CN201290195Y - Multi-lamp-tube backlight system and protection device thereof - Google Patents
Multi-lamp-tube backlight system and protection device thereof Download PDFInfo
- Publication number
- CN201290195Y CN201290195Y CNU2008201152158U CN200820115215U CN201290195Y CN 201290195 Y CN201290195 Y CN 201290195Y CN U2008201152158 U CNU2008201152158 U CN U2008201152158U CN 200820115215 U CN200820115215 U CN 200820115215U CN 201290195 Y CN201290195 Y CN 201290195Y
- Authority
- CN
- China
- Prior art keywords
- transformer
- coupled
- power supply
- subcoil
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Circuit Arrangements For Discharge Lamps (AREA)
Abstract
The utility model relates to a protection arrangement applying to a multi-tube backlight system. The multi-tube backlight system comprises a power supply, a first lamp tube, a second lamp tube, a first transformer and a second transformer. The protection arrangement comprises a detection circuit and a comparing module. The detection circuit is coupled between the first transformer and the first lamp tube and between the second transformer and the second lamp tube and generates a detecting voltage. The comparing module closes the power supply selectively based on the detecting voltage.
Description
Technical field
The present invention relates to many fluorescent tubes back lighting device, and be particularly related to a kind of many fluorescent tubes back light system and protective device thereof that improves circuit protection function that possess.
Background technology
In recent years, along with the size of display panels constantly increases, (ColdCathode Fluorescent Lamp, back lighting device CCFL) are applied to provide display panels required high-quality light source more widely to comprise a plurality of cold cathode fluorescent lamp.
Because the lighting tube brightness of many fluorescent tubes back lighting device is relevant with the lamp current of this fluorescent tube of flowing through, therefore, the biggest problem that many fluorescent tubes back lighting device is faced is: how to make each lamp tube current of flowing through all can keep about equally, and the light source of guaranteeing to offer display panels can have highly stable and uniform brightness and takes place with the phenomenon of avoiding each lighting tube brightness inequality.
In order to solve the above problems, a kind of Jin balancing circuitry (Jinbalancer) that can be applicable to many fluorescent tubes back light system is suggested.Fig. 1 illustrates the schematic diagram of the many fluorescent tubes back light system that has Jin balancing circuitry structure in the prior art.As shown in Figure 1, many fluorescent tubes back light system 9 comprises power supply 90, four fluorescent tube 91-94 and four balancing transformer 95-98.In Jin balancing circuitry structure, corresponding separately fluorescent tube of each balancing transformer and generation lamp current are to corresponding fluorescent tube.For example, the balancing transformer among Fig. 1 95 is corresponding to fluorescent tube 91 and produce lamp current to fluorescent tube 91.
As shown in Figure 1, the characteristic of Jin balancing circuitry structure is that the low-voltage side coil of each balancing transformer will form series loop.With balancing transformer 95 is example, and after the high-pressure side of balancing transformer 95 coil 951 received input current from power supply 90, its corresponding low-voltage side coil 952 will be exported induced current.Because the low-voltage side coil of each balancing transformer has formed series loop, so the electric current of this series loop of flowing through should be the electric current with fixed value.
Then, balancing transformer 95 will produce lamp current and export fluorescent tube 91 to according to this fixed current.The high-pressure side coil of supposing each balancing transformer equates that with the coiling number average of low-voltage side coil then each balancing transformer also can equate according to each lamp current that balanced balanced current produced.Thus, Jin balancing circuitry structure can be so that each lamp current in many fluorescent tubes back light system about equally, can have highly stable and uniform brightness to guarantee the light source that offers display panels.
In actual applications; though adopt many fluorescent tubes back light system of Jin balancing circuitry structure that highly stable and uniform brightness can be provided; yet; in case the circuit of many fluorescent tubes back light system is short-circuited or when abnormality such as opening circuit; if the circuit protection mechanism that none cover is perfect; except meeting shortens the useful life of many fluorescent tubes back light system, even may directly cause whole many fluorescent tubes back light system to damage and can't continue to use.
Therefore, the invention provides a kind of many fluorescent tubes back light system and protective device thereof that improves circuit protection function that possess, to address the above problem.
Summary of the invention
The technical problem to be solved in the present invention is to propose a kind of many fluorescent tubes back light system and protective device thereof that improves circuit protection function that possess.According to first specific embodiment of the present invention, a kind of protective device that is applied to many fluorescent tubes back light system is proposed.This many fluorescent tubes back light system comprises power supply, first fluorescent tube, second fluorescent tube, first transformer and second transformer.Wherein first transformer is coupled to power supply, first fluorescent tube and second transformer, and second transformer then is coupled to the power supply and second fluorescent tube.
In this embodiment, protective device comprises testing circuit and comparison module.Testing circuit is except being coupled between first transformer and first fluorescent tube, and testing circuit also is coupled between second transformer and second fluorescent tube.The main function of testing circuit is to produce detection voltage.Comparison module is coupled to testing circuit and power supply, and in order to according to detecting optionally powered-down of voltage.
According to second specific embodiment of the present invention, a kind of protective device that is applied to many fluorescent tubes back light system is proposed also.This many fluorescent tubes back light system comprises power supply, first fluorescent tube, second fluorescent tube, first transformer and second transformer.Wherein first transformer is coupled to power supply, first fluorescent tube and second transformer, and second transformer then is coupled to the power supply and second fluorescent tube.
