KR20110057522A - Method, driver apparatus and display apparatus for driving luminous device for back light unit - Google Patents

Abstract

PURPOSE: A method and device for driving a light emitting device for a backlight and a display device using the same are provided to enable a transformer to alternatively drive switching devices, thereby converting a DC voltage into an AC voltage. CONSTITUTION: An inverter unit(110) converts a DV voltage inputted from a voltage input terminal into an AC voltage. A transformer(120) boosts a transformed AC voltage according to a boost ratio. A rectifying unit(130) converts the boosted AC voltage into a DC voltage. A light emitting unit(150) drives a light emitting device array by a driving current. A sensor detects a current value flowing in at least one resistor for a sensor.

Description

Method and apparatus for driving a light emitting device for a backlight and a display device using the same {METHOD, DRIVER APPARATUS AND DISPLAY APPARATUS FOR DRIVING LUMINOUS DEVICE FOR BACK LIGHT UNIT}

The present invention relates to a method and apparatus for driving a light emitting device for a backlight and a display device using the same. More specifically, the present invention relates to a technology for driving a light emitting device for a backlight by using a high voltage DC voltage.

The backlight light emitting device driving apparatus receives a DC voltage and drives a light emitting device such as a light emitting diode (LED) using the DC voltage. Since the direct current voltage inputted by the conventional backlight LED driving device has a voltage value that is too low to efficiently drive the LED, the backlight LED driving device of the backlight requires a low voltage to efficiently drive the LED array. It is necessary to boost the input DC voltage. Therefore, the conventional light emitting device driving apparatus has driven a light emitting device array by boosting a DC voltage of a low voltage inputted by a boosting means such as a DC-DC converter.

However, even if the conventional light emitting device driving apparatus boosts a DC voltage having a low voltage by using a DC-DC converter or the like, the range in which the voltage can be boosted is very limited. For this reason, not only the light emitting devices cannot be connected in series, but also there is a problem in that the number of light emitting device arrays becomes large.

In addition, increasing the number of light emitting device arrays requires one or more more balancer devices to adjust the driving current for driving each light emitting device array, thereby increasing power consumption. The problem arises. Even if one or more balancer elements are additionally used to adjust the driving current for driving each light emitting element array, if a deviation between the driving currents supplied to the light emitting element arrays still occurs, due to the additional configuration of the one or more balancer elements, There is a problem in that the number of components constituting the light emitting device driving apparatus for the backlight increases and the manufacturing cost increases.

On the other hand, even when driving a light emitting device array by boosting a DC voltage of a low voltage input by using a boosting means such as a DC-DC converter, the range for boosting is very limited. In order to boost the voltage to, the boosting means such as a DC-DC converter must be connected in several steps to obtain a desired high voltage DC voltage. However, the method of obtaining a desired high voltage DC voltage by connecting boosting means such as a DC-DC converter in various stages requires a large number of components constituting the light emitting device driving device for the backlight and uses a switching device as a high voltage device. There is a problem.

In this background, it is an object of an embodiment of the present invention to efficiently drive a light emitting device for a backlight by boosting an input low voltage DC voltage to a high DC voltage.

In addition, another object of the embodiment of the present invention, while efficiently driving the backlight light emitting device using a high DC voltage, while reducing the number of components, lowering the manufacturing cost, and furthermore to conveniently drive the current supplied to the light emitting device array To be adjustable.

One embodiment of the present invention, the inverter unit for converting the DC voltage input from the voltage input terminal into an AC voltage; A transformer for boosting the converted AC voltage according to a predetermined boost ratio; A rectifying unit converting the boosted AC voltage into a DC voltage; And a light emitting unit for driving the light emitting device array by the driving current according to the converted DC voltage.

The above-described inverter driving control unit receives the converted DC voltage and compares it with the reference voltage. When the feedback DC voltage exceeds the reference voltage, the inverter driving control unit inputs the plurality of switching elements so that the converted DC voltage becomes less than or equal to the reference voltage. It may include an overvoltage protection unit for limiting the duty or amplitude of the pulse, or to stop the operation of the inverter driving control unit.

In addition, an embodiment of the present invention, the inverting step of converting the DC voltage input to the voltage input terminal into an AC voltage; A transformer step of boosting the converted AC voltage according to a predetermined boost ratio; A rectifying step of converting the boosted AC voltage into a DC voltage; And a light emitting step in which the light emitting device array is driven by the driving current according to the converted DC voltage.

