WO2009103587A1

WO2009103587A1 - Wireless dimmable electronic ballast and compact fluorescent lamp comprising the same

Info

Publication number: WO2009103587A1
Application number: PCT/EP2009/050754
Authority: WO
Inventors: Chao Hong Du; Ying Feng Lin
Original assignee: Osram Gesellschaft mit beschränkter Haftung
Priority date: 2008-02-20
Filing date: 2009-01-23
Publication date: 2009-08-27
Also published as: CN101516156A

Abstract

The present invention discloses a wireless dimmable electronic ballast and a compact fluorescent lamp comprising the same. The wireless dimmable electronic ballast comprises: a radio receiving unit for receiving a control signal from a controller; a dimming control unit for controlling the operation of a lamp; and a primary control unit for igniting and ballasting the lamp; wherein at least the radio receiving unit is spatially discrete. The electronic ballast may further comprise a joint unit for jointing the radio receiving unit, the dimming control unit and the primary control unit. Moreover, the joint unit, the radio receiving unit, the dimming control unit and the primary control unit may be located on different circuit boards respectively; and the circuit boards of the radio receiving unit, the dimming control unit and the primary control unit are respectively jointed with the circuit board of the joint unit and are vertical to the joint unit.

Description

WIRELESS DIMMABLE ELECTRONIC BALLAST AND COMPACT FLUORESCENT

LAMP COMPRISING THE SAME

Field of the Invention

[0001] The present invention relates to the field of illumination technologies, and in particular, to a wireless dimmable electronic ballast for Compact Fluorescent Lamp (CFL) and a Compact Fluorescent Lamp Integrated (CFLi) comprising the wireless dimmable electronic ballast.

Background of the Invention

[0002] Wireless dimmable electronic ballasts are more and more widely used for the ballasting and dimming of fluorescent lamps. Fig.1 shows a functional block diagram of a conventional wireless dimmable electronic ballast.

[0003] As show in Fig.1 , a wireless dimmable ballast usually comprises the following parts: a primary control unit 1 , a dimming control unit 2 and a radio receiving unit 3. The primary control unit 1 is adapted to provide an ignition voltage to a lamp during lighting up and control the current provided to the lamp during stable operation of the lamp. Further, the primary control unit 1 also provides power to other parts of the ballast circuit and controls the operation of the dimming control unit 2 according to a user instruction received by the radio receiving unit 3 from a remote control device 4. In response to the instruction of the primary control unit 1 , the dimming control unit 2 controls the power applied to the lamp to adjust the luminance of the lamp. The radio receiving unit 3 is adapted to receive dimming instructions sent by the user via a remote controller, and transfer the instruction to the primary control unit 1. Such a wireless dimmable electronic ballast has a favorable application effect in straight fluorescent lamps.

[0004] In recent years, CFL is popularized rapidly due to its low energy consumption and simple structure. With the wide use of CFL, it is more and more required that the dimming of a CFL should also be controlled remotely. However, as limited by the structure, the electronic ballast and the dimming device of the CFL both need to be installed in the lamp cap. [0005] Because the electronic ballast comprises temperature-sensitive integrated circuits and other electronic elements, especially the radio receiving unit which is more sensitive to temperature, these integrated circuits and electronic devices will not function normally when the ambient temperature rises to a certain degree. However, during the operation of a normal CFL, the steady-state temperature of the lamp cap is usually 90-100 ⁰C. Under such a temperature, such electronic circuits as the radio receiving unit will not function normally. Therefore, the application range of wireless dimmable electronic ballasts is only restricted to straight fluorescent lamps so far, and CFL can only be used for illumination of fixed luminance.

Summary of the Invention

[0006] Therefore, there is a need in this field to provide a wireless dimmable electronic ballast for a CFL and a CFL comprising the wireless dimmable electronic ballast. The object of the invention is to provide such an electronic ballast and CFL. [0007] In one aspect of the invention, there provides an electronic ballast comprising: [0008] a radio receiving unit for receiving a control signal from a controller; [0009] a dimming control unit for controlling the operation of a lamp; and

[0010] a primary control unit for providing power to the radio receiving unit and the dimming control unit; [0011] wherein at least the radio receiving unit is spatially discrete.

[0012] In one embodiment of the invention, the electronic ballast further comprises a joint unit for jointing the radio receiving unit, the dimming control unit and the primary control unit together.

