CN201248181Y - Backlight module - Google Patents
Backlight module Download PDFInfo
- Publication number
- CN201248181Y CN201248181Y CNU2008201191951U CN200820119195U CN201248181Y CN 201248181 Y CN201248181 Y CN 201248181Y CN U2008201191951 U CNU2008201191951 U CN U2008201191951U CN 200820119195 U CN200820119195 U CN 200820119195U CN 201248181 Y CN201248181 Y CN 201248181Y
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- transformer
- circuit board
- voltage
- voltage capacitance
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Abstract
The utility model discloses a backlight module comprising a circuit board, a first transformer, a second transformer, a first high-voltage capacitor, a second high-voltage capacitor, a first lamp, a second lamp, a high-voltage power supply and a detecting circuit. The low-voltage windings of the first transformer and the second transformer are connected in series into a circuit. Each high-voltage capacitor is respectively composed of an upper electrode plate and a lower electrode plate; the upper electrode plates are arranged on the upper surface of a circuit board and are near to the pins of the first transformer and the second transformer respectively, and the lower electrode plates are arranged on the lower surface of the circuit board and respectively correspond to the upper electrode plates. When detecting that one divided voltage value of the first high-voltage capacitor or the second high-voltage capacitor deviates from a predetermined voltage value, the detecting circuit can control the high-voltage power supply to stop supplying power to the first lamp and the second lamp.
Description
Technical field
The utility model is about a kind of backlight module, particularly about a kind of backlight module with protection circuit.
Background technology
In recent years, along with the size of display panels constantly increases, comprise that (ColdCathode Fluorescent Lamp, back lighting device CCFL) are applied to provide display panels required high-quality light source to a plurality of cold cathode fluorescent lamp more widely.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, can have highly stable and uniform brightness in order to ensure the light source that offers display panels and take place with the phenomenon of avoiding each lighting tube brightness inequality, a kind of Jin balancing circuitry (Jin balancer) that can be applicable to many fluorescent tubes back light system is suggested.
In actual applications; though adopt many fluorescent tubes back light system of Jin balancing circuitry framework 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.
See also Figure 1A and Figure 1B.Figure 1A is depicted as the circuit diagram of the circuit board upper surface of a traditional many fluorescent tubes back light system 1 with protection circuit.Figure 1B is depicted as the circuit diagram of the circuit board lower surface of traditional many fluorescent tubes back light system 1.Shown in Figure 1A, many fluorescent tubes back light system 1 comprises transformer 10, connector 11, high pressure wire jumper (high voltage jumper) 13 and fluorescent tube 12.To transformer 10, transformer 10 then is coupled to connector 11 to drive fluorescent tube 12 by high pressure wire jumper 13 to one high-pressure side cabling 140 in order to high-voltage power supply that input is provided.High pressure wire jumper 13 is to be provided with to carry out safe isolation with high-pressure side cabling 140, to avoid the arcing problem.
Traditional protection circuit wherein uses a high-voltage capacitance.High-voltage capacitance is laid in the place of high pressure output on the circuit board, and serial connection electric capacity or resistance come dividing potential drop with the design protection circuit.Generally can wish when this branch is pressed in operate as normal too not high in design.On configuration (layout), the high-voltage capacitance major part all designs under connector 11, and is made of electric pole plate 15 that is formed on the circuit board upper surface and the lower electrode plate 16 that is formed on the circuit board lower surface.
Yet, shown in Figure 1B, the low-pressure side cabling 142 of high-voltage capacitance can be subjected to importing the interference of high-voltage power supply, and owing to the factor of configuration intermesh (as the circled of mark among Figure 1B) be difficult for avoiding, make high-voltage capacitance can be subjected to importing the influence of high-voltage power supply, cause the voltage that comes out by the high-voltage capacitance dividing potential drop bigger.It is comparatively inconvenient that this situation will make when adjusting the design of protection circuit.
Therefore, main category of the present utility model is to provide a kind of backlight module, to address the above problem.
The utility model content
A purpose of the present utility model is to provide a kind of backlight module.
In a specific embodiment of the present utility model, backlight module comprises circuit board, first transformer, second transformer, first high-voltage capacitance, second high-voltage capacitance, first fluorescent tube, second fluorescent tube and testing circuit.
Circuit board has a upper surface and is a lower surface of the reverse side of this upper surface.First transformer and second transformer are arranged on the upper surface of circuit board, and wherein first transformer and second transformer include low-pressure side coiling, high-pressure side coiling, one first pin and one second pin.First pin is coupled to an end of high-pressure side coiling and is welded on the upper surface of circuit board.Second pin is welded on the upper surface of circuit board and is coupled to a high voltage source.Wherein, the coiling of the low-pressure side of first transformer and second transformer is connected into a loop.
First high-voltage capacitance and second high-voltage capacitance are made of an electric pole plate (upper electrode plate) and a lower electrode plate respectively.Described electric pole plate is arranged on the upper surface of circuit board and respectively near first pin of first transformer and second transformer.Described lower electrode plate is arranged on the lower surface of circuit board and corresponding described electric pole plate respectively.
