JP2005346976A - Fluorescent lamp and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easy-to-manufacture fluorescent lamp and luminaire, capable of certainly stopping an abnormal electric discharge in a lamp service life end stage or the like. <P>SOLUTION: This fluorescent lamp has: a glass bulb 2 formed with a phosphor layer 4 on the inner face, and sealed with a discharge medium; a pair of filament electrodes 6, 6 sealed in both the ends of the bulb; a pair of lead wires 5, 5 each supporting each the electrode of the pair; stems 3 each supporting an electricity introduction wire of each of the pair; metal plates 11 shielding the stems from the electrodes; and getters 12 formed in the metal plates, each discharging impure gas by temperature increase of the electrode by abnormal lighting in the lamp service life end stage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluorescent lamp and a luminaire that are improved in safety by preventing abnormal overheating of an electrode rarely occurring at the end of the life of the fluorescent lamp.

  In general, when a fluorescent lamp having a filament electrode (hot cathode) coated with an emitter (electron emitting material) is exhausted at the end of its life, the discharge current of a half cycle using the electrode as a cathode decreases and the half of the discharge current decreases. Abnormal discharge phenomenon such as wave discharge occurs. This abnormal discharge phenomenon causes the lamp voltage to rise above the rated value, so that when the lamp is lit at the commercial frequency, the lamp is quickly turned off, but it tends to occur continuously in the case of high-frequency lighting. Further, the cathode fall voltage in a normal lighting state before the emitter is consumed is normally about 10V, but the cathode fall voltage after the emitter disappears increases to 40 to 70V. For this reason, high energy is input to the electrode in which the abnormal discharge phenomenon continues, and an abnormal temperature rise of the electrode part or the base may be caused.

  On the other hand, during lighting of the fluorescent lamp, a filament material such as tungsten (W) that forms the filament electrode and a lead wire such as nickel (Ni) that forms a pair of lead wires (electrical lead wires) that support both ends of the filament A large amount of material is scattered, and this scattered material is deposited on the top of the glass stem that seals the lead wire and its surrounding members.

  Even when the filament electrode is melted, lighting is easy to continue in the case of high-frequency lighting, so that the starting point of discharge is transferred to the lead wire and the abnormal discharge phenomenon is continued. If this phenomenon continues, as described above, the electrode parts such as lead wires and glass stems will melt at an abnormally high temperature, and further, such as melting the base of the fluorescent lamp and the socket of the lighting device, etc. There is. Further, since the scattered material deposited on the top of the stem is conductive, there is a possibility that the filament current is energized and problems such as melting of the stem occur due to Joule heating.

As an example of a fluorescent lamp for solving this problem, a metal hydride such as hydrogen titanium having a decomposition temperature higher than the temperature at the time of normal lighting of the fluorescent lamp is applied to the surface of the glass stem. There has been proposed a method in which metal hydride is decomposed to release hydrogen gas into a lamp, and the lamp voltage is increased by increasing the concentration of hydrogen gas pressure to forcibly stop abnormal discharge (see Patent Document 1).
JP 2001-250503 A

  However, in the conventional fluorescent lamp described above, metal hydride must be applied to the surface of the glass stem so that hydrogen gas is not released during normal lighting, and hydrogen gas is reliably released into the bulb during abnormal discharge. Therefore, it is necessary to select the application position, the application amount, and the material and to manage the process, and there is a problem that manufacturing is not easy.

  That is, when the fluorescent lamp is manufactured, the glass stem is heated to a high temperature, so that the metal hydride may reach the decomposition temperature during the manufacturing, and hydrogen gas may be released therefrom. For this reason, process control such as strict temperature control at the time of manufacture is necessary.

  If the metal hydride application position is too close to the filament electrode, the metal hydride may reach a decomposition temperature and release hydrogen gas when the filament electrode is normally lit. In the above prior art, a structure is disclosed in which a getter material is provided in the vicinity of a metal hydride to adsorb hydrogen gas released during normal lighting. However, since it is considered that the amount of released hydrogen gas exceeds the gas adsorption capacity of the getter substance, it is difficult to say that this is a preferable improvement measure for preventing problems caused by the increase in the hydrogen gas concentration during normal lighting.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fluorescent lamp and a lighting fixture that can reliably stop abnormal discharge at the end of the lamp life and can be easily manufactured. .

