KR20100082158A - Method for driving a light source, light-source apparatus performing for the method and display apparatus having the same - Google Patents

Abstract

PURPOSE: A light source driving method, a light source device for performing the same, and a display device having the light source device are provided to control the generation of inrush current when driving the initial light source. CONSTITUTION: A dimming duty ratio of each light emitting block is decided by using a plural image blocks corresponding to the light emitting blocks(S120). Based on the dimming duty ratio and current peak value information, the first driving signal applied in each light emitting block is generated(S130). The second driving signal of the level lower than the level of the first driving signal is generated(S140). The light emitting blocks are driven with the second driving signal(S150). The light emitting blocks are driven with the first driving signal after set time(S160,170).

Description

A light source driving method, a light source device for performing the same, and a display device having the light source device TECHNICAL FIELD

A light source driving method of the present invention, a light source device for performing the same, and a display device including the light source device, and more particularly, a light source driving method for driving light emitting blocks, a light source device for performing the same, and the light source device It relates to a display device comprising a.

In general, liquid crystal displays have the advantages of thin thickness, light weight, and low power consumption, and are used in large TVs as well as monitors, laptops, and mobile phones. The liquid crystal display device includes a liquid crystal display panel that displays an image using a light transmittance of liquid crystal, and a backlight assembly disposed under the liquid crystal display panel to provide light to the liquid crystal display panel.

The backlight assembly includes a light source for generating light required to display an image on the liquid crystal display panel, wherein the light source includes a cold cathode fluorescent lamp (CCFL) and a flat fluorescent lamp (FFL). And light emitting diodes (LEDs). The light emitting diode has low power consumption and high color reproducibility, and thus is widely used as a light source of the liquid crystal display.

The backlight assembly includes a DC-DC converter for converting an input power applied from the outside into a driving voltage for driving the light sources. The DC-DC converter includes an inductor, a switching element, a diode, a capacitor, and the like to generate the driving voltage. Therefore, when the input power is applied to the DC-DC converter, an inrush current is generated instantaneously. The inrush current causes the elements to be destroyed or cause a malfunction.

Accordingly, the technical problem to be solved by the present invention is to focus on this point, an object of the present invention is to provide a light source driving method that can suppress the inrush current generated during the initial light source driving.

Another object of the present invention is to provide a light source device suitable for performing the light source driving method.

Still another object of the present invention is to provide a liquid crystal display device having the light source device.

In order to realize the above object of the present invention, the light source driving method according to an embodiment drives the light source with a second driving signal having a level lower than that of the first driving signal for a predetermined time in response to the power-on signal. After the set time has elapsed, the light source is driven with the first driving signal.

In an embodiment, the light source includes a plurality of light emitting blocks, and in the driving of the second driving signal, dimming each of the light emitting blocks using a plurality of image blocks corresponding to the light emitting blocks. The duty ratio is determined, and first driving signals applied to each light emitting block are generated based on the dimming duty ratio and the current peak value information. Subsequently, a second driving signal lower than the level of the first driving signal is generated, and the light emitting blocks are driven by the second driving signal.

In an embodiment of the present disclosure, the second driving signal may be generated by reducing the duty ratio of the first driving signal.

In an embodiment of the present invention, the second driving signal may be generated by reducing the current level of the first driving signal.

In an embodiment of the present invention, each of the light emitting blocks may include at least one light emitting diode string, and the light emitting diode string may include a plurality of light emitting diodes connected in series with each other.

In order to realize the above object of the present invention, a light source apparatus according to an embodiment includes a light source, a light source driver, and a light source controller. The light source provides light. The light source driver generates a driving signal for driving the light source. The light source controller drives the light source to a second driving signal having a level lower than a level of the first driving signal for a predetermined time in response to a power-on signal, and after the set time passes, the light source to drive the first driving signal. The light source driver is controlled to be driven by.

In an embodiment of the present invention, the light source includes a plurality of light emitting blocks, each light emitting block includes at least one light emitting diode string, and the light emitting diode string includes a plurality of light emitting diodes connected in series with each other.

In an exemplary embodiment of the present invention, the light source controller divides an image signal into a plurality of image blocks corresponding to the light emitting blocks, and adjusts the dimming duty ratio of each of the light emitting blocks by using a representative gray value extracted from each image block. Decide The light source driver includes a driving signal generator configured to generate a first driving signal applied to each of the light emitting blocks based on the dimming duty ratio, and reduce the level of the first driving signal to generate a second driving signal.