[0013] In one embodiment of the invention, the joint unit, the radio receiving unit, the dimming control unit and the primary control unit are located on different circuit boards respectively, and the circuit boards of the radio receiving unit, the dimming control unit and the primary control unit are respectively connected to the circuit board of the joint unit with an angle from the joint unit. Preferably, the angle is a right angle.

[0014] In one embodiment of the invention, temperature-sensitive circuit elements in the radio receiving unit, the dimming control unit and the primary control unit are respectively arranged on the circuit boards in locations far from the joint unit.

[0015] In one embodiment of the invention, the dimming control unit and the primary control unit are arranged parallel to each other, or arranged in a star shape, or arranged in a triangle shape.

[0016] In one embodiment of the invention, the primary control unit and the joint unit are located on a same circuit board. Preferably, the circuit board is manufactured from a thicker material.

[0017] In another aspect of the invention, there provides a CFL comprising: a lamp bulb; a lamp cap; and an electronic ballast. The electronic ballast is located in the lamp cap and comprises: a radio receiving unit for receiving a control signal from a controller; a dimming control unit for controlling the operation of the lamp according to the control signal received by the radio receiving unit; and a primary control unit for providing power to the radio receiving unit and the dimming control unit; wherein, at least the radio receiving unit is spatially discrete.

[0018] In one embodiment of the invention, the electronic ballast further comprises a joint unit for jointing the radio receiving unit, the dimming control unit and the primary control unit together.

[0019] In one embodiment of the invention, the joint unit is located between the lamp bulb and the radio receiving unit, the dimming control unit, and the primary control unit, so that the lamp bulb may be isolated from the radio receiving unit, the dimming control unit, and the primary control unit.

[0020] In another embodiment of the invention, the radio receiving unit is further adapted to transmit a signal. The dimming control unit detects the operation state of the lamp and sends the operation state information to a remote controller via the radio receiving unit. The state of the lamp comprises, but is not limited to, overvoltage, overcurrent, overheating and end of life (EOL).

[0021] By the technical solutions of the invention, the problem of temperature sensitivity of electronic elements in an electronic ballast may be effectively solved, so that the wireless dimmable electronic ballast may be integrated in the lamp cap of the CFL, thus wireless dimming of the CFL may be realized.

Brief Description of the Drawings [0022] The above and other objects and advantages of the invention will be further described in conjunction with the specific embodiments and drawings of the invention. In the drawings, the same or corresponding technical features or components will be represented by the same or corresponding reference signs, wherein: [0023] Fig.1 is a schematic diagram showing various functional blocks of a wireless electronic ballast;

[0024] Fig.2 is a structural perspective view of a wireless electronic ballast according to one embodiment of the invention;

[0025] Fig.3 is a structural plan view of a joint unit according to one embodiment of the invention; [0026] Fig.4 is a structural plan view of a radio receiving unit according to one embodiment of the invention;

[0027] Fig.5 is a plan view of the wireless electronic ballast according to the invention installed in the lamp cap of a CFL, wherein the lamp cap part is shown in a sectional view; [0028] Fig.6 is a structural perspective view of a wireless electronic ballast according to another embodiment of the invention;

[0029] Fig.7 is a structural perspective view of a wireless electronic ballast according to still another embodiment of the invention;

[0030] Fig.8a and Fig.8b are schematic diagrams of a CFL according to an exemplary embodiment of the invention, wherein Fig.8a is a schematic diagram in which a receiving unit is coupled with the lamp, and Fig.8b is a schematic diagram of a discrete receiving unit and a discrete remote control device;

[0031] Fig.9a shows an electronic transformer circuit for providing power to other circuit parts in the electronic ballast according to an exemplary embodiment of the invention; and

[0032] Fig.9b shows a circuit for replacing the electronic transformer according to an exemplary embodiment of the invention. Detailed Description of the Embodiments

[0033] Fig.2 is a structural representation of a wireless electronic ballast according to one embodiment of the invention. As show in Fig.2, the electronic ballast 1 according to this embodiment comprises four units, wherein: a first unit 11 is a dimming control unit for dimming a lamp, which comprises a circuit part for dimming; a second unit 12 is a radio receiving unit for receiving a control signal from a remote controller, which comprises a wireless receiving circuit; a third unit 13 is a primary control unit for providing an ignition voltage during lighting up of the lamp and controlling the operating current of the lamp in stable operation of the lamp. The primary control unit 13 further provides power to other circuit parts such as dimming control unit 11 and radio receiving unit 12, wherein the primary control unit 13 comprises a power circuit such as an electronic transformer; a fourth unit 14 is a joint unit for jointing the first unit 11 , the second unit 12 and the third unit 13 to form a whole electronic ballast. The fourth unit 14 comprises joint components for jointing the first unit 11 , the second unit 12 and the third unit 13 respectively and other circuit elements.

