KR200453684Y1 - Balance transformer and backlight apparatus - Google Patents

Abstract

The present invention provides a balance transformer and a backlight device using the same. The balance transformer includes a first main coil, a second main coil, a first induction coil and a conductor. The first main coil has a first contact point and a second contact point, and the second main coil has a third contact point and a fourth contact point. The first induction coil corresponds to the first main coil and the second main coil. The conductor is then connected in series with the first contact point and the fourth contact point. Thus, the balance transformer drives the backlight device to light and balances the currents of the plurality of light units of the backlight device.

Balance Transformer, Backlight, Coil, Induction Coil, Contact Point, Conductor, Lighting

Description

BALANCE TRANSFORMER AND BACKLIGHT APPARATUS}

The present invention relates to a balance transformer and a backlight device using the same, and more particularly, to the balance transformer capable of driving a plurality of lighting units and a backlight device using the same.

As the size of a liquid crystal display (LCD) panel increases, a backlight device having a plurality of Cold Cathode Fluorescent Lamps (CCFLs) is generally used as a light source of an LCD panel. come.

Multilamp backlight devices face a serious problem: how to ensure that the light sources providing the LCD panel have stable and constant illumination, and how the currents of the lamps can remain substantially the same with each other. have.

To solve the problems mentioned above, a Jin balance circuit for a multilamp backlight device has been applied. See FIG. 1. 1 is a schematic diagram showing a backlight device 1 having a true balance circuit of the prior art. As shown in FIG. 1, the backlight device 1 includes ten lighting units 12. The balance transformer 10 is connected in series to one lighting unit 12 in a true balance circuit, so that the backlight device 1 has 10 balances to ensure that the currents of the lighting units 12 are the same. Transformers 10 are required.

An increase in the size of the LCD panel means that the number of lamps required increases, and if a true balance circuit is used to balance the flow of currents through the lamps, a corresponding number of transformers is also needed. In addition, the size of a printed circuit board (PCB) must increase with an increase in the number of balance transformers.

On the other hand, although a two polarities source is required to drive the above-mentioned true balance circuit, a problem of spacing the distance between the two polarity lines arises in the present binary balance circuit. Traditional solutions publish double layer PCBs and high voltage jumpers for increasing separation distance.

As mentioned above, an increase in the number of balance transformers, an increase in the size of the PCB, an increase in the number of high voltage jumpers, and the use of double layer PCBs will result in the cost of the backlight device occurring. will be.

The scope of the present invention is to provide a balance transformer for driving and balancing the lighting units of the backlight device to solve the above problems.

According to one embodiment, the balance transformer of the present invention includes a first main coil, a second main coil, a first induction coil, and a conductor, wherein the first main coil, the second main coil, and the first induction. The number of coils of the coils is substantially the same. The first main coil has a first contact point and a second contact point, and the second main coil has a third contact point and a fourth contact point. The first induction coil corresponds to the first main coil and the second main coil. The conductor is connected in series with a first contact point of the first main coil and a fourth contact point of the second main coil.

According to another embodiment, the first contact point of the first main coil of the balance transformer of the present invention may be electrically connected to a monopolar high voltage power source, and the monopolar high voltage power may be conducted to the fourth contact point through a conductor. . The second contact point and the third contact point may be electrically connected to lighting units of the backlight module, respectively. Thus, the balance transformer can drive the lighting units, and since the number of coils of the first induction coil is substantially the same as those of the first main coil and the second main coil, the balance transformer can drive the lighting units. I can balance it. In addition, the first induction coil may be further electrically connected to a feedback control circuit.

Another category of the present invention is to provide a backlight device that uses new balance transformers to balance the currents of the lighting units.

According to one embodiment, the backlight device comprises 2N lamps and N balance transformers, where N is a positive integer.

