KR101685908B1 - Apparatus for supplying power, back light unit and display apparatus using the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a power supply device, a backlight unit, and a display device using the power supply device. The power supply device of the present invention includes an input power supply, a booster inductor connected between the input power supply and the first node, a first diode connected between the first node and the output node, a first diode connected between the first node and the second node, An inductor, a switching element connected between the second node and the base power supply, a second diode connected between the second node and the third node, a capacitor connected between the third node and the base power supply, and a capacitor connected between the third node and the output node And a second inductor connected to the second inductor.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device, a backlight unit using the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a power supply device, and more particularly, to a power supply device capable of reducing a switching loss of a switching device to improve efficiency, a backlight unit using the same, and a display device.

Generally, the power supply device rectifies and supplies a DC voltage to an apparatus (for example, a display device) by stepping up or down the DC voltage to a required voltage by rectifying the AC voltage using an AC voltage.

1 is a view schematically showing a conventional power supply apparatus.

Referring to FIG. 1, a conventional power supply device is a step-up converter including a booster inductor Lb, a diode D, a capacitor C, and a switching device S. The step-up converter boosts the input voltage Vin by outputting the energy stored in the booster inductor Lb through the diode D in accordance with the switching of the switching element S. [

However, in the conventional step-up converter, as shown in FIG. 2, when the switching element S is turned on, since the switching element S performs hard switching, the switch voltage V _The switching loss SL due to the area where the switch current I _s intersects with the switching current I _S is generated and the efficiency is lowered. Further, since the switching loss is proportional to the switching frequency of the switching element S, there is a problem that the switching loss also increases when the switching frequency is increased.

In addition, the conventional step-up converter has a problem that switching loss is generated due to the transient current and the input current due to the reverse recovery characteristic of the diode D and the efficiency is lowered.

As a result, the conventional step-up converter has a problem that the efficiency is lowered due to the switching loss due to the hard switching of the switching element S and the switching loss due to the reverse recovery characteristic of the diode D.

In recent years, the switching frequency has to be increased in order to meet the trend of high density and miniaturization of the power supply device, and a solution for solving the problem of efficiency reduction due to the switching loss is indispensable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a power supply device, a backlight unit, and a display device using the power supply device.

According to an aspect of the present invention, there is provided a power supply apparatus including an input power source, a booster inductor connected between an input power source and a first node, a first diode connected between a first node and an output node, A second diode connected between the second node and the third node, a capacitor connected between the third node and the base power supply, a second inductor connected between the second node and the base power supply, And a second inductor connected between the third node and the output node.

According to an aspect of the present invention, there is provided a power supply apparatus including an input power source, a booster inductor connected between an input power source and a first node, a first inductor connected between a first node and a second node, A switching device connected between the first node and the base supply, a second diode connected between the first node and the third node, a second diode connected between the third node and the base supply, A capacitor, and a second inductor connected between the third node and the output node.

According to an aspect of the present invention, there is provided a power supply device including a booster inductor to which a current is supplied from an input power source, a switching device to control a current flowing in the booster inductor according to switching, And a second current path, linearly increasing a current flowing through the switching element when the switching element is turned on, and switching at least one of the first and second current paths according to the switching of the switching element. And a current path forming portion forming a current path.

According to an aspect of the present invention, there is provided a backlight unit including a driving voltage supply unit including a power supply device according to the present invention, at least one light emitting diode connected in parallel to an output node of the power supply device according to the present invention, And a duty controller for generating a switching control signal having a predetermined duty and controlling the switching of the switching device configured in the power supply device according to the present invention.

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According to an aspect of the present invention, there is provided a display device including a liquid crystal display panel displaying a predetermined image by adjusting a light transmittance of a liquid crystal, and a backlight unit according to the present invention for irradiating light to a liquid crystal display panel do.

According to an aspect of the present invention, there is provided a display device including a display panel for displaying a predetermined image, and a power supply device for generating a power source for driving the display panel.

According to the above-mentioned solution, the present invention provides the following effects.

First, by switching the switching element when the switching element is turned on, the switching loss due to the area where the switching voltage and the switching current cross each other can be reduced to improve the efficiency of the power supply.

Second, it is possible to cope with high density and miniaturization tendency of the power supply device.