In addition, another embodiment of the present invention, the panel; A backlight unit including at least one light emitting device array; And converting the DC voltage input from the voltage input terminal into an AC voltage by using an inverter, boosting the converted AC voltage according to a predetermined boost ratio, converting the boosted AC voltage into a DC voltage, and converting the converted DC voltage. Provided is a display device including a light emitting device driving device for driving the at least one light emitting device array using a driving current according to the present invention.

According to the embodiment of the present invention as described above, there is an effect to efficiently drive the light emitting device for the backlight by boosting the input DC voltage of the low voltage to a high DC voltage.

In addition, according to an embodiment of the present invention, while efficiently driving the backlight light emitting device using a high DC voltage, it reduces the number of components, lowers the manufacturing cost, and furthermore, it is convenient to control the drive current supplied to the light emitting device array It has the effect of making it possible.

In addition, according to an embodiment of the present invention, in driving a light emitting device for a backlight using a high DC voltage, by monitoring the voltage (or current) before or after driving the light emitting device to detect the occurrence of overvoltage, through This has the effect of providing overvoltage protection.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to that other component, but there may be another configuration between each component. It is to be understood that the elements may be "connected", "coupled" or "connected".

1 is a block diagram of a backlight light emitting device driving apparatus 100 according to an embodiment of the present invention.

Referring to FIG. 1, the backlight light emitting device driving apparatus 100 according to an exemplary embodiment of the present invention may include an inverter unit 110 and an inverter unit 110 that convert a DC voltage input from a voltage input terminal into an AC voltage. A transformer unit 120 for boosting the converted AC voltage according to a predetermined boost ratio, a rectifier 130 for converting the AC voltage boosted by the transformer unit 120 into a DC voltage, and a DC voltage converted by the rectifier 130. And a light emitting unit 150 for driving the light emitting element array by the driving current.

As shown in FIG. 1, in the backlight light emitting device driving apparatus 100 according to an exemplary embodiment of the present invention, the at least one smoothing capacitor smoothes the converted DC voltage and inputs the light to the light emitting unit 150. The unit 140 may further include.

2 is a schematic circuit representation of the light emitting device driving apparatus 100 according to the embodiment of the present invention described above. Referring to the overall circuit diagram illustrated in FIG. 2, the transformer 120 is electrically insulated and implemented as a transformer that can easily adjust the boost ratio by adjusting the turn ratio, and the primary side of the transformer is X point. And the Y is connected to the inverter unit 110 and the secondary side of the transformer is connected to the rectifier 130. The rectifier 130 may be implemented as two rectifiers rectifying the AC current flowing from the transformer, and the smoother 140 may be implemented as one smoothing capacitor. The inverter unit 110 to be described with reference to the exemplary circuit diagrams in FIGS. 3 to 5 is connected to the inverter driving control unit 160 at a plurality of Z points.

On the other hand, although the light emitting unit 150 shown in FIG. 2 is illustrated assuming that the light emitting device is driving one array of light emitting devices connected in series, in some cases, the light emitting unit 150, As shown in FIG. 8, a plurality of light emitting element arrays connected in parallel may be driven.

Meanwhile, the inverter unit 110 includes a plurality of switching elements connected to the transformer unit 120. As the plurality of switching elements are alternately driven, the inverter unit 110 may convert a DC voltage input from the voltage input terminal into an AC voltage. Can be.

As described above, in order to convert the DC voltage input by the inverter unit 110 into an AC voltage, a plurality of switching elements included in the inverter unit 110 must be alternately driven. For this purpose, as illustrated in FIG. Similarly, in the backlight light emitting device driving apparatus 100 according to the exemplary embodiment of the present invention, the inverter alternately inputs driving pulses to the plurality of switching elements so that the plurality of switching elements included in the inverter unit 110 are alternately driven. The driving control unit 160 may further include.

Each of the plurality of switching elements included in the inverter unit 110 mentioned above may be any type of switching element that can be driven by receiving a driving pulse from the inverter driving control unit 160. For example, each of the plurality of switching elements may be one of an N-type or P-type field effect transistor (FET) and an NPN-type or PNP-type junction transistor (BJT: bipolar junction transistor). Can be.