  The invention according to claim 1 is a bulb in which a phosphor layer is formed on the inner surface and a discharge medium is sealed inside; a pair of filament electrodes sealed at both ends of the bulb; A supporting electrical lead; a stem for supporting each of the electrical lead; a metal plate supported by the stem while shielding the stem from the electrode; and formed on the metallic plate at the end of the lamp life And a getter that emits an impure gas when the temperature of the electrode rises due to abnormal lighting.

  The invention according to claim 2 is the fluorescent lamp according to claim 1, wherein the metal plate is formed in a V-shape that expands toward the electrode.

  The invention according to claim 3 is the fluorescent lamp according to claim 1 or 2, wherein the bulb has a tube outer diameter of 34 mm or less and a tube length of 1300 mm or less.

  According to a fourth aspect of the present invention, there is provided an instrument main body; the fluorescent lamp according to any one of claims 1 to 3 disposed in the instrument main body; a high frequency that supplies high frequency lamp power to a pair of electrodes of the fluorescent lamp A lighting circuit; and a life detection circuit that reduces or stops the output of the high-frequency lighting circuit when it detects that the lamp voltage applied to the pair of electrodes of the fluorescent lamp has reached a predetermined value or more. It is the lighting fixture characterized by having.

  According to the present invention, when the temperature of the electrode at the end of the life of the fluorescent lamp rises, impure gas is released from the getter of the metal plate and the lamp voltage rises. However, since the metal plate is made of metal, the thermal conductivity is increased. The temperature rises quickly. For this reason, the impure gas is released from the getter of the metal plate early in the abnormal discharge, and the lamp voltage rises early, so that the abnormal discharge at the end of the life can be prevented from continuing for a long time, and the abnormal discharge state It is possible to provide a highly reliable fluorescent lamp and lighting apparatus that can stop lighting at an early stage.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a partially cutaway longitudinal sectional view of a fluorescent lamp 1 according to a first embodiment of the present invention. As shown in FIG. 1, a fluorescent lamp 1 is a high-frequency lighting-only type and has a glass bulb 2 having a required size. A pair of glass stems 3 and 3 are airtightly attached to both ends of the glass bulb 2 in the axial direction.

  The glass bulb 2 is formed of a soft glass such as soda-lime glass into a required shape such as a straight tube, a ring, or a rectangle, and a phosphor film 4 such as a three-wavelength light emitting type is formed on almost the entire inner surface of the glass bulb 2. A rare gas and mercury are enclosed as a discharge medium. The rare gas of the discharge medium includes argon (Ar), neon (Ne), krypton (Kr), etc., and argon (Ar) is used in this embodiment.

  The glass bulb 2 is made of soft glass such as soda lime glass or lead glass, but may be made of hard glass such as borosilicate glass or quartz glass. The wall thickness of the valve is preferably about 0.8 to 1.2 mm, but is not limited thereto.

  The phosphor constituting the phosphor layer 4 can be a known phosphor such as a three-wavelength phosphor or a halophosphate phosphor. However, the use of a three-wavelength phosphor is preferable from the viewpoint of luminous efficiency. preferable.

As the three-wavelength emission type phosphor, BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ as a blue phosphor having an emission peak wavelength near 450 nm, and (La, Ce) as a green phosphor having an emission peak wavelength near 540 nm. , Tb) PO ₄ , Y ₂ O ₃ : Eu ³⁺ can be used as a red phosphor having an emission peak wavelength near 610 nm, but is not limited thereto.

A protective film may be interposed between the inner surface of the glass bulb 2 and the phosphor layer 4. The protective film is preferably composed of metal oxide fine particles, and well-known materials such as alumina (Al ₂ O ₃ ) and silica (SiO ₂ ) can be used as the metal oxide fine particles.

  Amalgam may be enclosed in the glass bulb 2. The amalgam is accommodated in an exhaust pipe 7 of a thin tube disposed on the stem 3 sealed at the end of the glass bulb 2. The amalgam is fixed or stored in any of these positions by means of melting, mechanical holding or the like. Moreover, the amalgam may be accommodated in the glass bulb 2 so as to be movable. When amalgam is disposed in the glass bulb 2, the fluorescent lamp is lit in an optimum state even when the ambient temperature is relatively high.