1 is a view schematically showing a conventional power supply apparatus.
2 is a waveform diagram for explaining a switching loss generated in a conventional power supply apparatus.
3 is a schematic view of a power supply apparatus according to a first embodiment of the present invention.
4 is a waveform diagram for explaining a switching loss of the power supply apparatus according to the first embodiment of the present invention.
FIGS. 5A to 5D are diagrams showing a step-by-step driving mode of the power supply apparatus according to the first embodiment of the present invention.
6 is a waveform diagram showing voltage and current waveforms according to the driving modes shown in Figs. 5A to 5D.
7 is a graph illustrating the efficiency of the power supply apparatus according to the first embodiment of the present invention.
8 is a schematic view of a power supply apparatus according to a second embodiment of the present invention.
9 is a waveform diagram for explaining a switching loss of the power supply device according to the second embodiment of the present invention.
FIGS. 10A to 10D are diagrams illustrating a driving mode of the power supply apparatus according to the second embodiment of the present invention.
11 is a waveform diagram showing voltage and current waveforms according to the driving mode shown in Figs. 10A to 10D.
12 is a graph illustrating the efficiency of the power supply device according to the second embodiment of the present invention.
13 is a view for schematically explaining a backlight unit according to an embodiment of the present invention.
FIG. 14 is a view for schematically explaining a display device according to the first embodiment of the present invention.
15 is a view for schematically explaining a display device according to a second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic view of a power supply apparatus according to a first embodiment of the present invention.

3, the power supply 100 according to the first embodiment of the present invention includes an input power source Vin, a booster inductor Lb, a switching element S, and a current path forming unit 110 .

The input power supply Vin generates a DC power of a predetermined level and supplies it to the booster inductor Lb.

The booster inductor Lb is connected between the input power supply Vin and the first node N1 and has a first terminal connected to the input power supply Vin and a second terminal connected to the first node N1 do. The booster inductor Lb stores the current supplied from the input power source Vin in accordance with the switching of the switching element S or supplies the stored current to the current path forming unit 110. [

The switching element S is connected between the first node N1 and the base power supply and is switched in response to a switching control signal having a predetermined duty from a switching control unit (not shown). The switching element S is switched according to the switching control signal to control the current flowing in the booster inductor Lb. At this time, the switching element S may be a field effect transistor (FET), an insulated gate bipolar transistor (IGBT), or an integrated gate commutated thyristor (IGCT).

The current path forming part 110 forms first and second current paths between the booster inductor Lb and the output node No and is connected to the switching element S on the turn- S and linearly increases at least one of the first and second current paths in accordance with the switching of the switching element S. [

To this end, the current path forming unit 110 includes a first diode D1, a first inductor L1, a second diode D2, a capacitor C, and a second inductor L2 .

The first diode D1 is connected between the first node N1 and the output node No and has an anode terminal connected to the first node N1 and a cathode terminal connected to the output node No . The first diode D1 is conductive when the voltage of the first node N1 is higher than the output node No to form a first current path between the booster inductor Lb and the output node No, And is opened when the voltage of the node N1 is lower than the output node No to shut off the reverse current flowing from the output node No to the booster inductor Lb.

The first inductor L1 has a first terminal connected to the first node N1 and a second terminal connected to the second node N2 connected to the switching element S. [ When the switching device S is turned on from the off state to the on state, the first inductor L1 linearly changes the current flowing from the booster inductor Lb to the switching device S And linearly decreases the current flowing to the first diode (D1). That is, the first inductor L1 adjusts the slope of the current flowing in the switching element S when the switching element S is turned on, so that the switching element S is switched to the soft switching Switching). Accordingly, the switching element (S) turn-turns on the switching element (S), a soft switching by being a region in which a switch voltage (V _S) and the switch current (I _S) crossing is minimized switching losses (Switching Loss) (SL) And the switching loss generated in the switching element S is reduced by the reverse recovery characteristic of the first diode D1.

3, the second diode D2 is connected between the second node N2 and the third node N3. The second diode D2 is connected between the anode terminal connected to the second node N2 and the third node N3 And has a cathode terminal connected thereto. The second diode D2 outputs the current supplied from the first inductor Ll to the third node N3 when the switching element S is off. At this time, the current output from the second diode D2 to the third node N3 when the switching element S is off gradually decreases in accordance with the voltage of the third node N3, and the voltage of the third node N3 Is equal to or higher than the voltage applied to the switching element (S).

The capacitor C is connected between the third node N3 and the base power supply. The capacitor C is charged by the current output from the second diode D2, and discharges the charged charge to the third node N3.

On the other hand, the capacitor C prevents the voltage applied to the switching element S from rising due to the resonance of the parasitic capacitors of the first inductor L1 and the switching element S when the switching element S is off.