First fluorescent tube is coupled to first pin of first transformer, and second fluorescent tube is coupled to first pin of second transformer.Testing circuit is coupled to first high-voltage capacitance, second high-voltage capacitance and high voltage source.When testing circuit detect first high-tension electricity perhaps a change in voltage of second high-voltage capacitance surpass or during less than a predetermined value, testing circuit can be controlled high voltage source and stop to provide electric power to first fluorescent tube and second fluorescent tube.
Can be further understood by following utility model detailed description and accompanying drawing about advantage of the present utility model and spirit.
Description of drawings
Figure 1A is depicted as the circuit diagram of the circuit board upper surface of a traditional many fluorescent tubes back light system with protection circuit.
Figure 1B is depicted as the circuit diagram of the circuit board lower surface of traditional many fluorescent tubes back light system.
Fig. 2 A is depicted as the circuit diagram according to the upper surface of the circuit board of the backlight module of a specific embodiment of the present utility model.
Fig. 2 B is depicted as the circuit diagram according to the lower surface of the circuit board of the backlight module of a specific embodiment of the present utility model.
Figure 3 shows that according to backlight module of the present utility model function circuit schematic diagram in one embodiment.
The main element symbol description
1: many fluorescent tubes back light system 10: transformer
11: connector 12: fluorescent tube
13: high pressure wire jumper 15: electric pole plate
16: lower electrode plate 140: the high-pressure side cabling
142: the low-pressure side cabling
2: backlight module
Transformer 21 in 20: the first: connector
Fluorescent tube 23,33 in 22: the first: the high pressure wire jumper
High- voltage capacitance 26,36 in 25: the first: passive component
200,300: the first pins 202,302: the second pins
204,304: low-pressure side coiling 206,306: the high-pressure side coiling
240: high-pressure side cabling 242: the low-pressure side cabling
250,350: electric pole plate 252,352: lower electrode plate
32: the second fluorescent tubes of 30: the second transformers
35: the second high-voltage capacitances
40: high voltage source 50: testing circuit
V1, V2: dividing potential drop
Embodiment
A purpose of the present utility model is to provide a kind of backlight module with protection circuit.
Backlight module comprises circuit board, first transformer, second transformer, first high-voltage capacitance, second high-voltage capacitance, first fluorescent tube, second fluorescent tube, high pressure wire jumper, connector and testing circuit.Circuit board has a upper surface and is a lower surface of the reverse side of this upper surface.
See also Fig. 2 A and Fig. 2 B.Fig. 2 A is depicted as the circuit diagram according to the upper surface of the circuit board of the backlight module 2 of a specific embodiment of the present utility model.Fig. 2 B is depicted as the circuit diagram according to the lower surface of the circuit board of the backlight module 2 of a specific embodiment of the present utility model.
Shown in Fig. 2 A, first transformer 20 and second transformer 30 are arranged on the upper surface of circuit board, and wherein first transformer 20 and second transformer 30 include low-pressure side coiling, high-pressure side coiling, one first pin 200,300 and one second pin 202,302.
First pin 200,300 is coupled to an end of corresponding high-pressure side coiling and is soldered to connecting circuit on the upper surface that is formed at circuit board.Second pin 202,302 also is soldered to the connecting circuit on the upper surface that is formed at circuit board and is coupled to a high voltage source by a high-pressure side cabling 240.First fluorescent tube 22 and second fluorescent tube 32 all couple with connector 21, and connector 21 is coupled to first pin 200 of first transformer 20 and first pin 300 of second transformer 30 respectively by high pressure wire jumper 23,33.High voltage source provides electrical power to first fluorescent tube 22 and second fluorescent tube 32 by first transformer 20 and second transformer 30.
First high-voltage capacitance and second high-voltage capacitance are made of an electric pole plate and a lower electrode plate respectively.Shown in Fig. 2 A, described electric pole plate 250,350 is arranged on the upper surface of circuit board and can be formed by the connecting circuit of part.In addition, first pin 200,300 of close respectively first transformer 20 of described electric pole plate 250,350 and second transformer 30.Described lower electrode plate 252,352 is arranged on the lower surface of circuit board and corresponding described electric pole plate 250,350 respectively, shown in Fig. 2 B.
Compare with prior art, first high-voltage capacitance and second high-voltage capacitance all are arranged on the high-voltage output end near first transformer 20 and second transformer 30.That is, shown in Fig. 2 B, described electric pole plate 250,350 can design under first pin 200,300 of first transformer 20 and second transformer 30, and described lower electrode plate 252,352 is arranged on the lower surface of circuit board and corresponding described electric pole plate 250,350 respectively.On configuration, advantage of the present utility model is to connect the low-pressure side cabling 242 of described lower electrode plate 252,352 and can avoids the high-pressure side cabling 240 of circuit board upper surface and disturbing factor is reduced, shown in Fig. 2 B.
