KR100958575B1 - Driving apparatus and method for lamp of liquid crystal display device - Google Patents

Abstract

The present invention relates to a lamp driving device and a method of a liquid crystal display device which can shut down the lamp driving device when any one of a plurality of lamps is defective.

Lamp driving apparatus of the liquid crystal display according to an embodiment of the present invention and a plurality of lamps; A plurality of inverters for driving each of the plurality of lamps; A pulse width control unit controlling the plurality of inverters by measuring a current of each of the lamps; And a power controller configured to shut down each of the plurality of inverters in response to a control signal from the pulse width controller.

Description

Lamp driving apparatus and method of liquid crystal display device {DRIVING APPARATUS AND METHOD FOR LAMP OF LIQUID CRYSTAL DISPLAY DEVICE}             

1 is a view showing a lamp driving device for driving one lamp with one inverter.

2 shows a lamp driving device for driving two lamps with one inverter;

3 is a block diagram illustrating a lamp driving apparatus of the liquid crystal display according to the first embodiment of the present invention.

4 is a circuit diagram illustrating a power control unit illustrated in FIG. 3.

5 is a block diagram illustrating a lamp driving device of a liquid crystal display according to a second exemplary embodiment of the present invention.

FIG. 6 is a diagram illustrating a current measuring unit illustrated in FIG. 5.

FIG. 7 is a diagram illustrating a microcomputer shown in FIG. 5; FIG.

FIG. 8 is a diagram illustrating a lamp on / off control unit illustrated in FIG. 7. FIG.

9 is a flowchart illustrating a lamp driving method of a liquid crystal display according to an exemplary embodiment of the present invention.                 

10 is a flowchart illustrating a lamp driving method of a liquid crystal display according to another exemplary embodiment of the present invention.

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

2 board 4 power control unit

10, 12, 14, 110, 111, 112, 113, 114, 115: Inverter

16,18,20,22,24,26,116,118,120,122,124,126: lamp

28,30,32,34,36,38,128,130,132,134,136,138

40: PWM control section 42: shutdown circuit

102a: back side of substrate 102b: front side of substrate

144: power input unit 146: communication port

150: current measuring unit 152: DAC

154: microcomputer 156: communication IC

200: detection current input port 202: luminance variable signal input port

204: communication unit 206: lamp on-off control unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamp driving device of a liquid crystal display device, and more particularly, to a lamp driving device and a method of shutting down a lamp driving device when one of a plurality of lamps is defective.

In general, a liquid crystal display (LCD) includes a backlight unit in a liquid crystal panel including a plurality of liquid crystal cells arranged in a matrix and a plurality of control switches for switching image signals to be supplied to each of the liquid crystal cells. The transmission amount of the light beam supplied from is adjusted to display a desired image on the screen.

Since the liquid crystal display device can be miniaturized as compared to the CRT, it is widely used not only for personal computers and laptops, but also for office automation devices such as photocopiers, mobile phones such as cell phones and PDAs. Such a liquid crystal display device requires a backlight unit used as a light source and optical sheets for reducing light loss generated by the backlight unit.

The liquid crystal display is classified into a direct type backlight unit and an edge light type backlight unit according to the position of the lamp.

The edge type backlight unit has a structure in which light generated from a lamp is uniformed by a diffusion plate and then incident on the liquid crystal panel, and has a structure in which light of the lamp is incident on the liquid crystal panel through the light guide plate. The lamp is attached to the side of the light guide plate which scatters and makes light uniform, and is surrounded by the lamp housing. The lamp housing supports the lamp and at the same time prevents the radiated light of the lamp from leaking to the side. The diffusion plate is disposed between the upper substrate of the light guide plate, the lower substrate on which the thin film transistor and the pixel electrode are arranged, the upper substrate on which the color filter is formed, and the lower polarizer of the panel composed of liquid crystal between the lower substrate and the upper substrate. The reflector serves to prevent light from leaking into the lower part of the light guide plate.

Cold Cathode Fluorescent Lamp (CCFL) or Halogen Cathode Fluorescent Lamp (HCFL) is used as the lamp.

Such lamps are driven by an inverter. The inverter depends on the number of lamps.

1 illustrates a lamp driving device for driving one lamp used in a notebook computer. The lamp driving device includes a substrate 502 including two output terminals, and an inverter for converting driving power from an external source into an AC voltage. 510, a transformer 530 for converting the voltage supplied from the inverter 510 into a lamp driving voltage, and the two output terminals of the substrate 502, for driving the lamp from the transformer 530. And a lamp 518 driven by a voltage.