The second inductor L2 is connected between the third node N3 and the output node No and has a first terminal connected to the third node N3 and a second terminal connected to the output node No Respectively. That is, the second inductor L2 is connected between the cathode terminals of the first and second diodes D1 and D2. The second inductor L2 forms a second current path between the second diode D2 and the output node No or charges the capacitor C and the output node No according to the charge charged in the capacitor C. [ Lt; RTI ID = 0.0 > current < / RTI >

Meanwhile, the power supply device according to the embodiment of the present invention may further include a smoothing capacitor Cd connected between the output node No and the base power supply.

The smoothing capacitor Cd makes the power output from the current path forming unit 110 to the output node No constant. The smoothing capacitor Cd may be embedded in a load circuit connected to the output node No. Here, the load may be a light emitting diode (LED), various information devices, a display device, or the like.

5A to 5D are diagrams showing a step-by-step driving mode of the power supply device according to the first embodiment of the present invention, and Fig. 6 is a waveform diagram showing voltage and current waveforms according to the driving mode shown in Figs. 5A to 5D .

5A to 5D and FIG. 6, a method of driving the power supply device according to the first embodiment of the present invention will be described.

5A and 6, when the switching device S is turned on from the off state to the on state, the booster inductor Lb ) a first diode ((I _D1 current that flows in D1)) decreases linearly and the current (I _S) flowing through the switching element (S) from an input from an input power supply (Vin) by a first inductor (L1) The input current I _In Lt; / RTI > increases linearly. In other words, when starting to come from the switching element (S) is turned off, input current (I _In) is the current of the first diode _(D1) (I D1) and the current of the switching element (S) (I _S) (or current of the first inductor _(L1) (I L1)) the first current of the diode (D1) from the sum of (I _D1) is reduced linearly, the current of the switching element _(S) (I S) comprises a first inductor (L1). ≪ / RTI > Accordingly, when the switching element S is turned on, the switching element S is soft-switched according to the switching current linearly increased by the first inductor Ll, The switching loss SL generated in the switching operation of the switching element S is minimized.

Next, in the second drive mode M2, as shown in FIGS. 5B and 6, when the switching element S is in the ON state, the first and second nodes N1 and N2 voltage since the base power and is open the first and second diodes (D1, D2), the charge (I _C) charging the capacitor (C) is output to the output node (No) through a second inductor (L2) .

Next, in the third drive mode M3, as shown in FIG. 5C and FIG. 6, when the switching element S is rapidly switched from the on state to the hard state, the input power Vin ), The booster inductor Lb, the first inductor L1, the second diode D2, the second inductor L2 and the output node No are formed, and the second diode D2 A part of the current outputted from the capacitor C is charged in the capacitor C. That is, when the switching element S is turned off, the input current I _In and the current I _Lb stored in the booster inductor Lb flow to the output node No through the second diode D2. The current I _D2 flowing through the second diode D2 flows through the third node N3 and the third node N3 through the second inductor L2 and the current I _L2 flowing to the output node No, Lt; RTI ID = 0.0 > I _C < / RTI >

Further, since the switching element S is off, the voltage of the first node N1 rises to the voltage of the output node No.

5D and FIG. 6, when the OFF state of the switching element S is maintained in the fourth drive mode M4, the charge charged in the capacitor C is transferred to the third node N3, The first diode D1 is turned on as the current flowing through the second diode D2 is reduced by the discharge of the capacitor C and the booster inductor (Lb), a first diode (D1), and an output node (No). That is, if the voltage of the capacitor C charged by the current I _D2 flowing through the second diode D2 becomes higher than the voltage of the output node No when the switching element S maintains the off state, The capacitor C discharges the charged electric charge I _C to the output node No through the third node N 3 and the second inductor L 2 so that the voltage of the third node N 3 is discharged from the capacitor C to be raised by the current (I _C) is equal to the switch voltage across the switching device _(S) (V S). Accordingly, as the voltage of the third node N3 rises and the current I _D2 flowing through the second diode D2 gradually decreases, the current I _L1 flowing through the first inductor L 1 also gradually decreases . On the other hand, since the voltage of the first node N1 gradually rises and becomes higher than the voltage of the output node No, the first diode D1 becomes conductive, so that the booster inductor Lb, the first diode D1, (No) is formed.

The power supply apparatus 100 according to the first embodiment of the present invention is different from the power supply apparatus 100 according to the first embodiment in that the first to fourth drive modes M1 to M4 are divided into operations for one cycle of the switching control signal, To the fourth drive mode (M1 to M4), thereby outputting a constant power to the output node (No).