  Amalgam is an alloy of mercury and a material that forms an alloy with mercury. For example, amalgam such as zinc-mercury may be encapsulated for quantitative encapsulation of mercury. The amalgam may have any shape such as a pellet shape, a column shape, or a plate shape.

  2 is an enlarged side sectional view showing electrode portions attached to both ends of the fluorescent lamp 1 shown in FIG. 1, and FIG.

  As shown in FIG. 2, each glass stem 3 has a pair of lead wires (electrical lead wires) 5, 5 that are sealed through in the axial direction and arranged in parallel at a predetermined interval. Between the inner ends of the pair of lead wires 5 and 5 extending to the side, the filament electrode 6 is bridged and fixed.

  The pair of electrodes 6 and 6 are hot cathode electrodes in which an emitter material is applied to a filament. In addition, when it is necessary to light the lamp at a high output, it is preferable to use a triple coil for the electrodes 6 and 6. Each pair of lead wires 5 and 5 that support the electrodes 6 and 6 is sealed and supported by a flare stem, a button stem, a bead stem, a pinch seal portion, and the like.

  The glass stem 3 is integrally formed with a small exhaust pipe 7 at an intermediate portion between the pair of lead wires 5 and 5. The exhaust pipe 7 is sealed after the glass bulb 2 is sealed, and an exhaust hole 7 a for communicating the inside of the exhaust pipe 7 and the discharge space in the glass bulb 2 is formed in the side surface of the glass stem 3.

  As shown in FIG. 1, a pair of caps 8 and 8 are fitted and fixed to the outer surfaces of both ends in the axial direction of the glass bulb 2 provided with these exhaust pipes 7, and a pair of lead wires are attached to the caps 8 and 8, respectively. A pair of base pins 9 and 9 are respectively provided in a protruding manner with two pieces connected to 5 and 5 respectively.

  The cap pins 9 and 9 are electrical connection means for connecting to power supply means such as a socket of a lighting fixture. The base pins 9, 9 may be provided at positions away from both end portions of the glass bulb 2. Moreover, the bases 8 and 8 may be configured to exhibit a function as a holding unit by mechanical connection with the power supply unit.

As shown in FIGS. 2 and 3, the glass stem 3 is implanted at a substantially central portion of the top end of the inner end in a state where the support wire 10 is electrically insulated from the pair of lead wires 5 and 5. doing. For example, a jumet wire having a thermal expansion coefficient difference of 20 × 10 ⁻⁷ cm / ° C. or less from the glass stem 3 is used for the support wire 10. Thereby, since the thermal expansion coefficient of the support wire 10 approximates that of the glass stem 3, the thermal distortion of the glass stem 3 can be reduced, and the occurrence of cracks can be prevented.

  The bottom portion (the lower end portion in FIGS. 2 and 3) of the metal plate 11 having a V-shaped cross section is fixed to the distal end portion (the upper end portion in FIGS. 2 and 3) of the support wire 10. The metal plate 11 is formed by bending a flat metal plate such as stainless steel (SUS), iron (Fe), nickel (Ni) or the like into a V-shaped cross section. The metal plate 11 is oriented so that its longitudinal direction (axial direction) is along the coil axial direction of the filament electrode 6, and the V-shaped opening faces the filament electrode 6 side (upward in FIGS. 2 and 3). The bottom of the V-shaped tip is attached to the support wire 10 so as to shield the stem 3 from the filament electrode 6. Therefore, the metal plate 11 surrounds the stem 3 side (the lower side in FIGS. 2 and 3) and the side of the filament electrode 6 with a predetermined distance from the filament electrode 6. The metal plate 11 is provided with getters 12 on the outer surfaces of the two V-shaped inclined surfaces.

  The getter 12 is made of a fine powder of an alloy of zirconium and aluminum (ZrAl), for example, and is applied to the outer surface of the metal plate 11 in a strip shape, for example.

  The getter 12 is a substance that adsorbs and stores an impurity gas such as hydrogen in the bulb, and releases the stored impurity gas again at an abnormally high temperature such as the end of the lamp life. That is, the getter 12 functions to suppress an impurity gas concentration in the bulb by adsorbing an impurity gas such as hydrogen gas in the glass bulb 2 in a normal state. The getter 12 is preferably a mixture containing Ti, Zr or Al, such as ZrAl. However, as the getter 12, a non-evaporable getter other than the Zr-Al alloy can be applied, and one of titanium (Ti), zirconium (Zr), aluminum (Al), vanadium (V) and iron (Fe). It may be a seed metal or an alloy containing two or more of these metals as a main component.

