JP3313106B2 - Bulb-type fluorescent lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD The present invention relates to a bulb-type fluorescent lamp including a fluorescent lamp and a lighting circuit for lighting the fluorescent lamp.

(Background Art) A bulb-type fluorescent lamp has a base (for example, an E26 type base) compatible with an incandescent lamp. This allows the bulb-type fluorescent lamp to be used by being screwed into the incandescent bulb socket. The bulb-type fluorescent lamp has a structure in which the fluorescent lamp and the lighting circuit are integrated.

[0003] Light-bulb-type fluorescent lamps have excellent features such as about one-third of power consumption and about six times as long as incandescent lamps. For this reason, the bulb-type fluorescent lamp has been rapidly spreading in recent years as a power-saving type light source replacing an incandescent lamp.

In general, a high frequency inverter circuit is used as a lighting circuit for a compact fluorescent lamp to reduce the size and weight of the compact fluorescent lamp.

[0005] The lighting circuit of the compact fluorescent lamp includes a circuit board and circuit components arranged on the circuit board. The layout of circuit components on the circuit board is determined in consideration of the electrical circuit design, and the size of the compact fluorescent lamp is reduced by effectively using the space in the case that houses the lighting circuit. Is determined as possible.

Japanese Utility Model Publication No. 63-4331 shows an example of the arrangement of circuit components. According to Japanese Utility Model Publication No. 63-4331, among the circuit components, the component having the maximum mounting height is arranged at the center of the circuit board, and the other circuit components having the transaction height are mounted on the mounting height. The components are arranged toward the peripheral side of the circuit board with the component having the maximum mounting height dimension as the center in the descending order. As a result, the size of the lighting circuit is reduced.

[0007] Japanese Utility Model Publication No. 63-4331 does not refer to disposing circuit components formed into ICs on a circuit board. Accordingly, Japanese Utility Model Publication No. 63-4331 does not consider a heat countermeasure for converting a circuit component into an IC.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bulb-type fluorescent lamp capable of reducing adverse thermal effects on circuit components made into ICs.

(Disclosure of the Invention) In order to achieve the above object, a bulb-type fluorescent lamp of the present invention is a bulb-type fluorescent lamp including a fluorescent lamp and a lighting circuit for lighting the fluorescent lamp, The lighting circuit is disposed on a circuit board, on a first surface of the circuit board, a heat-generating component that generates heat when the fluorescent lamp is lit, and on a second surface of the circuit board opposite to the first surface. Semiconductor component, wherein the semiconductor component corresponds to the second surface area corresponding to the first surface area where the heat-generating component is arranged.
It is arranged in an area other than the area of the surface, thereby achieving the above object.

[0010] The semiconductor component may be an inverter driving IC included in an inverter circuit for driving the fluorescent lamp.

The inverter circuit includes a first switching element driven by the inverter driving IC,
A second switching element driven by the inverter driving IC, wherein the heat-generating component is arranged in a substantially central region of the circuit board, and the circuit board on which the inverter driving IC is arranged And the area of the circuit board where the first and second switching elements are arranged may be located on the opposite side to the area where the heat generating components are arranged.

The inverter circuit includes a first switching element driven by the inverter driving IC,
A second switching element driven by the inverter driving IC; wherein the heat-generating component is disposed at an end of the circuit board; and the inverter driving IC, the first and second switching elements, May be arranged at an end opposite to the end where the heat-generating component is arranged.

[0013] The heat generating component may be a magnetic circuit component.

[0014] The semiconductor component may be arranged at a position at least 10 mm away from the end of the tube where the electrode of the fluorescent lamp is provided.

(Best Mode for Carrying Out the Invention) Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows a compact fluorescent lamp 50 according to Embodiment 1 of the present invention.
Is shown.

The bulb-type fluorescent lamp 50 is a fluorescent lamp 1
And a lighting circuit 2 for lighting the fluorescent lamp 1.