The inverter 510 receives an inverter driving voltage and converts the inverter driving voltage into an AC voltage to supply the transformer 530. The transformer 530 turns on the lamp 518 by converting an AC voltage from the inverter 510 into a lamp driving voltage level.

The lamp driver 502 turns on or off one lamp 518 using one inverter 510.

2 shows a lamp driving apparatus used for a monitor having a liquid crystal display module, wherein the lamp driving apparatus includes a substrate 552 including four output terminals. An inverter 560 for converting drive power from the outside into an AC voltage, first and second transformers 580 and 582 for converting a voltage supplied from the inverter 560 into a lamp driving voltage, and a substrate First and second lamps 568 connected between two output terminals of the four output terminals of 552, respectively, and driven by a lamp driving voltage from each of the first and second transformers 580 and 582. 570.

The inverter 560 receives an inverter driving voltage, converts the inverter driving voltage into an AC voltage, and supplies it to each of the first and second transformers 580 and 582. Each of the first and second transformers 580 and 582 converts an AC voltage from the inverter 560 into a lamp driving voltage level and supplies four output terminals formed on the substrate 552. Accordingly, each of the first and second lamps 568 and 570 is turned on or off by the driving voltage for the lamps from two output terminals of the four output terminals formed on the substrate 552.

The lamp driving device turns on or off each of the first and second lamps 568 and 570 using the inverter 560 and the first and second transformers 580 and 582. However, such a lamp driving device is driven only when the first and second lamps 568 and 570 are connected to four output terminals formed on the substrate 552 so that a load is provided. That is, when one of the first and second lamps 568 and 570 is defective, there is a problem in that the lamp driving device is not shut down.

On the other hand, depending on the number of lamps of two or more lamps, the lamp driving device uses different inverters. For this reason, there is a problem in that different inverters must be used depending on the number of lamps for each model.

Accordingly, an object of the present invention is to provide a lamp driving device and method for a liquid crystal display device which can shut down the lamp driving device when any one of a plurality of lamps is defective.

In addition, another object of the present invention is to provide a lamp driving apparatus and method of a liquid crystal display device capable of selectively driving a plurality of inverters by individually monitoring the current changes of the plurality of lamps.

In order to achieve the above object, the lamp driving apparatus of the liquid crystal display according to an embodiment of the present invention comprises a plurality of lamps; A plurality of inverters for driving each of the plurality of lamps; A pulse width control unit controlling the plurality of inverters by measuring a current of each of the lamps; And a power controller configured to shut down each of the plurality of inverters in response to a control signal from the pulse width controller.

In the lamp driving apparatus, the power control unit includes an inverter driving power supply and a shutdown circuit for switching driving power from the inverter driving power supply to each of the plurality of inverters in response to a control signal from the pulse width control unit. It is done.

In the lamp driving apparatus, the shutdown circuit includes a first switch driven in response to a control signal from the pulse width controller, a second switch driven in response to the driving of the first switch, and the driving of the second switch. And a third switch for switching paths of the inverter driving power source and each of the plurality of inverters.

In the lamp driving device, the shutdown circuit is connected between the second switch and the third switch, the fourth switch driving the third switch according to the driving of the second switch, the first switch and the second switch. And further comprising a diode connected between the switches.

The lamp driving device may further include a plurality of transformers connected to each of the inverters in two units to convert driving power from the inverter into lamp driving power.

Lamp driving apparatus of the liquid crystal display according to an embodiment of the present invention and a plurality of lamps; A plurality of inverters for driving each of the plurality of lamps; A current measuring unit measuring a current of each of the lamps to generate a current detection signal; And receiving and storing model information for controlling the inverter from a user, and individually controlling each of the plurality of inverters using the stored model information and the current detection signal.

In the lamp driving apparatus, the model information may be a lamp lighting number, a tube current, and a luminance value corresponding to the model of the liquid crystal display.

In the lamp driving apparatus, the controller generates a digital luminance control signal based on an input current of the model information.                     

The lamp driving apparatus may include a power supply unit generating driving power of the lamp driving apparatus of the liquid crystal display, a communication unit receiving the model information from the user and supplying the model information to the control unit, and receiving driving power from the power supply unit. And a digital analog converter which receives the digital luminance control signal from the controller and converts the digital luminance control signal into an analog signal.

The control unit may include a storage unit storing the model information supplied from the communication unit, a detection signal input unit receiving the current detection signal from the current measuring unit, and the current detection signal through the detection signal input unit. It characterized in that it comprises an inverter control unit for supplying an analog signal from the digital analog converter to each of the plurality of inverters by using.

The lamp driving device may further include a plurality of transformers connected to each of the inverters to convert driving power from the inverter into lamp driving power.