7 is a graph illustrating the efficiency of the power supply apparatus according to the first embodiment of the present invention.

As shown in FIG. 7, the efficiency (O) of the power supply apparatus 100 according to the first embodiment of the present invention is improved to 92.1 to 93.5% as compared with the conventional (□). 4, the power supply device 100 according to the first embodiment of the present invention includes a turn-on current path forming part 110 of the switching device S, That is, a region in which the switch voltage V _s and the switch current I _s cross each other by linearly increasing the current flowing through the first switching element S through the first inductor Ll so as to soft- . Therefore, the power supply device 100 according to the first embodiment of the present invention reduces the switching loss of the switching element S at the time of turn-on of the switching element S, thereby minimizing the efficiency reduction due to the switching loss. It is possible to provide improved efficiency.

8 is a schematic view of a power supply apparatus according to a second embodiment of the present invention.

Referring to FIG. 8, the power supply 200 according to the second embodiment of the present invention includes an input power source Vin, a booster inductor Lb, a switching device S, and a current path forming unit 210 .

The input power supply Vin generates a DC power of a predetermined level and supplies it to the booster inductor Lb.

The booster inductor Lb is connected between the input power supply Vin and the first node N1 and has a first terminal connected to the input power supply Vin and a second terminal connected to the first node N1 do. The booster inductor Lb stores the current supplied from the input power source Vin in accordance with the switching of the switching element S or supplies the stored current to the current path forming unit 210.

The switching element S is connected between the first node N1 and the base power supply and is switched in response to a switching control signal having a predetermined duty from a switching control unit (not shown). The switching element S is switched according to the switching control signal to control the current flowing in the booster inductor Lb. At this time, the switching element S may be a field effect transistor (FET), an insulated gate bipolar transistor (IGBT), or an integrated gate rectifying thyristor (IGCT).

The current path forming part 210 forms first and second current paths between the booster inductor Lb and the output node No and is connected to the switching element S 1 when the switching element S is turned on S and linearly increases at least one of the first and second current paths in accordance with the switching of the switching element S. [

To this end, the current path forming unit 210 includes a first inductor L1, a first diode D1, a second diode D2, a capacitor C, and a second inductor L2 .

The first inductor L1 has a first terminal connected to the first node N1 and a second terminal connected to the first diode D1. When the switching device S is turned on from the off state to the on state, the first inductor L1 linearly changes the current flowing from the booster inductor Lb to the switching device S And linearly decreases the current flowing to the first diode (D1). That is, the first inductor L1 controls the slope of the current flowing in the switching element S when the switching element S is turned on, so that the switching element S is soft-switched as shown in Fig. 9 . Accordingly, when the switching element S is turned on, the switching element S is soft-switched so that the area where the switch voltage V _s and the switch current I _s intersect is minimized, thereby reducing the switching loss SL In addition, the switching loss generated in the switching element S is reduced by the reverse recovery characteristic of the first diode D1.

The first diode D1 is connected between the second node N2 connected to the second terminal of the first inductor L1 and the output node No and includes an anode terminal connected to the second node N2, And a cathode terminal connected to the output node No. The first diode D1 is conductive when the voltage of the second node N2 is higher than the output node No to form a first current path between the booster inductor Lb and the output node No, And is opened when the voltage of the second node N2 is lower than the output node No to shut off the reverse current flowing from the output node No to the booster inductor Lb.

The second diode D2 is connected between the first node N1 and the third node N3 and includes an anode terminal connected to the first node N1 and a cathode terminal connected to the third node N3 Respectively. The second diode D2 outputs the current supplied from the booster inductor Lb when the switching element S is off to the third node N3. At this time, the current output from the second diode D2 to the third node N3 when the switching element S is off gradually decreases in accordance with the voltage of the third node N3, and the voltage of the third node N3 Is equal to or higher than the voltage applied to the switching element (S).

The capacitor C is connected between the third node N3 and the base power supply. The capacitor C is charged by the current output from the second diode D2, and discharges the charged charge to the third node N3.

On the other hand, the capacitor C prevents the voltage applied to the switching element S from rising due to the resonance of the off-state inductor of the switching element S and the parasitic capacitor of the switching element S.