In this embodiment, protective device comprises testing circuit and comparison module.Testing circuit is coupled between first transformer and second transformer, and detects voltage in order to produce.Comparison module is coupled to testing circuit and power supply, and in order to according to detecting optionally powered-down of voltage.
According to the 3rd specific embodiment of the present invention, a kind of protective device that is applied to many fluorescent tubes back light system is proposed.This many fluorescent tubes back light system comprises power supply, first fluorescent tube, second fluorescent tube, first transformer and second transformer.Wherein first transformer is coupled to power supply, first fluorescent tube and second transformer; Second transformer is coupled to the power supply and second fluorescent tube.First transformer comprises the first high-pressure side coil, the first low-pressure side main coil and first low-pressure side time coil; Second transformer comprises the second high-pressure side coil, the second low-pressure side main coil and second low-pressure side time coil.Wherein the first low-pressure side main coil is coupled to the second low-pressure side main coil.
In this embodiment, protective device comprises testing circuit and comparison module.Testing circuit is coupled to first low-pressure side time coil and second low-pressure side time coil, and detects voltage in order to produce.Comparison module is coupled to testing circuit and power supply, and in order to according to detecting optionally powered-down of voltage.
According to the 4th specific embodiment of the present invention, a kind of protective device that is applied to many fluorescent tubes back light system is proposed.This many fluorescent tubes back light system comprises power supply, first fluorescent tube, second fluorescent tube, first transformer and second transformer.First transformer is coupled to power supply, first fluorescent tube and second transformer; Second transformer is coupled to the power supply and second fluorescent tube.First transformer comprises the first high-pressure side coil and first low-voltage side coil, and first low-voltage side coil comprises first subcoil and second subcoil.Second transformer comprises the second high-pressure side coil and second low-voltage side coil, and second low-voltage side coil comprises the 3rd subcoil and the 4th subcoil.Wherein first subcoil is coupled to second subcoil and the 3rd subcoil is coupled to the 4th subcoil.
In this embodiment, protective device comprises testing circuit and comparison module.Testing circuit is coupled between first subcoil and second subcoil, and is coupled between the 3rd subcoil and the 4th subcoil.The function of testing circuit is to produce detection voltage.Comparison module is coupled to testing circuit and power supply, and in order to according to detecting optionally powered-down of voltage.
Than prior art, The present invention be directed to many fluorescent tubes back light system and propose to have the protective device that improves circuit protection function with Jin balancing circuitry structure.In case the circuit in many fluorescent tubes back light system is short-circuited or when abnormality such as opening circuit, this protective device immediately powered-down to prolong the useful life of many fluorescent tubes back light system.
Can be further understood by the following detailed description and accompanying drawings about the advantages and spirit of the present invention.
Description of drawings
Fig. 1 illustrates the schematic diagram of the many fluorescent tubes back light system that has Jin balancing circuitry structure in the prior art.
Fig. 2 (A) illustrates the schematic diagram that is applied to many fluorescent tubes back light system according to the protective device of first specific embodiment of the present invention.
Fig. 2 (B) illustrates the detailed circuit diagram of the testing circuit among Fig. 2 (A).
Fig. 3 (A) illustrates the schematic diagram that is applied to many fluorescent tubes back light system according to the protective device of second specific embodiment of the present invention.
Fig. 3 (B) illustrates the detailed circuit diagram of the testing circuit among Fig. 3 (A).
Fig. 4 (A) illustrates the schematic diagram that is applied to many fluorescent tubes back light system according to the protective device of the 3rd specific embodiment of the present invention.
Fig. 4 (B) illustrates the detailed circuit diagram of the testing circuit among Fig. 4 (A).
Fig. 5 (A) illustrates the schematic diagram that is applied to many fluorescent tubes back light system according to the protective device of the 4th specific embodiment of the present invention.
Fig. 5 (B) illustrates the detailed circuit diagram of the testing circuit among Fig. 5 (A).
Fig. 6 illustrates the schematic diagram according to many fluorescent tubes back light system of the 5th specific embodiment of the present invention.
Embodiment
According to first specific embodiment of the present invention, a kind of protective device that is applied to many fluorescent tubes back light system is proposed.Present embodiment is to adopt two fluorescent tube back light systems example as an illustration of Jin balancing circuitry structure.In the present embodiment; this protective device is positioned at the voltage of the high-pressure side coil of balancing transformer and the test point between fluorescent tube by detection and judges that whether this voltage is unusually optionally to close the power supply of many fluorescent tubes back light system, to reach the effect of many fluorescent tubes of protection back light system.
Please refer to Fig. 2 (A), Fig. 2 (A) illustrates the schematic diagram that this protective device is applied to many fluorescent tubes back light system.Shown in Fig. 2 (A), many fluorescent tubes back light system 1 comprises power supply 13, first fluorescent tube 11, second fluorescent tube 12, first transformer 15 and second transformer 16.First transformer 15 is coupled to power supply 13, first fluorescent tube 11 and second transformer 16.16 in second transformer is coupled to the power supply 13 and second fluorescent tube 12.First transformer 15 comprises the first high-pressure side coil 151 and first low-voltage side coil 152; Second transformer 16 comprises the second high-pressure side coil 161 and second low-voltage side coil 162.
