composed of the internal lead wire 15 may be arranged on the inner surface side of the bulb 6, that is, inside the container 2.

  The electrodes 3 and 4 may be electrically connected to the outside of the container 2 by connecting the base 5 and the external lead wires 11 and 12.

  The manufacturing method of the lighting tube 1 of this embodiment can easily manufacture a lighting tube including the electron emission portions 18 and 19 activated by adsorbing potassium supplied from the flare stem 7.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited to a following example.

Example 1
First, as flare glass, lead glass (K ₂ O: 4.7% by weight, SiO ₂ : 57.5% by weight, PbO: 29.0% by weight, Al ₂ O ₃ : 1.0% by weight, Na ₂ O : 7.8 wt%) was formed in a flare shape having an opening at the top. Two internal lead wires (iron: 50% by weight, nickel: 50% by weight) to which a jumet wire was connected as an external lead wire and a glass thin tube were prepared. Next, as shown in FIG. 2, the internal lead wire and the thin tube were fixed to the flare glass by being crushed while being heated. Further, as shown in FIG. 1, a bimetallic element (high expansion side: 70% by weight of iron—25% by weight of nickel—5% by weight of manganese, low expansion side: 64% by weight of iron, at the end of one internal lead wire. -Nickel 36% by weight). And the said flare glass and glass-made valve | bulb were airtightly adhered.

  In this manner, a container including a pair of electrodes, each composed of a movable electrode and a fixed electrode, was formed, which was composed of a flare stem (the above-described flare glass), an exhaust pipe (the above-mentioned thin tube), and a valve. Next, using the exhaust pipe, the air inside the container was exhausted, and discharge gas (neon: 95% by volume, argon: 5% by volume) was blown in. At this time, the gas pressure inside the container was set to 5.3 kPa. The end of the exhaust pipe not connected to the flare stem was sealed to seal the container. After the two external lead wires were electrically connected to the base, the base was attached to the container.

  Finally, a pulsed DC voltage having a rest period (peak voltage: 0.8 kV, minimum voltage: 0 kV, pulse width: 3 ms, pulse repetition period: 2 times / second) is applied to the electrode through the base. By applying the time, the surface of the electrode in contact with the flare stem was activated to complete the lighting tube of this example. In addition, the said DC voltage applied the movable pole and the fixed pole as a cathode alternately.

(Comparative Example 1)
The lighting tube of this comparative example was manufactured in the same manner as the lighting tube of Example 1 except that a nickel-plated wire was used as the internal lead wire and a pulsed DC voltage was not applied.

(Comparative Example 2)
The lighting tube of this comparative example was manufactured in the same manner as the lighting tube of Example 1 except that no pulsed DC voltage was applied.

(Elemental analysis)
Elemental analysis was performed on the partial surface (position a in FIG. 1) of the fixed electrode in the lighting tube of Example 1 and Comparative Example 2 using Auger electron spectroscopy. The height of the position a from the contact surface between the fixed pole and the flare stem is 2 mm.

  As a result of the analysis, potassium was detected from the position a for the lighting tube of Example 1. However, for the lighting tube of Comparative Example 2, potassium was not detected from position a. Therefore, the electrode of the lighting tube of Example 1 to which a pulsed DC voltage was applied has potassium adsorbed sufficiently on the surface, but Comparative Example 2 to which no pulsed DC voltage is applied. It was confirmed that potassium was not adsorbed on the surface of the lighting tube electrode.

(Dark start experiment)
Five lighting tubes of Example 1 and Comparative Examples 1 and 2 were prepared, and the dark start delay time of the lighting tubes was compared.

  In this experiment, first, each lighting tube whose number of blinks is 0 is left in a dark place for 15 hours, then connected to a fluorescent lamp (power: 30 W), and the time from energization to glow discharge ( The discharge delay time) and the time from when the current was applied until the fluorescent lamp was turned on (time required for lighting) were measured. Next, each lighting tube was blinked 6000 times and allowed to stand in the dark for 15 hours, and then connected to the same fluorescent lamp, and the discharge delay time and the lighting required time were measured. Table 1 shows the measurement results of the discharge delay time, and Table 2 shows the measurement results of the required lighting time.

  As shown in Tables 1 and 2, each lighting tube of Example 1 has a discharge delay time of within 0.1 seconds and a lighting required time of 4 seconds regardless of whether the number of lighting is 0 or 6000 times. Was within.