The second inductor L2 is connected between the third node N3 and the output node No and has a first terminal connected to the third node N3 and a second terminal connected to the output node No Respectively. That is, the second inductor L2 is connected between the cathode terminals of the first and second diodes D1 and D2. The second inductor L2 forms a second current path between the second diode D2 and the output node No or charges the capacitor C and the output node No according to the charge charged in the capacitor C. [ Lt; RTI ID = 0.0 > current < / RTI >

Meanwhile, the power supply device according to the embodiment of the present invention may further include a smoothing capacitor Cd connected between the output node No and the base power supply.

The smoothing capacitor Cd makes the power output from the current path forming unit 210 to the output node No constant. The smoothing capacitor Cd may be embedded in a load circuit connected to the output node No.

10A to 10D are diagrams showing a step-by-step driving mode of the power supply apparatus according to the second embodiment of the present invention, and Fig. 11 is a waveform diagram showing voltage and current waveforms according to the driving mode shown in Figs. 10A to 10D .

10A to 10D and FIG. 11, a method of driving the power supply device according to the second embodiment of the present invention will be described.

10A and 11, in the first drive mode M1, when the switching element S is turned on from the off state to the on state, the booster inductor Lb ) a first diode ((I _D1 current that flows in D1)) is a current (I _S) decreases linearly and flows to the switching element (S) by a first inductor (L1) from the input from the input power source (Vin) _Lt ; RTI ID = 0.0 > ( _IIn ) < / RTI > That is, when the switching element S starts to be turned on in the off state, the input current I _In becomes equal to the current I _D1 of the first diode D 1 (or the current I _L1 of the first inductor L 1) and the current of the switching element (S) the first diode (D1) from the sum of the currents (I _S) of (I _D1) is a current of the switching element (S) while the reduced linearly by a first inductor (L1) (I _S ) increases linearly. Accordingly, the slope of the current I _S flowing through the switching element S in the turn-on state of the switching element S is adjusted so as to linearly increase by the first inductor Ll, , The switching loss SL generated in switching of the switching element S is minimized.

Next, in the second drive mode M2, when the switching element S is in the ON state as shown in FIGS. 10B and 11, when the voltage of the first node N1 is lower than the voltage of the base power The first and second diodes D1 and D2 are opened and the charge charged in the capacitor C is output to the output node No through the second inductor L2

Next, in the third drive mode M3, as shown in FIG. 10C and FIG. 11, when the switching element S is quickly switched to the OFF state in the ON state, the input power Vin, A second current path leading to the first diode Lb, the second diode D2, the second inductor L2 and the output node No is formed and a part of the current output from the second diode D2 is connected to the capacitor C . That is, when the switching element S is turned off, the input current I _In and the current I _Lb stored in the booster inductor Lb flow to the output node No through the second diode D2. The current I _D2 flowing through the second diode D2 flows through the third node N3 and the third node N3 through the second inductor L2 and the current I _L2 flowing to the output node No, Lt; RTI ID = 0.0 > I _C < / RTI >

Further, since the switching element S is off, the voltage of the second node N2 rises to the voltage of the output node No.

Next, in the fourth drive mode M4, when the off state of the switching element S is maintained, as shown in Figs. 10D and 11, the charge charged in the capacitor C is transferred to the third node N3, The first diode D1 is turned on as the current flowing through the second diode D2 is reduced by the discharge of the capacitor C and the booster inductor A first current path leading to the first inductor Lb, the first inductor L1, the first diode D1, and the output node No is formed. That is, when the switching element S maintains the OFF state, when the charging voltage of the capacitor C due to the current I _D2 flowing through the second diode D2 becomes higher than the output node No, Since the charge of the third node N3 is discharged to the output node No through the third node N3 and the second inductor L2 to the current I _C discharged from the capacitor C . Accordingly, as the voltage of the third node N3 rises and the current I _D2 flowing through the second diode D2 gradually decreases, the current I _L1 flowing through the first inductor L 1 gradually increases . Accordingly, when the voltage of the second node N2 gradually rises and becomes higher than the voltage of the output node No, the first diode D1 is turned on, so that the booster inductor Lb, the first inductor L1, (D1), and the output node (No).

The power supply device 200 according to the second embodiment of the present invention is different from the power supply device 200 according to the first to fourth drive modes M1 to M4 described above, To the fourth drive mode (M1 to M4), thereby outputting a constant power to the output node (No).

12 is a graph illustrating the efficiency of the power supply device according to the second embodiment of the present invention.