In this embodiment, the N balance transformers are electrically connected to the 2N lamps. The kth balance transformer of the N balance transformers includes a first main coil, a second main coil, a first induction coil, and a conductor, where k is a positive integer in the range of 1 to N. The first main coil has a first contact point and a second contact point, and the second main coil has a third contact point and a fourth contact point. The first induction coil corresponds to the first main coil and the second main coil, and the number of coils of the first induction coil is substantially the same as those of the first main coil and the second main coil. The conductor is connected in series with a first contact point of the first main coil and a fourth contact point of the second main coil.

The second contact point of the first main coil of the kth balance transformer may be connected in series to the (2k-1) th lamp of the 2N lamps, and the third contact point of the second main coil of the kth balance transformer may be 2N It is connected in series with the 2k th lamp of the lamps. In addition, the fourth contact point of the second main coil of the kth balance transformer may be connected in series with the first contact point of the (k + 1) th balance transformer of the N balance transformers. Accordingly, the N balance transformers can drive 2N lighting units, and the number of coils of each of the first induction coils is substantially the same as each of the first main coils and each of the second main coils. The N balance transformers may balance 2N lighting units. In addition, all of the induction coils of the N balance transformers may be connected in series to each other to form a loop, and the loop may be further electrically connected to a feedback control circuit.

According to another embodiment, the backlight module of the present invention further includes a second induction coil in addition to the parts of the above-mentioned embodiment. The second induction coil may be electrically connected to a protection circuit. By the protection circuit, the balance transformers can prevent irregular operation.

According to another embodiment, the backlight module of the present invention further includes 2N high voltage capacitances each connected in series to 2N lamps in addition to the parts of the above-mentioned embodiment. Further, the first contact point of the first balance transformer of the N balance transformers may be electrically connected to a monopolar high voltage power source.

Compared with the prior art, the balance transformer of the present invention and the backlight device using the same can drive two or more lighting units, and can balance the currents flowing through the lighting units by one balance transformer. In addition, the balance transformer has conductors connected in series to each of the main coils, thereby avoiding high voltage jumpers. In addition, a monopolar power source can be used as a driving source of the backlight device according to the structure of the balance transformer to avoid the problem of the separation distance, and thus a single layer PCB can be applied. As shown in the above-mentioned descriptions, the balance transformer of the present invention and the backlight device using the same can effectively reduce the cost.

The advantages and spirit of the present invention can be understood by the following quotations in conjunction with the accompanying drawings.

See FIG. 2A. 2A is an internal structural diagram showing the internal structure of the balance transformer 2 according to an embodiment of the present invention. As shown in FIG. 2A, the balance transformer 2 includes a first main coil 20, a second main coil 22, a first induction coil 24, and a conductor 26.

In this embodiment, the first main coil 20 includes a first contact point 200 and a second contact point 202, the second main coil 22 having a third contact point 220 and a fourth contact point. 222. The first induction coil 24 corresponds to the first main coil 20 and the second main coil 22. The conductor 26 is connected in series with the first contact point 202 and the fourth contact point 222 so that when the first contact point 202 is electrically connected to a power source, the power source May provide power to the fourth contact point 222 through the conductor 26.

Further, in the same balance transformer 2, the number of coils of the first main coil 20, the second main coil 22, and the first induction coil 24 may be substantially the same, but It is not limited.

See FIG. 2B. 2B is a diagram illustrating an internal structure of the balance transformer 20 according to another embodiment of the present invention. As shown in FIG. 2B, the difference between this embodiment and the final embodiment is that the balance transformer 2 of this embodiment further includes a second induction coil 28. In fact, it should be noted that the second induction coil 28 can be formed by pulling out two contact points from the first induction coil 24. Also in this embodiment the other parts of the balance transformer 2 are the same as the corresponding parts of the last embodiment and will not be described here.

