KR101202578B1 - Apparatus and method for driving backlight of LCD - Google Patents

Abstract

The present invention provides a backlight driving device of a liquid crystal display device that can automatically cut off the voltage supply when an error occurs during operation of the lamps, and is generated by the phase difference between the master AC voltage and the slave AC voltage fed back from the master transformer and the slave transformer. Operation state detection means for converting an AC voltage into an analog DC voltage; Protection control means for determining an error occurrence of the lamps in operation using the analog DC voltage and generating an operation error signal or an enable signal according to the determination result; And ramp drive control means for stopping the operation of the master driver and the slave driver in response to an operation error signal from the protection control means, or for driving the master driver and the slave driver normally in response to the enable signal from the protection control means. Include.

LCD, backlight, feedback, control

Description

Apparatus and method for driving backlight of LCD

1 is an equivalent circuit diagram of a pixel formed in a general liquid crystal display device.

2 is a configuration diagram of a general liquid crystal display device.

3 is a block diagram of a backlight driving apparatus of a conventional liquid crystal display device.

4 is a block diagram of a backlight driving apparatus of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 5 is a circuit diagram of the first and second master voltage dividers shown in FIG. 4.

FIG. 6 is a circuit diagram of the first and second slave voltage dividers shown in FIG. 4.

FIG. 7 is a circuit diagram of the operation state detector of FIG. 4.

FIG. 8 is a circuit diagram of the master AC / DC converter shown in FIG. 4.

FIG. 9 is a circuit diagram of the slave AC / DC converter shown in FIG. 4.

10 is a configuration diagram of a backlight driving apparatus of a liquid crystal display according to another exemplary embodiment of the present invention.

11 is a block diagram of a backlight driving apparatus according to another embodiment of the present invention.

12 is a voltage waveform generated by an error during operation of a backlight driving apparatus of a liquid crystal display according to another exemplary embodiment of the present invention.

FIG. 13 is a configuration diagram of the protection controller shown in FIG. 11.

14 is a block diagram of a backlight driving apparatus of a liquid crystal display according to another exemplary embodiment of the present invention.

15 is a configuration diagram of a backlight driving apparatus of a liquid crystal display according to another exemplary embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight of a liquid crystal display device, and more particularly, to a backlight driving apparatus and method capable of automatically cutting off a voltage supply when an error occurs during operation of lamps.

A liquid crystal display device displays an image by adjusting light transmittance of liquid crystal cells according to a video signal, and an active matrix type liquid crystal display device in which a switching element is formed for each liquid crystal cell enables active control of the switching element. This is advantageous for video implementation. As the switching element used in the active matrix liquid crystal display device, a thin film transistor (hereinafter referred to as TFT) is mainly used as shown in FIG. 1.

Referring to FIG. 1, an active matrix type liquid crystal display device converts digital input data into an analog data voltage based on a gamma reference voltage and supplies it to the data line DL, and simultaneously supplies a scan pulse to the gate line GL. Supply to charge the liquid crystal cell (Clc).

The gate electrode of the TFT is connected to the gate line GL, the source electrode is connected to the data line DL, and the drain electrode of the TFT is connected to the pixel electrode of the liquid crystal cell Clc and one electrode of the storage capacitor Cst. Connected.

A common voltage Vcom is supplied to the common electrode of the liquid crystal cell Clc.

The storage capacitor Cst serves to charge the data voltage applied from the data line DL when the TFT is turned on to maintain the voltage of the liquid crystal cell Clc constant.

When a scan pulse is applied to the gate line GL, the TFT is turned on to form a channel between the source electrode and the drain electrode to apply a voltage on the data line DL to the pixel electrode of the liquid crystal cell Clc Supply. At this time, the liquid crystal molecules of the liquid crystal cell Clc modulate the incident light by changing the arrangement by the electric field between the pixel electrode and the common electrode.

A configuration of a conventional liquid crystal display device having pixels having such a structure will be described with reference to FIG. 2.

2 is a configuration diagram of a general liquid crystal display device.

Referring to FIG. 2, the liquid crystal display device 100 includes a thin film transistor TFT for driving data lines DL1 to DLm and gate lines GL1 to GLn and driving the liquid crystal cell Clc at an intersection thereof. The liquid crystal display panel 110 having the thin film transistor, the data driver 120 for supplying data to the data lines DL1 to DLm of the liquid crystal display panel 110, and the liquid crystal display panel 110. A gate driver 130 for supplying scan pulses to the gate lines GL1 to GLn, a gamma reference voltage generator 140 for generating a gamma reference voltage and supplying it to the data driver 120, and a liquid crystal display panel ( The backlight assembly 150 for irradiating light to the 110, the inverter 160 for applying an alternating voltage and current to the backlight assembly 150, and a common voltage Vcom are generated to generate the liquid crystal display panel 110. A common voltage generator 170 for supplying the common electrode of the liquid crystal cell Clc, The gate driving voltage generator 180 for generating the high voltage VGH and the gate low voltage VGL to supply the gate driver 130 to the gate driver 130, and for controlling the data driver 120 and the gate driver 130. A timing controller 190 is provided.

In the liquid crystal display panel 110, liquid crystal is injected between two glass substrates. On the lower glass substrate of the liquid crystal display panel 110, the data lines DL1 to DLm and the gate lines GL1 to GLn are orthogonal. TFTs are formed at intersections of the data lines DL1 to DLm and the gate lines GL1 to GLn. The TFT supplies the data on the data lines DL1 to DLm to the liquid crystal cell Clc in response to the scan pulse. The gate electrodes of the TFTs are connected to the gate lines GL1 to GLn, and the source electrodes of the TFTs are connected to the data lines DL1 to DLm. The drain electrode of the TFT is connected to the pixel electrode of the liquid crystal cell Clc and the storage capacitor Cst.

The TFT is turned on in response to the scan pulse supplied to the gate terminal via the gate lines GL1 to GLn. When the TFT is turned on, video data on the data lines DL1 to DLm is supplied to the pixel electrode of the liquid crystal cell Clc.

The data driver 120 supplies data to the data lines DL1 to DLm in response to the data driving control signal DDC supplied from the timing controller 190, and digital video data supplied from the timing controller 190. After sampling and latching the RGB, the liquid crystal cell Clc of the liquid crystal display panel 110 is converted into an analog data voltage capable of expressing gray scale based on the gamma reference voltage supplied from the gamma reference voltage generator 140. Supply to the data lines DL1 to DLm.

The gate driver 130 sequentially generates scan pulses, that is, gate pulses, in response to the gate driving control signal GDC and the gate shift clock GSC supplied from the timing controller 190, thereby providing the gate lines GL1 to GLn. To feed. The gate driver 130 determines the high level voltage and the low level voltage of the scan pulse in accordance with the gate high voltage VGH and the gate low voltage VGL supplied from the gate drive voltage generator 180, respectively.

The gamma reference voltage generator 140 receives the highest high potential power voltage VDD among the power voltages supplied to the liquid crystal display panel 110 to generate a positive gamma reference voltage and a negative gamma reference voltage to generate a data driver. 120).

The backlight assembly 150 is disposed on the rear surface of the liquid crystal display panel 110 and emits light by an AC voltage and a current supplied from the inverter 160 to irradiate light to each pixel of the liquid crystal display panel 110.

The inverter 160 converts a square wave signal generated therein into a triangular wave signal and compares the triangular wave signal with a DC power supply voltage (VCC) supplied from the system to generate a burst dimming signal proportional to the comparison result. do. When a burst dimming signal determined according to an internal square wave signal is generated, a driving IC (not shown) for controlling the generation of AC voltage and current in the inverter 160 is supplied to the backlight assembly 150 according to the burst dimming signal. Control the generation of alternating voltage and current.

