JP2007095475A - Compact self-ballasted fluorescent lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact self-ballasted fluorescent lamp which can be used safely even if a mixed defective thermally sensitive resistive element is used. <P>SOLUTION: This is equipped with a light emitting tube 1 in which a fluorescent layer is formed on the inner face and in which a discharge medium is sealed in; a cover body 2 which retains this light emitting tube and on which a base 3 is mounted; and a lighting device 10 which has a lighting circuit 5 to light the light emitting tube 1, the thermally sensitive resistive element 7 in which a resistivity increases according to temperature increase accompanied with self-heating, and a connection breaking means 12 to act so as to cut off the thermally sensitive resistive element 7 from the lighting circuit 5 when the thermally sensitive resistive element 7 generates heat abnormally, and which is housed in the cover body 2. Since the connection breaking means 12 acts so as to cut off the thermally sensitive resistive element 7 from the lighting circuit 5 when the thermally sensitive resistive element 7 raises the temperature because of abnormal heat generation, it can be prevented that the thermally sensitive resistive element 7 generates more heat while continuing lighting. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bulb-type fluorescent lamp having a temperature characteristic resistance element.

  For example, an inductor and a resonance capacitor are connected in series between output terminals of an inverter circuit, and a fluorescent lamp as a discharge lamp and a temperature positive characteristic resistance element are connected in parallel with the resonance capacitor. Has been configured.

  In this lighting device, a high starting voltage is not generated until the resistance value of the temperature positive characteristic resistance element rises to a predetermined value, and a high lamp starting voltage is applied after sufficiently preheating the filament electrode. Works to start lighting. For this reason, since the filament electrode is prevented from being deteriorated by sputtering or the like due to the application of the lamp starting voltage, it is possible to prevent the life from being shortened due to the filament deterioration due to an increase in the number of blinks. That is, immediately after the start of energization of the inverter circuit, the resistance value of the temperature positive characteristic resistance element is small and a low voltage at which the lamp does not start is applied between the filament electrodes while a preheating current flows to each filament electrode. The filament electrode is preheated. Thereafter, the resistance value increases as the temperature rises due to self-heating of the temperature positive characteristic resistance element, and the resonance voltage rises as the resonance component of the resonance circuit fluctuates. And when the time required for each inverter circuit to preheat the filament electrode has passed to such an extent that sufficient thermionic emission is performed, the resonance voltage is designed to rise to a voltage at which the lamp can be started. The lamp is started and lit after the filament electrode is sufficiently preheated.

In addition, a small amount of unnecessary current flows through the temperature positive characteristic resistance element after the lamp is turned on, but this slight current also leads to loss, so the current flowing through the temperature positive characteristic resistance element must be cut off after the fluorescent lamp is turned on. Is preferred. For this reason, there is known a configuration of a discharge lamp lighting device in which a voltage limiting element is connected in series to a temperature positive characteristic resistance element, and after the lamp is lit, the limiting element operates to bring the temperature characteristic resistance element into a non-conductive state. (For example, refer to Patent Document 1).
JP 2005-50801 A

  However, although it is extremely rare among the temperature characteristic resistance elements, there is a possibility that a defective product that abnormally generates heat when the arc tube is turned on may be mixed. If this defective product heats up abnormally, the cover body may be heated to cause problems such as smoke generation. Therefore, it is necessary to provide a product that can be used safely even if such defective products are mixed.

  The present invention has been made in view of the above problems, and when the temperature characteristic resistance element abnormally generates heat, the temperature characteristic resistance element is provided in the lighting device so that the heat generation does not continue, so that defective products are mixed. An object of the present invention is to provide a bulb-type fluorescent lamp that can be used safely.

  The bulb-type fluorescent lamp of the present invention has a phosphor layer formed on the inner surface, a luminous tube in which a discharge medium is sealed, a cover body that holds the luminous tube and has a base attached thereto, and the luminous tube. A lighting circuit to be lit, a temperature characteristic resistance element connected to the lighting circuit and having a resistance value that increases or decreases in response to a temperature rise due to self-heating, and the temperature characteristic resistance element is disconnected from the lighting circuit when the temperature characteristic resistance element abnormally generates heat It has the connection cutting | disconnection means which operate | moves like this, The lighting device accommodated in the said cover body was comprised.