In addition, the plurality of switching elements included in the inverter unit 110 mentioned above may be, for example, a full-bridge method, a half-bridge method, and a push-pull method. ) May be connected to the voltage input terminal, the inverter driving control unit 160 and the transformer unit 120 in one of the other methods.

In this regard, in the following, it is assumed that the switching element is an N-type field effect transistor, and a full-bridge method, a half-bridge method, and a push-pull method. The inverter units 110 implemented in the manners will be exemplarily described with reference to FIGS. 3, 4, and 5, respectively.

3 is an exemplary view in which the inverter unit 110 included in the backlight light emitting device driving apparatus according to an embodiment of the present invention is implemented in a full-bridge manner.

Referring to FIG. 3, the inverter unit 110 includes four N-type field effect transistors including Q11, Q12, Q21, and Q22. At this time, the driving stages of the Q11, Q12, Q21, and Q22 (which are 'gates' of the field effect transistors) receive driving pulses from the inverter driving control unit 160 connected to Z11, Z12, Z21, and Z22, respectively. (See the drive pulse shown in FIG. 6). In addition, the junction of the output terminal of Q11 (which is the 'source' of the field effect transistor) and the input terminal of the Q12 (which is 'drain' of the field effect transistor) is connected at one end of the primary side of the transformer to the X point. . In addition, the junction of the output terminal of Q21 (which is 'source' of the field effect transistor) and the input terminal of Q22 (which is 'drain' of the field effect transistor) is connected at the other end of the primary side of the transformer and the Y point. .

Referring to FIG. 3, the inverter unit 110 converts the DC voltage VIN input from the voltage input terminal into an AC voltage as Q11, Q12, Q21, and Q22 are alternately driven, and the driving stages of Q11 and Q22 The same drive pulse is input from the inverter drive control unit 160, and the drive terminals of Q12 and Q21 receive the same drive pulse from the inverter drive control unit 160. At this time, the driving pulses input to the driving stages of Q11 and Q22 and the driving pulses input to the driving stages of Q12 and Q21 are pulses having different turn-on timings (the driving shown in FIG. 6). Pulse). Therefore, when Q11 and Q22 are driven, Q12 and Q21 are not driven, and when Q11 and Q22 are not driven, Q12 and Q21 are driven. For this reason, the direction of the primary side current flow of a transformer will flow alternately, and an AC voltage will generate | occur | produce on the secondary side of a transformer according to a constant voltage-ratio ratio.

4 is an exemplary view in which the inverter unit 110 included in the backlight light emitting device driving apparatus according to an embodiment of the present invention is implemented in a half-bridge method.

Referring to FIG. 4, the inverter unit 110 includes two N-type field effect transistors including Q11 and Q12, and two capacitors including C21 and C22. At this time, the driving stages (which are 'gates' of the field effect transistors) of Q11 and Q12 receive driving pulses from the inverter driving control unit 160 connected to Z11 and Z12, respectively. In addition, the junction of the output terminal of Q11 (which is the 'source' of the field effect transistor) and the input terminal of the Q12 (which is 'drain' of the field effect transistor) is connected at one end of the primary side of the transformer to the X point. . In addition, the junction point of C21 and C22 is connected at the other end and the Y point of the primary side of the transformer, and C21 and C22 are charged / discharged according to the direction of current flow flowing through the primary side of the transformer.

Referring to FIG. 4, the inverter unit 110 converts the DC voltage VIN input from the voltage input terminal into an AC voltage as Q11 and Q12 are alternately driven, and the driving stage of Q11 and Q12 is an inverter driving control unit ( In operation 160, driving pulses having different turn-on timings are input. Therefore, Q12 is not driven when Q11 is driven, and Q12 is driven when Q11 is not driven. For this reason, the direction of the primary side current flow of a transformer will flow alternately, and an AC voltage will generate | occur | produce on the secondary side of a transformer according to a constant voltage-ratio ratio.

5 is an exemplary view in which the inverter unit 110 included in the backlight light emitting device driving apparatus according to an embodiment of the present invention is implemented in a pull-push method.

Referring to FIG. 5, the inverter unit 110 includes two N-type field effect transistors including Q1 and Q2. In this case, the driving stages of the Q1 and Q2 (which are 'gates' of the field effect transistors) receive driving pulses from the inverter driving control unit 160 respectively connected to the Z1 and Z2. In addition, the input terminal of Q1 (which is the 'drain' of the field effect transistor) is connected at one end of the primary side of the transformer at the X point. In addition, the input terminal of Q2 (which is the 'drain' of the field effect transistor) is connected at the Y point with the other end of the primary side of the transformer.