[0034] Fig.3 shows a structural plan view of the fourth unit 14, that is, a schematic diagram of a joint unit according to one embodiment of the invention. As show in Fig.3, the fourth unit 14 comprises a substrate 51 , joint components 23a, 33a and 43a for respectively jointing the first unit 11 , the second unit 12 and the third unit 13, and other circuit elements 6. The joint components 23a, 33a and 43a may be common interface components soldered on the substrate 51 or a plurality of regularly arranged via holes punched in the substrate 51. The substrate 51 is fabricated from a hard sheet material, preferably a printed circuit board(PCB). In the case that a PCB is employed as the substrate, a circuit pattern is etched on the substrate 51 so that the circuit pattern, the circuit elements and the joint components together form the circuit of the joint unit.

[0035] Fig.4 is a structural plan view of the second unit 12, that is, a schematic diagram of the radio receiving unit according to one embodiment of the invention. As show in Fig.3, the second unit 12 comprises a substrate 31 , circuit elements 32 and an interface 33. The substrate 31 is fabricated from a hard sheet material, preferably a PCB. In the case that PCB is employed as the substrate, the circuit elements 32 are installed on the substrate 31 and a circuit pattern is etched so that the circuit pattern and the circuit elements together form the circuit of the dimming unit. The interface 33 may be cut from the an integral circuit board of the substrate 31 , and formed by etching a corresponding circuit pattern, or it may be an interface element fixed on the substrate 31 by soldering, etc. Because the circuit elements in the radio receiving unit are especially sensitive to temperature, the circuit elements are arranged in a location as far as possible from the heat source when it is arranged on the substrate, for example, the location far from interface 33 as show in Fig.3. [0036] The first unit 11 is a dimming control unit, of which the physical structure is similar to that of second unit 12. The first unit 11 also comprises a substrate and circuit elements fixed on the substrate. When the circuit is designed, circuit elements that are heat sensitive, such as dimming chip, are preferably located far from the interface.

[0037] The third unit 13 is a primary control unit for providing power to other circuit parts of the ballast. The primary control unit is also fabricated from a hard sheet material such as PCB, and comprises elements such as electronic transformer thereon, which elements may also generate heat during operation. To furthest reduce the impact of heat generated by elements such as electronic transformer on temperature-sensitive elements such as radio receiving unit, when the first, second, third and fourth units are joint together, it is preferred that the side of the third unit 13 on which circuit elements such as electronic transformer are arranged is opposite to the second unit 12. The physical structure of the third unit 13 is similar to that of the second unit 12, so it will not be described again here.

[0038] Fig.9a shows the principle for providing power to other circuit parts using an electronic transformer. Referring to Fig.9a, a 120V or 220V AC voltage is input from the input port, and converted to a 180V or 330V DC voltage when rectified by rectification unit Ds1. A power management unit (such as chip TEA152x) controls the on-angle and frequency of the primary side of transformer TR1. The required DC output voltage, for example, a 5V DC voltage, is provided at the output port via the induction of the secondary side of the transformer TR1. The 5V output DC is provided to other circuit parts, for example, the receiving unit, as the operating power.

[0039] The advantage of employing the flyback electronic transformer as shown in Fig.9a is that a large operating voltage range may be obtained. For example, a stable 5V DC voltage may be provided with an input voltage range of 87V to 270V. Therefore, the supply voltage fluctuation occurring at the AC input port will have no impact on the output voltage, so that a stable operating power supply may be provided to other circuit parts in the ballast.