See FIG. 3. FIG. 3 is a schematic diagram showing that the balance transformer 2 of FIG. 2B forms a balance circuit. As shown in Fig. 3, the first contact point 200 of the balance transformer 2 is electrically connected to a single polarity high-voltage power source 30; The second contact point 202 is electrically connected to the first lighting unit 32; The third contact point 22 is then electrically connected to the second lighting unit 34. Through the monopolar high voltage power source 30, a first main coil 20, a second main coil 22, and a conductor 26, the first writing unit 32 and the second writing unit 34. ) Can be driven to write.

In this embodiment, the number of coils of the first main coil 20, the second main coil 22, and the first induction coil 24 are substantially equal to each other, and according to the law of energy conservation, The current provided to the first writing unit 32 will be substantially the same as the current provided to the second writing unit 34. In addition, the first induction coil 24 is electrically connected to a feedback control circuit 36, and the feedback control circuit 36 is connected to the first writing unit guided by the first induction coil 24. 32, and according to the currents of the second lighting unit 34, by adjusting the power provided by the single high voltage source 30, the current of the first lighting unit 32 and the second unit 34 Match the value set by the designer or user.

In addition, the second induction coil 28 of this embodiment is electrically connected to a protection circuit 38, and through the protection circuit 38, the balance transformer 2 is balanced by the transformer 2. Irregular operation can be avoided to protect the For example, the second induction coil 28 induces a change in the current of the first main coil 20, and the protection circuit 38, the first writing unit 32 or the writing unit ( When 34 is damaged and forms an open circuit, depending on the result induced by the second induction coil 28, the balance transformer 2 or the monopolar high voltage power source 30 is selectively stopped.

Indeed, in the above-mentioned embodiment, differences in the resistances between the respective parts of the balance circuit form deviations between the currents flowing through the lighting units. It should be noted that the magnitude of the deviations depends on the resistances of the first main coil, the second main coil, the conductor, the lighting unit, or other parts of the balance circuit, but is not a fixed value. To improve in this phenomenon, one side of the lighting unit can be connected in series to a high voltage capacitance having a small capacity, thereby the first main coil, the second main coil, the conductor, the lighting of the balance circuit Differences in resistors between the unit or other parts can be ignored to obtain stable and constant lamp currents.

See FIGS. 4A and 4B. 4A and 4B are schematic diagrams showing the lighting units of FIG. 3 connected in series to the high voltage capacitances C. FIGS. As shown in FIG. 4A, the high voltage capacitances C having a small capacitance are connected to the high voltage terminals of the first and second lighting units 32 and 34, that is, the balance transformer and the It is connected in series between the lighting units. Meanwhile, as illustrated in FIG. 4B, the high voltage capacitances C may be connected in series to low voltage terminals of the first lighting unit 32 and the lighting unit 34.

See FIG. 5 and FIG. 2B. 5 is a schematic view showing a backlight device 4 according to an embodiment of the present invention. As shown in FIG. 5, the backlight device 4 includes N balance transformers 2, 2N lighting units 40, a monopolar high voltage power source 42, a feedback control circuit 44 and A protection circuit 46, where N is a positive integer. The internal structure of each of the balance transformers 2 is shown in Fig. 2b. The function of each part of the balance transformer 2 is the same as that of the corresponding part in the above-mentioned embodiment, and they will not be described here.

In this example, the second contact point 202 of the kth balance transformer 2 of the N balance transformers 2 is the (2k-1) th writing unit 40 of the 2N lighting units 40. Is connected in series, the third contact point 220 is connected in series to the 2kth writing unit 40, where k is a positive integer in the range of 1 to N. The fourth contact point 222 of the k th balance transformer 2 is connected in series with the first contact point 200 of the (k + 1) th balance transformer 2. Thus, both the first contact points 200 and the fourth contact points 222 may be connected to each other through the respective conductors 26 of the balance transformers 2.