In this embodiment, because many fluorescent tubes back light system 1 adopts Jin balancing circuitry structure, so first low-voltage side coil 152 of first transformer 15 and second low-voltage side coil 162 of second transformer 16 will be coupled to each other to form series loop, shown in Fig. 2 (A).
In this embodiment, protective device 10 comprises testing circuit 101 and comparison module 102.Shown in Fig. 2 (A), testing circuit 101 is coupled to the first test point S1 and the second test point S2.Wherein the first test point S1 is between the first high-pressure side coil 151 and first fluorescent tube 11 of first transformer 15, and the second test point S2 is between the second high-pressure side coil 161 and second fluorescent tube 12 of second transformer 16.
The main function of testing circuit 101 is to produce detection voltage V
P1In fact, testing circuit 101 can produce according to second lamp current of first lamp current of first fluorescent tube 11 of flowing through and second fluorescent tube 12 of flowing through and detect voltage V
P1Please refer to Fig. 2 (B), Fig. 2 (B) illustrates the detailed circuit diagram of the testing circuit 101 shown in Fig. 2 (A).Shown in Fig. 2 (B), in the present embodiment, testing circuit 101 by the magnitude of voltage measuring P1 and order to obtain detecting voltage V
P1
Next, will be introduced at the comparison module 102 of protective device 10.Comparison module 102 is coupled to testing circuit 101 and power supply 13, and the detection voltage V in order to be produced according to testing circuit 101
P1Optionally powered-down 13.In actual applications, comparison module 102 is by relatively detecting voltage V
P1With reference voltage V
R1With powered-down 13 optionally.In this embodiment, reference voltage V
R1Can be the higher limit of the P1 point voltage scope when many fluorescent tubes back light system 1 is in the normal operation state, also promptly when detecting voltage V
P1Surpass reference voltage V
R1The time, represent that many fluorescent tubes back light system 1 has abnormal conditions to take place probably.
Generally speaking, be in when many fluorescent tubes back light system 1 under the state of normal operation, detect voltage V
P1Will be less than reference voltage V
R1Therefore, if comparison module 102 relatively detects voltage V
P1With reference voltage V
R1Resulting comparative result is for detecting voltage V
P1Less than reference voltage V
R1, the detection voltage V that represents testing circuit 101 to be produced
P1Be normal value, so comparison module 102 can't powered-down 13.
Yet, in case the circuit of many fluorescent tubes back light system 1 is short-circuited or when abnormality such as opening circuit, detect voltage V
P1Will be greater than reference voltage V
R1Therefore, if comparison module 102 relatively detects voltage V
P1With reference voltage V
R1Resulting comparative result is for detecting voltage V
P1Greater than reference voltage V
R1, the detection voltage V that represents testing circuit 101 to be produced
P1Be exceptional value.At this moment, comparison module 102 immediately powered-down 13 cause the damage of many fluorescent tubes back light system 1 to avoid these abnormalities.
For example, hypothetical reference voltage V
R1Be 2 volts, and testing circuit 101 resulting detection voltage V
P1Be 1.5 volts, then comparison module 102 relatively detects voltage V
P1With reference voltage V
R1Resulting comparative result is for detecting voltage V
P1Less than reference voltage V
R1, the detection voltage V that also promptly represents testing circuit 101 to be produced
P1Be normal value.Because many fluorescent tubes back light system 1 is under the state of normal operation, so comparison module 102 can't powered-down 13.
Hold example, if testing circuit 101 resulting detection voltage V
P1Be 3 volts, then comparison module 102 relatively detects voltage V
P1With reference voltage V
R1Resulting comparative result is for detecting voltage V
P1Greater than reference voltage V
R1, the detection voltage V that also promptly represents testing circuit 101 to be produced
P1Be exceptional value, thus comparison module 102 immediately powered-down 13 to protect many fluorescent tubes back light system 1.
According to second specific embodiment of the present invention, a kind of protective device that is applied to many fluorescent tubes back light system is proposed.Present embodiment is to adopt two fluorescent tube back light systems example as an illustration of Jin balancing circuitry structure.In the present embodiment; this protective device by the test point in the low-voltage side coil series loop that detects balancing transformer voltage and judge that whether this voltage is unusually optionally to close the power supply of many fluorescent tubes back light system, to reach the effect of many fluorescent tubes of protection back light system.
Please refer to Fig. 3 (A), Fig. 3 (A) illustrates the schematic diagram that this protective device is applied to many fluorescent tubes back light system.Shown in Fig. 3 (A), many fluorescent tubes back light system 2 comprises power supply 23, first fluorescent tube 21, second fluorescent tube 22, first transformer 25 and second transformer 26.First transformer 25 is coupled to power supply 23, first fluorescent tube 21 and second transformer 26.26 in second transformer is coupled to the power supply 23 and second fluorescent tube 22.First transformer 25 comprises the first high-pressure side coil 251 and first low-voltage side coil 252; Second transformer 26 comprises the second high-pressure side coil 261 and second low-voltage side coil 262.