  The connection cutting means connects the first lead wire derived from the temperature characteristic resistance element and the second lead wire connecting the first lead wire and the lighting circuit, and 130 to 300. It may be an adhesive that melts at a temperature of ° C. It has been confirmed by experiments that the temperature characteristic resistance element rises by 300 ° C. or more during abnormal heat generation, and the object of the present invention can be achieved by using an adhesive having a melting point of 130 to 300 ° C. At this time, the length from the temperature characteristic resistance element to the adhesive is preferably within 10 mm. It has been experimentally confirmed that the heat generated during abnormal heat generation of the temperature characteristic resistance element rises to a sufficiently high temperature to melt the adhesive material in the range of up to 10 mm on the lead wire derived from the temperature characteristic resistance element.

  Further, a deformable member that operates so as to disconnect a lead wire derived from the temperature characteristic resistance element by heat generated when the temperature characteristic resistance element abnormally generates heat may be used.

  The connection disconnection means may be a temperature fuse that is connected in series with the temperature characteristic resistance element and becomes non-conductive due to heat generated during abnormal heat generation of the temperature characteristic resistance element.

  Further, the bulb-type fluorescent lamp of the present invention has a phosphor layer formed on the inner surface, a light emitting tube in which a discharge medium is enclosed, a cover body that holds the light emitting tube and has a base attached thereto, and the light emitting device. A lighting circuit for lighting a tube and a temperature characteristic resistance element whose resistance value increases or decreases in accordance with a temperature rise due to self-heating, and within a region whose distance from the temperature characteristic resistance element is within 3 mm and from the temperature characteristic resistance element Each of the circuit elements that are one part of the lighting circuit and have relatively low heat resistance are located in a region where the distance from the portion within 10 mm of the derived length of the derived lead wire is within 3 mm. An element is disposed, and a lighting device housed in the cover body is provided.

  Furthermore, the bulb-type fluorescent lamp of the present invention has a phosphor layer formed on the inner surface, an arc tube in which a discharge medium is sealed, a cover body holding the arc tube and having a base attached thereto, and the arc tube A field effect transistor that performs a switching operation so as to turn on the light source, and a substrate on which the field effect transistor is mounted. The lighting circuit is housed in the cover body and lights the arc tube. A temperature characteristic resistance element having a resistance value that increases or decreases in response to a temperature rise caused by self-heating, wherein a lead wire is connected to the substrate position adjacent to the connection terminal of the field effect transistor and is mounted on the substrate. Features.

  The temperature characteristic resistance element may be either a temperature positive characteristic resistance element whose resistance value increases as the temperature rises or a temperature negative characteristic resistance element whose resistance value decreases as the temperature rises. In addition, the temperature characteristic resistance element is connected to the lighting circuit, and is configured to operate so as to appropriately preheat the filament when the lamp is lit, and flows to the circuit element when an overcurrent flows in the lighting circuit as at the end of the life of the arc tube. The present invention can be used for various purposes such as a configuration in which circuit elements are protected by reducing overcurrent and a circuit constant of a drive that controls the switching operation of the lighting circuit is changed according to the ambient temperature. Therefore, the connection relationship between the temperature resistance element and the lighting circuit is not particularly limited.

  According to the bulb-type fluorescent lamp of the present invention, since the connection cutting means is provided between the temperature characteristic resistance element and the lighting circuit, the temperature characteristic resistance element is disconnected when the temperature rises due to abnormal heat generation. The temperature characteristic resistance element does not generate any further heat and is reliably prevented from being affected by heat from the cover body.

  Further, by using an adhesive that melts at 130 to 300 ° C. for the connection cutting means, the temperature characteristic resistance element and the lighting circuit can be reliably cut with a simple configuration due to a temperature rise during abnormal heat generation of the temperature characteristic resistance element. If the distance from the temperature characteristic resistance element to the adhesive is within 10 mm, the temperature characteristic resistance element can be reliably cut.

  Also, by using a deformable member for the connection cutting means, it can be operated so as to disconnect the lead wire derived from the temperature characteristic resistance element, so that the connection is reliably cut with a simple configuration without the need for an adhesive. can do.

  Further, if a thermal fuse is used as the connection cutting means, the connection can be reliably cut with a simple configuration by setting so that the thermal fuse is blown when a predetermined temperature is reached.