Referring to FIG. 5, the inverter unit 110 converts a DC voltage VIN input from a voltage input terminal into an AC voltage as Q1 and Q2 are alternately driven, and the driving stage of Q1 and Q2 is an inverter driving control unit ( In operation 160, driving pulses having different turn-on timings are input. Therefore, Q2 is not driven when Q1 is driven, and Q2 is driven when Q1 is not driven. For this reason, the direction of the primary side current flow of a transformer will flow alternately, and an AC voltage will generate | occur | produce on the secondary side of a transformer according to a constant voltage-ratio ratio.

The inverter driving control unit 160 as described above receives a current value detected by a sensor connected to the light emitting element array for constant current control and based on the feedback current value, the plurality of inverters included in the inverter 110. The driving current for driving the light emitting device array may be controlled by adjusting the duty (also referred to as 'width') or amplitude of the driving pulses alternately input to the switching elements of the.

The above-mentioned sensor may be included in the cathode of the light emitting device array. For example, as illustrated in FIG. 2, one or more sensor resistors 200 may be implemented, and thus, one or more sensor resistors 200 may be included. The current value flowing in can be detected.

The inverter driving control unit 160 described above may include a pulse modulation controller for generating and generating a driving pulse to be input to the inverter unit 110 through a predetermined pulse modulation method. For example, the inverter driving controller 160 modulates the pulse width (called 'duty') according to the modulation signal size. When the amplitude of the signal wave is large, the width of the pulse ( This is called 'Duty'), and when the amplitude is small, the pulse width modulation controller (PWM: Pulse-Width Modulation) is used to control the driving pulse. Can be generated. Alternatively, the inverter driving control unit 160 may generate and control the driving pulse through a pulse amplitude modulation controller using pulse amplitude modulation (PAM), which is a pulse modulation method that changes the amplitude of the pulse according to the magnitude of the modulation signal. You can also Further, as the pulse modulation controller, in addition to the pulse width modulation controller or the pulse amplitude modulation controller mentioned above by way of example, any controller using other pulse modulation schemes is possible.

In the above-described light emitting device driving apparatus 100 according to an embodiment of the present invention, for example, when the DC voltage input from the voltage input terminal is 12 ~ 24V, such a low voltage DC voltage of the high voltage In order to convert to DC voltage, DC voltage of 12 ~ 24V low voltage is converted into AC voltage, and the converted AC voltage is boosted by a certain step-up ratio, and the boosted AC voltage is converted into DC voltage and converted into DC voltage. The voltage can be used to drive the light emitting element array.

As described above, the backlight LED driving apparatus 100 according to an embodiment of the present invention drives the LED array using a DC voltage much higher than that of the conventional LED driving apparatus which supplies power to the backlight. It is possible to connect the light emitting devices in series, which can greatly reduce the number of light emitting device arrays, thereby reducing the deviation between the driving currents supplied to the light emitting device arrays while driving the driving currents to drive each light emitting device array. It will also be possible to reduce or eliminate the number of balancer elements or channels of the balancer element that it adjusts. This greatly reduces component count and significantly reduces power consumption. In addition, the backlight light emitting device driving apparatus 100 according to an exemplary embodiment of the present invention may minimize the high voltage device by using a transformer that is electrically insulated when boosting the converted AC voltage. It is easy and convenient to adjust the output voltage by adjusting the turn ratio of.

On the other hand, the backlight light emitting device driving apparatus 100 according to an embodiment of the present invention, by driving the light emitting device array using a DC voltage much higher than in the conventional light emitting device driving device that supplies power to the backlight, One effect can be obtained, but if the DC voltage used to drive the light emitting element array becomes too high, it may cause a problem in the light emitting element array or the light emitting element driving apparatus for the backlight.

Therefore, the backlight LED driving apparatus 100 according to an exemplary embodiment of the present invention may perform an overvoltage protection function to protect the LED array or the backlight LED driving apparatus from the high voltage. To this end, the inverter driving control unit 160 included in the backlight LED driving apparatus 100 according to an embodiment of the present invention, the DC voltage smoothed by the rectifying unit 130 or the DC smoothing unit 140 When the feedback DC voltage exceeds the reference voltage by receiving the feedback voltage and comparing it with a predetermined reference voltage (allowed voltage), the plurality of switchings included in the inverter unit 110 so that the converted DC voltage becomes less than the reference voltage. The electronic device may further include an overvoltage protection unit configured to limit the duty or amplitude of the driving pulse to be input to the device or to stop the operation of the inverter driving controller 160.

