KR100903822B1 - Led backlight unit and display device including the same - Google Patents

Abstract

An LED(Light Emitting Diode) backlight unit and a display device including the same are provided to reduce the cost for components and the inferiority of an assembling process by not including a connector or wring between LED arrays and an LED driving unit. An LED backlight unit includes plural LED modules, and the each module includes an LED driving unit(141). The LED driving unit drives at least one LED array on which the plural LEDs are arranged and at least one LED array based on a brightness control signal. The LED array and the LED driving unit are electrically connected to each other, and some of brightness control signals are transmitted to the LED driving unit within the LED modules by being electrically connected to each other.

Description

Light emitting diode backlight unit and display device including the same {LED backlight unit and display device including the same}

The present invention relates to a light emitting diode backlight unit (LED BLU), and more particularly, to a light emitting diode backlight unit for minimizing a connection between a light emitting diode driver and a light emitting diode array.

Recently, flat panel display devices have shown explosive growth. Flat panel display devices are widely used not only for mobile devices requiring miniaturization and low power, but also for large digital TVs that require weight and thickness reduction. Among them, the LCD (Liquid Crystal Display) method is the most widely used among flat panel display methods because it can be applied to small devices and large devices.

The LCD device requires a light source called a backlight unit on the rear side of the liquid crystal panel because the liquid crystal panel does not emit light by itself. The light generated from the backlight unit passes through the liquid crystal layer and the color filter to show the screen to the outside. Therefore, the backlight unit significantly affects the performance of the LCD device. For example, the display unit color quality, maximum brightness, contrast ratio, white uniformity, color temperature, as well as the weight, design, life, power consumption, etc. can be significantly affected by the backlight unit.

Conventional backlight units are widely used as Cold Cathode Fluorescent Lamps (CCFLs) and External Electrode Fluorescent Lamps (EEFLs). However, these fluorescent lamps have large dimensions, high power consumption, and have a significant limitation on maximum brightness. LCD devices employing such fluorescent lamps exhibit up to about 80% color reproduction based on the National Television System Committee (NTSC). In particular, since these fluorescent lamps are linear light sources, an expensive light diffusion film or the like can be used to supply uniform light to the entire LCD surface. In addition to these technical factors, there has been a need to develop other light sources besides fluorescent lamps since 2006, prohibiting the use of CCFLs in automobiles.

On the other hand, LEDs did not initially provide sufficient brightness to be used as backlights and were expensive to manufacture, but recently, LEDs with high brightness, low power consumption, and low manufacturing costs have been developed. By constructing an array of white LEDs or using an array of properly arranged three primary (RGB) LEDs, the array can function like a surface light source. Therefore, the backlight unit can be made with such an LED array. The LED backlight unit does not need to use an expensive diffusion film, and does not require an inverter, unlike a fluorescent lamp, so that the manufacturing cost can be reduced, it is advantageous for large size, thickness and weight, and power consumption can be reduced. The high brightness also allows NTSC reference color reproducibility to reach 110%, which was not possible with CCFLs.

The LED backlight unit is composed of a number of LEDs, and the light is emitted by such LEDs, the performance of which is determined by how each LED is driven. The amount of light emitted by the LED can be said to be approximately proportional to the magnitude of the drive current passing through the active layer of the LED. Here, LED driving is a method of supplying and controlling such driving current.

Conventional LED backlight units are coupled to each other using an LED driver and an interface. In this case, since the LED arrays of the LED backlight unit are arranged in panels with diagonal lines ranging from tens of inches to several tens of inches, the LED driver and the LED arrays must be connected through a plurality of interface lines. These interfaces usually consist of connectors and cables, which are susceptible to external influences such as noise, temperature, and so on, as well as causing component cost increases, as well as a factor of performance degradation when improperly coupled during assembly. This can be

Accordingly, an object of the present invention is to provide an LED backlight unit and a display device including the LED backlight unit that can minimize the connection between the LED driver and the LED array.

LED backlight unit according to the present invention for solving the above problems is at least one LED array (array) is arranged a plurality of light emitting diodes (LED); And an LED driver for driving the at least one LED array, wherein the at least one LED array and the LED driver are directly connected in one circuit board.

The at least one LED array may be formed on a first side of the circuit board, and the LED driver may be formed on a second side of the circuit board. The at least one LED array and the LED driver may be formed on the same surface of the circuit board.