The fluorescent lamp 1 is constituted by, for example, connecting three substantially U-shaped arc tubes by a bridge.

The lighting circuit 2 comprises a circuit board 6 and a circuit board 6
And at least one circuit component disposed on the first surface 6a of the circuit board 6 and at least one circuit component disposed on the second surface 6b of the circuit board 6.
And two circuit components. Here, the first surface 6 of the circuit board 6
a is defined as a surface on the opposite side to the fluorescent lamp 1, and the second surface 6 b of the circuit board 6 is defined as a surface on the same side as the fluorescent lamp 1.

In the following description, the “first surface” is referred to as “front surface” or “upper surface”. The “second surface” is referred to as “back surface” or “lower surface”.

In the example shown in FIG. 1, circuit components such as a choke coil 7 are arranged on a front surface 6a of a circuit board 6, and circuit components such as FETs 8 and 9 are arranged on a back surface 6b of the circuit board 6. ing.

The cover 3 is formed so as to house the lighting circuit 2 therein. The translucent globe 5 is formed so as to cover the periphery of the fluorescent lamp 1.

One end of the bulb-type fluorescent lamp 50 has a base 4
Is attached. By designing the base 4 to have the same size and the same shape as a base for an incandescent lamp (for example, an E26 type base for an incandescent lamp), a lighting fixture having a socket for an incandescent lamp (not shown) )
It becomes possible to mount the bulb-type fluorescent lamp 50 on the light source.

The fluorescent lamp 1 is electrically connected to a lighting circuit 2, and the lighting circuit 2 is electrically connected to a base 4. When the bulb-type fluorescent lamp 50 is mounted on a lighting fixture, the lighting circuit 2 is supplied with power from the lighting fixture via the base 4. As a result, the fluorescent lamp 1 is turned on.

FIG. 2 shows the configuration of the lighting circuit 2 of the bulb-type fluorescent lamp 50.

The lighting circuit 2 includes a line filter circuit 12
Rectifier circuit 13, power supply smoothing capacitor 14, inverter circuit 15, choke coil 7, and resonance capacitor 16. When the bulb-type fluorescent lamp 50 is mounted on a lighting fixture, the line filter circuit 1
2 is supplied with power.

The inverter circuit 15 is used to drive the fluorescent lamp 1 at a high frequency. Inverter circuit 15
Is used, the circuit components of the lighting circuit 2 can be reduced in size and weight.

The inverter circuit 15 includes an inverter driving IC 17, FETs 8 and 9 driven by the inverter driving IC 17, and an inverter capacitor 18. The FETs 8 and 9 are transistors that function as switching elements.

The inverter driving IC 17 includes an FET 8
9 is a circuit for driving the IC 9. FE
By forming the circuits for driving T8 and T9 into an IC, at least the following advantages (1) and (2) can be obtained. (1) It is possible to easily design a drive circuit suitable for various kinds of fluorescent lamps. For example, by changing external components (for example, resistors and capacitors) connected to the inverter driving IC 17, various specifications (for example,
A drive circuit suitable for a fluorescent lamp having specifications of wattage, input voltage and frequency) can be easily realized. As a result, it is possible to reduce the manufacturing cost of the compact fluorescent lamp. (2) A compact compact fluorescent lamp having a dimming function can be realized. The dimming function refers to a function of adjusting the brightness of the fluorescent lamp. In order to realize the dimming function, it is necessary to control the frequency at which the fluorescent lamp is turned on. This is because it is necessary to change the current flowing through the fluorescent lamp by controlling the frequency. When the current flowing through the fluorescent lamp is increased, the fluorescent lamp is lit brightly, and when the current flowing through the fluorescent lamp is reduced, the fluorescent lamp is lit darkly. The circuit for controlling the frequency is very complex,
If it is not integrated, it becomes a large-scale circuit. Therefore, in order to reduce the size of a compact fluorescent lamp having a dimming function,
It is essential that a circuit for driving the FETs 8 and 9 be integrated into an IC, and that the IC be provided with a frequency control function.