The common voltage generator 170 receives the high potential power voltage VDD to generate the common voltage Vcom and supplies the common voltage Vcom to the common electrodes of the liquid crystal cells Clc of each pixel of the liquid crystal display panel 110.

The gate driving voltage generator 180 receives the high potential power voltage VDD to generate the gate high voltage VGH and the gate low voltage VGL to supply the gate driver 130 to the gate driver 130. Here, the gate driving voltage generation unit 180 generates a gate high voltage VGH that is greater than or equal to the threshold voltage of the TFTs provided in each pixel of the liquid crystal display panel 110, and the gate low voltage that is less than or equal to the threshold voltage of the TFT. VGL). The gate high voltage VGH and the gate low voltage VGL generated as described above are used to determine the high level voltage and the low level voltage of the scan pulse generated by the gate driver 130, respectively.

The timing controller 190 supplies digital video data RGB, which is supplied from a digital video card (not shown), to the data driver 120, and also horizontal / vertical synchronization signals H and V according to the clock signal CLK. The data driving control signal DDC and the gate driving control signal GDC may be generated and supplied to the data driver 120 and the gate driver 130, respectively. The data driving control signal DDC includes a source shift clock SSC, a source start pulse SSP, a polarity control signal POL, a source output enable signal SOE, and the gate driving control signal GDC. ) Includes a gate start pulse (GSP) and a gate output enable (GOE).

Looking at the configuration of the conventional backlight drive device provided in the backlight assembly of the liquid crystal display device having the configuration as described above are as follows.

3 is a block diagram of a backlight driving apparatus of a conventional liquid crystal display device.

Referring to FIG. 3, the conventional backlight driving apparatus 200 includes a lamp driving controller 202, a master driver 203, a slave driver 204, a master DC / AC switching unit 205, and a slave DC / AC switching. A unit 206, a master transformer 207 and a slave transformer 208 are provided.

The lamp driving controller 202 generates a push-pull gate signal for driving control of the plurality of lamps 201 according to the burst dimming signal.

The master driver 203 and the slave driver 204 generate a full bridge gate signal for driving the plurality of lamps 201 in response to the push-pull gate signal.

The master DC / AC switching unit 205 switches the applied DC high voltage (DC 400V) according to the full bridge gate signal input from the master driver 302 to output AC voltage 400Vrms to the master transformer 207. , AC 400Vrms of positive (+) and AC 400Vrms of negative (-) are respectively supplied to the master transformer 207 through two signal paths.

The slave DC / AC switching unit 206 switches the applied DC high voltage (DC 400V) according to the full bridge gate signal input from the slave driver 303 to output AC 400Vrms to the slave transformer 208. The positive and negative AC 400Vrms and the negative and negative AC 400Vrms are respectively supplied to the slave transformer 208 through two signal paths. In particular, the master DC / AC switching unit 205 and the slave DC / AC switching unit 206 output AC 400Vrms having the same phase.

The master transformer 207 boosts AC 400Vrms input from the master DC / AC switching unit 205 through two signal paths and supplies AC 750Vrms to one end of the plurality of lamps 201.

The slave transformer 208 boosts the AC 400Vrms inputted through the two signal paths from the slave DC / AC switching unit 206 and supplies AC 750Vrms to the other end of the plurality of lamps 201, but the master transformer 207 It supplies AC 750Vrms with out of phase with AC 750Vrms output from

As the AC 750Vrms is supplied to both ends of the plurality of lamps 201, the plurality of lamps 201 are substantially supplied with 1500Vrms, but the present invention is not limited thereto. The magnitude of the voltage is varied.

Since the conventional backlight driving apparatus as described above does not have a function of determining the occurrence of an error even if an error occurs during operation, damages such as electric shock caused by the error during the driving test are applied to the inspector. Have

The present invention has been made to solve the above problems, an object of the present invention to provide a backlight driving device and method that can automatically cut off the voltage supply when an error occurs during the operation of the lamps of the liquid crystal display device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a backlight driving apparatus and method capable of preventing a human body from being damaged by an error by automatically blocking a voltage supply when an error occurs during operation of lamps of a liquid crystal display.

SUMMARY OF THE INVENTION An object of the present invention is to provide a backlight driving apparatus and method capable of significantly shortening the time required to cut off a voltage supply when an error occurs during operation of lamps of a liquid crystal display.

An object of the present invention is to significantly reduce the time required to cut off the voltage supply when an error occurs during the operation of the lamps of the liquid crystal display device, thereby preventing the generation of voltage waveforms such as electric shock damage to the human body. And a method.

In order to achieve the above object, the present invention relates to a backlight driving apparatus of a liquid crystal display device including a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Operation state detecting means for converting an AC voltage generated by a phase difference between a master AC voltage and a slave AC voltage fed back from the master transformer and the slave transformer into an analog DC voltage; Protection control means for determining an error occurrence of the lamps in operation using the analog DC voltage and generating an operation error signal or an enable signal according to a determination result; And a ramp for stopping the driving of the master driver and the slave driver in response to an operation error signal from the protection control means or for normally driving the master driver and the slave driver in response to the enable signal from the protection control means. Drive control means. Herein, the present invention converts a master AC voltage fed back from the master transformer into a master DC voltage, and also converts a slave AC voltage fed back from the slave transformer into a slave DC voltage and outputs the voltage to the protection control means. It includes more.

According to an aspect of the present invention, there is provided a method of driving a backlight of a liquid crystal display device including a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Converting an AC voltage generated by a phase difference between the master AC voltage fed back from the slave transformer and the slave AC voltage into an analog DC voltage; Determining an error occurrence of the lamps in operation using the analog DC voltage and generating an operation error signal or an enable signal according to a determination result; And stopping driving of the master driver and the slave driver in response to the operation error signal, or driving the master driver and the slave driver normally in response to the enable signal. Herein, the present invention includes the steps of converting a master AC voltage fed back from the master transformer into a master DC voltage and converting a slave AC voltage fed back from the slave transformer into a slave DC voltage; Determining an initial error occurrence of the lamps in an initial driving state by using the fed back master DC voltage and slave DC voltage, and generating an initial error signal or the enable signal according to a determination result; And stopping initial driving of the master driver and the slave driver in response to the initial error signal.

The present invention provides a backlight driving apparatus of a liquid crystal display device having a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps, the feedback from the master transformer. Voltage feedback means for converting the master AC voltage into a master DC voltage and converting the slave AC voltage fed back from the slave transformer into a slave DC voltage; Protection control means for determining an initial error occurrence of the lamps in an initial driving state by using the fed back master DC voltage and slave DC voltage and generating an initial error signal or an enable signal according to the determination result; And stopping the initial driving of the master driver and the slave driver in response to the initial error signal from the protection control means, or for driving the master driver and the slave driver normally in response to the enable signal from the protection control means. Lamp driving control means.

According to an aspect of the present invention, there is provided a method of driving a backlight of a liquid crystal display device including a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Converting the fed back master AC voltage into a master DC voltage and converting a slave AC voltage fed back from the slave transformer into a slave DC voltage; Determining an initial error occurrence of the lamps in an initial driving state by using the fed back master DC voltage and slave DC voltage and generating an initial error signal or an enable signal according to the determination result; And stopping the initial driving of the master driver and the slave driver in response to the initial error signal, or driving the master driver and the slave driver normally in response to the enable signal.