In the lamp driving apparatus, the controller compares the current detection signal with the number of lamp lightings, and individually turns on / off driving of each of the plurality of inverters according to a comparison result.

In the lamp driving apparatus, the controller turns on all of the plurality of lamps, and then turns on only the inverters that normally drive the lamps using the current detection signal and shuts down the remaining inverters.

In the lamp driving device, the controller is configured to shut down all inverters when the measured current detection signal is out of a range between a set maximum value and a minimum value while continuously measuring current of the lamps normally driven.

In the lamp driving apparatus, the control unit turns on the plurality of lamps and then turns off the plurality of lamps when at least one of the plurality of lamps is defective based on the current detection signal.

The lamp driving method of the liquid crystal display according to the embodiment of the present invention comprises the steps of turning on a plurality of inverters for driving each of the plurality of lamps, measuring the current of each of the lamps to generate a current detection signal; And shutting down each of the plurality of inverters in response to the detection signal.

In the lamp driving method, the shutting down may include shutting off driving power supplied to each of the plurality of inverters by using a plurality of switch elements in response to the detection signal.

A lamp driving method of an LCD according to an exemplary embodiment of the present invention includes a first step of receiving model information for controlling each of the plurality of inverters from a user, and a plurality of inverters for driving each of the plurality of lamps. A second step of turning on; a third step of measuring a current of each of the lamps to generate a current detection signal; and a fourth step of individually controlling each of the plurality of inverters using the stored model information and the current detection signal. Characterized in that it comprises a step.

In the lamp driving method, the model information is a lamp lighting number, a tube current, and a luminance value corresponding to the model of the liquid crystal display.                     

The lamp driving method may further include generating a digital luminance control signal based on the input current of the model information.

The lamp driving method may further include generating driving power of the lamp driving apparatus of the liquid crystal display, and converting the digital luminance control signal into an analog signal.

The lamp driving method may further include supplying an analog signal from the digital analog converter to each of the plurality of inverters by using the current detection signal.

The lamp driving method may further include converting driving power output from the inverters into lamp driving power.

In the lamp driving method, the fourth step includes comparing the current detection signal with the number of lamp lightings, and individually turning on / off driving of each of the plurality of inverters according to the comparison result. It features.

In the lamp driving method, the fourth step includes turning on all of the plurality of lamps, and turning on only the inverters which normally drive the lamps using the current detection signal and shutting down the remaining inverters. It is done.

In the lamp driving method, the fourth step includes shutting down all inverters when the measured current detection signal is out of a range between a set maximum value and a minimum value while continuously measuring current of the normally driven lamps. It features.

In the lamp driving method, the fourth step includes controlling all of the plurality of lamps to be turned on, and turning off the plurality of lamps when at least one of the plurality of lamps is defective based on the current detection signal. Characterized in that it comprises a step.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 10.

Referring to FIG. 3, the lamp driving apparatus of the liquid crystal display according to the first exemplary embodiment of the present invention may include first to third inverters 10, 12, and 14 disposed on the substrate 2 to drive two lamps. And first to sixth transformers 28, 30, 32 and 34 connected to each of the first to third inverters in two units and converting the AC voltage from the inverters 10, 12 and 14 into lamp driving voltages. , 36, 38, and first through sixth lamps 16, 18, 20, driven by voltages for driving lamps from the first through sixth transformers 28, 30, 32, 34, 36, 38, respectively. 22, 24, 26, and the power supply control part 4 which supplies an input voltage Vin to each of the 1st-3rd inverters 10, 12, 14 is provided.

The first inverter 10 receives an input voltage Vin from the power control unit 4, converts the input voltage Vin into an AC voltage, and supplies the first and second transformers 28 and 30 to the first and second lamps 16 and 18. ) Is driven. The second interleaver 12 receives an input voltage Vin from the power control unit 4, converts the input voltage Vin into an alternating voltage, and supplies it to the third and fourth transformers 32 and 34 to supply the third and fourth lamps 20,. 22) to be driven. The third inverter 14 receives the input voltage Vin from the power control unit 4, converts the input voltage Vin into an AC voltage, and supplies the fifth and sixth lamps 36 and 38 to the fifth and sixth transformers 36 and 38. 26) to be driven.