For the above reasons, the inverter driving IC 1
7 is regarded as a promising next-generation compact fluorescent lamp.

The configuration of the lighting circuit 2 is not limited to the configuration shown in FIG. The lighting circuit 2 may have any configuration as long as it has a function of lighting the fluorescent lamp 1.
Since the operation of the lighting circuit 2 is well known, its description is omitted here.

The choke coil 7 is a magnetic circuit component used to limit the current flowing through the fluorescent lamp 1. The choke coil 7 is a heat-generating component that generates heat when the fluorescent lamp 1 is turned on. While the fluorescent lamp 1 is turned on, the temperature of the choke coil 7 reaches a high temperature of about 150 ° C. at the maximum, although the temperature slightly changes depending on the surrounding temperature. As a result, the circuit board 6 on which the choke coil 7 is disposed
The temperature of the region of the back surface 6b corresponding to the region of the front surface 6a also reaches approximately 150 ° C.

On the other hand, the FET 8 in the inverter circuit 15
9 and the inverter driving IC 17 are semiconductor components and have low heat resistance. The preferable operating temperature of the FETs 8 and 9 is 150 ° C. or less as a catalog value, and the preferable operating temperature of the inverter driving IC is 125 ° C. or less. Therefore, in order to improve the reliability of the bulb-type fluorescent lamp 50, it is necessary to arrange these semiconductor components in a position that is not affected as much as possible by the heat from the heat-generating components.

FIG. 3 shows a bulb-type fluorescent lamp 50.
2 shows an arrangement of circuit components arranged on a circuit board 6. Here, FIG. 3 is a view of the circuit board 6 viewed from the direction A shown in FIG. However, illustration of the cover 3 and the glove 5 is omitted in FIG.

In FIG. 3, the circuit components indicated by solid lines indicate that they are arranged on the upper surface 6a of the circuit board 6, and the circuit components indicated by broken lines are arranged on the lower surface 6b of the circuit board 6. Is shown.

In the example shown in FIG. 3, the choke coil 7, which is a heat-generating component, is disposed substantially at the center of the upper surface 6a of the circuit board 6. The FETs 8 and 9 and the inverter driving IC 17 which are semiconductor components are arranged on the lower surface 6 b of the circuit board 6.

FET8, 9 and inverter driving IC
Reference numeral 17 is arranged in a region other than the region of the lower surface 6b corresponding to the region of the upper surface 6a in which the choke coil 7 is arranged. Further, the area where the FETs 8 and 9 are arranged and the area where the inverter driving IC 17 is arranged are located on the opposite side to the area where the choke coil 7 is arranged. In the example shown in FIG. 3, the FETs 8 and 9 are arranged at one end of the circuit board 6, and the inverter driving IC 17 is arranged at the other end of the circuit board 6.

As described above, the heat-sensitive semiconductor component F
By disposing the ETs 8 and 9 and the inverter driving IC 17 at a position away from the choke coil 7 which is a heat-generating component, it is possible to minimize the influence of heat generated by the choke coil 7 on the FETs 8 and 9 and the inverter driving IC 17. it can.

Further, while the FETs 8 and 9 are heat-sensitive semiconductor components, the FETs 8 and 9 themselves have a property of generating heat. Although the amount of heat generated by the FETs 8 and 9 is sufficiently smaller than the amount of heat generated by the choke coil 7, the amount of heat generated by the FETs 8 and 9 is reduced by the inverter driving IC1.
The effect on 7 cannot be ignored. This is because the inverter driving IC 17 has a lower heat-resistant temperature than the FETs 8 and 9 and is more susceptible to heat generation than the FETs 8 and 9. As described above, by arranging the inverter driving IC 17 at a position away from the FETs 8 and 9, F
The influence of the heat generated by the ETs 8 and 9 on the inverter driving IC 17 can be minimized.