A multi-dimmable dimming control unit for dimming control of each of the at least one LED array is further included, and the multi-dividing dimming control unit may be directly connected to the LED driver in the one circuit board. The at least one LED array may be formed on a first surface of the circuit board, and the LED driver and the multi-dimmable dimming controller may be formed on a second surface of the circuit board. The at least one LED array, the LED driver, and the multi-dimmable dimming controller may be formed on the same surface of the circuit board.

The LED driver may supply the at least one LED array with a driving current modulated by any one of pulse amplitude modulation (PAM), pulse width modulation (PWM), or pulse width amplitude modulation (PWAM).

The at least one LED array and the LED driver are directly connected on one circuit board to constitute one LED module, wherein the LED backlight unit includes a plurality of LED modules, and each LED driver in the LED modules. They may be connected to each other and configured to transmit an externally provided brightness control signal to an LED driver in another LED module. The plurality of LED modules may be arranged to be in close contact with the case of the LED backlight unit.

Each of the LED drivers in the LED modules may be daisy chained with each other, and may be configured to sequentially transmit externally provided luminance control signals to the LED drivers in the adjacent LED modules.

Each of the LED drivers in the LED modules may include a decoder, and the decoders may be connected to each other in a daisy chain manner so as to sequentially transmit the luminance control signal to decoders in adjacent LED drivers.

The LED driver receives a brightness control data corresponding to the corresponding LED module from the applied brightness control signal, outputs all or part of the brightness control signal, and generates a brightness setting signal based on the received brightness control signal ; And a driving circuit which generates a driving current based on the luminance setting signal, wherein the decoders may be connected to each other in a daisy chain manner so as to sequentially transfer the luminance control signals to decoders in adjacent LED modules. .

The driving current may be modulated by any one of a PAM method, a PWM method, and a PWAM method.

The image control unit providing the luminance control signal to the LED driver and the power supply unit supplying power to the LED driver may be implemented as a separate package from a circuit board on which the LED module is formed.

The brightness control signal or power may be provided wirelessly.

Two or more image controllers may be provided to provide one or more luminance control signals to one LED backlight unit in one-to-many communication.

The LED module may be formed on a first surface of the circuit board, and the at least one LED driver may be formed on a second surface of the circuit board. Meanwhile, the LED module and the at least one LED driver may be formed on the same surface of the circuit board.

In addition, a display device according to the present invention for solving the above problems is a display panel; At least one LED array in which a plurality of light emitting diodes (LEDs) are arranged and an LED driver for driving the at least one LED array, wherein the at least one LED array and the LED driver are in one circuit board. LED backlight unit, characterized in that directly connected in; And an image controller which provides luminance control information for each of the at least one LED array to the LED backlight unit, and provides a color signal for pixels of the display panel to the display panel.

Since the LED backlight unit according to the embodiments of the present invention directly connects the LED arrays and the LED driver, noise or current ripple can be minimized to minimize deviations between the LED strings and drive control errors due to noise. Can be attenuated. In addition, since the LED backlight unit according to the embodiments of the present invention does not have a connector or wiring between the LED arrays and the LED driver, component cost can be reduced and assembly defects can be reduced. As a result, the reliability of the product can be improved. In addition, the LED backlight unit according to the embodiments of the present invention can be arranged in close contact with the case of the LED backlight unit, it is possible to prevent the temperature rise of the LED module.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. The same reference numerals are used for the same elements in the drawings, and duplicate descriptions of the same elements are omitted.

Hereinafter, the LCD device including the LED backlight unit according to the embodiments of the present invention will be described in detail. However, the present invention is not limited thereto and may be applied to other display devices including the LED backlight unit.

1 is a block diagram schematically illustrating an LCD device according to an embodiment of the present invention.

Referring to FIG. 1, the LCD device 10 includes a power supply unit 11, an image control unit 12, a multi-dimmable dimming control unit 13, an LED backlight unit 14, and an LCD panel 15. Here, the LED backlight unit 14 includes an LED driver 141 and a plurality of LED arrays 142.

The image controller 12 is connected to the LCD panel 15 by using an interface to provide the LCD panel 15 with color signals for pixels of the LCD panel 15. In addition, the image control unit 12 provides the dimming control unit 13 with a luminance control signal for each of the plurality of LED arrays 142 in the LED backlight unit 14. The multi dimming control unit 13 is connected to the LED backlight unit 14 by using an interface to provide a dimming signal to the LED backlight unit 14.

The dimming signal may be a digital signal or an analog signal generated to maintain overall color temperature and brightness with respect to the LED arrays 142 in the LED backlight unit 14. In one embodiment of the present invention, the dimming signal may be a digital signal in which the information of the dimming signal is not modified while passing through the interface.