  Furthermore, according to the light bulb-type fluorescent lamp of the present invention, one part of the lighting circuit is provided in a region within 10 mm from a portion within 10 mm from the temperature characteristic resistance element of the temperature characteristic resistance element and the lead wire derived from the temperature characteristic resistance element. Since each element is mounted so that at least a part of the circuit element having relatively low heat resistance is located, when the temperature characteristic resistance element abnormally generates heat, the heat of the abnormal heat generation causes relatively low heat resistance. The circuit element can be destroyed, the oscillation of the lighting circuit can be stopped, and the temperature characteristic resistance element can be reliably prevented from further rising in temperature.

  Furthermore, according to the bulb-type fluorescent lamp of the present invention, it is mounted on the substrate at the previous substrate position adjacent to the connection terminal of the field effect transistor which is mounted on the substrate and performs a switching operation so as to light the arc tube. The lead wire of the temperature characteristic resistance element whose resistance value increases or decreases according to the temperature rise due to self-heating is connected, and the heat generated when the temperature characteristic resistance element abnormally generates heat is generated between the temperature characteristic resistance element and the field effect transistor. Since it is arranged to be transmitted through a conductive path that is electrically connected, when the temperature characteristic resistance element abnormally generates heat, the field effect transistor can be surely destroyed, and the lamp oscillation can be stopped. It is possible to reliably prevent the characteristic resistance element from further rising in temperature.

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

  FIG. 1 is a cross-sectional view showing a configuration of a bulb-type fluorescent lamp according to a first embodiment of the present invention.

The bulb-type fluorescent lamp 50 includes a light-emitting tube 1 as a fluorescent lamp, a cover body 2 that holds the light-emitting tube 1, and a globe 4 that is installed to cover the light-emitting tube 1 and is attached to the cover body 2 together with the base 3. And. A lighting device 10 is disposed inside the cover body 2. The lighting device 10 includes a lighting circuit 5, a circuit board 6 on which circuit elements constituting the lighting circuit 5 are mounted, and a temperature characteristic resistance element 7 mounted on the board. The lighting circuit 5 includes at least electronic components such as a circuit element 8 having a relatively high heat resistance and a circuit element 9 having a relatively low heat resistance. Although the temperature characteristic resistance element 7 is extremely rare, there is a possibility that a defective product that abnormally generates heat during operation of the lighting circuit may be mixed. Therefore, in order to prevent the cover body 2 from being melted when the heat is generated, 6 is arranged at a substantially central position. In order to prevent melting of the cover body 2, the volume of the space formed by the cover body 2, the base 3 and the circuit board 5 is V (m ³ ), and the distance from the temperature characteristic resistance element 7 to the cover body 2 is d. (M) When the power input to the arc tube 7 is W (W), the bulb-type fluorescent lamp 50 is configured to satisfy the conditional expression of W / (V × d) <0.3. Is desirable. If it exceeds 0.3, the cover 2 may be melted by the temperature characteristic resistance element 7 that generates heat, which is not preferable.

  FIG. 2 is a circuit diagram showing a lighting circuit of the bulb-type fluorescent lamp according to the first embodiment.

  The lighting circuit 5 includes an inverter circuit unit 16 that is driven by a commercial power source 15 to light the arc tube 1. A filament 18a directly connected to the inverter circuit section 16 is sealed at one end side of the arc tube 1, and the other end side of the arc tube 1 is connected to the inverter circuit section 16 via a current limiting inductance element 17. Filament 18b is sealed. A resonance capacitor 19 is connected to the non-power supply side of the filaments 18 a and 18 b installed at both ends of the arc tube 1, and the temperature characteristic resistance element 7 is connected in parallel with the resonance capacitor 19 and the arc tube 1. ing. That is, immediately after the start of energization of the inverter circuit, the resistance value of the temperature positive characteristic resistance element is small and a low voltage at which the lamp does not start is applied between the filament electrodes while a preheating current flows to each filament electrode. The filament electrode is preheated. Thereafter, the resistance value increases as the temperature rises due to self-heating of the temperature positive characteristic resistance element, and the resonance voltage rises as the resonance component of the resonance circuit fluctuates. And when the time required for each inverter circuit to preheat the filament electrode has passed to such an extent that sufficient thermionic emission is performed, the resonance voltage is designed to rise to a voltage at which the lamp can be started. The lamp is started and lit after the filament electrode is sufficiently preheated.