  By the way, the temperature in the vicinity of the electrode rises to, for example, 700 ° C. to 800 ° C. with the continuation of the abnormal discharge phenomenon at the end of the life of the fluorescent lamp. Therefore, if the abnormal discharge phenomenon continues, impure gas such as hydrogen gas stored at the time of activation is released from the getter 12 to increase the lamp sustaining voltage and stop the abnormal discharge. I found out that Therefore, after the glass bulb 2 is evacuated and sealed, impure gas such as hydrogen gas in the glass bulb 2 can be occluded by the getter 12.

  The fluorescent lamp 1 is lit when high frequency power of, for example, 10 KHz or more is supplied to a pair of filament electrodes 6 and 6 from a high frequency lighting circuit (not shown). In some cases, the emitters of the filament electrodes 6 and 6 are consumed and the abnormal discharge phenomenon is maintained.

  Thereby, although the electrode part of the fluorescent lamp 1 is abnormally heated, the metal plate 11 is also heated to a high temperature almost simultaneously, and the getter 12 is also heated to 700 ° C. to 800 ° C., for example. For this reason, impure gas such as hydrogen gas that has been occluded by the adsorption action during the exhaust process or the like is released into the glass bulb 2.

  As a result, the concentration of impure gas in the glass bulb 2 is increased, and the lighting sustaining voltage of the lamp continues to rise so as to exceed the output voltage of the high-frequency lighting circuit, so that the abnormal discharge stops and the lamp is extinguished. Further, since the metal plate 11 shields the radiation heat from the filament electrode 6 from being radiated to the stem 3, it is possible to prevent the stem 3 from being heated to a high temperature and melted by the radiation heat from the filament electrode 6. it can. As described above, it is possible to prevent the abnormal discharge phenomenon at the end of the life of the fluorescent lamp from continuing for a long period of time and the melting of the glass stem 3, the lead wire 5, the base 8, the socket of the lighting device, and the like.

  As described above, the metal plate 11 provided with the getter 12 is provided at a position closer to the electrode than the glass stem 3 and is formed of a metal having high thermal conductivity. It reaches a higher temperature faster than the glass stem 3.

  Therefore, the getter 12 is not necessarily provided on the metal plate 11 and may be welded to, for example, the lead wire 5, the glass stem 3, or the lead wire as long as the impure gas can be released due to the influence of overheating during abnormal discharge. However, it is more effective to provide the getter 12 on the metal plate 11 than to the glass stem 3 in order to quickly release the impure gas at the time of abnormal discharge of the fluorescent lamp 1.

  Further, the temperature difference between the non-operating state in which the getter 12 occludes impure gas (during normal lighting) and the operating state in which the stored gas is released (during abnormal discharge) is made of metal rather than the glass stem 3. Since the plate 11 is larger, providing the getter 12 on the metal plate 11 can widen the selection range when selecting the material of the getter 12. For this reason, the getter 12 can be prevented from releasing the occluded gas at a high temperature during the exhaust process of the glass bulb 2, so that strict temperature control is not required, and the ease of manufacturing the getter 12 and the cost are improved. Reduction can be achieved together.

  In addition, since the temperature range from the non-operating state to the operating state of the getter 12 can be increased, it is easy to set the temperature at which the getter 12 is reliably operated. For this reason, the certainty that the impure gas storage operation and the storage gas release operation of the getter 12 can be reliably performed can be improved, so that safety and reliability can be improved.

  In addition, since the electrode scattering material that is scattered from the filament electrode 6 toward the tube wall of the glass bulb 2 is captured by the metal plate 11 before being scattered to the tube wall, the electrode scattering material adheres to the tube wall. Blackening can be prevented or reduced. The getter 12 of the metal plate 11 does not necessarily need to be activated during the exhaust process, and even if it is a getter that does not activate, as long as the impure gas is occluded, the getter 12 operates well at the end of its life. I was able to confirm.