[0040] Additionally, in the invention, when the dimming control unit and the radio receiving unit are set in power-saving mode, the quiescent power dissipation consumed by the whole electronic transformer may be lowered by about 60%. In such a case, a simpler power supply mode may replace the electronic transformer, so that the size of the ballast may be further reduced, and the heat generated by the ballast may be reduced. Thus, the operating environment of temperature-sensitive devices in the ballast may be further improved. [0041] Fig.9b shows a circuit that may replace the electronic transformer. In the circuit shown in Fig.9b, a voltage doubler circuit consisted of C1 , C2, D1 and D2 provides a DC voltage to the latter stages of the ballast, so that the ballast may accomplish the basic functions of ignition and ballasting. For the structure and operational principle of the latter stage, reference may be made to those of an ordinary ballast, so it will not be described again here.

[0042] To provide power to the radio receiving unit 11 and the dimming control unit 12, in the circuit shown in Fig.9b, a voltage is taken via capacitor C4 at point A in the voltage doubler circuit consisted of C1 , C2, D1 and D2, and a 5V AC voltage is obtained at point B after a voltage division process performed by C4; said 5V AC voltage is regulated at 3.3 V via Zener diode DZ1 after being rectified by D3 and D4, which is supplied to the receiving unit operating in power-saving mode. C3 and C5 have the function of filtering and energy storage.

[0043] By using the power supplying circuit shown in Fig.9b, a favorable operating effect may be obtained in the case that the overall power consumption of the electronic ballast is several hundred milliwatts. Moreover, in comparison with the technical solution in which the electronic ballast shown in Fig.9a is employed to provide a power supply, the size of the ballast may be further reduced, thus it is easier to be installed in a CFL cap.

[0044] Of course, other circuits may also be employed to replace the electronic transformer, rather than being limited to the specific circuit shown in Fig.9.

[0045] Referring back to Fig.2, according to the embodiment shown in Fig.2, the first unit 11 , second unit 12, third unit 13 and fourth unit 14 are in the following connection relationship: the fourth unit 14 functions as a backplane providing joint components or interfaces (see components 23a, 33a, 43a in Fig.3) to joint the first unit 11 , second unit 12 and third unit 13. The first unit 11 , second unit 12 and third unit 13 are respectively jointed to a corresponding interface, so that the plane of the respective circuit board of the first unit 11 , second unit 12 and third unit 13 is vertical to the plane of the circuit board of fourth unit 14.

[0046] Fig.5 shows the case that electronic ballast 1 according to this embodiment is installed in the lamp cap of the CFL. In Fig.5, 10 represents a CFL, 101 represents a lamp bulb or a tube, 102 represents a lamp cap, 103 represents a lamp head, and 1 represents an electronic ballast installed in lamp cap 102.

[0047] As show in Fig.5, when electronic ballast 1 is installed in the lamp cap of the CFL, the side of the circuit board of the joint unit 5 that is opposite to the first unit 11 , second unit 12 and the third unit 13 faces the lamp bulb/ tube; in other words, the joint unit 14 is located between the bulb/tube 101 and the first unit 11 , second unit 12 and third unit 13.

[0048] Because the lamp bulb/tube is the main heat source in the CFL, in such a structure, the fourth unit may effectively isolate the temperature-sensitive circuit elements in the ballast circuit from the main heat source of the lamp, so that the ambient temperature of the electronic ballast circuit may be effectively lowered, the operating condition of the electronic ballast circuit may be improved, the operational reliability of the electronic ballast may be improved, and the lifetime of the electronic ballast may be extended. [0049] To further improve the heat insulation effect, the substrate of the fourth unit 14 employs a thick printed circuit board with good heat insulation effect, for example, a circuit board having a thickness of 1.5mm. The substrates of the first unit 11 , second unit 12 and third unit 13 may employ a comparatively thin printed circuit board, for example, a circuit board having a thickness of 1.0mm. The thin circuit board employed by the first unit 11 , second unit 12 and third unit 13 may reduce the transfer of heat in the plane direction of the corresponding circuit board, thus the temperature in the locations where temperature-sensitive circuit elements are located may be effectively lowered. [0050] In the above embodiment, when the first unit 11 , second unit 12 and third unit 13 are jointed together via the fourth unit 14, the planes of their circuit boards respectively are parallel to each other. However, the invention is not limited to such a specific structure; instead, there may be other construction modes.