In an exemplary embodiment of the present invention, the driving signal generator may be configured to determine a duty ratio of the first driving signal based on the dimming duty ratio and the current peak value information provided from the light source controller. And a current controller for determining the current level.

In an embodiment of the present disclosure, the light source controller controls the driving signal generator to generate the second driving signal by reducing the duty ratio of the first driving signal or the current level of the first driving signal during the set time. .

In an embodiment of the present invention, the light source driver includes a DC-DC converter generating the driving voltage for driving the light emitting blocks by boosting a voltage applied from the outside and input channels connected to an output terminal of the light emitting blocks; The apparatus may further include a multi-channel current controller configured to control a driving current applied to each of the light emitting blocks based on the signals applied to the input channels.

In an embodiment of the present invention, the light source driver is connected between the DC-DC converter and the output terminal of the light emitting blocks, the feedback control unit for controlling the level of the driving voltage based on the voltage applied to the output terminal of the light emitting blocks; It includes more.

In an embodiment of the present disclosure, the multi-channel current controller may include a current control transistor connected to each of the input channels, a first input terminal to which a reference voltage is applied, a second input terminal connected to an output terminal of the current control transistor, and the current control transistor. An amplifier including an output terminal connected to a control terminal of the amplifier and an output terminal of the amplifier and a control terminal of the current control transistors, and on / off in response to a duty ratio of the first or second driving signal provided from the duty controller. It includes a switching unit for performing a switching operation.

In accordance with another aspect of the present invention, a display device includes a display panel, a light source, a light source driver, and a light source controller. The display panel displays an image. The light source provides light to the display panel. The light source controller drives the light source to a second driving signal having a level lower than a level of the first driving signal for a predetermined time in response to a power-on signal, and after the set time passes, the light source to the first driving signal. The light source driver is controlled to drive.

According to such a light source driving method, a light source device for performing the same, and a display device including the light source device, the initial light source is driven by reducing the level of the drive signal for driving the light source for a predetermined time in response to a power-on signal. Inrush current generated during driving can be suppressed.

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

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structure is shown in an enlarged scale than actual for clarity of the present invention. The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, parts, or combinations thereof. In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 is a block diagram of a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the display device according to the present exemplary embodiment includes a display panel 100, a timing controller 110, a panel driver 130, and a light source device 300.

The display panel 100 includes a plurality of pixels for displaying an image. For example, the pixels are M × N (where M and N are natural numbers). Each pixel P includes a switching element TR connected to a gate line GL and a data line DL, a liquid crystal capacitor CLC connected to the switching element TR, and a storage capacitor CST.

The timing controller 110 receives a control signal CON and an image signal DATA from the outside. The control signal CON may include a vertical synchronization signal, a horizontal synchronization signal, and a clock signal. The timing controller 110 generates a panel control signal 120 that controls the driving timing of the panel driver 130 using the control signal CON.

The panel driver 130 drives the display panel 100 using the panel control signal 120 provided from the timing controller 110.

The panel driver 130 may include a data driver 132 and a gate driver 134. The panel control signal 120 receives the first control signal 120a for controlling the driving timing of the data driver 132 and the second control signal 120b for controlling the driving timing of the gate driver 134. It may include. The first control signal 120a may include a clock signal and a horizontal start signal, and the second control signal 120b may include a vertical start signal.

The data driver 132 generates data signals using the first control signal 120a and the image signal DATA provided from the timing controller 110, and generates the generated data signals on the data line DL. To provide.

The gate driver 134 generates a gate signal for activating the gate line GL by using the second control signal 120b provided from the timing controller 110 and converts the generated gate signal into the gate line ( GL).

The light source device 300 may include a light source module 200, a light source controller 210, a storage 220, and a light source driver 260.

The light source module 200 may be divided into a plurality of light emitting blocks B. FIG. Each light emitting block may include at least one light emitting diode string (hereinafter referred to as an LED string). For example, the light emitting blocks B may each include a white LED string in which a plurality of white light emitting diodes are connected in series. In contrast, the light emitting blocks B each include a red LED string in which a plurality of red light emitting diodes are connected in series, a green LED string in which a plurality of green light emitting diodes are connected in series, and a blue LED string in which a plurality of blue light emitting diodes are connected in series. It may include.