12, it can be seen that the efficiency (●) of the power supply device 200 according to the second embodiment of the present invention is 94 to 94.8%, which is improved compared to the conventional case (3). 9, the power supply device 200 according to the second embodiment of the present invention includes a turn-on current path forming unit 210 of the switching device S, That is, a region in which the switch voltage V _s and the switch current I _s cross each other by linearly increasing the current flowing through the first switching element S through the first inductor Ll so as to soft- . Therefore, the power supply device 200 according to the second embodiment of the present invention reduces the switching loss of the switching element S when the switching element S is turned on, minimizes the efficiency reduction caused by the switching loss, It is possible to provide improved efficiency.

13 is a view for schematically explaining a backlight unit according to an embodiment of the present invention.

Referring to FIG. 13, a backlight unit 300 according to an embodiment of the present invention includes a driving voltage supplier 310, a plurality of light emitting diode arrays LA1 to LAn, and a duty controller 320. Referring to FIG.

The driving voltage supplying unit 310 generates a driving voltage necessary for driving the plurality of light emitting diode arrays LA1 to LAn under the control of the duty controller 320 using the input power Vin supplied from the outside, And supplies a driving voltage to the plurality of light emitting diode arrays LA1 to LAn. To this end, the driving voltage supply unit 310 may include a power supply device 100 according to the first embodiment of the present invention shown in FIG. 3 or a power supply device 200 according to the second embodiment of the present invention shown in FIG. ). Hereinafter, the description of the power supply apparatuses 100 and 200 will be replaced with the above description of Figs. 3 to 12.

Each of the plurality of light emitting diode arrays LA1 to LAn is electrically connected in parallel to the driving voltage supply unit 310, that is, the output node No (see FIG. 3 or 8) of the power supply units 100 and 200. Each of the plurality of light emitting diode arrays LA1 to LAn includes a plurality of light emitting diodes (LEDs) electrically connected in series between the output node No of the power supply devices 100 and 200 and the base power supply.

The duty controller 320 generates a switching control signal SCS having a predetermined duty to control switching of the switching elements Sl of the power supply devices 100 and 200 (see FIG. 3 or FIG. 8).

The duty controller 320 detects the current flowing through the plurality of light emitting diode arrays LA1 to LAn and controls the duty of the switching control signal SCS to adjust the current flowing in the plurality of light emitting diode arrays LA1 to LAn to a constant .

The backlight unit 300 according to the exemplary embodiment of the present invention controls the switching of the switching elements S included in the driving voltage supply unit 310 so that a constant driving voltage Vs is applied to the plurality of light emitting diode arrays LA1 to LAn, Emitting diodes (LEDs) of the plurality of light emitting diode arrays LA1 to LAn to generate light having a predetermined luminance by supplying a predetermined voltage Vd.

FIG. 14 is a view for schematically explaining a display device according to the first embodiment of the present invention.

Referring to FIG. 14, the display apparatus according to the first embodiment of the present invention includes a display panel 400, a panel driver 500, and a power supply 600.

The display panel 400 displays an image corresponding to input data (R, G, B) supplied according to the driving of the panel driver 500. The display panel 400 may include a liquid crystal display panel, an organic light emitting display panel, a field emission display panel, or a plasma display panel. And the like can be used as the display panel of the digital display device.

The panel driver 500 displays an image corresponding to the input data RGB input from the outside on the display panel 400. To this end, the panel driver 500 includes a timing controller 510, a data driver circuit 520, and a scan driver 530.

The timing controller 510 aligns the input data (RGB) input from the outside to be suitable for driving the display panel 200, and supplies the data to the data driving circuit unit 520.

The timing controller 510 includes a vertical synchronization signal Vsync; A horizontal synchronizing signal Hsync; A data enable signal (Data Enable); A data control signal DDS for controlling the operation timings of the data driving circuit portion 520 and the scan driving circuit portion 530 and a scan control signal DSS for controlling the operation timing of the scan driving circuit portion 530 using a timing synchronization signal TSS including a dot clock DCLK, SDS).

The data driving circuit unit 520 latches the data signals R, G, and B input from the timing control unit 510 according to the data control signal DDS supplied from the timing control unit 510, And supplies it to the data lines DL.

The scan driving circuit unit 530 generates scan pulses in accordance with the scan control signal SDS supplied from the timing controller 510 and sequentially supplies the scan pulses to the scan lines SL.

The power supply unit 600 generates driving voltages necessary for driving the display panel 400 and the panel driver 500 using input power supplied from the outside. To this end, the power supply unit 600 may include the power supply 100 according to the first embodiment of the present invention shown in FIG. 3 or the power supply 200 according to the second embodiment of the present invention shown in FIG. 8, . Hereinafter, the description of the power supply apparatuses 100 and 200 will be replaced with the above description of Figs. 3 to 12.