In this example, the first contact point 200 of the first balance transformer 2 of the N balance transformers 2 is electrically connected to a monopolar high voltage power source 42. The conductors 26 are connected in series to the first contact points 200 and the fourth contact points 222 so that the single polarity high voltage power source 42 is connected to the first contact points 200 and the Power may be provided to each of the fourth contact points 222. The N lighting units 40 may be driven to write each of the first main coils 20 and each of the second main coils 22 via the monopolar high voltage power source 42. Can be. Indeed, since the balance transformer 2 connects the first contact point 200 and the fourth contact point 222 in series through the conductor 26 therein, a high voltage jumper is used to It can be avoided in the circuit configuration.

The number of coils of the first main coils 20, the second main coils 22, and the first induction coils 24 are substantially the same, so that currents provided to the lighting units 40 According to the law of energy conservation, they are substantially the same. In addition, the first induction coils 24 are connected in series to each other to form a loop, and the loop may be further connected in series to the feedback control circuit 44. The feedback control circuit 44 can adjust the power provided by the single high voltage source 30 in accordance with the currents of the lighting units 40 induced by the first induction coils 24, and thus Due to this, the currents of the lighting unit 40 may reach a value set by the designer or the user.

Further, in this embodiment each of the second induction coils 28 is electrically connected to the protection circuit 46, and through the protection circuit, the balance transformers 2 are connected to the balance transformers 2. ), The irregular operation can be prevented. For example, the second induction coil 28 of the k-th balance transformer 2 induces the fluctuation of the first main coil 29, and the protection circuit 46 is the (2k + 1) th lighting unit ( When the 40 is damaged and forms an open circuit, depending on the result induced by the second induction coil 28, the kth balance transformer 2, all balance transformers 2 or the monopolar high voltage power Selectively stop source 30.

Similarly, the backlight device 4 may have high capacitance and include high voltage capacitances C connected in series to the lighting units 40, respectively. In this embodiment, the high voltage capacitances C are each connected in series to the low voltage terminals of the lighting units 40. In practice, however, high voltage capacitances C are connected in series to the high voltage terminals of the lighting units 40, ie between each of the balance transformers 2 and each of the lighting units 40. Can be connected. High voltage capacitances C are not actually required for the backlight device 4, but the currents of the lighting units 40 caused by differences in the resistances between the respective parts of the backlight device 4. It should be noted that if the deviations of these are too large, the presence of the high voltage capacitances C is determined. For example, if the deviation of the currents of any two lighting units exceeds 5% and the designer determines that the user can easily recognize the imbalance between the two lighting units in this condition, the high voltage capacities (C) may be connected in series to each of the lighting units to improve the deviation of the currents between the two lighting units.

See FIG. 6. 6 is a schematic view showing a backlight device 5 according to another embodiment of the present invention. As shown in FIG. 6, the difference between this embodiment and the above-mentioned embodiment is that the backlight device 5 in this example includes M balance transformers 50, and the M balance transformers ( Each of 50) further includes N main coils 500, where M and N are positive integers. For the sake of brevity and clarity, only one balance transformer 50 is shown in FIG. 6.

In this example, each one contact point of the main coils 500 is connected in series to one of the N lighting units 52, respectively, and each other contact point of the main coils 500 is connected to each other. have. Thus, the balance transformer 50 can drive N lighting units. Similarly, the balance transformer 50 includes a first induction coil 504 and a second induction coil 506, where the number of coils of the first induction coil 504 is each of the main coil 500. Is substantially equal to the number of coils of; The first main coil 500 of the first balanced transformer 50 is electrically connected to a single polarity high voltage power source 54, and the N th main coil 500 of the k th balanced transformer 50 is (k + 1). By connecting to the first main coil 500 of the second balance transformer 50, all balance transformers 50 can receive the power provided by a single polarity high voltage power source 54 to drive the lighting units. , Where k is a positive integer in the range of 1 to M; The first induction coils 504 of the M balance transformers 50 of the backlight 5 are connected in series to form a loop (not shown), which loop is in addition to the feedback control circuit 56. And connected in series; The second induction coils 506 are electrically connected to the protection circuit 58; The lighting units 52 are connected in series to each of the high voltage capacitances C. The functions of these parts are the same as the functions of corresponding parts of the above-mentioned embodiment, and they will not be described here.