The light source controller 210 controls the driving of the light source driver 260 based on the image signal DATA and the light source control signal received from the timing controller 110. The light source controller 210 determines a dimming duty ratio for controlling the luminance of each of the light emitting blocks B based on the image signal DATA received from the timing controller 110. To provide. For example, the light source controller 210 divides the image signal DATA into a plurality of image blocks corresponding to the light emitting blocks B, extracts a representative gray value from each image block, and extracts a representative gray value from each light block. The dimming duty ratio of B) can be determined.

The light source controller 210 may reduce the level of a driving signal for driving each light emitting block B for a predetermined time in response to a power on signal received from the timing controller 110. The light source driver 260 is controlled.

The storage unit 220 stores the set time information and current peak value information applied to the light emitting blocks B.

The light source driver 260 generates a driving voltage for driving the light emitting blocks and provides them to the light emitting blocks. The light source driver 260 generates first driving signals for driving each of the light emitting blocks B based on the dimming duty ratio and current peak value information of each light emitting block provided from the light source control unit 210. . For example, the first driving signals may be pulse width modulated (PWM) signals.

The light source driver 260 may be configured as second driving signals having a level lower than that of the first driving signals for a predetermined time (for example, about 50 ms) from the time when the driving is started under the control of the light source controller 210. The light emitting blocks B are driven. Here, the first driving signals are driving signals generated based on dimming duty ratio and current peak value information of each light emitting block, and the second driving signals have a reduced level for each level of the first driving signals. Drive signals. The light source driver 260 may generate the second driving signals by reducing the duty ratio of each of the first driving signals or the current level of each of the first driving signals.

The light source driver 260 generates the first driving signals based on the dimming duty ratio and the current peak value information provided from the light source controller 210 after the set time has elapsed. Drive the light emitting blocks (B).

FIG. 2 is a block diagram of the light source driver shown in FIG. 1.

1 and 2, the light source driver 260 may include a DC-DC converter 230, a feedback controller 235, a driving signal generator 240, and a multi-channel current controller 250. .

The DC-DC converter 230 includes a plurality of output channels and provides a driving voltage Vd to the plurality of light emitting blocks B connected in parallel to the output channels. The DC-DC converter 230 boosts an external input voltage Vin applied from the outside to generate the driving voltage Vd. For example, the DC-DC converter 230 may be a boosting converter that boosts and outputs a DC voltage of about 24V applied to an external voltage of about 40V.

The feedback control unit 235 is connected between the DC-DC converter 230 and the output terminals of the light emitting blocks B and based on the voltage applied to the output terminals of the light emitting blocks B. Control the level of Vd).

The driving signal generator 240 generates the first driving signals for driving each of the light emitting blocks B based on the dimming duty ratio and the current peak value information provided from the light source controller 210.

The driving signal generator 240 may include a duty controller 242 and a current controller 244.

The duty controller 242 determines the duty ratio of the first driving signals based on the dimming duty ratio provided from the light source controller 210 and provides the duty ratio to the multi-channel current controller 250. The duty controller 242 decreases the duty ratio of the first driving signals by a predetermined level during the set time under the control of the light source controller 210, so that the multi-channel current controller 250 is used as the duty ratio of the second driving signals. To provide. The duty controller 242 provides the multi-channel current controller 250 with the duty ratio of the first driving signals determined by the dimming duty ratio after the set time elapses.

In the present exemplary embodiment, the case in which the duty controller 242 reduces the duty ratio of the first driving signals for all of the light emitting blocks B during the set time is not limited thereto. That is, a design change can be made to reduce the duty ratio of the first driving signals only for light emitting blocks in which the dimming duty ratio of the light emitting blocks is set to a dimming duty ratio equal to or greater than a predetermined set duty ratio (eg, 50%). Of course.

The current controller 244 generates a reference voltage Vref that determines current levels of the first or second driving signals based on the current peak value information provided from the light source controller 210.

The current controller 244 reduces the level of the reference voltage during the set time under the control of the light source controller 210 and provides it to the multi-channel current controller 250. The current controller 244 provides the multi-channel current controller 250 without decreasing the level of the reference voltage after the set time has elapsed. For example, the current controller 244 may reduce the level of the reference voltage such that the level of the reference voltage becomes about 50% of the reference voltage level corresponding to the current peak value during the set time.

The multi-channel current controller 250 includes a plurality of input channels connected to each of the output terminals of the light emitting blocks B. The multi-channel current controller 250 may control the old coins applied to each of the light emitting blocks B based on the signals applied to the input channels.