  In a fluorescent lamp having a glass bulb 2 with a tube outer diameter exceeding 34 mm and a tube length longer than 1300 mm (for example, a 110 W type fluorescent lamp “FLR110” having a tube outer diameter of 38 mm and a tube length of about 2370 mm), an abnormal discharge phenomenon Even if there was an impure gas release from the getter 12 due to the above, the impure gas concentration did not rise above a desired level because the internal volume of the glass bulb 2 was large, and the lamp lighting maintenance voltage did not increase. On the other hand, in the case of a fluorescent lamp having a bulb with a tube outer diameter of 34 mm or less and a tube length of 1300 mm or less, if the impure gas is released from the getter due to an abnormal discharge phenomenon, the impure gas concentration is effectively increased and the lamp is kept on. The voltage rises. Accordingly, the lighting sustaining voltage of the fluorescent lamp rises so as to exceed the output voltage of the high frequency lighting circuit, so that the abnormal discharge phenomenon stops. The tube outer diameter of the valve is optimally 10 to 28 mm, and the tube length is preferably 500 to 1200 mm. For example, the high-frequency lighting type 32W model “FH32F” with a tube outer diameter of 25.5 mm, a tube inner diameter of 24.0 mm, a wall thickness of 0.75 mm, and a tube length of about 1200 mm effectively increases the impurity gas concentration from the getter 12. The abnormal discharge phenomenon was stopped early.

Further, a 40 W type fluorescent lamp (model names “FL40” and “FLR40”) having a bulb outer diameter of 32.5 mm and a tube length of about 1200 mm is configured in the same manner as in the first embodiment, and is operated at high frequency. As a result, similarly, the abnormal discharge phenomenon at the end of the life did not continue for a long time, and the same effect as the above embodiment was recognized.

  Here, the tube length of the glass bulb 2 refers to the length from the outer end of one base 8 to the outer end of the other base 8.

  Further, since the electrode material that scatters from the filament electrode 6 to the stem 3 during the abnormal discharge and the lead material that scatters from the lead wires 5 and 5 to the stem 3 are received by the metal plate 11, the electrode material and the lead material Can be prevented or reduced from being deposited on the top surface of the stem 3. For this reason, it is possible to prevent or reduce the pair of lead wires 5 and 5 from shorting through the conductive electrode material and lead material deposited on the stem 3 and melting the stem 3 due to Joule heating. it can.

  Further, since the radiant heat radiated from the filament electrode 6 to the stem 3 is also shielded by the metal plate 11, overheating of the stem 3 can be prevented.

  In addition, since the metal plate 11 is made of a metal having a high thermal conductivity and is close to the filament electrode 6, it is expected that the metal plate 11 is heated quickly and the impurity gas is easily released from the getter 12. Can do.

  4A to 4F are side sectional views showing various modifications of the metal plate 11. If the metal plate 11 has a portion that shields the stem 3 side from the filament electrode 6 as shown in FIGS. 4 (a) to 4 (f), the shape thereof may be appropriately changed.

  FIG. 4 (a) shows a cylindrical metal plate 11a, which covers (shields) almost the entire circumference of the filament electrode 6 over the entire length in the axial direction at a required interval, while the shaft It is formed in a cylindrical shape having both ends in the direction opened, and a discharge path is formed in the both ends in the axial direction.

  A U-shaped metal plate 11b shown in FIG. 4 (b) covers the filament electrode 6 in the U shape over almost the entire length in the axial direction, and opens the filament electrode 6 side.

  The small flat metal plate 11c shown in FIG. 4C covers the stem 3 side of the filament electrode 6 with a rectangular flat plate having a width substantially equal to or smaller than the diameter of the filament electrode 6. .

  The small V-shaped metal plate 11d shown in FIG. 4 (d) is formed in a V shape smaller than the V-shaped metal plate 11, and is formed over almost the entire length of the filament electrode 6 in the axial direction. However, the V-shaped open end is formed lower than the top of the filament electrode 6.

  The middle V-shaped metal plate 11 e shown in FIG. 4 (e) is formed in a V shape over substantially the entire axial length of the filament electrode 6, and its substantially V-shaped opening end is substantially equal to the top of the filament electrode 6. It is formed with a height or slightly lower.

  The large V-shaped metal plate 11f shown in FIG. 4 (f) is formed so that its V-shaped open end is higher than the top of the filament electrode 6, and other than this, the large V-shaped metal plate 11f is almost the same as the above-mentioned medium V-shaped metal plate 11f. It is constituted similarly.