6 illustrates an overall circuit diagram of the backlight LED driving apparatus 100 including the inverter driving controller 160 including the overvoltage protection unit according to an embodiment of the present invention. However, the inverter unit 110 in FIG. 6 is illustrated on the assumption that it is implemented in a full-bridge manner as shown in FIG. 3.

Referring to FIG. 6, the inverter driving controller 160 measures the voltage applied to the sensor resistor 610 using the sensor resistor 610 connected to the light emitting unit 150 including the light emitting element array. The driving current for driving the light emitting device array may be controlled by receiving a feedback current (I_FB: Feedback Current) according to the measured voltage.

Referring to FIG. 6, the overvoltage protection unit 600 included in the inverter driving controller 160 divides a voltage (DC voltage converted from a boosted AC voltage) output from the rectifier 130 for overvoltage protection. The voltage V_FB received from the feedback (hereinafter referred to as 'voltage feedback') is monitored through the distribution by the resistance 620.

FIG. 7 is a diagram illustrating an overvoltage protection unit 600 that monitors a feedback voltage V_FB and performs an overvoltage protection function according to a monitoring result.

Referring to FIG. 7, the overvoltage protection unit 600 includes a comparator 710 and a protection circuit 720. The comparator 710 includes an output voltage (DC voltage or smoothed by the rectifier 130). The DC voltage smoothed to the unit 140 is fed back and the monitored voltage V_FB is compared with a predetermined reference voltage (permitted voltage, reference voltage). As a result of the comparison, when the feedback DC voltage exceeds the reference voltage, the protection circuit 720 has an output voltage (the DC voltage converted by the rectifying unit 130 or the DC voltage smoothed on the smoothing unit 140) is less than or equal to the reference voltage. May cause the driving block to limit the duty or amplitude of the driving pulse to be input to the plurality of switching elements included in the inverter unit 110, or the protection circuit 720 may cause the power supply block to In addition, the operation of the inverter driving controller 160 may be stopped.

The light emitting device array referred to herein may include one or more light emitting diodes (LEDs). The light emitting diode includes an organic light emitting diode (OLED), wherein the organic light emitting diode is one of a low molecular organic light emitting diode and a high molecular organic light emitting diode, which are classified according to the amount of organic material. The organic light emitting diode may be one of a passive matrix organic light emitting diode (PM) and an active matrix organic light emitting diode (AM).

The method of driving the backlight light emitting device provided by the backlight LED driving device 100 according to the exemplary embodiment of the present invention described above will be briefly described with reference to the flowchart of FIG. 9.

Referring to FIG. 9, in the method of driving a backlight light emitting device according to an embodiment of the present invention, an inverting step (S900) of converting a DC voltage input to a voltage input terminal into an AC voltage, and converts the converted AC voltage A voltage conversion step (S902) for boosting according to the boost ratio, a rectification step (S904) for converting the boosted AC voltage into a DC voltage, and a light emission step (S908) for driving the light emitting device array by the driving current according to the converted DC voltage. And the like.

As shown in FIG. 9, after the rectifying step S904, the converted DC voltage is fed back and compared with the reference voltage at S9061. As a result of the comparison, the feedback DC voltage V_FB (feedback voltage) is defined. If the reference voltage (V_RF: Reference Voltage) is not exceeded, the light emission step S908 is continuously performed. However, as a result of the comparison, when the feedback DC voltage exceeds the predetermined reference voltage, the duty or amplitude of the driving pulse to be input to the plurality of switching elements is limited so that the converted DC voltage becomes less than the reference voltage. An overvoltage for performing inverter drive control (S9062) such as inverting the operation (S900) or stopping the operation of the inverter driving control unit 160 by inputting a driving pulse having a limited duty or amplitude to the plurality of switching elements. A protection step S806 may further be included.

According to one embodiment of the present invention as described above, by increasing the input DC voltage of the low voltage to a high DC voltage has the effect of providing a light emitting device driving device for backlight 100 that can drive the light emitting device efficiently have.