The multi-channel current controller 250 may include a plurality of current control circuits 252 connected to each of the input channels. Each of the current control circuits 252 may include a current control transistor 252a, an amplifier 252b, and a switching unit 252c.

In the current control transistor 252a, an input terminal is electrically connected to the other ends of the light emitting blocks B, an output terminal is electrically connected to ground, and a control terminal is the amplifier 252b through the switching unit 252c. It is electrically connected to the output terminal of.

The amplifier 252b has a first input terminal electrically connected to the current controller 244 to receive the reference voltage Vref, and a second input terminal electrically connected to an output terminal of the current control transistor 252a. The output voltage of the output terminal of the current control transistor 252a is received. The output terminal of the amplifier 252b is electrically connected to the control terminal of the current control transistor 252a through the switching unit 252c to control the current control transistor 252a.

The amplifier 252b compares the output voltage with the reference voltage Vref and performs feedback control to allow the output voltage to approach the reference voltage Vref. Accordingly, the driving current applied to each of the light emitting blocks B may be controlled to have a constant value.

One end of the switching unit 252c is electrically connected to the output terminal of the amplifier 252b, and the other end thereof is electrically connected to the control terminal of the current control transistor 252a. The switching unit 252c receives a driving signal from the duty controller 242. The switching unit 252c performs an on / off switching operation in response to the first or second driving signal, and the driving currents flowing through each of the light emitting blocks B through the on / off switching operation. Can be controlled.

As such, the inrush current is generated when the initial light source is driven by decreasing the duty ratio of the driving signal applied to the multi-channel current controller 250 or the current level of the driving signal for a predetermined time from the start of driving. Can be prevented.

3 is a flowchart illustrating a light source driving method according to an embodiment of the present invention.

1 to 3, when a power on signal, which is a power control signal, is received from the timing controller 110 (step S110), the light source controller 210 performs the timing controller 110 together with the power on signal. The dimming duty ratio of the light emitting blocks is determined by analyzing the video signal provided from step S120. For example, the light source controller 210 divides the image signal DATA into a plurality of image blocks corresponding to the light emitting blocks, extracts a representative gray value from each image block, and uses the representative gray value. The dimming duty ratio for controlling the luminance of the light emitting block B may be determined. The dimming duty ratio is provided to the driving signal generator 240.

The driving signal generator 240 generates the first driving signals based on the dimming duty ratio and the current peak value information (step S130). The duty controller 242 determines the duty ratio of the first driving signals based on the dimming duty ratio. The current controller 244 generates the reference voltage Vref for determining current levels of the first driving signals based on the current peak value information.

The driving signal generator 240 maintains the current ratio of the first driving signal while maintaining the current ratio of the first driving signals at a predetermined level (for example, under the control of the light source controller 210). About 50%) to generate the second driving signals (step S140). The current level of the second driving signals is set to correspond to the current peak value provided from the light source controller 210. The driving signal generator 240 provides the second driving signal to the multi-channel current controller 250.

The multi-channel current controller 250 drives the light emitting blocks B by using the second driving signals provided from the driving signal generator 240 (step S150).

In the present embodiment, for example, the driving signal generator 240 generates the second driving signal by reducing the duty ratio of the first driving signals by a predetermined level under the control of the light source controller 210. Although described, it is not limited thereto. That is, when the light source controller 210 provides the dimming duty ratio to the duty controller 242, the dimming duty ratio itself may be reduced and transmitted for a predetermined level during the set time.

When the set time has elapsed (S160), the driving signal generator 240 generates first driving signals based on the dimming duty ratio and the current peak value information provided from the light source controller 210. The channel current controller 250 is provided. The multi-channel current controller 250 drives the light emitting blocks B with the first driving signals (step S170).

When the power-off signal, which is the power control signal, is received from the timing controller 110 while driving the light emitting blocks B as described above (step S180), the driving signal generator 240 generates the light emitting blocks ( The driving of the light emitting blocks B is terminated by blocking the first driving signals provided to B).

4 is a flowchart illustrating a light source driving method according to another embodiment of the present invention.

1, 2, and 4, when a power on signal, which is a power control signal, is received from the timing controller 110 (step S210), the light source controller 210 may include the timing controller (with the power on signal). The image signal provided from 110 is analyzed to determine the dimming duty ratio of the light emitting blocks (step S220). For example, the light source controller 210 divides the image signal DATA into a plurality of image blocks corresponding to the light emitting blocks, extracts a representative gray value from each image block, The dimming duty ratio for controlling luminance may be determined. The dimming duty ratio is provided to the driving signal generator 240.