The first transformer 28 receives an AC voltage from the first inverter 10, converts it into a lamp driving voltage, and supplies the same to the first lamp 16. The second transformer 30 receives an AC voltage from the first inverter 10, converts it into a lamp driving voltage, and supplies the same to the second lamp 18. The third transformer 30 receives an AC voltage from the second inverter 12, converts it into a lamp driving voltage, and supplies the same to the third lamp 20. The fourth transformer 34 receives the AC voltage from the second inverter 12, converts it into a lamp driving voltage, and supplies the same to the fourth lamp 22. The fifth transformer 36 receives an AC voltage from the third inverter 14, converts it into a lamp driving voltage, and supplies the same to the fifth lamp 24. The sixth transformer 38 receives an AC voltage from the third inverter 14, converts it into a lamp driving voltage, and supplies the same to the sixth lamp 26.

As shown in FIG. 4, the power control unit 4 includes a PWM controller 40 for controlling output voltages of each of the first to third inverters 10, 12, and 14, the PWM controller 40, and the first to third power supplies. A shutdown circuit 42 is connected between the third inverters 10, 12, 14 to filter out lamp failures.

The PWM controller 40 controls each of the switching elements not shown in each of the first to third inverters 10, 12, and 14, and supplies power to the first to third inverters 10, 12, and 14. Supply a control signal for the shutdown circuit (42). To this end, the PWM controller 40 detects the tube current of each of the first to sixth lamps 16, 18, 20, 22, 24, and 26, and brightness of each of the first to third inverters 10, 12, and 14. The control signal is supplied and the shutdown circuit 42 is supplied.

The shutdown circuit 42 includes a first transistor Q1 to which a brightness control signal from the PWM control unit 40 is supplied, a zener diode ZD1 connected between the first transistor Q1 and the PWM control unit 40, In response to the driving of the field effect transistor FET and the second transistor Q2 and the second transistor Q2 driven by the first transistor Q1, the inverter driving voltage Vcc is applied to the first to third inverters ( A third transistor Q3 is switched to each of 10, 12, and 14.

The first transistor Q1 is connected between the inverter driving voltage Vcc and the ground voltage source GND, and the bypass capacitor C1 is connected between the control terminal and the input terminal of the first transistor Q1. The field effect transistor FET is in the form of an N-channel MOS and is connected between the inverter driving voltage Vcc and the ground voltage source GND and driven according to the driving state of the first transistor Q1. At this time, a diode D1 for blocking the reverse current from the control terminal of the field effect transistor FET is connected between the output terminal of the first transistor Q1 and the control terminal of the field effect transistor FET. In addition, a bypass capacitor C2 is connected between the node point between the output terminal of the first transistor Q1 and the control terminal of the field effect transistor FET and the ground voltage source GND.

The PWM controller 40 outputs a control signal for supplying the inverter driving voltage Vcc to each of the first to third inverters 10, 12, and 14, thereby providing a first signal through the zener diode ZD1 and the resistor R1. It is applied to the base of the transistor Q1. At this time, the first transistor Q1 is turned on when a voltage higher than the zener voltage of the zener diode ZD1 is applied to the base. When the first transistor Q1 is turned on, the diode D1 is turned off, so that the gate terminal of the field effect transistor FET is turned low, and the field effect transistor FET is turned on. When the field effect transistor FET is turned on, the second transistor Q2 is turned on. When the second transistor Q2 is turned on, the third transistor Q3 is turned on to turn on the inverter driving voltage ( VCC) is supplied to each of the first to third inverters 10, 12, 14. Accordingly, each of the first to third inverters 10, 12, and 14 turns on the first to sixth lamps 16, 18, 20, 22, 24, and 26.

In addition, the PWM controller 40 outputs a control signal for supplying the inverter driving voltage Vcc to the first to third inverters 10, 12, and 14, respectively, through the zener diode ZD1 and the resistor R1. It is applied to the base of the first transistor Q1. At this time, the first transistor Q1 is turned off when a voltage lower than the zener voltage of the zener diode ZD1 is applied to the base. When the first transistor Q1 is turned off, the diode D1 is turned on so that the gate terminal of the field effect transistor FET becomes high, and the field effect transistor FET is turned off. When the field effect transistor FET is turned off, the second transistor Q2 is turned off, and when the second transistor Q3 is turned off, the third transistor Q4 is turned off so that the first to the first transistors are turned off. 3 The inverter driving voltage VCC supplied to the inverters 32, 34, 36 is cut off. Accordingly, each of the first to third inverters 10, 12, 14 turns off the first to sixth lamps 16, 18, 20, 22, 24, and 26.                     

As described above, the lamp driving apparatus according to the first exemplary embodiment of the present invention uses the shutdown circuit 42 driven in response to the control signal from the PWM control unit 40. Inverter driving voltage (Vcc) supplied to each is controlled. Accordingly, the lamp driving apparatus according to the first embodiment of the present invention shuts off all lamps by turning off the lamps when at least one of the first to sixth lamps 16, 18, 20, 22, 24, and 26 is defective. do.