See also Fig. 3.Figure 3 shows that according to backlight module 2 of the present utility model function circuit schematic diagram in one embodiment.As shown in Figure 3, the low-pressure side of first transformer 20 and second transformer 30 coiling 204,304 is connected into a loop.
Because first transformer 20 is connected in series to form a loop each other with the low-pressure side coiling 204,304 of second transformer 30, the electric current of all low-pressure side coilings 204,304 of therefore flowing through has equal current value.Whereby, high-pressure side coiling 206,306 electric currents of being sensed of first transformer 20 and second transformer 30 also have equal current value, cause the current value that is supplied to first fluorescent tube 22 and second fluorescent tube 32 all identical, can keep highly stable and uniform brightness so can guarantee all fluorescent tubes.
In addition, testing circuit 50 is coupled to first high-voltage capacitance 25, second high-voltage capacitance 35 and high voltage source 40.In actual applications, first high-voltage capacitance 25 and second high-voltage capacitance 35 can connects with a passive component 26,36 respectively, and testing circuit 50 is coupled to respectively between first high-voltage capacitance 25 and its passive component 26 and reaches between second high-voltage capacitance 35 and its passive component 36.In this embodiment, passive component 26,36 adopts a capacitor, but on the practice not as limit.
On circuit design, when cold cathode fluorescent lamp is in an open-circuit condition, can make testing circuit 50 detected dividing potential drops surpass a predetermined value; And when cold cathode fluorescent lamp is in a short-circuit condition, can make testing circuit 50 detected dividing potential drops less than a predetermined value.Above circuit design is only enumerated an embodiment, can design according to the actual requirements on the practice.
In sum, according to backlight module of the present utility model high-voltage capacitance is arranged on the pin below of transformer, to avoid being coupled in the backlight module high-pressure side cabling of high voltage source.Whereby, the disturbing factor that the voltage that is come out by the high-voltage capacitance dividing potential drop is subjected to can significantly reduce, so comparatively convenient when design or adjustment protection circuit.
By the detailed description of above preferred specific embodiment, hope can be known description feature of the present utility model and spirit more, and is not to come category of the present utility model is limited with above-mentioned disclosed preferred specific embodiment.On the contrary, its objective is that hope can contain being arranged in the category of the present utility model of various changes and tool equality.Therefore, category of the present utility model should be done the broadest explanation according to above-mentioned explanation, contains the arrangement of all possible change and tool equality to cause it.
Claims (3)
1. a backlight module is characterized in that, comprising:
One circuit board, this circuit board have a upper surface and are a lower surface of the reverse side of this upper surface;
One first transformer and one second transformer, this first transformer and this second transformer are arranged on this upper surface of this circuit board, and wherein this first transformer and this second transformer include:
The coiling of one low-pressure side, wherein the coiling of the low-pressure side of this first transformer and this second transformer is connected into a loop;
The coiling of one high-pressure side;
One first pin, this first pin are coupled to an end of this high-pressure side coiling and are welded on this upper surface of this circuit board; And
One second pin, this second pin are welded on this upper surface of this circuit board and are coupled to a high voltage source;
One first high-voltage capacitance and one second high-voltage capacitance, constituted by an electric pole plate and a lower electrode plate respectively, described electric pole plate is arranged on this upper surface of this circuit board and respectively near first pin of this first transformer and this second transformer, and described lower electrode plate is arranged on this lower surface of this circuit board and corresponding described electric pole plate respectively;
One first fluorescent tube is coupled to first pin of this first transformer;
One second fluorescent tube is coupled to first pin of this second transformer; And
One testing circuit, be coupled to this first high-voltage capacitance, this second high-voltage capacitance and this high voltage source, when this testing circuit detect this first high-tension electricity perhaps a change in voltage of this second high-voltage capacitance surpass or during less than a predetermined value, this testing circuit is controlled this high voltage source and stopped to provide electric power to this first fluorescent tube and this second fluorescent tube.
2. backlight module according to claim 1, it is characterized in that, wherein this first high-voltage capacitance and this second high-voltage capacitance are connected with a passive component respectively, and this testing circuit is coupled to respectively between this first high-voltage capacitance and its passive component and reaches between this second high-voltage capacitance and its passive component.
3. backlight module according to claim 2 is characterized in that, wherein this passive component is a capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201191951U CN201248181Y (en) | 2008-07-15 | 2008-07-15 | Backlight module |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201191951U CN201248181Y (en) | 2008-07-15 | 2008-07-15 | Backlight module |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201248181Y true CN201248181Y (en) | 2009-05-27 |
Family
ID=40732008
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008201191951U Expired - Fee Related CN201248181Y (en) | 2008-07-15 | 2008-07-15 | Backlight module |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201248181Y (en) |
-
2008
- 2008-07-15 CN CNU2008201191951U patent/CN201248181Y/en not_active Expired - Fee Related
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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: 20090527 Termination date: 20120715 |