  On the other hand, the lighting tube of Comparative Example 1 had three lighting tubes having a discharge delay time of 1 second or more and three lighting tubes having a lighting required time of 10 seconds or more in the case of zero blinking. Further, when blinking 6000 times, there were 4 lighting tubes with a discharge delay time of 1 second or longer and 2 lighting tubes with a lighting required time of 10 seconds or longer. Therefore, it turned out that the lighting tube of Example 1 shows the outstanding dark place starting characteristic rather than the conventionally used lighting tube of the comparative example 1. FIG.

  Further, the lighting tube of Comparative Example 2 is fluorescent with two lighting tubes having a discharge delay time of 1 second or more and one lighting tube having a lighting required time of 10 seconds or more when blinking 6000 times. There was one lighting tube that could not light the lamp. Therefore, the internal lead wire containing iron and the flare stem containing potassium are in contact, but the pulsed DC voltage is higher than that of the lighting tube of Comparative Example 2 to which no pulsed DC voltage is applied. It was found that the applied lighting tube of Example 1 showed excellent dark start characteristics.

  In addition, since the number of times the life of the lighting tube blinks is set to 6000 according to the durability test criteria defined in JIS standard C7603, the lighting tube of this embodiment does not use a radioactive substance. However, it can be said that it is a lighting tube capable of maintaining sufficient dark place starting characteristics.

  As described above, the present invention can provide a lighting tube that can easily emit electrons without using a radioactive substance, has a short dark start delay time, and a method for manufacturing the same.

It is a fragmentary sectional view which shows an example of the lighting tube of this invention. It is a figure explaining an example of the manufacturing method of the stem part of the lighting tube of this invention.

Explanation of symbols

1 lighting tube 2 container 3 electrode (movable electrode)
4 electrodes (counter electrode)
5 Base 6 Valve 7 Flare Stem 8 Inside Container 9 Exhaust Pipe 10 Exhaust Hole 11, 12 External Lead Wire 13, 15 Internal Lead Wire 14 Bimetallic Element 16 Flare Glass 16a Small Opening 16b Opening 17 Narrow Tube 18, 19 Electron Emission Part 20 Stem Part

Claims (11)

A lighting tube comprising a movable electrode including a thermoresponsive element and a pair of electrodes composed of a counter electrode of the movable electrode, and a discharge gas, inside the sealed container,
At least one of the pair of electrodes includes an electron emission portion containing iron,
The lighting tube according to claim 1, wherein the electron emission portion is in contact with an alkali metal supply material containing potassium and is activated by applying a pulsed DC voltage to the pair of electrodes.   2. The lighting tube according to claim 1, wherein the surface of the electron emission portion is adsorbed with potassium supplied from the alkali metal supply material by application of the voltage.   The lighting tube according to claim 1, wherein the pulsed DC voltage has a rest period.   2. The lighting tube according to claim 1, wherein the electron emission portion contains at least one metal selected from iron and an alloy containing iron on a surface in contact with the alkali metal supply material.   The lighting tube according to claim 1, wherein the alkali metal supply material is glass containing an alkali metal oxide.   The lighting tube according to claim 1, wherein the alkali metal supply material constitutes at least a part of the sealed container. A method of manufacturing a lighting tube comprising a movable electrode including a thermoresponsive element and a pair of electrodes composed of a counter electrode of the movable electrode and a discharge gas inside a sealed container,
Placing an alkali metal-containing substance containing potassium in contact with an electron-emitting portion contained in at least one of the pair of electrodes and containing iron;
By applying a pulsed DC voltage to the pair of electrodes, the electron emission part is heated while discharging the discharge gas,
A method for manufacturing a lighting tube, wherein potassium contained in the alkali metal supply substance is adsorbed to the electron emission portion.   The method of manufacturing a lighting tube according to claim 7, wherein the pulsed DC voltage has a pause period.   The said electron emission part is a manufacturing method of the lighting tube of Claim 7 which contains at least 1 metal chosen from the alloy containing iron and the iron in the surface which contacted the said alkali metal supply substance.   The method for manufacturing a lighting tube according to claim 7, wherein the alkali metal supply material is glass containing an alkali metal oxide.   The said alkali metal supply substance is a manufacturing method of the lighting tube of Claim 7 which comprises at least one part of the said airtight container.

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