  Here, since the temperature characteristic resistance element 7 is connected in parallel with the resonance capacitor 19, the arc tube 1 can continue to be lit even if the connection of the temperature characteristic resistance element 7 is disconnected from the lighting circuit 5.

  FIG. 3 is a partially enlarged cross-sectional view showing the lighting device 10 for the light bulb shaped fluorescent lamp according to the first embodiment of the present invention.

  The temperature characteristic resistance element 7 and the first lead wires 11 and 11 led out from the temperature characteristic resistance element 7 are second leads connected to the lighting circuit by connection cutting means 12 and 12 made of an adhesive such as solder. The lines 13 and 13 are held. When the temperature characteristic resistance element 7 abnormally generates heat, the temperature of the temperature characteristic resistance element 7 rises, heat is transferred to the first lead wires 11, 11 derived from the temperature characteristic resistance element 7, and the connection cutting means 12, 12 are also connected. As the temperature rises, at least one of these melts. When the connection cutting means 12, 12 as solder is melted, the connection between the first lead wires 11, 11 and the second lead wires 13, 13 is cut, and the temperature characteristic resistance element 7 is electrically disconnected from the lighting circuit 5. Therefore, no current flows through the temperature characteristic resistance element 7 and the temperature rise of the temperature characteristic resistance element 7 stops.

  If a current continues to flow through the temperature characteristic resistance element 7 after the temperature characteristic resistance element 7 has abnormally generated heat, the temperature of the temperature characteristic resistance element 7 rises to about 300 to 700 ° C. On the other hand, since the melting point of solder is generally about 180 to 220 ° C., when the distance from the temperature characteristic resistance element 7 to the solder is within 10 mm, the solder is surely melted by heat conduction through the first lead wire 11. To do. When the distance from the temperature characteristic resistance element 7 to the solder exceeds 10 mm, the solder remains without melting, and it has been confirmed by experiments that the temperature characteristic resistance element 7 is not separated from the lighting circuit.

  FIG. 4 is a partially enlarged cross-sectional view showing a lighting apparatus 10 for a bulb-type fluorescent lamp according to a second embodiment of the present invention. In the second embodiment, a temperature characteristic resistance element 7 and a circuit element 8 having a relatively high heat resistance, such as an inductance element, are bonded with a silicone adhesive 14, and other configurations are the same as those in the first embodiment. is there. When the first lead wires 11 and 11 are held only by the connection cutting means 12 and 12 made of an adhesive material such as solder, both the connection cutting means 12 and 12 are melted, and the temperature characteristic resistance element 7 becomes the second. When the lead wires 13 are disconnected from the lead wires 13, the temperature characteristic resistance element 7 in a high temperature state may come into contact with the cover body 2 or the circuit board 6 to cause a malfunction such as melting or smoke generation. Therefore, the temperature characteristic resistance element 7 and the circuit element 8 having relatively high heat resistance are bonded with a silicone adhesive 14. As a result, even if the first lead wires 11 and 11 are completely disconnected from the second lead wires 13 and 13, the temperature characteristic resistance element 7 is held by the circuit element 8 having a relatively high heat resistance. 6 and the cover body 2 are not touched.

  Means for holding the temperature characteristic resistance element 7 in the circuit element 8 having a relatively high heat resistance include a method of holding the temperature characteristic resistance element 7 and the circuit element 8 having a relatively high heat resistance in a heat resistant band, and a temperature characteristic. For example, the resistance element 7 and the circuit element 8 having a relatively high heat resistance may be bound and fixed with an insulating wire.

  FIG. 5 is a partially enlarged sectional view showing a lighting device 10 for a light bulb shaped fluorescent lamp according to a third embodiment of the present invention. In the third embodiment, the connection cutting means is a deformable member that performs an operation of deforming by heat, and the other configuration is the same as that of the first embodiment.