  And these metal plates 11a-11f arrange | position at least one of the said getter 12 and a metal hydroxide to at least one of the filament electrode 6 side inner surface and outer surface, and the inner surface and outer surface of metal plates 11a-11f The other of the getter 12 and the metal hydroxide may be disposed on the other side.

  As the mercury emitter, for example, a mercury alloy (TiHg) made of an alloy powder of mercury (Hg) and titanium (Ti) is used in a layered manner.

  In this mercury emitter, after the inside of the glass bulb 2 is evacuated, the metal plates 11, 11a to 11f are induction-heated from the outside of the glass bulb 2 to be heated to a predetermined temperature. The glass bulb 2 is discharged and sealed.

  FIG. 5 is a perspective view showing the configuration in the vicinity of the filament electrode 6 according to the second embodiment of the present invention. In this embodiment, instead of the metal plates 11, 11 a to 11 f, a metal ring 13 surrounding the filament electrode 6 with a required gap and a support for supporting the metal ring 13 on the stem 3. A feature is that a flat shielding plate 14 made of, for example, ceramics or glass, which is fixed in the middle of the wire 10a and covers the top surface side of the stem 3, is provided.

  The metal ring 13 is formed by a cylindrical ring in which a band-shaped metal plate such as stainless steel (SUS), iron (Fe), nickel (Ni) or the like is formed in an oval or elliptical cross section. The metal ring 13 is formed so that its longitudinal direction is along the coil axis direction of the filament electrode 6, and both axial ends (upper and lower ends in FIG. 5) are open. The metal ring 13 has a mercury emitter 15 disposed on the inner surface (on the filament electrode 6 side) and a getter 12 disposed on the outer surface. The mercury emitter 15 may be provided on each of the metal rings 13 and 13 provided on both ends of the glass bulb 2, but is provided only on one of the metal rings 13 and 13. It may be. However, it is necessary to provide the getter 12 on the metal rings 13 and 13 provided at both ends of the valve.

  Therefore, according to the second embodiment, after the glass bulb 2 is evacuated and sealed, the metal ring 13 is heated from the outside of the glass bulb 2 to a predetermined temperature by high-frequency induction heating, and the mercury emitter is thereby heated. By heating 15, a predetermined amount of mercury vapor is released from the mercury emitter 15, while the getter 12 is heated to be activated and impure gas such as hydrogen gas in the glass bulb 2 is occluded by the getter 12. Can do. Similarly to the above embodiment, the getter 12 releases impure gas into the glass bulb 2 at the time of abnormal discharge at the end of the lamp life, etc., increases the impure gas concentration to increase the lamp lighting voltage, and stops the abnormal discharge. be able to.

  Further, since the electrode material that scatters from the filament electrode 6 to the stem 3 and the lead material that scatters from the lead wires 5 and 5 to the stem 3 during the abnormal discharge are received by the shielding plate 14, the electrode material and the lead material are Accumulation on the top surface of the stem 3 can be prevented or reduced. For this reason, it is possible to prevent or reduce the pair of lead wires 5 and 5 from shorting through the conductive electrode material and lead material deposited on the stem 3 and melting the stem 3 due to Joule heating. it can.

  Further, since the radiant heat radiated from the filament electrode 6 to the stem 3 is also shielded by the shielding plate 14, the stem 3 can be prevented from being overheated.

  FIG. 6 is a side view of the lighting fixture 21 according to the third embodiment of the present invention. This luminaire 21 shows a state in which the fluorescent lamp 1 according to the first embodiment is mounted on a fixture main body 22 such as a direct ceiling type. The appliance body 22 may be a direct ceiling type, a ceiling suspended type, or a wall-mounted type, to which a glove, shade, reflection shade, etc. may be attached, a fluorescent lamp exposed, or a light guide plate It may be provided.

  The lighting fixture 21 is provided with a pair of sockets 23 and 23 for detachably mounting the pair of caps 8 and 8 of the fluorescent lamp 1 on one surface of the fixture main body 22, while the pair of sockets 23 and 23 are electrically connected. A high-frequency lighting circuit 24 that is connected to each other and supplies high-frequency power of, for example, 10 KHz or more is built in the instrument body 22. The high frequency lighting circuit 24 includes an end of life detection circuit 25.