Shown in Fig. 3 (A), because many fluorescent tubes back light system 2 adopts Jin balancing circuitry structures, so first low-voltage side coil 252 and second low-voltage side coil 262 will be coupled to each other to form the loop of connecting.
In this embodiment, protective device 20 comprises testing circuit 201 and comparison module 202.Shown in Fig. 3 (A), suppose that testing circuit 201 is coupled to the first test point S1, and the first test point S1 is between first low-voltage side coil 252 and second low-voltage side coil 262.
The main function of testing circuit 201 is to produce detection voltage V
P2In fact, testing circuit 201 can produce according to the induced current of flow through first low-voltage side coil 252 and second low-voltage side coil 262 and detect voltage V
P2Please refer to Fig. 3 (B), Fig. 3 (B) illustrates the detailed circuit diagram of the testing circuit 201 shown in Fig. 3 (A).Shown in Fig. 3 (B), in the present embodiment, testing circuit 201 by the magnitude of voltage measuring P2 and order to obtain detecting voltage V
P2
Shown in Fig. 3 (A), comparison module 202 is coupled to testing circuit 201 and power supply 23.In this embodiment, comparison module 202 is by relatively detecting voltage V
P2With reference voltage V
R2With powered-down 23 optionally.In actual applications, reference voltage V
R2It can be the higher limit of the P2 point voltage scope when 2 normal operations of many fluorescent tubes back light system.That is to say, if detect voltage V
P2Surpass reference voltage V
R2, promptly represent to have probably in the circuit of many fluorescent tubes back light system 2 abnormal conditions to take place.
Next, will inquire into regard to 202 issuable two kinds of comparative results of comparison module respectively.First kind of comparative result is to detect voltage V
P2Less than reference voltage V
R2, representative detects voltage V
P2Being normal value, also is that many fluorescent tubes back light system 2 is under the state of normal operation, so comparison module 202 can powered-down 23.
As for another kind of comparative result then is to detect voltage V
PGreater than reference voltage V
R2, also promptly detect voltage V
P2Be exceptional value, on behalf of this moment many fluorescent tubes back light systems circuit of 1, this short circuit is arranged probably or abnormality such as open circuit takes place.Therefore, comparison module 202 promptly immediately powered-down 23 to protect many fluorescent tubes back light system 2.
According to the 3rd specific embodiment of the present invention, a kind of protective device that is applied to many fluorescent tubes back light system is proposed.Present embodiment is to adopt two fluorescent tube back light systems example as an illustration of Jin balancing circuitry structure.In the present embodiment; the voltage of the test point of the low-pressure side time coil (for example be built in the protection induction coil of balancing transformer) of this protective device by detecting balancing transformer also judges that whether this voltage is unusually optionally to close the power supply of many fluorescent tubes back light system, to reach the effect of many fluorescent tubes of protection back light system.
Please refer to Fig. 4 (A), Fig. 4 (A) illustrates the schematic diagram that this protective device is applied to many fluorescent tubes back light system.Shown in Fig. 4 (A), many fluorescent tubes back light system 3 comprises power supply 33, first fluorescent tube 31, second fluorescent tube 32, first transformer 35 and second transformer 36.Wherein first transformer 35 is coupled to power supply 33, first fluorescent tube 31 and second transformer 36, is coupled to the power supply 33 and second fluorescent tube 32 as for 36 in second transformer.
In this embodiment, the low-voltage side coil of all transformers all comprises main coil and primary winding.Shown in Fig. 4 (A), first transformer 35 comprises the first high-pressure side coil 351, the first low-pressure side main coil 352 and first low-pressure side time coil 353; Second transformer 36 comprises the second high-pressure side coil 361, the second low-pressure side main coil 362 and second low-pressure side time coil 363.Because many fluorescent tubes back light system 3 adopts Jin balancing circuitry structure, so the first low-pressure side main coil 352 and the second low-pressure side main coil 362 will be coupled to each other to form series loop.
In actual applications, first low-pressure side time coil 353/ second low-pressure side time coil 363 can be the protection induction coil that is built in first transformer, 35/ second transformer 36.If is example with first transformer 35, when first transformer 35 after power supply 33 receives first input current, first low-pressure side time coil 353 will produce first induced current to the first test point S1.In like manner, when second transformer 36 after power supply 33 receives second input current, second low-pressure side time coil 363 will produce second induced current to the second test point S2.Wherein the first test point S1 is positioned at first low-pressure side time coil 353 and the second test point S2 is positioned at second low-pressure side time coil 363.
In this embodiment, protective device 30 comprises testing circuit 301 and comparison module 302.Shown in Fig. 4 (A), suppose that testing circuit 301 is coupled to the first test point S1 and the second test point S2.The main function of testing circuit 301 is to produce one and detects voltage V
P3In fact, testing circuit 301 can produce detection voltage V according to the first above-mentioned induced current and second induced current
P3Please refer to Fig. 4 (B), Fig. 4 (B) illustrates the detailed circuit diagram of the testing circuit 301 shown in Fig. 4 (A).Shown in Fig. 4 (B), in the present embodiment, testing circuit 301 by the magnitude of voltage measuring P3 and order to obtain detecting voltage V
P3
Shown in Fig. 4 (A), comparison module 302 is coupled to testing circuit 301 and power supply 33.In this embodiment, comparison module 302 is by relatively detecting voltage V
P3With reference voltage V
R3With powered-down 33 optionally.