[0051] Fig.6 is a structural representation of a wireless electronic ballast according to another embodiment of the invention. As show in Fig.6, the first unit 11 , second unit 12 and third unit 13 are jointed via the joint components of the fourth unit 14, and they have a star-shaped location relationship. In the electronic ballast of such a structure, temperature-sensitive circuit elements in the ballast may also be far from the heat source, so the electronic ballast may have the function of protecting these circuit elements from being damaged by high temperature and guaranteeing the normal operation of the ballast.

[0052] Fig.7 is a structural representation of a wireless electronic ballast according to another embodiment of the invention. As show in Fig.7, the first unit 11 , second unit 12 and third unit 13 are jointed via the joint components of the fourth unit 14, and they have a triangle-type location relationship. In the electronic ballast of such a structure, temperature-sensitive circuit elements in the ballast may also be far from the heat source, so the electronic ballast may have the function of protecting these circuit elements from being damaged by high temperature and guaranteeing the normal operation of the ballast. [0053] Additionally, the first unit 11 , second unit 12 and third unit 13 may be vertical to the fourth unit 14, or they may not be vertical. For example, in the case shown in Fig.7, to be adapted to the space inside the lamp cap, first unit 11 , second unit 12 and third unit 13 may be inclined at a certain angle toward the center of the lamp cap.

[0054] Additionally, the third unit 13, i.e., the primary control unit, may be located on the fourth unit 14 and be integrated with the joint unit. In such a case, the second unit 12 needs to be arranged in a location on the fourth unit 14 far from the heat-generating elements such as electronic transformer.

[0055] The circuit structure of the above described wireless electronic ballast according to the invention may be divided into circuit units of other number, so that each circuit unit may be located on different circuit boards. In such a case, the number of the circuit boards is not limited to 4; instead, it may be other numbers, for example, 2 or 5.

[0056] In each of the above described embodiments, the radio receiving unit 3 is only used for receiving a control signal from a controller. However, the radio receiving unit 3 may also be replaced with a transceiver, so that it may not only receive a control signal from a remote controller, but also send a signal. For example, the dimming control unit 2 may detect the operation state of the lamp and send the detected operation state information to the remote controller or other receiving devices via the radio receiving unit 3. The lamp state comprises, but is not limited to, overvoltage, overcurrent, overheating and EOL, etc. According to the lamp state signal, a user may perform reasonable control measures and avoid misoperations.

[0057] According to another embodiment of the invention, the above receiving unit may not be included in the ballast; instead, it may form a separated unit. Fig.8 is a schematic diagram of this embodiment. Fig.8a shows the case that a receiving unit and a lamp are assembled together, and Fig.8b shows a separated receiving unit and remote control device. In this structure, because the receiving unit lies outside the lamp cap, it is further from the heat source (such as lamp tube and transformer), and the heat dissipation condition is improved. As a result, the temperature of the receiving unit may be further lowered, and the operating condition of the receiving unit may be improved.

[0058] Referring to Fig.8a and Fig.8b, the radio receiving unit 11 is shown in the form of a receiver, wherein interface 33 is in the form of a plurality of pins on the receiver 11. The corresponding interface 33a is provided on the out surface of the lamp cap. When the receiving unit is connected to the lamp cap via the interfaces 33 and 33a, the lamp is a wireless dimmable CFL; when the receiving unit is separated from the lamp, the lamp 10 becomes an ordinary CFL. [0059] The remote control device 4 is adapted to control the dimming of the lamp. Moreover, it may be extended to control other Zigbee-based electronic devices by using Zigbee wireless communication protocol; for example, if a household TV set supports Zigbee wireless communication, the remote control device may be used to control the TV set. It means that all the household appliances may be controlled by only one remote control device.

[0060] Additionally, the lifetime of the ballast is usually much longer than that of the lamp tube. However, because the current lamp tube is usually integrated with the lamp cap, when the lamp tube is damaged, the ballast may be discarded with the lamp tube.

[0061] According to one embodiment of the invention, the lamp tube and the lamp cap are detachably coupled. Thus, once the lamp tube is damaged, the ballast may continue to be used by replacing the damaged lamp tube with a new lamp tube only, so that the environmental protection and economization performance of the product may be improved.

[0062] The technical solutions of the invention have been described above in conjunction with specific embodiments. But it should be understood that these embodiments are only used to clearly illustrate the technical solutions of the invention, rather than being intended to limit the scope of the invention to the specific embodiments. Moreover, various modifications and variations may be made by those skilled in the art without departing from the spirit or scope of the invention. For example, the power unit may also be replaced with a dry battery or a rechargeable battery, etc.