The present invention provides a backlight driving apparatus of a liquid crystal display device having a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Operation state detection means for converting an AC voltage generated by a phase difference between a master AC voltage fed back from the slave transformer and a slave AC voltage into an analog DC voltage; And main control means for stopping the driving of the master driver and the slave driver or driving the master driver and the slave driver normally according to a determination result by determining an error occurrence of the lamps which are operated by using the analog DC voltage. do. Herein, the present invention converts a master AC voltage fed back from the master transformer into a master DC voltage, and also converts a slave AC voltage fed back from the slave transformer into a slave DC voltage and outputs the voltage to the protection control means. It further comprises means.

According to an aspect of the present invention, there is provided a method of driving a backlight of a liquid crystal display device including a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Converting an AC voltage generated by a phase difference between the master AC voltage fed back from the slave transformer and the slave AC voltage into an analog DC voltage; And determining an error occurrence of the lamps in operation using the analog DC voltage and stopping driving of the master driver and the slave driver or driving the master driver and the slave driver normally according to a determination result.

The present invention provides a backlight driving apparatus of a liquid crystal display device having a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps, the feedback from the master transformer. Voltage feedback means for converting the master AC voltage into a master DC voltage and converting the slave AC voltage fed back from the slave transformer into a slave DC voltage; And determining the initial error occurrence of the lamps in the initial driving state by using the fed back master DC voltage and the slave DC voltage, and stopping the initial driving of the master driver and the slave driver according to the determination result or stopping the master driver and the slave. Main control means for driving the driver normally.

The present invention provides a backlight driving method of a liquid crystal display device comprising a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Converting the fed back master AC voltage into a master DC voltage and converting a slave AC voltage fed back from the slave transformer into a slave DC voltage; And determining the initial error occurrence of the lamps in the initial driving state by using the fed back master DC voltage and the slave DC voltage, and stopping the initial driving of the master driver and the slave driver according to the determination result or stopping the master driver and the slave. Driving the driver normally.

The present invention provides a backlight driving apparatus of a liquid crystal display device having a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Operation state detection means for converting an AC voltage generated by a phase difference between a master AC voltage fed back from the slave transformer and a slave AC voltage into an analog DC voltage; Protection control means for determining an error occurrence of the lamps in operation by using the analog DC voltage and stopping driving of the master driver and the slave driver or driving the master driver and the slave driver normally according to a determination result; And lamp driving control means for controlling outputs of the master driver and the slave driver according to the input burst dimming signal. Herein, the present invention converts a master AC voltage fed back from the master transformer into a master DC voltage, and also converts a slave AC voltage fed back from the slave transformer into a slave DC voltage and outputs the voltage to the protection control means. It further comprises means.

According to an aspect of the present invention, there is provided a method of driving a backlight of a liquid crystal display device including a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Converting an AC voltage generated by a phase difference between the master AC voltage fed back from the slave transformer and the slave AC voltage into an analog DC voltage; And determining an error occurrence of the lamps in operation using the analog DC voltage, and supplying a disable signal or an enable signal to the master driver and the slave driver according to a determination result. Here, the present invention includes the steps of converting a master AC voltage fed back from the master transformer into a master DC voltage and converting a slave AC voltage fed back from the slave transformer into a slave DC voltage; Determining an initial error occurrence of the lamps in an initial driving state by using the fed back master DC voltage and slave DC voltage, and generating an initial error signal or an initial normal signal according to a determination result; And stopping initial driving of the master driver and the slave driver in response to the initial error signal.

The present invention provides a backlight driving apparatus of a liquid crystal display device having a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Operation state detection means for converting an AC voltage generated by a phase difference between a master AC voltage fed back from the slave transformer and a slave AC voltage into an analog DC voltage; And controlling the outputs of the master driver and the slave driver in response to the input burst dimming signal, and determining an error occurrence of the lamps in operation by using the analog DC voltage. Main control means for stopping the driving or driving the master driver and the slave driver normally. Here, the present invention, the voltage feedback means for converting the master AC voltage fed back from the master transformer into a master DC voltage, and also converts the slave AC voltage fed back from the slave transformer into a slave DC voltage to output to the main control means. It includes more.

The present invention provides a backlight driving device of a liquid crystal display device having a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps, the output being from the master transformer. A feedback unit for feeding back a master AC voltage and a slave AC voltage output from the slave transformer; And a protection controller for determining an error occurrence by using the master AC voltage and the slave AC voltage fed back by the feedback unit to stop driving of the master driver and the slave driver when an error occurs.

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

4 is a block diagram of a backlight driving apparatus of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the backlight driving apparatus 300 according to the exemplary embodiment of the present invention is the same as the backlight driving apparatus 200 illustrated in FIG. 2, and the master DC / AC switching unit 205 and the slave DC / AC switching unit 206, master transformer 207 and slave transformer 208 is provided.

In addition, the backlight driving apparatus 300 according to an embodiment of the present invention includes a lamp driving controller 301 for generating a push-pull gate signal for driving control of the plurality of lamps 201 according to the burst dimming signal, In response to the push-pull gate signal, the master driver 302 and the slave driver 303 which generate the full bridge gate signal for driving the plurality of lamps 201 and the master AC voltage output from the master transformer 207 The first and second master voltage dividers 304 and 305 for dropping and feeding back, and the first and second slave voltage dividers 306 and 307 for dropping and feeding back a slave AC voltage output from the slave transformer 208. And the AC error voltage during operation generated by the phase difference between the master AC voltage and the slave AC voltage fed back by the first master voltage divider 304 and the first slave voltage divider 306. An operation state detector 308 for converting into a common error voltage, a master AC / DC converter 309 for converting a master AC voltage fed back by the second master voltage distribution unit 305 into a master DC voltage, Operation using the slave AC / DC converter 310 for converting the slave AC voltage fed back by the second slave voltage divider 307 into the slave DC voltage and the voltage fed back through the operation state detector 308 Outputs an operation error signal for instructing the driving stop of the master driver 302 and the slave driver 303 to the lamp drive control unit 301 when the error occurs, and outputs the master AC / DC converter 309 and / or The error of the initial driving is determined by using the voltage fed back through the slave AC / DC converter 310 and, when an error occurs, the master driver 302 and the slave driver ( And a protection controller 311 for outputting an initial error signal instructing the driving stop of the 303 to the lamp driving control unit 301.

The lamp driving control unit 301 generates a push-pull gate signal for controlling the switching operation of the master DC / AC switching unit 205 and the slave DC / AC switching unit 206 according to the burst dimming signal for the lamp. 302 and slave driver 303. When the initial error signal is input from the protection controller 311 in the initial driving state, the lamp driving control unit 301 outputs a disable signal in response to the initial error signal, so that the master driver 302 and the slave driver 303 receive the initial error signal. Stop the drive. In addition, when an operation error signal is input from the protection controller 311 in the operation state, the lamp driving control unit 301 outputs a disable signal in response to the operation error signal to drive the master driver 302 and the slave driver 303. To stop. Here, the burst dimming signal for a lamp is a signal for adjusting the luminance of the plurality of lamps 201 and is a conventional signal. That is, the technique in which the lamp driving control unit 301 generates the push-pull gate signal according to the burst burst dimming signal for a lamp corresponds to a conventional technique.

The master driver 302 generates a full bridge gate signal for controlling the switching of the master DC / AC switching unit 205 in response to the push-pull gate signal input from the lamp driving controller 301 to generate a master DC / AC switching unit. Output to (205). The master driver 302 does not generate a full bridge gate signal when a disable signal is input from the lamp driving controller 301 in an initial driving state or an operating state.