  Note that the high-frequency lighting circuit 24 may be provided with switching means. The switching means may be divided into a mode in which the fluorescent lamp 1 is turned on with high efficiency and a mode in which the fluorescent lamp 1 is turned on with high output, or may be changed continuously between these modes. By switching the switching means of the lighting circuit 24, the lighting of the fluorescent lamp 1 is adjusted. For example, when the switching means is divided into a mode in which high-efficiency lighting is performed and a mode in which high-power lighting is performed, the fluorescent lamp can be used by appropriately selecting these modes according to use conditions.

  The fluorescent lamp 1 is attached according to the shape of the main body of the lighting fixture 22 or the optical characteristics of the lighting fixture 21, and a plurality of fluorescent lamps having the same shape or different shapes are combined to change the arrangement height of the same plane or bulbs. Is mounted on the instrument body 22.

  The end of life detection circuit 25 has a function of detecting abnormal discharge by detecting that the lamp voltage applied to the pair of filament electrodes 6 and 6 of the fluorescent lamp 1 has risen to a predetermined value or more. When the end of life detection circuit detects an abnormal discharge of the fluorescent lamp 1, the high-frequency lighting circuit 24 stops the output operation and forcibly stops the abnormal discharge, or reduces the output to prevent sudden turn-off. Even in abnormal discharge, the fluorescent lamp operates so as to be dimly lit so that the temperature of the electrode portion does not increase excessively.

  Therefore, according to this luminaire 21, when the fluorescent lamp 1 is abnormally discharged due to the end of its life and rises to an abnormally high temperature, the getter 12 in the glass bulb 2 of the fluorescent lamp 1 is impure as described above. Release gas.

  Thereby, since the concentration of impure gas in the glass bulb 2 is increased and the discharge voltage is increased, the abnormal discharge is forcibly stopped or the output is reduced to prevent the temperature of the electrode portion from rising.

  That is, according to the third embodiment, at the end of the life of the fluorescent lamp 1, the dual gas emission action of the getter 12 of the fluorescent lamp 1 and the action of the life detection circuit 25 of the lighting fixture 21 are combined. Since the abnormal discharge phenomenon is prevented from continuing for a long time by the safe operation, the safety can be further improved.

1 is a partially cutaway longitudinal sectional view of a fluorescent lamp according to a first embodiment of the present invention. FIG. 2 is a side sectional view of one electrode end portion shown in FIG. 1. The perspective view of one electrode mount shown in FIG. (A)-(f) is a side view which shows the modification of the shape of the metal plates shown in FIGS. 1-3, respectively. The principal part perspective view of the 2nd Embodiment of this invention. The side view of the state which mounted | wore the irradiation lamp which concerns on Embodiment 3 of this invention with the fluorescent lamp which concerns on 1st Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fluorescent lamp, 2 ... Glass bulb, 3 ... Glass stem, 4 ... Phosphor layer, 5 ... Lead wire, 6 ... Filament electrode, 11 ... Metal plate, 12 ... Getter, 13 ... Metal ring, 15 ... Mercury Emitter, 21 ... lighting fixture, 22 ... fixture body, 23 ... socket, 24 ... high frequency lighting circuit.

Claims (4)

A bulb having a phosphor layer formed on the inner surface and a discharge medium enclosed therein;
A pair of filament electrodes sealed at both ends of the bulb;
An electrical lead that supports each end of the electrode;
A stem for supporting each of the electrical lead wires;
A metal plate supported by the stem while shielding the stem from the electrode;
A getter formed on this metal plate and releasing impure gas due to temperature rise of the electrode due to abnormal lighting at the end of the lamp life;
A fluorescent lamp characterized by comprising: The fluorescent lamp according to claim 1, wherein the metal plate is formed in a V shape that expands toward the electrode. The fluorescent lamp according to claim 1 or 2, wherein the bulb has a tube outer diameter of 34 mm or less and a tube length of 1300 mm or less. An instrument body;
The fluorescent lamp according to any one of claims 1 to 3, which is disposed in the instrument body;
A high-frequency lighting circuit for supplying high-frequency lamp power to a pair of electrodes of the fluorescent lamp;
An end-of-life detection circuit that lowers or stops the output of the high-frequency lighting circuit when it detects that the lamp voltage applied to the pair of electrodes of the fluorescent lamp has reached a predetermined value or higher;
The lighting fixture characterized by comprising.

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