Referring to FIG. 5, the lamp driving apparatus of the liquid crystal display according to the second exemplary embodiment of the present invention is disposed on the back surface 102a of the substrate and selectively drives a plurality of inverters by individually monitoring current changes of the plurality of lamps. And an inverter unit disposed on the front surface 102b of the substrate and driving a plurality of lamps in response to the control of the controller.

The control unit controls to supply power to the inverter when the power is turned on, receives model information prepared in advance, sets model information, and measures only the inverter with a load by measuring the current of the lamp. At the time of lamp inspection, all lamps that are turned on are controlled to turn off all lamps in case of failure.

To this end, the control unit detects the power input unit 144, the power integrated circuit 158 for generating various driving powers using the power from the power input unit 144, and the output power from the power integrated circuit 158. A communication IC 156 that receives the current measurement unit 150, various information for inspecting lamp characteristics from a user, a microcomputer 154 that receives the various information from the communication IC 156 and controls the entire control unit; And a DAC unit 152 for varying the luminance of each model to a voltage range of 256 ranges in response to a control signal from the microcomputer 154.

The backlight driving power is supplied to the power input unit 144. The backlight driving power is supplied to the power integrated circuit 158 through the power input unit 144 to generate power of various components used in the controller and supply the power to the components of the controller.

As illustrated in FIG. 6, the current measuring unit 150 includes six current measuring circuits IC1 to IC6. Each of the current measuring circuits IC1 to IC6 measures tube currents VBL1 to VBL6 supplied to each of the plurality of inverters, and generates detection signals CH1 to CH6 based on the measured tube currents VBL1 to VBL6. Supply to the microcomputer 154. That is, the current measuring unit 150 detects whether the lamp is turned on or not by measuring the tube currents VBL1 to VBL6 supplied to the inverters.

The communication IC 156 receives the setting information SI including the model lamp lighting number, the tube current, and the luminance value from the communication port 146 to check the characteristics of the lamp, and supplies the setting information SI to the microcomputer 154. At this time, the setting information SI supplied to the communication port 146 is input from the system by a user's operation.

The DAC unit 152 receives the 8-bit digital luminance variable signals F0 to F7 supplied from the microcomputer 154 to generate an analog reference voltage VBR in which the luminance of the lamps is changed to 256 ranges. The analog reference voltage VBR generated by the DAC unit 152 is fed back to the microcomputer 154.

As shown in FIG. 7, the microcomputer 154 includes a communication unit 204 which receives the setting information SI from the communication IC 156 and the 8-bit luminance variable signals F0 to F7 based on the user setting information SI. Brightness variable signal input port 202 for supplying DAC to the DAC unit 152, detection current input port 200 for receiving detection signals CH1 to CH6 from the current measuring unit 150, and detection signal CH1. And a lamp on / off control unit 206 for generating lamp driving control signals Lon1 to Lon6 using the CH6 and the analog reference voltage VBR from the DAC unit 152.

The communication unit 204 includes a memory (not shown) for receiving and storing setting information SI supplied from the communication IC 156. The luminance variable signal input port 202 supplies an 8-bit digital signal corresponding to a luminance value in the user setting information SI to the DAC unit 152. The detection current input port 200 supplies the detection signals CH1 to CH6 supplied from the current measuring unit 150 to the lamp on / off control unit 206 using internal circuit wiring.

The lamp on / off controller 206 supplies the analog reference voltage VBR supplied from the DAC unit 152 to the inverter by using the detection signals CH1 to CH6 supplied through the detection current input port 200. To this end, the lamp on / off control unit 206 may output the analog reference voltage VBR in response to each of the detection signals CH1 to CH6 from the current measuring unit 150 as shown in FIG. A plurality of integrated circuits LS1 to LS6 output to Lon6 are provided.

The plurality of integrated circuits LS1 to LS6 receive the analog reference voltage VBR fed back from the DAC unit 152 using the detection signals CH1 to CH6 supplied from the current measuring unit 150, and the lamp driving control signal Lon1. To Lon6). The lamp driving control signals Lon1 to Lon6 generated by the plurality of integrated circuits LS1 to LS6 are supplied to the inverter unit.

The microcomputer 154 uses the setting information SI from the communication IC 156 stored in the memory to output the 8-bit luminance variable signals F0 to F7 for adjusting the luminance values for the plurality of lamps. Supplies). In addition, the microcomputer 154 generates lamp driving control signals Lon1 to Lon6 for randomly driving the plurality of inverters based on the number of lamp lightings of the user stored in the memory.