The slave driver 303 generates a full bridge gate signal for controlling the switching of the slave DC / AC switching unit 206 in response to the push-pull gate signal input from the lamp driving controller 301 to output the slave DC / AC switching unit. Output to (206). The slave driver 303 does not generate a full bridge gate signal when a disable signal is input from the lamp driving controller 301 in an initial driving state or an operating state.

The first master voltage divider 304 drops the master AC voltage of 1.2 KV to 1.3 KV output from the master transformer 207 to 12 V to 13 V and feeds it back to the operation state detector 308.

The second master voltage divider 305 drops the master AC voltage of 1.2 KV to 1.3 KV output from the master transformer 207 to 12 V to 13 V and feeds it back to the master AC / DC converter 309.

The first slave voltage divider 306 drops the slave AC voltage of 1.2KV to 1.3KV output from the slave transformer 208 to 12V to 13V and feeds it back to the operation state detector 308.

The second slave voltage divider 307 drops the 1.2KV to 1.3KV slave AC voltage output from the slave transformer 208 to 12V to 13V and feeds it back to the slave AC / DC converter 310.

The first and second master voltage dividers 304 and 305 and the first and second slave voltage dividers 306 and 307 are applied from the master transformer 207 and the slave transformer 208 to the lamps 201. Since the voltage is very high, such as 1.2KV to 1.3KV, it is not directly fed back, so that the voltage applied to the lamps 201 is dropped to 12V to 13V to be distributed to suit the feedback.

The operation state detection unit 308 directly converts the AC error voltage during operation generated by the phase difference between the master AC voltage and the slave AC voltage fed back by the first master voltage divider 304 and the first slave voltage divider 306. The signal is converted into an error voltage and output to the protection controller 311. When the phase difference between the master AC voltage and the slave AC voltage fed back by the first master voltage divider 304 and the first slave voltage divider 306 does not occur, the first master voltage divider 304 Since the master AC voltage and the slave AC voltage fed back by the first slave voltage divider 306 have a reverse phase, the operation state detector 308 substantially outputs a 0V voltage to the protection controller 311.

The master AC / DC converter 309 converts the master AC voltage fed back by the second master voltage divider 305 into a master DC voltage and outputs it to the protection controller 311.

The slave AC / DC converter 310 converts the slave AC voltage fed back by the second slave voltage divider 307 into a slave DC voltage and outputs the slave AC voltage to the protection controller 311.

The protection controller 311 converts the analog DC voltage fed back through the master AC / DC converter 309 and the slave AC / DC converter 310 into the first and second digital feedback voltages in the initial driving state. It is determined whether an error in the initial driving state occurs by comparing the reference initial voltage of the first and second magnitudes of the first and second digital feedback voltages. If the result of the comparison matches, the protection controller 311 determines that the initial driving state is normal, and outputs the enable signal to the lamp driving control unit 301. As a result of the comparison, when the predetermined reference initial voltage and the magnitudes of the first and second digital feedback voltages do not match, the protection controller 311 determines that an error has occurred in the initial driving state and transmits the initial error signal to the lamp driving controller 301. Output

In addition, the protection controller 311 converts the analog DC voltage fed back through the operation state detector 308 into the digital feedback voltage in the operating state, and compares the magnitude of the predetermined reference operating voltage with the digital feedback voltage in the operating state. Determine whether an error occurs. If the result of the comparison matches, the protection controller 311 determines that the operation state is normal, and outputs the enable signal to the lamp driving controller 301. As a result of the comparison, when the predetermined reference operating voltage and the digital feedback voltage do not match, the protection controller 311 determines that an error has occurred in the operating state, and outputs an operation error signal to the lamp driving controller 301. Here, when the operating state is normal, since the phases of the master AC voltage and the slave AC voltage fed back by the first master voltage divider 304 and the first slave voltage divider 306 are the same, the operation state detector 308 ) Substantially outputs a 0V voltage to the protection controller 311. If an error occurs during operation, the phase difference between the master AC voltage fed back by the first master voltage divider 304 and the first slave voltage divider 306 and the slave AC voltage is generated. The AC error voltage during operation generated by the phase difference between the fed back master AC voltage and the slave AC voltage is converted into a DC error voltage and output to the protection controller 311. That is, the protection controller 311 converts the analog DC error voltage converted by the operation state detector 308 into a digital error voltage and compares the magnitude of the predetermined reference operation voltage with the digital error voltage to determine whether an error occurs during operation. To judge.

As described above, when an error occurs during the operation of the backlight driving apparatus 300 according to an embodiment of the present invention, the protection controller 311 determines the error occurrence during operation using the feedback voltage and then the master driver 302. An operation error signal for instructing the driving stop of the slave driver 303 is output to the lamp driving control unit 301, and the lamp driving control unit 301 outputs a disable signal in response to the operation error signal, thereby causing the master driver 302 to output. ) And the slave driver 303 are stopped.

When an error occurs during the operation as described above, the lamp driving control unit 301 is controlled by the protection controller 311 to stop the driving of the master driver 302 and the slave driver 303. It is possible to prevent damage such as electric shock caused by the inspector from being applied.

FIG. 5 is a circuit diagram of the first and second master voltage dividers shown in FIG. 4.

Referring to FIG. 5, the first master voltage divider 304 includes capacitors C1 and C2 connected in series between the output side of the master transformer 207 and ground. Here, the voltage distributed by the capacitors C1 and C2 is transferred to the operation state detector 308 through a node located between the capacitors C1 and C2.

The second master voltage divider 305 is composed of capacitors C3 and C4 connected in series between the output side of the master transformer 207 and ground, wherein the capacitors C3 and C4 are capacitors C1 and C2. Connected in parallel with Here, the voltage distributed by the capacitors C3 and C4 is transferred to the master AC / DC converter 309 through a node located between the capacitors C3 and C4.

FIG. 6 is a circuit diagram of the first and second slave voltage dividers shown in FIG. 4.

Referring to FIG. 6, the first slave voltage divider 306 includes capacitors C5 and C6 connected in series between the output side of the slave transformer 208 and ground. Here, the voltage distributed by the capacitors C5 and C6 is transferred to the operation state detector 308 through a node located between the capacitors C5 and C6.

The second slave voltage divider 307 is composed of capacitors C7 and C8 connected in series between the output side of the slave transformer 208 and ground, wherein the capacitors C7 and C8 are capacitors C5 and C6. Connected in parallel with Here, the voltage distributed by the capacitors C7 and C8 is transferred to the slave AC / DC converter 310 through a node located between the capacitors C7 and C8.

FIG. 7 is a circuit diagram of the operation state detector of FIG. 4.

Referring to FIG. 7, the operation state detector 308 includes a resistor R1 connected to the output side of the first master voltage divider 304 and a resistor R2 connected to the output side of the first slave voltage divider 306. ), A resistor R3 having one side commonly connected to the resistors R1 and R2 and the other side connected to ground, and a resistor connected at one side to the protection controller 311 and the other side connected in series to the resistor R1 ( R4), one side of which is commonly connected to the protection controller 311 and the resistor R4, the other of which is connected to ground, and the other side of which is commonly connected to the resistors R1 and R4, and the other side of the resistor is connected to ground. The capacitor C9 connected in parallel with the resistor R3 and one side connected to the protection controller 311 and the resistor R4 in common, the other side connected to the ground, and the capacitor R9 connected in parallel with the resistor R5. (C10) is provided.

FIG. 8 is a circuit diagram of the master AC / DC converter shown in FIG. 4.