  In the temperature characteristic resistance element 7, one lead wire 20 a derived from the temperature characteristic resistance element 7 is attached to the circuit board 6 and connected to the lighting circuit 5, and the other lead wire 20 b is supported by the deformable member 21. ing. A contact 22 is disposed at the tip of a substantially L-shaped lead wire 20 c connected to the circuit board 6. The lead wire 20 b is held by the deformable member 21 so that the tip end portion thereof is connected to the contact 22. When the temperature characteristic resistance element 7 rises in temperature due to abnormal heat generation, the deformable member 21 is deformed in a direction in which the distal end side thereof falls to the circuit board 6 side and operates so as to disconnect the connection between the lead wire 20 b and the contact 22. If the temperature at which the deformable member 21 starts to deform is set to 130 to 180 ° C., the temperature characteristic resistance element 7 is operated so as to disconnect the connection of the lead wire 20b only during abnormal heat generation without operating during normal lighting. Can do. The deformable member 21 may be a material such as a bimetal that deforms as the temperature rises. However, it is not preferable that the connection with the contact 22 is restored after the light is extinguished. It is desirable to use a member that does not return.

  FIG. 6 is a circuit diagram of a lighting circuit of a light bulb shaped fluorescent lamp showing a fourth embodiment of the present invention. In the fourth embodiment, the connection cutting means is a thermal fuse, and other configurations are the same as those of the first embodiment.

  The lighting device of the present embodiment is different from the circuit diagram of FIG. 2 in the connection relationship of the temperature characteristic resistance element and the configuration of the connection disconnecting means, so only the different parts will be described in detail and the other description will be omitted. . The inverter circuit unit 16 is connected to the power source side of the filament 18 a and the power source side of the filament 18 b via the inductor coil 17. The thermal fuse 23 serving as the connection disconnecting means is connected in series to the temperature characteristic resistance element 7, and this serial body is between the power source side of the filament 18b and the non-power source side of the inductor coil 19, and the power source side of the filament 18a and the inverter. It is connected between the circuit unit 16 and connected in parallel to the resonance capacitor 19 and the arc tube 1 as a fluorescent lamp. Since the temperature fuse 23 becomes non-conductive due to a temperature rise at the time of abnormal heat generation of the temperature characteristic resistance element 7, the temperature characteristic resistance element 7 is disconnected from the lighting circuit 5 and prevents further temperature rise. Can do. Moreover, since the current flows through the lighting circuit 5 even when the temperature fuse 23 is turned off, the arc tube 1 can be continuously lit. Further, by setting so that the thermal fuse is cut at a predetermined temperature, the current flowing to the temperature characteristic resistance element 7 can be surely cut off.

  FIG. 7 is a partially enlarged cross-sectional view of a lighting apparatus 10 for a bulb-type fluorescent lamp according to a fifth embodiment of the present invention. The present embodiment is characterized in that the components of the lighting circuit are destroyed when the temperature characteristic resistance element 7 is abnormally heated to stop the oscillation of the lighting circuit. The overall configuration and basic circuit configuration of the bulb-type fluorescent lamp are the same as those shown in FIGS. 1 and 2, and therefore detailed description thereof is omitted.

  When the temperature characteristic resistance element 7 abnormally generates heat, the heat generated when the temperature characteristic resistance element 7 abnormally generates heat is mounted on the circuit board 6 as a method for preventing a problem such as melting of the cover body 2. If the circuit element 9 having a low heat resistance is transmitted to the circuit element 9 having a low heat resistance, the oscillation of the lighting circuit can be stopped. At this time, examples of the circuit element 9 having a relatively low heat resistance to be destroyed include a resonance capacitor, a field effect transistor, and an electrolytic capacitor. These are elements that have low heat resistance and reliably stop oscillation when broken.

  The circuit element 9 having relatively low heat resistance is placed in a space within 3 mm from the temperature characteristic resistance element 7 or in a space within 3 mm from a portion within 10 mm from the temperature characteristic resistance element 7 of the lead wire 25 derived from the temperature characteristic resistance element 7. If it is arranged so that at least a part thereof is located, the heat at the time of abnormal heat generation of the temperature characteristic resistance element 7 is transmitted to the circuit element 9 having relatively low heat resistance by heat conduction, convection or radiation, and the temperature of itself is increased. It has been confirmed by experiment that the temperature rises and breaks down, the function as a circuit element stops, and the oscillation of the lighting circuit stops.

  In the present embodiment, as shown in FIG. 7, at least a part of the circuit element 9 having relatively low heat resistance is disposed in a space within 3 mm from the main body of the temperature characteristic resistance element 7. If the circuit element 9 having a relatively low heat resistance is provided in this manner, the temperature characteristic resistance element 7 is thermally destroyed due to a temperature rise at the time of abnormal heat generation, the function is stopped, and the oscillation of the lighting circuit 5 can be stopped. .