As described above, the inverter driving IC 1
Since FET 7 is more susceptible to heat generation than FETs 8 and 9, it is more necessary to prevent thermal adverse effects than FETs 8 and 9. Therefore, when arranging the circuit components on the circuit board 6, the inverter drive I
It is important to properly determine the location of C17. The inverter driving IC 17 has a lower surface 6b corresponding to a region of the upper surface 6a of the circuit board 6 on which the choke coil 7 is arranged.
Must be arranged in an area other than the area of Meanwhile, FE
T8 and T9 are lower surfaces 6 corresponding to a region of the upper surface 6a of the circuit board 6 where a part of them and the choke coil 7 are arranged.
The region b may be arranged so as to overlap with the region b. Such an arrangement does not impair the reliability of the bulb-type fluorescent lamp 50.

Further, during the operation of the fluorescent lamp 1, the electrodes 21 and 22 of the fluorescent lamp 1 are at a very high temperature of about 1000 ° C. As a result, the temperature within a range of approximately 10 mm or less within the radius of the tube end of the fluorescent lamp 1 in which the electrodes 21 and 22 are sealed is 150 ° C. or higher.

The FETs 8 and 9 are arranged at a distance of 10 mm or more from the tube end of the fluorescent lamp 1 in which the electrodes 21 and 22 are sealed. Thereby, the temperature of the FETs 8 and 9 can be reduced to 150 ° C. or less. In FIG. 3, d
_21-8 ≧ 10 mm and d _21-9 ≧ 10 mm and d
_22-8 ≧ 10 mm and d _22-9 ≧ 10 mm. Here, d _21-8 indicates the distance between the electrode 21 and the FET 8, and d _21-8
21-9 indicates the distance between the electrode 21 and the FET 9, d _22-8 indicates the distance between the electrode 22 and the FET 8, and d _22-9 indicates the distance between the electrode 22 and the FET 9.

The inverter driving IC 17 has electrodes 21,
15 m from the end of the tube of the fluorescent lamp 1 in which 22 is sealed
m or more. Thereby, the temperature of the inverter driving IC 17 can be set to 125 ° C. or less. In FIG. 3, d _21-17 ≧ 15 mm and d _21-17
22-17 ≧ 15 mm. Here, d _21-17 indicates the distance between the electrode 21 and the inverter driving IC 17, and d _22-17 indicates the distance between the electrode 22 and the inverter driving IC 17.

As described above, according to the first embodiment, the circuit board 6 on which the choke coil 7 to be heated is disposed.
The inverter driving IC 17 is not disposed almost directly on the rear surface of the device. Thereby, the influence of the heat generated by the choke coil 7 on the inverter driving IC 17 can be reduced.

Further, the inverter driving IC 17 is
It is arranged at a position away from ET8, ET9. This allows
The effect of heat generated by the FETs 8 and 9 on the inverter driving IC 17 can be reduced.

Further, the inverter driving IC 17 is arranged at a position away from the electrodes 21 and 22 of the fluorescent lamp 1. As a result, the influence of the heat generated by the electrodes 21 and 22 of the fluorescent lamp 1 on the inverter driving IC 17 can be reduced.

As described above, by arranging the inverter driving IC 17 which is a semiconductor component which is weak to heat at a position away from the heat generating component, it is possible to suppress a temperature rise of the inverter driving IC 17. Thus, it is possible to reduce a possibility that a malfunction occurs in the operation of the lighting circuit 2 due to a thermal influence from the heat generating component. As a result, it is possible to improve the reliability of the lighting circuit 2 and, consequently, it is possible to improve the reliability of the bulb-type fluorescent lamp 50 as a whole.

Second Embodiment In a second embodiment, an example will be described in which a choke coil 7 as a heat-generating component is arranged at an end of a circuit board 6.

FIG. 4 shows an example of the arrangement of circuit components on the circuit board 6. In FIG. 4, the circuit components indicated by solid lines indicate that they are arranged on the upper surface 6a of the circuit board 6, and the circuit components indicated by broken lines indicate that they are arranged on the lower surface 6b of the circuit board 6. I have.