Referring to FIG. 8, the master AC / DC converter 309 includes a diode D1 having an anode connected to the output side of the second master voltage divider 305 and a cathode connected to the protection controller 311 side. The anode is connected to ground, the cathode is connected to the cathode of the diode D1, and the diode D2 is connected in parallel with the diode D1, and one side is connected between the cathode of the diode D1 and the protection controller 311. In addition, the other side is connected to the ground and the resistor R6 connected in parallel with the diode D2, and one side is connected between the cathode of the diode D1 and the protection controller 311, the other side is connected to the ground and the resistance ( And a capacitor C11 connected in parallel with R6).

FIG. 9 is a circuit diagram of the slave AC / DC converter shown in FIG. 4.

Referring to FIG. 9, the slave AC / DC converter 310 may include a diode D3 having an anode connected to an output side of a second slave voltage divider 307 and a cathode connected to a protection controller 311. The anode is connected to ground, the cathode is connected to the cathode of the diode D3, and the diode D4 is connected in parallel with the diode D3, and one side is connected between the cathode of the diode D3 and the protection controller 311. In addition, the other side is connected to the ground, and the resistor R7 connected in parallel with the diode D4, one side is connected between the cathode of the diode D3 and the protection controller 311, the other side is connected to the ground, and the resistance ( And a capacitor C12 connected in parallel with R7).

10 is a configuration diagram of a backlight driving apparatus of a liquid crystal display according to another exemplary embodiment of the present invention.

Referring to FIG. 10, the backlight driving apparatus 300 according to the exemplary embodiment of the present invention is the same as the backlight driving apparatus 300 shown in FIG. 4, and the master DC / AC switching unit 205 and the slave DC / AC switching unit 206, master transformer 207, slave transformer 208, master driver 302, slave driver 303, first and second master voltage divider 304, 305, first and second A two slave voltage divider 306, 307, an operation state detector 308, a master AC / DC converter 309 and a slave AC / DC converter 310 are provided.

In addition, the backlight driving apparatus 400 according to another embodiment of the present invention generates a push-pull gate signal for driving control of the plurality of lamps 201 according to the burst dimming signal, and operates the operation state detector 308. An error during operation is determined using a voltage fed back through the controller to generate an operation error signal instructing the stop of the master driver 302 and the slave driver 303 when an error occurs, and the master AC / DC converter 309 and / or Alternatively, an error of initial driving may be determined using a voltage fed back through the slave AC / DC converter 310 to generate an initial error signal instructing driving stop of the master driver 302 and the slave driver 303 when an error occurs. The main control unit 410 is provided.

The main controller 410 implements the lamp driving controller 301 and the protection controller 311 illustrated in FIG. 4 as one chip, and its functions are as follows.

The main controller 410 generates a push-pull gate signal for controlling the switching operation of the master DC / AC switching unit 205 and the slave DC / AC switching unit 206 according to the burst dimming signal for the lamp, and thus, the master driver 302. ) And the slave driver 303.

The main controller 410 converts the analog DC voltage fed back through the master AC / DC converter 309 and the slave AC / DC converter 310 into the first and second digital feedback voltages in the initial driving state. It is determined whether an error in the initial driving state occurs by comparing the reference initial voltage of the first and second magnitudes of the first and second digital feedback voltages. If the result of the comparison matches, the main controller 410 determines that the initial driving state is normal and generates an enable signal. As a result of the comparison, if the predetermined reference initial voltage and the magnitudes of the first and second digital feedback voltages do not match, the main controller 410 determines that an error has occurred in the initial driving state, and generates an initial error signal.

The main controller 410 converts the analog DC voltage fed back through the operation state detector 308 into the digital feedback voltage in the operating state, and compares whether the predetermined reference operating voltage matches the magnitude of the digital feedback voltage in the operating state. Determine whether an error occurs. If the result of the comparison matches, the main controller 410 determines that the operation state is normal and generates an enable signal. As a result of the comparison, if the predetermined reference operating voltage and the digital feedback voltage do not match, the main controller 410 determines that an error has occurred in the operating state and generates an operation error signal. That is, the main controller 410 converts the analog DC error voltage converted by the operation state detector 308 into a digital error voltage and compares the magnitude of the predetermined reference operation voltage with the digital error voltage to determine whether an error occurs during operation. To judge.

When the initial error signal is generated in the initial driving state, the main controller 410 outputs a disable signal in response to the initial error signal to stop driving of the master driver 302 and the slave driver 303. In addition, when an operation error signal is generated in the operation state, the main controller 410 outputs a disable signal in response to the operation error signal to stop driving of the master driver 302 and the slave driver 303.

As described above, when an error occurs during operation, the backlight driving apparatus 400 according to another embodiment of the present invention outputs a disable signal after the main controller 410 determines that an error occurs during operation using a feedback voltage. The driving of the master driver 302 and the slave driver 303 is stopped.

11 is a block diagram of a backlight driving apparatus according to another embodiment of the present invention.

Referring to FIG. 11, the backlight driving apparatus 500 according to another embodiment of the present invention is the same as the backlight driving apparatus 300 illustrated in FIG. 4, such as the master DC / AC switching unit 205 and the slave DC. / AC switching unit 206, master transformer 207, slave transformer 208, master driver 302, slave driver 303, first and second master voltage divider 304, 305, first and A second slave voltage divider 306 and 307, an operation state detector 308, a master AC / DC converter 309 and a slave AC / DC converter 310 are provided.

In addition, the backlight driving apparatus 500 according to another embodiment of the present invention includes a lamp driving controller 510 for generating a push-pull gate signal for driving control of the plurality of lamps 201 according to the burst dimming signal. By using the voltage fed back through the operation state detector 308, the error during operation is determined, and when the error occurs, the disable signal for instructing the driving stop of the master driver 302 and the slave driver 303 to the master driver 302. Outputs directly to the slave driver 303, and judges an initial driving error using a voltage fed back through the master AC / DC converter 309 and the slave AC / DC converter 310, and when an error occurs, the master driver 302. ) And a protection controller 520 for outputting an initial error signal for instructing the driving stop of the slave driver 303 to the lamp driving control unit 510.

The lamp driving control unit 510 generates a push-pull gate signal for controlling the switching operation of the master DC / AC switching unit 205 and the slave DC / AC switching unit 206 according to the burst dimming signal for the lamp to generate a master driver ( 302 and slave driver 303. When the initial error signal is input from the protection controller 520 in the initial driving state, the lamp driving control unit 510 outputs a disable signal in response to the initial error signal, so that the master driver 302 and the slave driver 303 receive the initial error signal. Stop the drive.

When the protection controller 520 receives the analog master DC voltage fed back through the master AC / DC converter 309 in the initial driving state and the analog slave DC voltage fed back through the slave AC / DC converter 310, After converting the fed back analog master DC voltage to the first digital feedback voltage and converting the fed back analog slave DC voltage to the second digital deep back voltage, the predetermined reference initial voltage and the first and second digital feedback voltage The occurrence of errors in the initial operation is determined by comparing whether the magnitudes are the same. If the comparison result is the same, the protection controller 520 determines that the initial operation is normal, and controls the lamp driving control unit 510 to continuously drive the lamps 201. If the comparison result is not the same, the protection controller 520 determines that an error has occurred in the initial operation, and outputs an initial error signal to the lamp driving controller 510. When the initial rare signal is generated in this way, the lamp driving controller 510 outputs a disable signal to the master driver 302 and the slave driver 303 in response to the initial error signal, and thus the master driver 302 and the slave driver 303. ) Is stopped.