Inverters of the lamp driving apparatus of the liquid crystal display according to an exemplary embodiment of the present invention may receive first and second inverters, which are supplied with an inverter driving voltage VBL from the power input unit 144 and converted into AC voltages under the control of the microcomputer 154. Sixth inverter 110, 111, 112, 113, 114, 115 and the first to sixth inverter (110, 111, 112, 113, 114, 115) is supplied with an alternating voltage to boost the lamp driving voltage One to sixth transformers 128, 130, 132, 134, 136, 138.

Each of the first to sixth inverters 110, 111, 112, 113, 114, and 115 receives the inverter driving voltage VBL from the power input unit 144, and the lamp driving control signal Lon1 from the microcomputer 154. To Lon6). Accordingly, each of the first to sixth inverters 110, 111, 112, 113, 114 and 115 exchanges the inverter driving voltage VBL in response to the lamp driving control signals Lon1 to Lon6 from the microcomputer 154. The voltage is converted into a voltage and supplied to each of the first to sixth transformers 128, 130, 132, 134, 136, and 138.

Each of the first to sixth transformers 128, 130, 132, 134, 136, and 138 is an inverter driving voltage VBL supplied from each of the first to sixth inverters 110, 111, 112, 113, 114, and 115. Is converted into a lamp driving voltage and supplied to each of the first to sixth lamps 116, 118, 120, 122, 124, and 126.

Accordingly, the inverter unit turns on / off the first to sixth lamps 116, 118, 120, 122, 124, and 126 in response to the lamp driving control signals Lon1 to Lon6 of the microcomputer 154.

9 and 5, a lamp driving method of a liquid crystal display according to an exemplary embodiment of the present invention is described as follows. First, as in the first step S1, the user stores setting information SI for the number of lamp lighting, the tube current, and the luminance value for each model of the liquid crystal display in the memory through the communication IC 156 of the microcomputer 154.

Then, when power is first supplied to the liquid crystal display, the microcomputer 154 controls the first to sixth inverters 102, 104, 106, 108, 110, and 112 to be supplied with power as in step S1. As a result, power is supplied to the inverter unit as in step S2.

When power is supplied to the inverter unit, the microcomputer 154 is loaded with setting information (SI) stored in the memory through the communication IC 156 as in step S3, the number of lamps, tube current and The model information on the luminance value and the like are compared with the model information of the inverter unit to which the power is supplied. When the comparison result of the model information is the same, the microcomputer 154 loads the model information as in step S4 and sets the number of lamps, the tube current, and the luminance value of the model. At this time, the microcomputer 154 supplies the 8 bit brightness variable signals F0 to F7 for setting the luminance value of the lamp to the DAC unit 152 based on the set model information. The DAC unit 152 generates an analog reference voltage VBR in response to the 8-bit luminance variable signals F0 to F7 and supplies it to the lamp on / off control unit 206 of the microcomputer 154.

The lamp on / off control unit 206 of the microcomputer 154 controls each of the first to sixth inverters 110, 111, 112, 113, 114, and 115 according to the number of lamp lightings set as in the step S5. . Thus, the first to sixth lamps 116, 118, 29, 122, 124, and 126 are turned on to have the set luminance value according to the set number of lamp lightings. At this time, the tube current supplied to the first to sixth lamps 116, 118, 29, 122, 124, and 126 to be turned on has a current value set by the user.

Then, the microcomputer 154 uses the current measuring circuits IC1 to IC6 of the current measuring unit 150 as in the step S6, respectively, to display the first to sixth inverters 110, 111, 112, 113, 114, 115) The input current (tube current) supplied to each is detected.

Subsequently, the microcomputer 154 and the number of lamp lightings set using the input current (tube current) value of the first to sixth inverters 110, 111, 112, 113, 114, and 115 detected as in step S7. Matches are matched.

If the lamp lighting result is matched, the microcomputer 154 returns to the step S6 and continuously measures and sets the input current (tube current) of the first to sixth inverters 110, 111, 112, 113, 114, and 115. It compares continuously with the number of lamp turns on. On the other hand, when the lamp lighting number comparison does not match, the microcomputer 154 cuts the input current supplied to the first to sixth inverters 110, 111, 112, 113, 114, and 115 as in the first step S2. All lamps will go out.

Such a lamp driving apparatus and method of a liquid crystal display according to an exemplary embodiment of the present invention will be described by way of example. First, the user inputs setting information SI for the number of lamp lighting, the tube current, and the luminance value of each model of the liquid crystal display device through the communication IC 156 of the microcomputer 154. In the embodiment of the present invention, for the sake of simplicity, the LM181E06-D4 lamp having a tube current of 3 mA to 8 mA and a luminance of 200 nits to 250 nits will be described as an example. In addition, the lamps used are the first to sixth lamps 116, 118, 120, 122, 124, 126, the first lamp 116 and the third lamp 120 is turned on, the luminance value is set to 2V Shall be.