When detecting voltage V
P3Less than reference voltage V
R3The time, representative detects voltage V
P3Being normal value, also is that many fluorescent tubes back light system 3 is under the state of normal operation, so comparison module 302 can powered-down 33.On the other hand, when detecting voltage V
P3Greater than reference voltage V
R3The time, also promptly represent this moment many fluorescent tubes back light systems circuit of 3 to be short-circuited probably or abnormality such as open circuit.Therefore, comparison module 302 immediately powered-down 33 to protect many fluorescent tubes back light system 3.
According to the 4th specific embodiment of the present invention, a kind of protective device that is applied to many fluorescent tubes back light system is proposed.Present embodiment is to adopt two fluorescent tube back light systems example as an illustration of Jin balancing circuitry structure.In the present embodiment, this protective device detects the voltage of low-voltage side coil and judges whether this voltage is unusual optionally to close the power supply of many fluorescent tubes back light system by the mode of low-voltage side coil center tap.
Please refer to Fig. 5 (A), Fig. 5 (A) illustrates the schematic diagram that this protective device is applied to many fluorescent tubes back light system.Shown in Fig. 5 (A), many fluorescent tubes back light system 4 comprises power supply 43, first fluorescent tube 41, second fluorescent tube 42, first transformer 45 and second transformer 46.Wherein first transformer 45 is coupled to power supply 43, first fluorescent tube 41 and second transformer 46, is coupled to the power supply 43 and second fluorescent tube 42 as for 46 in second transformer.
In this embodiment, the low-voltage side coil of all transformers all comprises two subcoils and two subcoils are coupled to each other.Shown in Fig. 5 (A), first transformer 45 comprises the first high-pressure side coil 451 and first low-voltage side coil 452.Wherein first low-voltage side coil 452 comprises first subcoil 4521 and second subcoil 4522 and first subcoil 4521 and is coupled to second subcoil 4522.Similarly, second transformer 46 comprises the second high-pressure side coil 461 and second low-voltage side coil 462.Wherein second low-voltage side coil 462 comprises the 3rd subcoil 4621 and the 4th subcoil 4622 and the 3rd subcoil 4621 and is coupled to the 4th subcoil 4622.
Because many fluorescent tubes back light system 4 adopts Jin balancing circuitry structure, so first low-voltage side coil 452 and second low-voltage side coil 462 will be coupled to each other to form series loop.Shown in Fig. 5 (A), the 4th subcoil 4622 that second subcoil 4522 of first low-voltage side coil 452 is coupled to the 3rd subcoil 4621, the second low-voltage side coils 462 of second low-voltage side coil 462 then is coupled to first subcoil 4521 of first low-voltage side coil 452.
In this embodiment, protective device 40 comprises testing circuit 401 and comparison module 402.Shown in Fig. 5 (A), suppose that testing circuit 401 is coupled to the first test point S1 and the second test point S2.Wherein the first test point S1 between first subcoil 4521 and second subcoil 4522 and the second test point S2 between the 3rd subcoil 4621 and the 4th subcoil 4622.
The main function of testing circuit 401 is to produce detection voltage V
P4In fact, testing circuit 401 can produce according to second induced current of first induced current of flow through first subcoil 4521 and second subcoil 4522 and flow through the 3rd subcoil 4621 and the 4th subcoil 4622 and detect voltage V
P4Please refer to Fig. 5 (B), Fig. 5 (B) illustrates the detailed circuit diagram of the testing circuit 401 shown in Fig. 5 (A).Shown in Fig. 5 (B), in the present embodiment, testing circuit 401 by the magnitude of voltage measuring P4 and order to obtain detecting voltage V
P4
Shown in Fig. 5 (A), comparison module 402 is coupled to testing circuit 401 and power supply 43.In this embodiment, comparison module 402 is by relatively detecting voltage V
P4With reference voltage V
R4With powered-down 43 optionally.
Specifically, if detect voltage V
P4Less than reference voltage V
R4, represent many fluorescent tubes back light system 4 to be under the state of normal operation, so comparison module 402 can powered-down 43; If detect voltage V
P4Greater than reference voltage V
R4, represent this moment many fluorescent tubes back light systems circuit of 4 short circuit to be arranged probably or abnormality such as open circuit takes place.Therefore, comparison module 402 immediately powered-down 43 to protect many fluorescent tubes back light system 4.
According to the 5th specific embodiment of the present invention, a kind of many fluorescent tubes back light system with protective device is proposed.In the present embodiment, be to describe with the two fluorescent tube back light systems that adopt Jin balancing circuitry structure.Please refer to Fig. 6, Fig. 6 illustrates the schematic diagram of this many fluorescent tubes back light system.As shown in Figure 6, many fluorescent tubes back light system 5 comprises power supply 53, circuit board 57, first fluorescent tube 51, second fluorescent tube 52 and support 58.Wherein power supply 53 is coupled to circuit board 57, and in order to provide many fluorescent tubes back light system 5 required electric power.All be coupled to circuit board 57 and support 58 as for first fluorescent tube 51 and second fluorescent tube 52, its medium-height trestle 58 ground connection and in order to fixing and support first fluorescent tube 51 and second fluorescent tube 52.