When the analog DC voltage fed back through the operation state detector 308 is input in the operating state, the protection controller 520 compares the magnitude of the feedback voltage with a predetermined reference operating voltage and enables or disables the signal according to the comparison result. The enable signal is output to the master driver 302 and the slave driver 303. As a result of the comparison, when the feedback voltage and the predetermined reference operating voltage are the same, the protection controller 520 generates an enable signal and outputs the enable signal to the master driver 302 and the slave driver 303. If the feedback result and the predetermined reference operating voltage is not the same, the protection controller 520 generates a disable signal and outputs to the master driver 302 and the slave driver 303. When the disable signal is input from the protection controller 520 in this way, the master driver 302 and the slave driver 303 are stopped by the disable signal.

The master driver 302 generates a full bridge gate signal for controlling switching of the master DC / AC switching unit 205 in response to the push-pull gate signal input from the lamp driving controller 510 to generate a master DC / AC switching unit. Output to (205). The master driver 302 does not generate a full bridge gate signal when a disable signal is input from the lamp driving controller 510 in an initial driving state. The master driver 302 does not generate a full bridge gate signal when the disable signal is input from the protection controller 520 in the operating state, and conversely, when the enable signal is input from the protection controller 520 in the operating state, the lamp driving controller The full bridge gate signal is generated in response to the push-pull gate signal input from the 510.

The slave driver 303 generates a full bridge gate signal for controlling the switching of the slave DC / AC switching unit 206 in response to the push-pull gate signal input from the lamp driving controller 510 to output the slave DC / AC switching unit. Output to (206). The slave driver 303 does not generate a full bridge gate signal when a disable signal is input from the lamp driving controller 510 in an initial driving state. In addition, the slave driver 303 does not generate a full bridge gate signal when the disable signal is input from the protection controller 520 in the operating state, and conversely, when the enable signal is input from the protection controller 520 in the operating state, The full bridge gate signal is generated in response to the push-pull gate signal input from the driving controller 510.

When an error occurs during operation in the backlight driver 500 as described above, the protection controller 520 directly outputs a disable signal to the master driver 302 and the slave driver 303 to stop their driving. The backlight driver 500 may take about 10 ms from an error occurrence during operation to a driving stop of the master driver 302 and the slave driver 303. Accordingly, the backlight driving apparatus 500 according to another embodiment of the present invention greatly reduces the number of voltage waveforms that cause damage such as electric shock to a person, as shown in FIG. 12.

The lamp driving controller 510 and the protection controller 520 may be implemented as one chip.

FIG. 13 is a configuration diagram of the protection controller shown in FIG. 11.

Referring to FIG. 13, the protection controller 520 may convert the first and second digital analog DC voltages fed back through the master AC / DC converter 309 and the slave AC / DC converter 310 in an initial driving state. The A / D converter 521 for converting the feedback voltage to the first and second digital feedback voltages and the magnitudes of the predetermined reference initial voltages. The error determination unit 522 outputting a signal to the lamp driving controller 510 and the magnitude of the analog DC voltage fed back through the operation state detector 308 and the predetermined reference operating voltage in the operation state are compared. Accordingly, a comparator 523 for outputting an enable signal or a disable signal to the master driver 302 and the slave driver 303 is provided.

In the A / D converter 521, the analog master DC voltage fed back through the master AC / DC converter 309 is input in the initial driving state and the analog slave DC voltage fed back through the slave AC / DC converter 310 is inputted. When input, the feedback analog master DC voltage is converted into the first digital feedback voltage, and the feedback analog slave DC voltage is converted into the second digital feedback voltage and output to the error determining unit 522. Here, the A / D converter 521 sequentially outputs the first and second digital feedback voltages, which are set in hardware. For example, the A / D converter 521 preferentially outputs the first digital feedback voltage input to one of the two input terminals and then outputs the second digital feedback voltage input to the other input terminal.

The error determining unit 522 compares whether the magnitudes of the first and second digital feedback voltages converted by the A / D converter 521 and the predetermined reference initial voltage are the same to determine occurrence of an error in the initial operation. If the comparison result is the same, the error determination unit 522 determines that the initial operation is normal, and outputs the initial normal signal to the lamp driving controller 510. If the comparison result is not the same, the error determination unit 522 generates an error in the initial operation. In response to the determination, the initial error signal is output to the lamp driving controller 510.

The comparator 523 receives a predetermined reference operating voltage through the non-inverting input terminal (+), receives a voltage fed back through the operation state detector 308 through the inverting input terminal (-), and disables the signal or the enable signal. Is output to the master driver 302 and the slave driver 303 connected to the output terminal.

When the analog DC voltage fed back through the operation state detecting unit 308 is input to the inverting input terminal (-) and the predetermined reference operating voltage is input to the non-inverting input terminal (+) in the operating state, the comparator 523 is connected with the feedback voltage. The magnitudes of the predetermined reference operating voltages are compared and the enable signal or the disable signal is output to the master driver 302 and the slave driver 303 according to the comparison result. If the comparison result is the same as the feedback voltage and the predetermined reference operating voltage, the comparator 523 generates an enable signal and outputs the enable signal to the master driver 302 and the slave driver 303. If the operating voltages are not the same, the comparator 523 generates a disable signal and outputs the disable signal to the master driver 302 and the slave driver 303.

14 is a block diagram of a backlight driving apparatus of a liquid crystal display according to another exemplary embodiment of the present invention.

Referring to FIG. 14, the backlight driver 600 according to another exemplary embodiment of the present invention may include the master driver 302, the slave driver 303, similarly to the backlight driver 500 illustrated in FIG. 11. The master DC / AC switching unit 205, the slave DC / AC switching unit 206, the master transformer 207, and the slave transformer 208 are provided.

In addition, the backlight driving apparatus 600 according to another exemplary embodiment of the present invention may include a lamp driving controller 610 for controlling driving of the master driver 302 and the slave driver 303 according to the input burst dimming signal. The feedback unit 620 feeds back the master AC voltage output from the master transformer 207 and the slave AC voltage output from the slave transformer 208, and the master AC voltage and slave AC voltage fed back by the feedback unit 620. The protection controller 630 may be configured to determine an error occurrence and to stop driving of the master driver 302 and the slave driver 303 when an error occurs.

The feedback unit 620 feeds back output voltages of the master driver 302 and the slave driver 303. The feedback method may be variously implemented as follows. In addition, the driving method of the protection controller 630 also changes according to the feedback method of the feedback unit 620.

First, the case where the feedback unit 620 is implemented by the first feedback method will be described.

The feedback unit 620 drops and feeds back the master AC voltage output from the master transformer 207 in the initial state and drops and feeds back the slave AC voltage output from the slave transformer 208. Here, the feedback unit 620 converts the feedback master AC voltage into the feedback master DC voltage and converts the feedback slave AC voltage into the feedback slave DC voltage to feed back to the protection controller 630.

In particular, the feedback unit 620 sequentially outputs the feedback master DC voltage and the feedback slave unit DC voltage to the protection controller 630 in the initial state.

The feedback unit 620 drops the master AC voltage fed back from the master transformer 207 and the slave AC voltage fed back from the slave transformer 208 in the operating state, and then feeds back the master AC voltage and the slave AC voltage fed back. The analog AC voltage generated by the phase difference of is converted into an analog DC voltage and output to the protection controller 630. Here, if the phase difference between the fed back master AC voltage and the slave AC voltage does not occur, the feedback unit 620 has a reverse phase since the fed back master AC voltage and the slave AC voltage have a substantially zero voltage to the protection controller 630. Output

The protection controller 630 converts the analog DC voltage fed back through the feedback unit 620 into the digital feedback voltage in the initial state and compares whether the predetermined reference initial voltage matches the magnitude of the digital feedback voltage. Determine whether or not it occurred. If the result of the comparison matches, the protection controller 630 determines that the initial driving state is normal and outputs an enable signal to the master driver 302 and the slave driver 303. As a result of the comparison, if the magnitude of the predetermined reference initial voltage and the digital feedback voltage do not match, the protection controller 630 determines that an error has occurred in the initial state and outputs a disable signal to the master driver 302 and the slave driver 303. do.