The driving signal generator 240 generates the first driving signals based on the dimming duty ratio and the current peak value information (step S230). The duty controller 242 determines the duty ratio of the first driving signals based on the dimming duty ratio. The current controller 244 generates the reference voltage Vref for determining current levels of the first driving signals based on the current peak value information.

The driving signal generator 240 maintains a current level of the driving signal at a predetermined level (for example, about 50) while maintaining the duty ratio of the first driving signals for the set time under the control of the light source controller 210. %) To generate the second driving signal (step S240). The duty ratio of the second driving signals is set to correspond to the dimming duty ratio provided from the light source controller 210. The driving signal generator 240 provides the second driving signal to the multi-channel current controller 250.

The multi-channel current controller 250 drives the light emitting blocks B by using the second driving signal provided from the driving signal generator 240 (step S250).

Meanwhile, in the present exemplary embodiment, the driving signal generator 240 generates the second driving signal by decreasing the current level of each of the first driving signals by a predetermined level under the control of the light source controller 210. Although described as an example, it is not limited thereto. That is, when the light source controller 210 provides the current peak value information to the current controller 244, the light source controller 210 may reduce the predetermined level in advance and transmit the same. In this case, the driving signal generator 240 generates the first driving signals using the dimming duty ratio and the current peak value information provided from the light source controller 120 and provides the first driving signals to the multi-channel current controller 250. Just do it.

When the set time elapses (step S260), the driving signal generator 240 generates the first driving signal based on the dimming duty ratio and the current peak value information provided from the light source controller 210. The channel current controller 250 is provided. The multi-channel current controller 250 drives the light emitting blocks B with the first driving signals (step S270).

When the power-off signal, which is the power control signal, is received from the timing controller 110 while driving the light emitting blocks B as described above (step S280), the driving signal generator 240 generates the light emitting blocks ( The driving of the light emitting blocks B is terminated by blocking the first driving signals provided to B).

As described above, according to the exemplary embodiment of the present invention, the driving signal for driving the light emitting blocks B is reduced during the set time from the start of driving in response to the power-on signal, thereby driving the initial light source. Inrush current can be prevented from occurring.

Although described above with reference to preferred embodiments of the present invention, those skilled in the art or those skilled in the art without departing from the spirit and scope of the invention described in the claims to be described later It will be understood that various modifications and variations can be made within the scope of the invention.

1 is a block diagram of a display device according to an exemplary embodiment of the present invention.

FIG. 2 is a block diagram of the light source driver shown in FIG. 1.

3 is a flowchart illustrating a light source driving method according to an embodiment of the present invention.

4 is a flowchart illustrating a light source driving method according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: display panel 110: timing control unit

130: panel driver 132: data driver

134: gate driver 200: light source module

210: light source control unit 220: storage unit

230: DC-DC converter 235: feedback control unit

240: driving signal generator 242: duty controller

244 current controller 250 multi-channel current controller

300: light source device

Claims (20)