Compared with the prior art, the balance transformer of the present invention and the backlight device using the same can drive two or more lighting units, and can balance the currents flowing through the lighting units by one balance transformer. In addition, the balance transformer has conductors connected in series to each of the main coils, thereby avoiding high voltage jumpers. In addition, a monopolar power source can be used as a driving source of the backlight device according to the structure of the balance transformer to avoid the problem of separation distance, and thus a single layer PCB can be applied. As shown in the above-mentioned descriptions, the balance transformer of the present invention and the backlight device using the same can effectively reduce the cost.

Together with the examples and descriptions above, the features and spirits of the present invention will be explained promisingly well. Those skilled in the relevant art will readily observe that many modifications and variations of the device can be made while maintaining the teachings of the present invention. Accordingly, the above publication should be construed as limited only by the limitations and boundaries of the appended claims.

1 is a schematic diagram showing a backlight device having a true balance circuit in the prior art;

2A is an internal structural diagram showing an internal structure of a balance transformer according to an embodiment of the present invention,

Figure 2b is an internal structure showing the internal structure of the balance transformer according to another embodiment of the present invention,

3 is a schematic diagram showing that the balance transformer of FIG. 2B forms a balance circuit;

4A and 4B are schematic diagrams showing the lighting units of FIG. 3 connected to high-voltage capacitances, FIG.

5 is a schematic view showing a backlight device according to an embodiment of the present invention, and

6 is a schematic view showing a backlight device according to another embodiment of the present invention.

Claims (17)

As a balance transformer, A first main coil having a first contact point and a second contact point; A second main coil having a third contact point and a fourth contact point; A first induction coil corresponding to the first main coil and the second main coil; And And a conductor connected in series with the first contact point of the first main coil and the fourth contact point of the second main coil. The method of claim 1, And a first contact point of the first main coil is electrically connected to a high voltage power source. The method of claim 2, Wherein said high voltage power source is a single polarity high voltage power source. The method of claim 1, The number of coils of the first main coil, the second main coil, and the first induction coil are equal to each other. The method of claim 1, The first induction coil further comprises a second induction coil electrically connected to the protection circuit. delete The method of claim 1, The second contact point is electrically connected to the first lighting unit of the backlight device, and the third contact point is electrically connected to the backlight device second lighting unit. The method of claim 7, wherein The first and second lighting units are each connected in series and in series with a high voltage capacitance. The method of claim 8, The high voltage capacitances are respectively connected in series and in series between the first lighting unit and the second contact point and between the second lighting unit and the third contact point. As a backlight device, 2N lamps (N is a positive integer); And N balance transformers electrically connected to the 2N lamps; kth balance transformer (k is a positive integer ranging from 1 to N), A first main coil having a first contact point and a second contact point connected in series with the (2k-1) th lamps of the 2N lamps; A second main coil having a third contact point connected in series to a 2k th lamp of the 2N lamps and a fourth contact point connected in series to a first contact point of the (k + 1) th balance transformer of the N balance transformers; A first induction coil corresponding to the first main coil and the second main coil; And       And a conductor connected in series with the first contact point and the fourth contact point. And N first induction coils of the N balance transformers are connected in series to each other to form a loop. 11. The method of claim 10, And a single polarity high voltage power source electrically connected to the first balanced transformers of the N balanced transformers. 11. The method of claim 10, The number of coils of the first main coil, the second main coil, and the first induction coil are the same. 11. The method of claim 10, Each of the first induction coils further comprises a second induction coil electrically connected to the protection circuit. delete 11. The method of claim 10, And the loop formed of N first induction coils connected in series to each other is further connected in series to a feedback control circuit. 11. The method of claim 10, Each of said lamps is connected in series to a high voltage capacitance. The method of claim 16, The high voltage capacitances are respectively connected in series and in series between all of the lamps and the corresponding first main coil, or between all of the lamps and the corresponding second main coil.

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