The protection controller 630 converts the analog DC voltage fed back through the feedback unit 620 into the digital AC voltage in the operation state and compares whether the predetermined reference operating voltage matches the magnitude of the digital AC voltage to generate an error in the operation state. Determine whether or not. If the result of the comparison matches, the protection controller 630 determines that the operation state is normal and outputs the enable signal to the master driver 302 and the slave driver 303. As a result of the comparison, if the predetermined reference operating voltage and the digital AC voltage do not match, the protection controller 630 determines that an error has occurred in the operating state, and outputs a disable signal to the master driver 302 and the slave driver 303. .

Next, a case in which the feedback unit 620 is implemented as the second feedback method will be described.

The feedback unit 620 drops and feeds back the master AC voltage output from the master transformer 207 in the operation state, and feeds back the slave AC voltage output from the slave transformer 208. Here, the feedback unit 620 converts the feedback master AC voltage into the feedback master DC voltage and converts the feedback slave AC voltage into the feedback slave DC voltage to feed back to the protection controller 630. In particular, the feedback unit 620 sequentially outputs the feedback master DC voltage and the feedback slave unit DC voltage to the protection controller 630 in the operating state.

In addition, the feedback unit 620 drops the master AC voltage fed back from the master transformer 207 in the initial state, and drops the slave AC voltage fed back from the slave transformer 208, and then fed back the master AC voltage and the slave AC voltage. The analog AC voltage generated by the phase difference of is converted into an analog DC voltage and output to the protection controller 630. Here, if the phase difference between the fed back master AC voltage and the slave AC voltage does not occur, the feedback unit 620 has a reverse phase since the fed back master AC voltage and the slave AC voltage have a substantially zero voltage to the protection controller 630. Output

The protection controller 630 converts the analog DC voltage fed back through the feedback unit 620 into the digital feedback voltage in the operating state, and compares whether the predetermined reference operating voltage and the magnitude of the digital feedback voltage match the error in the operating state. Determine whether or not it occurred. If the result of the comparison matches, the protection controller 630 determines that the operation state is normal and outputs the enable signal to the master driver 302 and the slave driver 303. As a result of the comparison, if the magnitude of the predetermined reference operating voltage and the digital feedback voltage do not match, the protection controller 630 determines that an error has occurred in the operating state, and outputs a disable signal to the master driver 302 and the slave driver 303. do.

The protection controller 630 converts the analog DC voltage fed back through the feedback unit 620 into a digital AC voltage in an initial state, and compares whether a predetermined reference initial voltage matches the magnitude of the digital AC voltage to generate an error in the initial state. Determine whether or not. If the result of the comparison matches, the protection controller 630 determines that the initial state is normal and outputs an enable signal to the master driver 302 and the slave driver 303. As a result of the comparison, when the predetermined reference initial voltage and the digital AC voltage do not match, the protection controller 630 determines that an error has occurred in the initial state, and outputs a disable signal to the master driver 302 and the slave driver 303.

The protection controller 630 may be implemented to determine whether an error occurs in an initial state or an operating state by comparing the magnitude of the analog DC voltage fed back through the feedback unit 620 with a predetermined reference voltage. In this case, the protection controller 630 does not perform a process of converting the feedback analog DC voltage into a digital voltage.

15 is a configuration diagram of a backlight driving apparatus of a liquid crystal display according to another exemplary embodiment of the present invention.

Referring to FIG. 15, the backlight driver 700 according to another exemplary embodiment of the present invention may include a master driver 302, a slave driver 303, similarly to the backlight driver 600 illustrated in FIG. 11. The master DC / AC switching unit 205, the slave DC / AC switching unit 206, the master transformer 207, and the slave transformer 208 are provided.

In addition, the backlight driving apparatus 700 according to another exemplary embodiment of the present invention may include a lamp driving controller 710 for controlling driving of the master driver 302 and the slave driver 303 according to the input burst dimming signal. The feedback unit 720 feeds back the master AC voltage output from the master transformer 207 and the slave AC voltage output from the slave transformer 208, and the master AC voltage and the slave AC voltage fed back by the feedback unit 720. The protection controller 730 is configured to determine the occurrence of an error and to stop driving of the master driver 302 and the slave driver 303 when an error occurs.

The feedback unit 720 feeds back the output voltages of the master driver 302 and the slave driver 303. The feedback method may be variously implemented as follows. In addition, the driving method of the protection controller 730 also changes according to the feedback method of the feedback unit 720.

First, the case where the feedback unit 720 is implemented by the third feedback method will be described.

The feedback unit 720 drops and feeds back the master AC voltage output from the master transformer 207 in an initial state or an operating state, and feeds back the slave AC voltage output from the slave transformer 208. Here, the feedback unit 720 converts the feedback master AC voltage into a feedback master DC voltage and converts the feedback slave AC voltage into a feedback slave DC voltage and feeds it back to the protection controller 730. In particular, the feedback unit 720 sequentially outputs the feedback master DC voltage and the feedback slave unit DC voltage to the protection controller 730.

The protection controller 730 converts the analog DC voltage fed back through the feedback unit 720 into the digital feedback voltage in the initial state or the operating state, and compares the magnitude of the predetermined reference voltage with the digital feedback voltage. Determine whether an error in the operation state occurs. If the result of the comparison matches, the protection controller 730 determines that the initial state or the operating state is normal and outputs the enable signal to the master driver 302 and the slave driver 303. As a result of the comparison, if the magnitudes of the predetermined reference voltage and the digital feedback voltage do not match, the protection controller 730 determines that an error has occurred in an initial state or an operating state and transmits a disable signal to the master driver 302 and the slave driver 303. Will output

Next, a case in which the feedback unit 720 is implemented by the fourth feedback method will be described.

The feedback unit 720 drops the master AC voltage fed back from the master transformer 207 in the initial state or the operating state, drops the slave AC voltage fed back from the slave transformer 208, and then feeds back the fed master AC voltage and the slave AC. The analog AC voltage generated by the phase difference of the voltage is converted into an analog DC voltage and output to the protection controller 730. Here, when the phase difference between the fed back master AC voltage and the slave AC voltage is not generated, the feedback unit 720 substantially protects the 0V voltage because the fed back master AC voltage and the slave AC voltage have a reverse phase. Will output

The protection controller 730 converts the analog DC voltage fed back through the feedback unit 720 into the digital AC voltage in the initial state or the operating state, and compares the predetermined reference voltage with the magnitude of the digital AC voltage to match the initial state or operation. Determine whether an error occurred in the state. If the result of the comparison matches, the protection controller 730 determines that the initial state or the operating state is normal and outputs the enable signal to the master driver 302 and the slave driver 303. As a result of the comparison, if the predetermined reference voltage and the digital AC voltage do not match, the protection controller 730 determines that an error has occurred in an initial state or an operating state and outputs a disable signal to the master driver 302 and the slave driver 303. do.

The protection controller 730 may be implemented to determine whether an error occurs in an initial state or an operating state by comparing the magnitude of the analog DC voltage fed back through the feedback unit 720 with a predetermined reference voltage. In this case, the protection controller 730 does not perform a process of converting the feedback analog DC voltage into a digital voltage.

Meanwhile, the present invention detects an error in an initial state by using the fed back master AC voltage and the slave AC voltage. However, the present invention is not limited thereto, and the present invention uses only one of the fed back master AC voltage and the slave AC voltage. It may be implemented to determine whether there is an error in the state.