When the setting information is input to the microcomputer 154 as described above, the microcomputer 154 controls the lamp on / off control unit 206 to generate a lamp driving control signal for turning on the first lamp 116 and the third lamp 120. Create This lamp control signal is supplied to the first and third inverters 110 and 112. Accordingly, only the first and third inverters 110 and 112 of the first to sixth inverters 110, 111, 112, 113, 114, and 115 are driven to drive the first lamp 116 and the third lamp 120. Lights up. At this time, each of the first lamp 116 and the third lamp 120 has a luminance value corresponding to 2V of the 256 range by the DAC unit 152.

Then, the microcomputer 154 detects a tube current supplied to each of the first to sixth inverters 110, 111, 112, 113, 114, and 115, and inputs the number of lamps lit and the user input as setting information SI. The number of selected lights will be compared. That is, when the current measuring unit 150 detects the current supplied to the inverter and supplies it to the microcomputer 154, the microcomputer 154 lights the first and third lamps 116 and 120 instructed to turn on by the user. The number of lighting of the lamp is determined by continuously monitoring whether current is input to the first and third inverters 110 and 112. As a result, when the number of lighting of the lamp detected by the microcomputer 154 and the number of lighting of the lamp input as setting information match, the lamps selected by the user to be turned on, that is, the first and third lamps 116 and 120 are turned on and compared. If the results do not coincide, the driving of the first to sixth inverters 110, 111, 112, 113, 114, and 115 is shut down, and thus the first to sixth lamps 116, 118, 29, 122, 124, and 126. ) Turned off everyone.

The lamp driving apparatus and method of the liquid crystal display according to the exemplary embodiment of the present invention drive the first to sixth inverters 110, 111, 112, 113, 114, and 115 to operate the first to sixth lamps 116. Each of the first to sixth inverters 110, 29, 122, 124, and 126 is turned on and the input current of each of the first to sixth inverters 110, 111, 112, 113, 114, and 115 is measured. Only the inverters to which the first to sixth lamps 116, 118, 29, 122, 124, and 126 of the 111, 112, 113, 114, and 115 are driven, that is, the loads can be selectively driven.

On the other hand, the lamp driving device and method of the liquid crystal display according to an embodiment of the present invention is at least one of the first to sixth lamp (116, 118, 29, 122, 124, 126) in the backlight unit inspection of the liquid crystal display device When there is no input current value measured from the lamp, all of the first to sixth inverters 110, 111, 112, 113, 114, and 115 are turned off.

Referring to FIG. 10, a case of inspecting a backlight unit of a liquid crystal display using the lamp driving method of the liquid crystal display according to another exemplary embodiment will be described below.

In the method of driving the lamp of the liquid crystal display according to another exemplary embodiment of the present invention, steps S1 to S7 have the same steps as the method of driving the lamp of the liquid crystal display according to the embodiment of the present invention, and step S8. In step S7 shown in FIG. 9, when the detected detection signal coincides with the set number of lamp lighting, it is determined whether the detected detection signal is out of a range between a preset maximum value and a minimum value.

In detail, the lamp driving method of the liquid crystal display according to another exemplary embodiment of the present invention continuously supplies current from the first to sixth lamps 116, 118, 29, 122, 124, and 126 as in step S8. Will be measured. Then, the microcomputer 154 may check the first to sixth inverters 110, 111, 112, 113, 114, and 115 as in the first step S3 when the measured current detection signal is out of a range between the preset maximum value and the minimum value. ) Are all turned off. In addition, the microcomputer 154 returns to step S6 when the measured current detection signal is within a range between a preset maximum value and a minimum value, and the first to sixth lamps 116, 118, 29, 122, 124, and 126. Current is continuously measured.

As described above, the lamp driving apparatus and method of the liquid crystal display according to the exemplary embodiment of the present invention include a shutdown circuit for shutting down all lamps when at least one of the plurality of lamps is defective. Accordingly, the lamp driving apparatus and method of the liquid crystal display according to the embodiment of the present invention can filter the lamp failure.