As shown in FIG. 4, the choke coil 7
Are disposed at one end of the circuit board 6 and include the FETs 8 and 9 and the inverter drive circuit 1 which are semiconductor components.
7 is arranged at the other end on the circuit board 6.

As described above, the heat-sensitive semiconductor component F
By disposing the ETs 8 and 9 and the inverter driving IC 17 at a position away from the choke coil 7 which is a heat-generating component, it is possible to minimize the influence of heat generated by the choke coil 7 on the FETs 8 and 9 and the inverter driving IC 17. it can.

The line filter circuit 12 may include a large choke coil. In particular, when the bulb-type fluorescent lamp 50 has a dimming function, the line filter circuit 12 needs to include a large choke coil in order to improve noise resistance. As the size of the choke coil increases, the resistance increases and the loss increases, so that the amount of heat generated increases. Therefore, when the line filter circuit 12 includes a large choke coil, the line filter circuit 12
It is necessary to consider the influence of heat generation due to heat.

FIG. 5 shows an example of the arrangement of circuit components on the circuit board 6. The circuit board 6 can be suitably used when the line filter circuit 12 includes a large choke coil and the amount of heat generated by the choke coil is large.

In FIG. 5, the circuit components indicated by solid lines indicate that they are arranged on the upper surface 6a of the circuit board 6, and the circuit components indicated by broken lines are arranged on the lower surface 6b of the circuit board 6. Is shown.

Even when the line filter circuit 12 includes a large choke coil, the line filter circuit 12
The amount of heat generated by the choke coil 7 is larger than the amount of heat generated by the choke coil 7. Therefore, the distance between the inverter driving IC 17 and the choke coil 7 needs to be longer than the distance between the inverter driving IC 17 and the line filter circuit 12.

As shown in FIG. 5, the choke coil 7
Are disposed at one end of the circuit board 6 and include the FETs 8 and 9 and the inverter drive circuit 1 which are semiconductor components.
7 is arranged at the other end on the circuit board 6. Further, the line filter circuit 12 is disposed at a position as far as possible from the FETs 8 and 9 and the inverter drive circuit 17.

As described above, the heat-sensitive semiconductor component F
By disposing the ETs 8 and 9 and the inverter driving IC 17 at a position away from the choke coil 7 which is a heat-generating component, it is possible to minimize the influence of heat generated by the choke coil 7 on the FETs 8 and 9 and the inverter driving IC 17. it can. Further, by disposing the FETs 8 and 9 which are semiconductor components which are weak to heat and the IC 17 for driving the inverter at a position away from the line filter circuit 12 which is a heat generating component, heat generated by the line filter circuit 12 is reduced. The influence on the IC 17 can be minimized.

Note that, as in the first embodiment, the FET 8,
9 and the inverter driving IC 17 are electrodes 21 and 22
It is preferable to be arranged at a position away from the electrodes 21 and 22 to such an extent as not to be affected by the heat generated by the heat.

In the first and second embodiments, it has been described that the fluorescent lamp 1 has a shape in which three substantially U-shaped arc tubes are connected by a bridge. However, the shape of the fluorescent lamp 1 is not limited to this. The fluorescent lamp 1 can have any shape. For example, the fluorescent lamp 1 may have a WU shape. However, if the shape of the fluorescent lamp 1 changes, the positions of the electrodes 21 and 22 change.
The locations of the ICs 8 and 9 and the inverter driving IC 17 are different.

In the first and second embodiments, the circuit board 6 has been described as having a rectangular shape. However, the shape of the circuit board 6 is not limited to this. The circuit board 6 can have any shape. For example, the circuit board 6
It may have a circular shape.

In Embodiments 1 and 2, F
The ETs 8 and 9 and the inverter driving IC have been described as examples of the semiconductor component. However, semiconductor components other than these semiconductor components (for example, diodes, ICs) may be used. By arranging the heat-sensitive semiconductor component at a position away from the heat-generating component, it is possible to reduce the influence of heat generated by the heat-generating component on the semiconductor component.