In this embodiment, circuit board 57 is provided with protective device 50, first transformer 55 and second transformer 56.Wherein first transformer 55 is coupled to power supply 53, first fluorescent tube 51 and second transformer, 56, the second transformers 56 and then is coupled to the power supply 53 and second fluorescent tube 52.First transformer 55 and second transformer 56 are in order to receive input current and to export lamp current to the first fluorescent tube 51 and second fluorescent tube 52 from power supply 53.Be coupled to first transformer 55, second transformer 56 and power supply 53 as for 50 of protective devices, and in order to generation detection voltage and according to detecting optionally powered-down 53 of voltage.
In this embodiment, protective device 50 comprises testing circuit 501 and comparison module 502.Wherein testing circuit 501 is coupled to first transformer 55 and second transformer 56, and comparison module 502 then is coupled to testing circuit 501 and power supply 53.The main function of testing circuit 501 is to produce detection voltage.502 of comparison modules are in order to according to detecting optionally powered-down 53 of voltage.
In actual applications, the protective device 50 of many fluorescent tubes back light system 5 can change different circuit protection patterns with the different test points of second transformer 56 by testing circuit 501 being coupled to first transformer 55.Next, four kinds of circuit protection patterns that provided with regard to the protective device 50 of many fluorescent tubes back light system 5 are respectively inquired into.
In first kind of circuit protection pattern, testing circuit 501 is coupled to first test point and second test point.Wherein first test point is between the high-pressure side coil of first transformer 55 and first fluorescent tube 51 and between the high-pressure side coil and second fluorescent tube 52 of second test point at second transformer 56.In fact, testing circuit 501 can produce according to second lamp current of first lamp current of first fluorescent tube 51 of flowing through and second fluorescent tube 52 of flowing through and detect voltage.Details can be with reference to figure 2 (A) and Fig. 2 (B).
In second kind of circuit protection pattern, testing circuit 501 is coupled to first test point.First test point is between the low-voltage side coil of the low-voltage side coil of first transformer 55 and second transformer 56.In fact, testing circuit 501 can produce according to the induced current of the low-voltage side coil of the low-voltage side coil of first transformer 55 of flowing through and second transformer 56 and detect voltage.Details can be with reference to figure 3 (A) and Fig. 3 (B).
In the third circuit protection pattern, first transformer 55 and second transformer 56 comprise high-pressure side coil, low-pressure side main coil and low-pressure side time coil respectively.The low-pressure side main coil of first transformer 55 is coupled to the low-pressure side main coil of second transformer 56, and testing circuit 501 is coupled to first test point and second test point.Wherein first test point is positioned at the low-pressure side time coil (for example being built in the protection induction coil of balancing transformer) of first transformer 55 and the low-pressure side time coil that second test point is positioned at second transformer 56.In fact, testing circuit 501 can produce according to second induced current of the low-pressure side time coil of first induced current of the low-pressure side of first transformer 55 of flowing through time coil and second transformer 56 of flowing through and detect voltage.Details can be with reference to figure 4 (A) and Fig. 4 (B).
In the 4th kind of circuit protection pattern, each self-contained two subcoil of the low-voltage side coil of first transformer 55 and second transformer 56, two subcoils of first transformer 55 are coupled to each other and two subcoils of second transformer 56 also are coupled to each other.Testing circuit 501 is coupled to first test point and second test point.Wherein first test point is between two low-pressure side subcoils of first transformer 55 and between two low-pressure side subcoils of second test point at second transformer 56.
In fact, testing circuit 501 can produce according to second induced current of two low-pressure side subcoils of first induced current of two low-pressure side subcoils of first transformer 55 of flowing through and second transformer 56 of flowing through and detect voltage.Details can be with reference to figure 5 (A) and Fig. 5 (B).
After testing circuit 501 detected voltage by above-mentioned various circuit protection mode producing, comparison module 502 promptly can relatively detect voltage and reference voltage.When detecting voltage greater than reference voltage, represent this moment many fluorescent tubes back light system circuit of 5 short circuit to be arranged probably or abnormality generation such as open circuit, comparison module 502 promptly can powered-down 53 to protect many fluorescent tubes back light system 5.
Than prior art, the present invention is directed to many fluorescent tubes back light system and propose to have the protective device that improves circuit protection function with Jin balancing circuitry structure.In case the circuit in many fluorescent tubes back light system is short-circuited or when abnormality such as opening circuit, protective device powered-down immediately causes the damage of many fluorescent tubes back light system to avoid these abnormalities, to prolong the useful life of many fluorescent tubes back light system.
By the above detailed description of preferred embodiments, hope can be known description feature of the present invention and spirit more, and is not to come category of the present invention is limited with above-mentioned disclosed preferred embodiment.On the contrary, its objective is that hope can contain in the category that is arranged in the claim that the present invention asks in desiring of various changes and tool equality.Therefore, the present invention in the category of the claim of asking do the broadest explanation according to above-mentioned explanation, contain the arrangement of all possible change and tool equality to cause it.