15 is a view for schematically explaining a display device according to a second embodiment of the present invention.

Referring to FIG. 15, a display apparatus according to a second embodiment of the present invention includes a liquid crystal display panel 700, a panel driver 800, a backlight unit 300, and a power supply unit 900.

The liquid crystal display panel 700 includes a plurality of pixels P formed in regions defined by a plurality of gate lines GL and a plurality of data lines DL.

Each of the plurality of pixels P includes a thin film transistor (not shown) connected to the gate line GL and the data line DL, and a liquid crystal cell connected to the thin film transistor.

The liquid crystal display panel 700 displays an image by adjusting the transmittance of the light emitted from the backlight unit 300 by forming an electric field in the liquid crystal cell according to the pixel voltage supplied to each pixel P. [

The panel driver 800 displays an image corresponding to input data (RGB) input from the outside on the liquid crystal display panel 700. To this end, the panel driver 800 includes a timing controller 810, a data driving circuit 820, and a gate driving circuit 830.

The timing controller 810 arranges input data (RGB) input from the outside to be suitable for driving the liquid crystal display panel 700, and supplies the data to the data driving circuit portion 820.

The timing control unit 810 receives the data control signal DCS and the gate control signal DCS for controlling the operation timing of the data driving circuit unit 820 and the gate driving circuit unit 830 using the input timing synchronization signal TSS GCS).

The timing synchronization signal TSS includes a vertical synchronization signal Vsync; A horizontal synchronizing signal Hsync; A data enable signal (Data Enable); And a dot clock (DCLK).

The data control signal DCS includes a source start pulse (Source Start Pulse); A source sampling clock; Source Output Enable; And a polarity control signal POL.

The gate control signal GCS includes a gate start pulse (Gate Start Pulse); A gate shift clock; And gate output enable (Gate Output Enable).

The data driving circuit 820 latches the data signals R, G and B inputted from the timing controller 810 in accordance with the data control signal DCS supplied from the timing controller 810 and outputs the analog positive / Converts the latched data signal to a positive / negative polarity analog pixel voltage using a gamma voltage, generates a pixel voltage having a polarity corresponding to the polarity control signal, and supplies the pixel voltage to the data lines DL.

The gate driving circuit unit 830 generates gate pulses in accordance with the gate control signal GCS supplied from the timing controller 810 and sequentially supplies the gate pulses to the gate lines GL.

The backlight unit 300 irradiates light to the liquid crystal display panel 700 using a light emitting diode (LED). To this end, the backlight unit 300 includes the backlight unit according to the embodiment of the present invention shown in FIG. 13, so that the description thereof will be replaced with the above description.

Meanwhile, the backlight unit 300 may further include a plurality of optical members for improving the brightness characteristics of light emitted from the plurality of light emitting diode arrays.

The power supply unit 900 generates driving voltages necessary for driving the liquid crystal display panel 700 and the panel driving unit 800 using input power supplied from the outside. To this end, the power supply unit 900 may include the power supply 100 according to the first embodiment of the present invention shown in FIG. 3 or the power supply 200 according to the second embodiment of the present invention shown in FIG. 8, . Hereinafter, the description of the power supply apparatuses 100 and 200 will be replaced with the above description of Figs. 3 to 12.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100, 200: power supply unit 110, 210: current path forming unit
300: backlight unit 310: driving voltage supply unit
320: duty controller 400: display panel
500, 800: a panel driving part 700: a liquid crystal display panel

Claims (16)