In the first and second embodiments, F
It has been described that the ETs 8 and 9 and the inverter driving IC 17 are arranged on the surface opposite to the surface of the circuit board on which the choke coil 7 is arranged. The FETs 8 and 9 and the inverter driving IC 17 can be arranged on the same surface as the surface of the circuit board on which the choke coil 7 is arranged. in this case,
Radiant heat from the fluorescent lamp 1 is blocked by the circuit board.
As a result, it is possible to reduce the influence of the heat generated by the fluorescent lamp 1 on the FETs 8 and 9 and the inverter driving IC 17.

(Industrial Applicability) According to the present invention, the heat-generating component that generates heat when the fluorescent lamp is turned on is disposed on the first surface of the circuit board, and the semiconductor component is disposed on the opposite side from the first surface. The semiconductor components are arranged on two surfaces, and the semiconductor components are arranged in a region other than the region on the second surface corresponding to the region on the first surface where the heat generating components are arranged. Thus, by arranging the semiconductor component which is weak to heat at a position away from the heat-generating component, it is possible to suppress the temperature rise of the semiconductor component. Thus, it is possible to reduce a possibility that a malfunction occurs in the operation of the lighting circuit due to a thermal influence from the heat generating component. As a result, it is possible to improve the reliability of the lighting circuit, and it is possible to improve the reliability of the whole bulb-type fluorescent lamp. [Brief description of drawings]

FIG. 1 is a side view showing a configuration of a bulb-type fluorescent lamp 50 according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a lighting circuit 2 of the bulb-type fluorescent lamp 50.

FIG. 3 is a plan view showing an example of the arrangement of circuit components on a circuit board 6;

FIG. 4 is a plan view showing an example of the arrangement of circuit components on a circuit board 6;

FIG. 5 is a plan view showing an example of the arrangement of circuit components on a circuit board 6;

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masanobu Murakami 7-25 Hiyoshidai, Takatsuki City, Osaka Prefecture Hiyoshiso A-406 (56) References JP-A-11-25751 (JP, A) JP-A-3-219596 (JP, A) JP-A-63-245803 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 61/30 F21S 2/00

Claims (4)

(57) [Claims] 1. A bulb-type fluorescent lamp comprising a fluorescent lamp and a lighting circuit for lighting the fluorescent lamp, wherein the lighting circuit is disposed on a circuit board, and on a first surface of the circuit board; A choke coil that generates heat when the fluorescent lamp is turned on, and an inverter driving IC included in an inverter circuit that drives the fluorescent lamp disposed on a second surface opposite to the first surface of the circuit board; The light bulb shaped fluorescent lamp, wherein the inverter driving IC is disposed in a region other than the region on the second surface corresponding to the region on the first surface where the choke coil is disposed. 2. An inverter circuit comprising: a first switching element driven by the inverter driving IC; and a second switching element driven by the inverter driving IC.
A switching element, wherein the choke coil is disposed in a substantially central region of the circuit board,
The area of the circuit board where the inverter driving IC is arranged and the area of the circuit board where the first and second switching elements are arranged are different from the area where the choke coil is arranged. The light bulb shaped fluorescent lamp according to claim 1, which is located on the opposite side. 3. The inverter circuit includes a first switching element driven by the inverter driving IC, and a second switching element driven by the inverter driving IC.
A switching element, wherein the choke coil is arranged at an end of the circuit board, and wherein the inverter driving IC and the first and second switching elements are arranged with the choke coil. The light bulb shaped fluorescent lamp according to claim 1, wherein the light bulb-shaped fluorescent lamp is arranged at an end opposite to the end. 4. The method according to claim 1, wherein the inverter driving IC is at least one end from a tube end provided with an electrode of the fluorescent lamp.
The light bulb shaped fluorescent lamp according to claim 1, which is arranged at a position separated by 0 mm.