  FIG. 8 is a partially enlarged cross-sectional view of a lighting apparatus 10 for a bulb-type fluorescent lamp according to a sixth embodiment of the present invention.

  In the present embodiment, at least one of the circuit elements 9 having relatively low heat resistance is in a region where the distance from the portion within 10 mm of the temperature characteristic resistance element 7 of the lead wire 25 derived from the temperature characteristic resistance element 7 is within 3 mm. The circuit element 9 having relatively low heat resistance is disposed so that a part of the circuit element 9 is located.

  Although the temperature characteristic resistance element 7 needs to be disposed at the center of the circuit board 6 in order to prevent the cover body 2 from melting as described above, according to the present embodiment, the circuit element 9 having relatively low heat resistance is provided. Even when it is not disposed around the temperature characteristic resistance element 7, it is possible to apply a thermal effect by using the lead wire 25, and it is possible to thermally destroy the circuit element 9.

  FIG. 9 is a partially enlarged cross-sectional view showing a modification of the embodiment of FIGS. 7 and 8. As shown in FIG. 9, the temperature characteristic resistance element 7 and the circuit element 9 having relatively low heat resistance may be bonded with a silicone adhesive 14. With this configuration, the heat of the temperature characteristic resistance element 7 that has abnormally generated heat can be transmitted to the circuit element 9 by the silicone adhesive material 12 having high thermal conductivity, and the operation of the circuit element 9 can be stopped reliably. The oscillation of the lighting circuit 5 can be stopped.

  A seventh embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a partially enlarged cross-sectional view of the lighting device 10 for the light bulb shaped fluorescent lamp of the present embodiment. FIG. 11 is a part of a circuit diagram showing the connection relationship between the temperature characteristic resistance element 7 and the field effect transistor of the present embodiment. FIG. 12 is a partially enlarged bottom view of the lighting device 10 for the bulb-type fluorescent lamp of the present embodiment. As in the fifth and sixth embodiments, the present embodiment is characterized in that the oscillation of the lighting circuit is stopped by the temperature rise of the temperature characteristic resistance element, and the destruction target is a field effect transistor. is doing.

  The temperature characteristic resistance element 7 is disposed on one main surface side of the circuit board 6, and the lead wire 25 led out from the temperature characteristic resistance element 7 is inserted into the circuit board 6 through an insertion hole formed in advance in the circuit board 6. It is connected to a connection land 27 formed on the other main surface by solder 28. Next to the land 27, a connection land 29 of a drain 26D, which is a part of a connection terminal of the field effect transistor 26, is formed. By connecting the drain 26 </ b> D of the field effect transistor 26 to the land 29, the lead wire 25 and the drain 26 </ b> D are electrically connected via the wiring pattern 30. The temperature characteristic resistance element 7 is connected to the arc tube 1 in parallel, and a lead wire 25 at one end thereof is connected to the drain 26D of the field effect transistor 26 at the same potential. The gate 26G and the source 26S are connected to the lighting circuit element through a pattern wired on the circuit board.

  Next, the operation of this embodiment will be described. When the temperature characteristic resistance element 7 rises due to abnormal heat generation, excessive heat is transmitted from the temperature characteristic resistance element 7 to the drain 26D of the field effect transistor 26 through the lead wire 25, the lands 27 and 29, and the wiring pattern 30 connecting them. . The wiring pattern 30 that connects the lead wire 25 and the drain 26D of the field effect transistor 26 has a relatively large area because the main current flows. For this reason, the heat generated during the abnormal heat generation from the temperature characteristic resistance element 7 is easily transmitted to the drain 26D of the field effect transistor 26. The drain 26D connected to the land 29 is a pad of the field effect transistor 26. Since the contact portion with the land 28 can be widened, heat can be efficiently transmitted to the field effect transistor 26. Here, the land 27 and the drain 26 </ b> D of the temperature characteristic resistance element 7 may be connected by a conductive material such as solder to improve the thermal conductivity.