Input power;
A booster inductor connected between the input power supply and a first node;
A first diode connected between the first node and the output node;
A first inductor connected between the first node and the second node;
A switching element connected between the second node and the base power supply;
A second diode connected between the second node and the third node;
A capacitor connected between the third node and the base power supply, charged by the current output from the second diode, and discharging the charged charge to the third node; And
And a second inductor connected between the third node and the output node, the second inductor being connected between a cathode terminal of the first diode and a cathode terminal of the second diode. Input power;
A booster inductor connected between the input power supply and a first node;
A first inductor connected between the first node and the second node;
A first diode connected between the second node and the output node;
A switching element connected between the first node and a base power supply;
A second diode connected between the first node and the third node;
A capacitor connected between the third node and the base power supply, charged by the current output from the second diode, and discharging the charged charge to the third node; And
And a second inductor connected between the third node and the output node, the second inductor being connected between a cathode terminal of the first diode and a cathode terminal of the second diode. A booster inductor to which a current is supplied from an input power supply;
A switching device for controlling a current flowing in the booster inductor according to switching; And
Wherein the first and second current paths are formed between the booster inductor and the output node and linearly increase the current flowing through the switching element when the switching element is turned on, And a current path forming part forming at least one current path of the first and second current paths according to the current path,
The current path forming unit includes:
A capacitor charged by the current output from the second diode and discharging the charged charge to the third node; And
And a second inductor connected between the cathode terminal of the first diode and the cathode terminal of the second diode. The method of claim 3,
The current path forming unit includes:
A first diode forming the first current path between the booster inductor and the output node;
A first inductor for linearly increasing a current supplied from the booster inductor to the switching element;
A second diode for outputting a current supplied from the first inductor;
A capacitor charged by a current output from the second diode; And
And a second inductor forming the second current path between the second diode and the output node or forming a third current path between the capacitor and the output node in accordance with the voltage of the capacitor. Power supply. 5. The method of claim 4,
In a first drive mode in which the switching element is turned on from an Off state to an On state,
Wherein a current flowing from the booster inductor to the first diode is linearly decreased and a current flowing from the booster inductor to the switching element through the first inductor is a current flowing from the booster inductor Lt; RTI ID = 0.0 > 1, < / RTI > 5. The method of claim 4,
In a second drive mode in which the switching element is kept on,
Wherein the first and second diodes are opened and charge charged in the capacitor is output to the output node through the second inductor. 5. The method of claim 4,
In the third drive mode in which the switching element is turned off in the on state to maintain the off state,
The second current path leading to the input power source, the booster inductor, the first inductor, the second diode, the second inductor, and the output node is formed, and a part of the current output from the second diode is And the capacitor is charged. 8. The method of claim 7,
In the fourth drive mode after the third drive mode in which the switching element maintains the OFF state,
The charge stored in the capacitor is output to the output node through the second inductor, and as the current flowing through the second diode is reduced by the discharge of the capacitor, the first diode is turned on and the booster inductor and the first A diode and the first current path leading to the output node are formed. The method of claim 3,
The current path forming unit includes:
A first inductor for linearly increasing a current supplied from the booster inductor to the switching element;
A first diode forming the first current path between the first inductor and the output node;
A second diode for outputting a current output from the booster inductor;
A capacitor charged by a current output from the second diode; And
And a second inductor forming the second current path between the second diode and the output node or forming a third current path between the capacitor and the output node in accordance with the voltage of the capacitor. Power supply. 10. The method of claim 9,
In a first drive mode in which the switching element is turned on from an Off state to an On state,
Wherein a current flowing from the booster inductor to the first diode through the first inductor is linearly decreased by the first inductor and a current flowing from the booster inductor to the switching element is a current flowing from the booster inductor Lt; RTI ID = 0.0 > 1, < / RTI > 10. The method of claim 9,
In a second drive mode in which the switching element is kept on,
Wherein the first and second diodes are opened and charge charged in the capacitor is output to the output node through the second inductor. 10. The method of claim 9,
In the third drive mode in which the switching element is turned off in the on state to maintain the off state,
Wherein the second current path leading to the input power source, the booster inductor, the second diode, the second inductor, and the output node is formed and a portion of the current output from the second diode is charged to the capacitor Features a power supply. 13. The method of claim 12,
In the fourth drive mode after the third drive mode in which the switching element maintains the OFF state,
The charge stored in the capacitor is output to the output node through the second inductor, and as the current flowing through the second diode is reduced by the discharge of the capacitor, the first diode is turned on and the booster inductor and the first And the first current path leading to the inductor and the first diode and the output node is formed. A driving voltage supplier configured to include the power supply device according to any one of claims 1 to 13;
At least one light emitting diode array connected in parallel to an output node of the power supply; And
And a duty controller for generating a switching control signal having a predetermined duty and controlling switching of the switching device configured in the power supply device,
Wherein the light emitting diode array comprises a plurality of light emitting diodes electrically connected in series. A liquid crystal display panel that displays a predetermined image by adjusting a light transmittance of a liquid crystal; And
The display device according to claim 14, comprising a backlight unit according to claim 14 for emitting light to the liquid crystal display panel. A display panel for displaying a predetermined image; And
And a power supply device according to any one of claims 1 to 13 for generating a power supply necessary for driving the display panel.

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