In addition, according to an embodiment of the present invention, while efficiently driving the light emitting device using a high DC voltage, it is possible to reduce the number of components and to reduce the manufacturing cost, and furthermore to conveniently drive the driving current supplied to the light emitting device array There is an effect of providing an adjustable light emitting device driving apparatus 100 for the backlight.

In addition, according to an embodiment of the present invention, in driving a light emitting device using a high DC voltage, by detecting a voltage (or current) before or after driving the light emitting device to detect the occurrence of overvoltage, and thereby There is an effect that can protect the light emitting device driving apparatus 100 and the light emitting device from the.

10 is a block diagram of a display apparatus 1000 for driving a backlight light emitting device according to another exemplary embodiment of the present invention.

Referring to FIG. 10, a display apparatus 1000 according to another exemplary embodiment of the present invention may include a panel (Pannel, 1300), a backlight unit 1200 including at least one light emitting device array, and a voltage using an inverter. Converts the DC voltage input from the input terminal into AC voltage, boosts the converted AC voltage according to a certain step-up ratio, converts the boosted AC voltage into DC voltage, and uses one or more driving currents according to the converted DC voltage. And a light emitting device driving device 1100 for driving the light emitting device array. The above-described light emitting device driving apparatus 1100 may be the same as the light emitting device driving apparatus 100 illustrated in FIG. 1.

The above-described light emitting device driving apparatus 1100 receives a current value detected by a sensor connected to the light emitting element array for constant current control, and based on the feedback current value, the width or amplitude of the driving pulse for driving the inverter. By adjusting, the driving current for driving one or more light emitting device arrays can be controlled.

In addition, the above-described light emitting device driving apparatus 1100 receives the converted DC voltage and compares it with the reference voltage. The width or amplitude of the driving pulse for driving may be adjusted (restricted) or an overvoltage protection function for stopping the operation of the light emitting device driving apparatus 1100 may be performed.

According to another embodiment of the present invention as described above, there is an effect of providing a display device 1000 capable of efficiently driving a light emitting device by boosting the input DC voltage of the low voltage to a high DC voltage.

In addition, according to another embodiment of the present invention, while efficiently driving the light emitting device using a high DC voltage, it is possible to reduce the number of components and to reduce the manufacturing cost, and furthermore to conveniently drive the driving current supplied to the light emitting device array There is an effect of providing an adjustable display device 1000.

In addition, according to an embodiment of the present invention, in driving a light emitting device using a high DC voltage, by detecting a voltage (or current) before or after driving the light emitting device to detect the occurrence of overvoltage, and thereby There is an effect that can protect the display apparatus 1000 from the.

In the above description, all elements constituting the embodiments of the present invention are described as being combined or operating in combination, but the present invention is not necessarily limited to the embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more. In addition, while all of the components may be implemented in one independent hardware, each of some or all of the components may be selectively combined to be implemented in one or a plurality of hardware.

In addition, the terms "comprise", "comprise" or "having" described above mean that the corresponding component may be included, unless otherwise stated, and thus excludes other components. It should be construed that it may further include other components instead. All terms, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms commonly used, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a block diagram of a backlight light emitting device driving apparatus according to an embodiment of the present invention;

2 is a schematic overall circuit diagram of a light emitting device driving apparatus for a backlight according to an embodiment of the present invention;

3 is an exemplary view of an inverter unit included in a backlight light emitting device driving apparatus according to an embodiment of the present invention;

4 is another exemplary view of an inverter unit included in a light emitting device driving apparatus for a backlight according to an embodiment of the present invention;

5 is another exemplary view of an inverter unit included in a light emitting device driving apparatus for a backlight according to an embodiment of the present invention;

6 is an exemplary overall circuit diagram of a case in which a backlight light emitting device driving apparatus according to an embodiment of the present invention performs an overvoltage protection function;

FIG. 7 is a diagram illustrating an overvoltage protection unit that performs an overvoltage protection function in a backlight LED driving apparatus according to an embodiment of the present invention;

8 is a schematic overall circuit diagram of a light emitting device driving apparatus for a backlight according to an embodiment of the present invention when there are a plurality of light emitting device arrays;

9 is a flowchart illustrating a method of driving a light emitting device for a backlight according to an embodiment of the present invention;

10 is a block diagram illustrating a display device according to another embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: light emitting device driving device for backlight