It is sectional drawing which shows the structure of the lightbulb-type fluorescent lamp of embodiment by this invention. It is a circuit diagram of the lighting circuit of the lightbulb-type fluorescent lamp which shows the 1st, 2nd and 3rd embodiment of this invention. It is a partial expanded sectional view of the lighting device of the bulb-type fluorescent lamp of the first embodiment of the present invention. It is a partial expanded sectional view of the lighting device of the bulb-type fluorescent lamp of the second embodiment of the present invention. It is a partial expanded sectional view of the lighting device of the lightbulb-type fluorescent lamp of the 3rd Embodiment of this invention. It is a circuit diagram of the lighting circuit of the lightbulb-type fluorescent lamp which shows the 4th Embodiment of this invention. It is a partial expanded sectional view of the lighting device of the bulb-type fluorescent lamp of the fifth embodiment of the present invention. It is a partially expanded sectional view of the lighting device of the bulb-type fluorescent lamp of the sixth embodiment of the present invention. It is a partially expanded sectional view which shows the modification of 5th, 6th embodiment of this invention. It is a partially expanded sectional view of the lighting device of the bulb-type fluorescent lamp of the seventh embodiment of the present invention. It is a part of circuit diagram which shows the lighting circuit of the bulb-type fluorescent lamp of the 7th Embodiment of this invention. It is a partially expanded bottom view of the lighting device of the bulb-type fluorescent lamp of the seventh embodiment of the present invention.

Explanation of symbols

1 arc tube 2 cover body 3 base
DESCRIPTION OF SYMBOLS 5 Lighting circuit 7 Temperature characteristic resistance element 10 Lighting device 12 Adhesive material 21 Deformation member 23 Thermal fuse 26 Field effect transistor

Claims (7)

An arc tube having a phosphor layer formed on the inner surface and enclosing a discharge medium;
A cover body holding the arc tube and having a base attached thereto;
A lighting circuit for lighting the arc tube, a temperature characteristic resistance element connected to the lighting circuit and having a resistance value that increases or decreases in response to a temperature rise due to self-heating, and the temperature characteristic resistance element when the temperature characteristic resistance element is abnormally heated A lighting device having connection disconnection means operating to disconnect from the lighting circuit and housed in the cover body;
A bulb-type fluorescent lamp characterized by comprising:   The connection cutting means connects between the first lead wire derived from the temperature characteristic resistance element and the second lead wire connecting the first lead wire and the lighting circuit, and 130 ° C. to 300 ° C. The bulb-type fluorescent lamp according to claim 1, wherein the fluorescent lamp is an adhesive that melts at a temperature of ° C.   The bulb-type fluorescent lamp according to claim 2, wherein a length from the temperature characteristic resistance element to the adhesive is within 10 mm.   The connection disconnecting means is a deforming member disposed in the lighting device so as to be deformed by heat generated when the temperature characteristic resistance element is abnormally heated and to disconnect the temperature characteristic resistance element from the lighting circuit. The bulb-type fluorescent lamp according to claim 1.   2. The electric bulb shape according to claim 1, wherein the connection disconnecting means is a temperature fuse that is connected in series with the temperature characteristic resistance element and becomes non-conductive due to heat generated during abnormal heat generation of the temperature characteristic resistance element. Fluorescent lamp. An arc tube having a phosphor layer formed on the inner surface and enclosing a discharge medium;
A cover body holding the arc tube and having a base attached thereto;
A lighting circuit for lighting the arc tube and a temperature characteristic resistance element whose resistance value increases or decreases in accordance with a temperature rise due to self-heating, and a temperature characteristic resistance within a region whose distance from the temperature characteristic resistance element is within 3 mm At least a part of the circuit element that is a component of the lighting circuit and has relatively low heat resistance is located in a region where the distance from the portion within 10 mm of the lead length derived from the element is within 3 mm. A lighting device in which each element is disposed and accommodated in the cover body;
A bulb-type fluorescent lamp characterized by comprising: An arc tube having a phosphor layer formed on the inner surface and enclosing a discharge medium;
A cover body holding the arc tube and having a base attached thereto;
A field effect transistor that performs a switching operation to light the arc tube, and a substrate on which the field effect transistor is mounted; a lighting circuit that is housed in the cover body and that lights the arc tube;
A temperature characteristic resistance element whose resistance value increases or decreases in response to a temperature rise caused by self-heating, wherein a lead wire is connected to the substrate position adjacent to the connection terminal of the field effect transistor of the lighting circuit and is mounted on the substrate;
A bulb-type fluorescent lamp characterized by comprising:

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