Reference numerals list
1,2,3,4,5,9: many lamp-tube backlight systems
10,20,30,40,50: protective device
11,21,31,41,51: the first fluorescent tubes
12,22,32,42,52: the second fluorescent tubes
13,23,33,43,53,90: power supply
15,25,35,45,55: the first transformers
16,26,36,46,56: the second transformers
101,201,301,401,501: testing circuit
102,202,302,402,502: comparison module
151,251,351,451: the first high-pressure side coils
161,261,361,461: the second high-pressure side coils
152,252,452: the first low-voltage side coils
162,262,462: the second low-voltage side coils
362: the second low-pressure side main coils of 352: the first low-pressure side main coils
363: the second low-pressure side time coils of 353: the first low-pressure side time coils
4522: the second subcoils of 4521: the first subcoils
4622: the four subcoils of 4621: the three subcoils
57: circuit board 58: support
91-94: fluorescent tube 95-98: balancing transformer
951: high-pressure side coil 952: low-voltage side coil
S1: the first test point S2: second test point
P: voltage measurement point
Claims (15)
1. protective device; be used for many fluorescent tubes back light system; this many fluorescent tubes back light system comprises power supply, first fluorescent tube, second fluorescent tube, first transformer and second transformer; this first transformer is coupled to this power supply, this first fluorescent tube and this second transformer; this second transformer is coupled to this power supply and this second fluorescent tube; it is characterized in that this protective device comprises:
Testing circuit is coupled between this first transformer and this first fluorescent tube and this testing circuit is coupled between this second transformer and this second fluorescent tube, detects voltage in order to produce; And
Comparison module is coupled to this testing circuit and this power supply, in order to optionally to close this power supply according to this detection voltage.
2. protective device according to claim 1, wherein, first coil of this first transformer couples second coil of this second transformer.
3. protective device; be used for many fluorescent tubes back light system; this many fluorescent tubes back light system comprises power supply, first fluorescent tube, second fluorescent tube, first transformer and second transformer; this first transformer is coupled to this power supply, this first fluorescent tube and this second transformer; this second transformer is coupled to this power supply and this second fluorescent tube; it is characterized in that this protective device comprises:
Testing circuit is coupled between this first transformer and this second transformer, detects voltage in order to produce; And
Comparison module is coupled to this testing circuit and this power supply, in order to optionally to close this power supply according to this detection voltage.
4. protective device according to claim 3, wherein, first coil of this first transformer couples second coil of this second transformer.
5. protective device; be used for many fluorescent tubes back light system; this many fluorescent tubes back light system comprises power supply, first fluorescent tube, second fluorescent tube, first transformer and second transformer; this first transformer is coupled to this power supply, this first fluorescent tube and this second transformer and this first transformer and comprises first main coil and coil for the first time; this second transformer is coupled to this power supply and this second fluorescent tube and this second transformer and comprises second main coil and coil for the second time; it is characterized in that this protective device comprises:
Testing circuit, be coupled to this first time coil and this second time coil, detect voltage in order to produce; And
Comparison module is coupled to this testing circuit and this power supply, in order to optionally to close this power supply according to this detection voltage.
6. protective device according to claim 5, wherein, this first main coil couples this second main coil.
7. protective device; be used for many fluorescent tubes back light system; this many fluorescent tubes back light system comprises power supply; first fluorescent tube; second fluorescent tube; first transformer and second transformer; this first transformer is coupled to this power supply; this first fluorescent tube and this second transformer and this first transformer comprise first subcoil and second subcoil; this first subcoil couples this second subcoil; this second transformer is coupled to this power supply and this second fluorescent tube and this second transformer and comprises the 3rd subcoil and the 4th subcoil; the 3rd subcoil couples the 4th subcoil; it is characterized in that this protective device comprises:
Testing circuit is coupled between this first subcoil and this second subcoil and this testing circuit is coupled between the 3rd subcoil and the 4th subcoil, detects voltage in order to produce; And
Comparison module is coupled to this testing circuit and this power supply, in order to optionally to close this power supply according to this detection voltage.
8. protective device according to claim 7, wherein, this second subcoil couples the 3rd subcoil and the 4th subcoil couples this first subcoil.
9. fluorescent tube back light system more than a kind comprises:
Power supply;
First fluorescent tube;
Second fluorescent tube;
First transformer is coupled to this power supply and this first fluorescent tube;
Second transformer is coupled to this power supply, this second fluorescent tube and this first transformer; It is characterized in that,
Comprise as the described protective device of one of above-mentioned claim, be coupled to this power supply, this first transformer and this second transformer, detect voltage and optionally close this power supply according to this detection voltage in order to produce.
10. many fluorescent tubes back light system according to claim 9, wherein this protective device comprises:
Testing circuit is coupled between this first transformer and this first fluorescent tube and this testing circuit is coupled between this second transformer and this second fluorescent tube, in order to produce this detection voltage; And
Comparison module is coupled to this testing circuit and this power supply, in order to relatively this detection voltage and reference voltage are also optionally closed this power supply.
11. many fluorescent tubes back light system according to claim 9, wherein this protective device comprises:
Testing circuit is coupled between this first transformer and this second transformer, in order to produce this detection voltage; And
Comparison module is coupled to this testing circuit and this power supply, in order to relatively this detection voltage and reference voltage are also optionally closed this power supply.