110: inverter unit

120: transformer

130: rectifier

140: smooth part

150: light emitting unit

160: inverter drive control unit

200: resistor for sensor

1000: display device

1100: light emitting device driving device

1200: backlight unit

1300: panel

Claims (16)

An inverter unit for converting a DC voltage input from the voltage input terminal into an AC voltage; A transformer for boosting the converted AC voltage according to a predetermined boost ratio; A rectifier for converting the boosted AC voltage into a DC voltage; And A light emitting unit for driving the light emitting device array by the drive current according to the converted DC voltage Light emitting device driving apparatus comprising a. The method of claim 1, The inverter unit, And a plurality of switching elements connected to the transformer unit are alternately driven, thereby converting the input DC voltage into an AC voltage. 3. The method of claim 2, And an inverter driving control unit for alternately inputting driving pulses to the plurality of switching elements so that the plurality of switching elements are alternately driven. The method of claim 3, wherein The plurality of switching elements, One of a full-bridge method, a half-bridge method, and a push-pull method, which is connected to the voltage input terminal, the inverter driving control unit and the transformer unit Light emitting device driving apparatus for the backlight. The method of claim 3, wherein Each of the plurality of switching elements, An N-type or P-type field effect transistor (FET) and an NPN-type or PNP-type junction transistor (BJT: Bipolar Junction Transistor), characterized in that the light emitting device driving device. The method of claim 3, wherein The inverter drive control unit, The light emission is received by receiving a current value detected by a sensor connected to the light emitting element array and adjusting a duty or amplitude of the driving pulses alternately input to the plurality of switching elements based on the fed back current value. The light emitting device driving apparatus for a backlight, characterized in that for controlling the drive current for driving the device array. The method of claim 6, The sensor, And a device for detecting the current value flowing through at least one sensor resistor. The method of claim 3, wherein The inverter drive control unit, And a pulse width modulation (PWM) controller or a pulse amplitude modulation (PAM) controller to control and generate the driving pulses. The method of claim 3, wherein The inverter drive control unit, Receiving the converted DC voltage and comparing it with a reference voltage, when the feedback DC voltage exceeds the reference voltage, the driving to be input to the plurality of switching elements such that the converted DC voltage is equal to or less than the reference voltage; And an overvoltage protection unit for limiting the duty or amplitude of the pulse or stopping the operation of the inverter driving control unit. The method of claim 1, And a smoothing unit for smoothing the converted DC voltage and inputting the converted DC voltage to the light emitting unit through at least one smoothing capacitor. The method of claim 1, The light emitting device array, A light emitting device driving apparatus for a backlight comprising at least one light emitting diode (LED). An inverting step of converting a DC voltage input to the voltage input terminal into an AC voltage; A transformer step of boosting the converted AC voltage according to a predetermined boost ratio; A rectifying step of converting the boosted AC voltage into a DC voltage; And The light emitting step of driving the light emitting device array by the drive current according to the converted DC voltage A light emitting device driving method comprising a. The method of claim 12, After the rectifying step, Receiving the converted DC voltage and comparing the feedback voltage with a reference voltage, when the feedback DC voltage exceeds the reference voltage, the inputted DC voltage is inputted to the plurality of switching elements such that the converted DC voltage becomes less than or equal to the reference voltage. And an overvoltage protection step of limiting the duty or amplitude of the driving pulse or stopping the operation of the inverter driving controller. panel; A backlight unit including at least one light emitting device array; And Converts the DC voltage input from the voltage input terminal into an AC voltage using an inverter, boosts the converted AC voltage according to a predetermined step-up ratio, converts the boosted AC voltage into a DC voltage, and converts the DC voltage into the converted DC voltage. Light emitting device driving apparatus for driving the at least one light emitting device array using a driving current according to Display device comprising a. 15. The method of claim 14, The light emitting device driving apparatus, In order to control the constant current, the at least one light emitting device array is driven by receiving a feedback of a current value detected by a sensor connected to the light emitting device array and adjusting a driving pulse for driving the inverter based on the fed back current value. Display device characterized in that for controlling the drive current. 15. The method of claim 14, The light emitting device driving apparatus, By receiving the converted DC voltage and comparing it with a reference voltage, when the feedback DC voltage exceeds the reference voltage, a driving pulse for driving the inverter is adjusted so that the converted DC voltage becomes less than or equal to the reference voltage. Or an overvoltage protection function for stopping the operation of the light emitting element driving apparatus.

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