As described above, the present invention can prevent the human body from being damaged by an error by automatically cutting off the voltage supply when an error occurs during operation of the lamps of the liquid crystal display.

In addition, the present invention significantly shortens the time required to cut off the voltage supply when an error occurs during the operation of the lamps of the liquid crystal display device, thereby preventing generation of voltage waveforms such as electric shocks to the human body, thereby driving the backlight. In the event of an error in the device, it is possible to prevent the inspector from being damaged by the voltage waveform.

Although the technical spirit of the present invention has been described in detail according to the above-described preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

Claims (100)

A backlight driver of a liquid crystal display device comprising a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps. Operation state detection means for converting an AC voltage generated by a phase difference between a master AC voltage and a slave AC voltage fed back from the master transformer and the slave transformer into an analog DC voltage; Protection control means for determining an error occurrence of the lamps in operation using the analog DC voltage and generating an operation error signal or an enable signal according to a determination result; And A lamp driving for stopping the driving of the master driver and the slave driver in response to an operation error signal from the protection control means or for normally driving the master driver and the slave driver in response to an enable signal from the protection control means; Control means Backlight driving device of the liquid crystal display device comprising a. The method of claim 1, The operation state detection means, A first master voltage divider for dropping and feeding back the master AC voltage output from the master transformer; A first slave voltage divider for dropping and feeding back the slave AC voltage output from the slave transformer; And An operation state detector for converting the AC voltage generated by the phase difference between the fed back master AC voltage and the slave AC voltage into the analog DC voltage and outputting the analog DC voltage to the protection control means. Backlight driving device of the liquid crystal display device comprising a. The method of claim 2, The protective control means converts the analog DC voltage into a digital feedback voltage in the operating state, and then compares a predetermined reference operating voltage with the magnitude of the digital feedback voltage to determine whether an error occurs in the operating state. Backlight drive of display device. The method of claim 3, wherein The protection control means determines that the operation state is normal when the predetermined reference operating voltage and the magnitude of the digital feedback voltage match, and outputs the enable signal to the lamp driving control means. Drive system. The method of claim 3, wherein If the predetermined reference operation voltage and the digital feedback voltage do not match, the protection control means determines that an error has occurred in an operation state, and outputs the operation error signal to the lamp driving control means. Backlight drive of the device. The method of claim 1, And a voltage feedback means for converting the master AC voltage fed back from the master transformer into a master DC voltage and converting the slave AC voltage fed back from the slave transformer into a slave DC voltage and outputting the slave DC voltage to the protection control means. The protection control means determines the occurrence of an error in the initial driving state using the master DC voltage and the slave DC voltage, And the lamp driving control means controls the initial driving of the master driver and the slave driver according to the determination result of the protection control means. The method of claim 6, The voltage feedback means, A second master voltage divider for dropping and feeding back the master AC voltage output from the master transformer; A second slave voltage distribution unit for dropping and feeding back the slave AC voltage output from the slave transformer; A master AC / DC converter for converting the master AC voltage fed back through the second master voltage divider into the master DC voltage and outputting the master AC voltage to the protection control means; And A master AC / DC converter for converting the slave AC voltage fed back through the second slave voltage distribution unit into the slave DC voltage and outputting the same to the protection control means. Backlight driving device of the liquid crystal display device comprising a. The method of claim 7, wherein The protection control unit converts the feedback master DC voltage and the slave DC voltage into first and second digital feedback voltages, and then compares the predetermined reference initial voltages with the magnitudes of the first and second digital feedback voltages. The backlight driving device of the liquid crystal display device, characterized in that for determining whether an error occurs in the state. 9. The method of claim 8, The protection control means determines that the initial driving state is normal when the predetermined reference initial voltage and the magnitude of the first and second digital feedback voltages match, and outputs the enable signal to the lamp driving control means. Backlight drive device of liquid crystal display device. 9. The method of claim 8, If the predetermined reference initial voltage and the magnitude of the first and second digital feedback voltages do not match, the protection control means determines that an error has occurred in the initial driving state and outputs an initial error signal to the lamp driving control means. A backlight drive device for a liquid crystal display device. 11. The method of claim 10, And the lamp driving control means stops the initial driving of the master driver and the slave driver in response to the initial error signal in the initial driving state. The method of claim 1, And the protection control means and the lamp driving control means are implemented as a single chip. In the backlight driving method of a liquid crystal display device having a master transformer and a slave transformer for supplying current to a plurality of lamps, and a master driver and a slave driver for driving the lamps, Converting an AC voltage generated by a phase difference between a master AC voltage and a slave AC voltage fed back from the master transformer and the slave transformer into an analog DC voltage; Determining an error occurrence of the lamps in operation using the analog DC voltage and generating an operation error signal or an enable signal according to a determination result; And Stopping driving of the master driver and the slave driver in response to the operation error signal or driving the master driver and the slave driver normally in response to the enable signal; Backlight driving method of the liquid crystal display device comprising a. The method of claim 13, The voltage conversion step, Dropping and feeding back the master AC voltage output from the master transformer; Dropping and feeding back the slave AC voltage output from the slave transformer; And Converting the AC voltage generated by the phase difference between the feedback master AC voltage and the slave AC voltage to the analog DC voltage. Backlight driving method of the liquid crystal display device comprising a. 15. The method of claim 14, In the signal generation step, after converting the analog DC voltage into a digital feedback voltage in the operating state of the lamps to determine whether an error occurs in the operating state by comparing a predetermined reference operating voltage and the magnitude of the digital feedback voltage. A backlight driving method of a liquid crystal display device. 16. The method of claim 15, And when the magnitude of the predetermined reference operating voltage and the digital feedback voltage coincide with each other, generating the enable signal by determining that it is in a normal operating state. 16. The method of claim 15, And when the magnitude of the predetermined reference operating voltage and the digital feedback voltage do not match, it is determined that an error has occurred in an operating state, and generates the operation error signal. The method of claim 13, Converting a master AC voltage fed back from the master transformer into a master DC voltage and converting a slave AC voltage fed back from the slave transformer into a slave DC voltage; Determining an initial error occurrence of the lamps in an initial driving state by using the fed back master DC voltage and slave DC voltage, and generating an initial error signal or the enable signal according to a determination result; And Stopping initial driving of the master driver and the slave driver in response to the initial error signal; Backlight driving method of the liquid crystal display further comprising. The method of claim 18, The voltage conversion step, Dropping and feeding back the master AC voltage output from the master transformer; Dropping and feeding back the slave AC voltage output from the slave transformer; Converting the master AC voltage fed back through the second master voltage distributor to the master DC voltage; And Converting the slave AC voltage fed back through the second slave voltage divider into the slave DC voltage; Backlight driving method of the liquid crystal display device comprising a. 20. The method of claim 19, In the generation of the initial error signal or the enable signal, after converting the fed back master DC voltage and slave DC voltage into first and second digital feedback voltages, a predetermined reference initial voltage and the first and second digital feedback voltages are converted. A method of driving a backlight of a liquid crystal display device, characterized in that it is determined whether an error occurs in an initial driving state by comparing a magnitude of a voltage. 21. The method of claim 20, And when the magnitudes of the predetermined reference initial voltage and the first and second digital feedback voltages coincide with each other, determine that the initial driving state is normal and generate the enable signal. 21. The method of claim 20, And when the magnitudes of the predetermined reference initial voltage and the first and second digital feedback voltages do not match, determining that an error has occurred in an initial driving state and generating the initial error signal. . delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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