Therefore, all these variations and modifications will be regarded in the scope of the invention as defined by the appended claims and their equivalents.

Claims

1. A wireless dimmable electronic ballast comprising: a radio receiving unit for receiving a control signal from a controller; a dimming control unit for dimming a lamp according to the control signal received by the radio receiving unit; and a primary control unit for igniting the lamp and stabilizing the current of the lamp; wherein at least the radio receiving unit is spatially discrete.

2. The electronic ballast according to claim 1 further comprising: a joint unit for jointing the radio receiving unit, the dimming control unit and the primary control unit together.

3. The electronic ballast according to claim 2, wherein the joint unit, the radio receiving unit, the dimming control unit and the primary control unit are located on different circuit boards respectively, and the circuit boards of the radio receiving unit, the dimming control unit and the primary control unit are respectively jointed to the circuit board of the joint unit and form an angle with respect to the joint unit.

4. The electronic ballast according to claim 3, wherein in the radio receiving unit, the dimming control unit and the primary control unit, temperature-sensitive circuit elements are arranged on the circuit boards in locations far from the joint unit.

5. The electronic ballast according to claim 3, wherein the angle is a right angle.

6. The electronic ballast according to any of claims 3 to 5, wherein the circuit boards of the radio receiving unit, the dimming control unit and the primary control unit are parallel to each other.

7. The electronic ballast according to any of claims 3 to 5, wherein the circuit boards of the radio receiving unit, the dimming control unit and the primary control unit are arranged in a star shape.

8. The electronic ballast according to any of claims 3 to 5, wherein the circuit boards of the radio receiving unit, the dimming control unit and the primary control unit are arranged in a triangle shape.

9. The electronic ballast according to claim 2, wherein the primary control unit and the joint unit are located on a same circuit board.

10. The electronic ballast according to claim 2, wherein the radio receiving unit is further adapted to transmit a signal.

11. The electronic ballast according to claim 1 further comprising a power unit for providing power to the radio receiving unit and the dimming control unit, wherein the power unit comprises: a rectification unit for rectifying a first AC voltage; and an output unit for filtering the output voltage of the first rectification unit and outputting the filtered DC voltage to the radio receiving unit and the dimming control unit.

12. The electronic ballast according to claim 11 further comprising: a second converting unit for converting a second AC voltage into the first AC voltage.

13. The electronic ballast according to claim 12, wherein the second AC voltage is a power-frequency AC voltage.

14. A compact fluorescent lamp comprising: a lamp bulb; a lamp cap; and an electronic ballast arranged in the lamp cap and comprising a radio receiving unit for receiving a control signal from a controller; a dimming control unit for dimming the lamp according to the control signal received by the radio receiving unit; and a primary control unit for igniting and ballasting the lamp; wherein at least the radio receiving unit is spatially discrete.

15. The compact fluorescent lamp according to claim 14, wherein the electronic ballast further comprises a joint unit for jointing the radio receiving unit, the dimming control unit, and the primary control unit.

16. The compact fluorescent lamp according to claim 15, wherein the joint unit, the radio receiving unit, the dimming control unit and the primary control unit are arranged on different circuit boards respectively, and the circuit boards of the radio receiving unit, the dimming control unit and the primary control unit are respectively jointed with the circuit board of the joint unit and form an angle with respect to the joint unit.

17. The compact fluorescent lamp according to claim 16, wherein, in the radio receiving unit, the dimming control unit and the primary control unit, temperature-sensitive circuit elements are arranged on the circuit boards in locations far from the joint unit.

18. The compact fluorescent lamp according to claim 15, wherein the joint unit is located between the lamp bulb and the radio receiving unit, the dimming control unit, and the primary control unit.

19. The electronic ballast according to claim 15, wherein the primary control unit and the joint unit are located on a same circuit board.

20. The compact fluorescent lamp according to any of claims 14 to 19, wherein the radio receiving unit is further adapted to transmit a signal.

21. The compact fluorescent lamp according to claim 20, wherein the radio receiving unit is detachably coupled to other units of the electronic ballast from out surface of the lamp via the hosing of the lamp cap.

22. The compact fluorescent lamp according to claim 20, wherein the lamp cap and the lamp tube are detachably coupled together.