Driving the light source to a second driving signal having a level lower than that of the first driving signal for a predetermined time in response to the power-on signal; And And driving the light source with the first driving signal after the set time has elapsed. The method of claim 1, wherein the light source comprises a plurality of light emitting blocks, The driving with the second driving signal is Determining a dimming duty ratio of each of the light emitting blocks using a plurality of image blocks corresponding to the light emitting blocks; Generating a first driving signal applied to each light emitting block based on the dimming duty ratio and current peak value information; Generating a second driving signal having a level lower than that of the first driving signal; And And driving the light emitting blocks with the second driving signal. 3. The method of claim 2, wherein the generating of the second driving signal comprises generating the second driving signal by reducing a duty ratio of the first driving signal. The method of claim 2, wherein the generating of the second driving signal reduces the current level of the first driving signal to generate the second driving signal. The light emitting device of claim 2, wherein each of the light emitting blocks comprises at least one light emitting diode string, The light emitting diode string includes a plurality of light emitting diodes connected in series with each other. A light source for providing light; A light source driver to generate a driving signal for driving the light source to drive the light emitting blocks; And In response to a power-on signal, the light source is driven by a second driving signal having a level lower than a level of the first driving signal for a predetermined set time, and after the set time has elapsed, the light emitting blocks are driven by the first driving signal. And a light source controller for controlling the light source driver. The method of claim 6, wherein the light source comprises a plurality of light emitting blocks, Each light emitting block comprises at least one light emitting diode string, The light emitting diode string includes a plurality of light emitting diodes connected in series with each other. The display apparatus of claim 7, wherein the light source controller divides an image signal into a plurality of image blocks corresponding to the light emitting blocks, and determines a dimming duty ratio of each of the light emitting blocks using a representative gray value extracted from each of the inverse phase blocks. and, The light source driver may include a driving signal generator configured to generate a first driving signal applied to each of the light emitting blocks based on the dimming duty ratio, and reduce the level of the first driving signal to generate a second driving signal. Light source device characterized by the above-mentioned. The method of claim 8, wherein the drive signal generator, A duty controller configured to determine a duty ratio of the first driving signal based on the dimming duty ratio; And And a current controller configured to determine a current level of the first driving signal based on current peak value information provided from the light source controller. The method of claim 9, wherein the light source controller controls the driving signal generator to generate the second driving signal by reducing the duty ratio of the first driving signal or the current level of the first driving signal during the set time. Light source device characterized by the above-mentioned. The method of claim 9, wherein the light source driver A DC-DC converter generating a driving voltage for driving the light emitting blocks by boosting a voltage applied from the outside; And And a multi-channel current controller including input channels connected to output terminals of the light emitting blocks, and controlling a driving current applied to each of the light emitting blocks based on signals applied to the input channels. The method of claim 11, wherein the light source driver And a feedback controller connected between the DC-DC converter and the output terminals of the light emitting blocks and controlling the level of the driving voltage based on a voltage applied to the output terminals of the light emitting blocks. The method of claim 11, wherein the multi-channel current control unit A current control transistor connected to each of the input channels; An amplifier including a first input terminal to which a reference voltage is applied, a second input terminal connected to an output terminal of the current control transistor, and an output terminal connected to a control terminal of the current control transistor; And And a switching unit connected between an output terminal of the amplifier and a control terminal of the current control transistors and configured to perform an on / off switching operation in response to a duty ratio of the first or second driving signal provided from the duty controller. A display panel displaying an image; A light source providing light to the display panel; A light source driver for generating a driving signal for driving the light source; And In response to a power-on signal, driving the light source to a second driving signal having a level lower than a level of the first driving signal for a predetermined set time, and driving the light source to the first driving signal after the set time elapses. A display device including a light source controller for controlling the light source driver. The method of claim 14, wherein the light source comprises a plurality of light emitting blocks, Each light emitting block comprises at least one light emitting diode string, The light emitting diode string includes a plurality of light emitting diodes connected in series with each other. The method of claim 14, wherein the light source controller divides an image signal into a plurality of image blocks corresponding to the light emitting blocks, and determines a dimming duty ratio of each of the light emitting blocks using a representative gray value extracted from each image block. and, The light source driver may include a driving signal generator configured to generate a first driving signal applied to each of the light emitting blocks based on the dimming duty ratio, and reduce the level of the first driving signal to generate a second driving signal. Light source device characterized by the above-mentioned. The method of claim 16, wherein the drive signal generator, A duty controller configured to determine a duty ratio of the first driving signal based on the dimming duty ratio; And And a current controller configured to determine a current level of the first driving signal based on current peak value information provided from the light source controller. The method of claim 17, wherein the light source controller controls the driving signal generator to generate the second driving signal by reducing the duty ratio of the first driving signal or the current level of the first driving signal during the set time. Light source device characterized by the above-mentioned. The method of claim 17, wherein the light source driver A DC-DC converter generating a driving voltage for driving the light emitting blocks by boosting a voltage applied from the outside; A multichannel current controller including input channels connected to output terminals of the light emitting blocks and controlling driving currents applied to the light emitting blocks based on signals applied to the input channels; And And a feedback controller connected between the DC-DC converter and output terminals of the light emitting blocks and controlling the level of the driving voltage based on a voltage applied to the output terminals of the light emitting blocks. The method of claim 19, wherein the multi-channel current control unit A current control transistor connected to each of the input channels; An amplifier including a first input terminal to which a reference voltage is applied, a second input terminal connected to an output terminal of the current control transistor, and an output terminal connected to a control terminal of the current control transistor; And And a switching unit connected between the output terminal of the amplifier and the control terminal of the current control transistors.

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