12. many fluorescent tubes back light system according to claim 9, wherein this first transformer comprise first main coil and for the first time coil and this second transformer comprise second main coil and coil for the second time, this first main coil couples this second main coil.
13. many fluorescent tubes back light system according to claim 12, wherein this protective device comprises:
Testing circuit, be coupled to this first time coil and this second time coil, in order to produce this detection voltage; And
Comparison module is coupled to this testing circuit and this power supply, in order to relatively this detection voltage and reference voltage are also optionally closed this power supply.
14. many fluorescent tubes back light system according to claim 9, wherein this first transformer comprises first subcoil and second subcoil and this second transformer and comprises the 3rd subcoil and the 4th subcoil, and this first subcoil couples this second subcoil and the 3rd subcoil couples the 4th subcoil.
15. many fluorescent tubes back light system according to claim 14, wherein this protective device comprises:
Testing circuit is coupled between this first subcoil and this second subcoil and this testing circuit is coupled between the 3rd subcoil and the 4th subcoil, in order to produce this detection voltage; And
Comparison module is coupled to this testing circuit and this power supply, in order to relatively this detection voltage and reference voltage are also optionally closed this power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201152158U CN201290195Y (en) | 2008-05-12 | 2008-05-12 | Multi-lamp-tube backlight system and protection device thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201152158U CN201290195Y (en) | 2008-05-12 | 2008-05-12 | Multi-lamp-tube backlight system and protection device thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201290195Y true CN201290195Y (en) | 2009-08-12 |
Family
ID=40981875
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008201152158U Expired - Fee Related CN201290195Y (en) | 2008-05-12 | 2008-05-12 | Multi-lamp-tube backlight system and protection device thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201290195Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012000217A1 (en) * | 2010-07-02 | 2012-01-05 | 深圳市华星光电技术有限公司 | Liquid crystal display and backlight module for detecting abnormity of lamp tube |
| CN102348302A (en) * | 2010-08-02 | 2012-02-08 | 艾默龙电子科技（嘉兴）有限公司 | High-efficiency light-emitting diode (LED) balanced driving and dimming controlling method |
| US8829814B2 (en) | 2010-07-02 | 2014-09-09 | Shenzhen China Star Optoelectronics Technology Co., Ltd. | Backlight module detecting abnormal lamp tubes and an LCD thereof |
-
2008
- 2008-05-12 CN CNU2008201152158U patent/CN201290195Y/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012000217A1 (en) * | 2010-07-02 | 2012-01-05 | 深圳市华星光电技术有限公司 | Liquid crystal display and backlight module for detecting abnormity of lamp tube |
| US8829814B2 (en) | 2010-07-02 | 2014-09-09 | Shenzhen China Star Optoelectronics Technology Co., Ltd. | Backlight module detecting abnormal lamp tubes and an LCD thereof |
| CN102348302A (en) * | 2010-08-02 | 2012-02-08 | 艾默龙电子科技（嘉兴）有限公司 | High-efficiency light-emitting diode (LED) balanced driving and dimming controlling method |
| CN102348302B (en) * | 2010-08-02 | 2014-07-16 | 艾默龙电子科技（嘉兴）有限公司 | High-efficiency light-emitting diode (LED) balanced driving and dimming controlling method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN2924579Y (en) | Driving circuit for external electrode fluorescent lamp and liquid crystal display device using same | |
| US7224286B2 (en) | Solar panel having visual indicator | |
| CN201290195Y (en) | Multi-lamp-tube backlight system and protection device thereof | |
| CN101188896A (en) | Inverter circuit and backlight assembly having the same | |
| CN100530320C (en) | Electric voltage detecting circuit and electric discharge lamp driven apparatus using same | |
| CN101600285B (en) | Liquid crystal display, backlight module and drive method thereof | |
| CN101115340B (en) | Inverter circuit | |
| US20070115001A1 (en) | System for driving a plurality of lamps and fault detecting circuit thereof | |
| CN201369867Y (en) | Multi lamp-tube driving system | |
| CN109144160A (en) | Correction method and device | |
| CN108984368A (en) | A kind of method and device based on CPLD quick lock in server master board problem power supply | |
| CN103969595A (en) | Electric quantity detecting device and method | |
| CN101442864A (en) | Current regulation circuit and power supply component containing the same | |
| CN201263238Y (en) | Multi-lamp tube backlight device | |
| CN101009084B (en) | LCD, backlight module and its lamp tube driving device | |
| CN106102255A (en) | Simulation filament impedances circuit, LED lamp tube and LED illumination System | |
| CN201171244Y (en) | Backlight device | |
| CN201063926Y (en) | Back light source driving circuit and LCD device | |
| CN101311793B (en) | Backlight module | |
| CN201341262Y (en) | Multi-lamp-tube backlighting system and protecting device thereof | |
| CN201248181Y (en) | Backlight module | |
| CN109856564A (en) | A kind of power detecting system | |
| CN201197215Y (en) | Current balancing apparatus and multi-light tube backlight module | |
| CN102290029B (en) | A kind of driving chip of pointwise adjustment | |
| TWI421839B (en) | Balancing transforming circuit for cold cathode fluorescent lamps |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090812 Termination date: 20120512 |