The lamp driving apparatus and method of the liquid crystal display according to an exemplary embodiment of the present invention may include a plurality of inverters for driving each of the plurality of lamps to individually drive each of the plurality of lamps. It can be used for all lamps without any change, and it can be detected as a failure if the current value of the lamp is continuously monitored and it is out of the set value.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

Claims (27)

A plurality of lamps; A plurality of inverters for driving each of the plurality of lamps; A pulse width control unit controlling the plurality of inverters by measuring a current of each of the lamps; And a power control unit for shutting down each of the plurality of inverters in response to a control signal from the pulse width control unit. The method of claim 1, The power control unit, Inverter drive power, And a shutdown circuit for switching drive power from the inverter drive power to be supplied to each of the plurality of inverters in response to a control signal from the pulse width controller. The method of claim 2, The shutdown circuit, A first switch driven in response to a control signal from the pulse width controller; A second switch driven according to the driving of the first switch; And a third switch for switching paths of the inverter driving power source and the plurality of inverters according to the driving of the second switch. The method of claim 3, wherein The shutdown circuit, A fourth switch connected between the second switch and the third switch to drive the third switch according to the driving of the second switch; And a diode connected between the first switch and the second switch. The method of claim 1, And a plurality of transformers connected to each of the inverters in two units to convert driving power from the inverter into lamp driving power. A plurality of lamps; A plurality of inverters for driving each of the plurality of lamps; A current measuring unit measuring a current of each of the lamps to generate a current detection signal; And a controller for receiving and storing model information for controlling the inverter from a user and individually controlling each of the plurality of inverters using the stored model information and the current detection signal. Drive system. The method of claim 6, And the model information is a lamp lighting number, a tube current, and a luminance value corresponding to the model of the liquid crystal display device. The method of claim 7, wherein And the controller generates a digital luminance control signal based on the input current of the model information. The method of claim 8, A power supply unit for generating driving power for the lamp driving device of the liquid crystal display device; A communication unit receiving the model information from the user and supplying the model information to the control unit; And a digital analog converter which receives driving power from the power supply unit and receives a digital luminance control signal from the controller and converts the analog signal into an analog signal. The method of claim 9, The control unit, A storage unit for storing the model information supplied from the communication unit; A detection signal input unit receiving the current detection signal from the current measuring unit; And an inverter controller for supplying an analog signal from the digital analog converter to each of the plurality of inverters by using the current detection signal through the detection signal input unit. The method of claim 6, And a plurality of transformers connected to each of the inverters to convert driving power from the inverter into lamp driving power. The method of claim 8, And the control unit compares the current detection signal with the number of lamp lightings and individually turns on / off driving of each of the plurality of inverters according to a comparison result. The method of claim 6, And the controller is configured to turn on only the inverters which normally drive the lamps using the current detection signal and to shut down the remaining inverters after turning on the plurality of lamps. The method of claim 13, And the controller is configured to shut down all inverters when the measured current detection signal is out of a range between a set maximum value and a minimum value while continuously measuring currents of the normally driven lamps. The method of claim 6, The controller may turn on the plurality of lamps and then turn off the plurality of lamps when at least one of the plurality of lamps is defective based on the current detection signal. . Turning on the plurality of inverters for driving each of the plurality of lamps; Measuring a current of each of the lamps to generate a current detection signal; And shutting down each of the plurality of inverters in response to the detection signal. The method of claim 16, The shutdown step includes the step of shutting off the driving power supplied to each of the plurality of inverters by using a plurality of switch elements in response to the detection signal. A first step of receiving model information for controlling each of the plurality of inverters from a user; A second step of turning on the plurality of inverters for driving each of the plurality of lamps; Generating a current detection signal by measuring a current of each of the lamps; And a fourth step of individually controlling each of the plurality of inverters by using the model information and the current detection signal. The method of claim 18, And the model information is a lamp lighting number, a tube current, and a luminance value corresponding to the model of the liquid crystal display device. The method of claim 19, And generating a digital luminance control signal based on the input current of the model information. The method of claim 20, Generating driving power of a lamp driving device of the liquid crystal display; And receiving the digital brightness control signal and converting the signal into an analog signal. The method of claim 21, And supplying the analog signal to each of the plurality of inverters using the current detection signal. The method of claim 18, And converting the driving power output from the inverters into a lamp driving power. The method of claim 20, The fourth step, Comparing the current detection signal with the number of lamp lightings; And individually turning on / off driving of each of the plurality of inverters according to the comparison result. The method of claim 18, The fourth step, Turning on all of the plurality of lamps; And turning on only the inverters which normally drive the lamps using the current detection signal and shutting down the remaining inverters. The method of claim 25, The fourth step, And shutting down all inverters when the measured current detection signal is out of a range between a preset maximum value and a minimum value while continuously measuring current of the normally driven lamps. Way. The method of claim 18, The fourth step, Controlling all of the plurality of lamps to be turned on; And extinguishing the plurality of lamps when at least one of the plurality of lamps is defective based on the current detection signal.

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