In one embodiment of the present invention, the LED backlight unit 14 is integrally formed including the LED driver 141 and the plurality of LED arrays 142. Each of the plurality of LED arrays 142 includes a plurality of LEDs arranged in a predetermined number of rows and columns over a portion of a printed circuit board (PCB). Here, the LED driver 141 and the LED arrays 142 may be directly connected. In other words, the LED driving currents supplied from the LED driver 141 to each of the LED arrays 142 may be transmitted using, for example, a line formed directly on the printed circuit board, without using a connector and an interface winding. have. In this case, the LED driver 141 and the LED arrays 142 may be formed together on one printed circuit board.

According to an embodiment, the LED driver 141 may drive LEDs in each LED array 142 in a constant voltage driving method or a constant current driving method. The constant voltage driving method has the advantage of simple circuit configuration, but when the heat is generated as the LED emits heat, and the temperature increases, the forward voltage drop (Vf) of the LED generally increases and the current passing through the LED active layer is increased. Since the amount of emitted light tends to increase, the change in luminance may occur severely as the emission time increases.

On the other hand, in the constant current driving method, since the driving current is controlled to be constant even when the temperature changes, the amount of emitted light is also kept constant, thereby greatly reducing the luminance change. In this case, the expression that the driving current is constant means that the driving current is kept constant on average even though the driving current is continuously variable with time. Preferably, the LED driver 141 operates in a constant current driving method.

The LED driver 141 generates driving currents capable of driving each of the plurality of LED arrays 142 by modulating the current provided from the power supply unit 11 according to the information of the dimming signal. According to an embodiment of the present invention, the dimming signal may have modulation information of any one of pulse width modulation (PWM), pulse amplitude modulation (PAM), or pulse width-amplitude modulation (PWAM) scheme, and the driving current. May be a current modulated in any one of a PWM, PAM, and PWAM scheme based on the dimming signal scheme.

In one embodiment of the present invention, the dimming signal is PWM data and the driving current may be a PWM modulated current signal as indicated by the dimming signal. In this case, the image controller 12 may provide the luminance control signal to the dimming dimming controller 13 through an appropriate encoding. The multi dimming control unit 13 may properly decode the encoded luminance control signal, generate a separate PWM dimming signal for each of the plurality of LED arrays 142, and provide the same to the LED driver 141. Specifically, the LED driver 141 may control the amount of light of each LED array 142 by controlling the duty ratio of the driving current according to the duty ratio information designated by the PWM data.

In other embodiments of the present invention, the dimming signal may be PAM data and the driving current may be a PAM modulated current signal. The multi dimming control unit 13 generates an individual PAM dimming signal for each LED array 142 and provides it to the LED driver 141. In detail, the LED driver 141 may control the amount of light of each LED array 142 by controlling the amplitude of the driving current according to the amplitude information designated by the PAM data.

In still other embodiments of the present invention, the dimming signal may be PWAM data and the driving current may be a PWAM modulated current signal. The multi dimming control unit 13 generates an individual PWAM dimming signal for each LED array 142 and provides it to the LED driver 141. When the dimming signal is PWAM data, the dimming signal may include a luminance setting component and a fine control signal component of the LED array. Specifically, the LED driver 141 controls the amplitude of the driving current according to the luminance setting component, and also controls the duty ratio of the driving current according to the fine control signal component, thereby providing each LED array 142. The amount of light can be controlled.

2 is a block diagram schematically illustrating an LCD device according to another embodiment of the present invention.

Referring to FIG. 2, the LCD device 20 includes a power supply unit 21, an image control unit 22, an LED backlight unit 23, and an LCD panel 24. Here, the LED backlight unit 23 includes an LED driver 231, a multi-dimmable dimming controller 232, and a plurality of LED arrays 233.

The image controller 22 is connected to the LCD panel 24 by using an interface to provide the LCD panel 24 with color signals for pixels of the LCD panel 24. The image controller 22 also provides the LED backlight unit 23 with luminance control information regarding each of the plurality of LED arrays 233 in the LED backlight unit 23. The dimming signal may be a digital signal or an analog signal generated to maintain the overall color temperature and brightness with respect to the LED arrays 233 in the LED backlight unit 23.

In one embodiment of the present invention, the LED backlight unit 23 is integrally formed by including an LED driver 231, a dimming dimming controller 232, and a plurality of LED arrays 233. Each of the plurality of LED arrays 233 includes a plurality of LEDs arranged with a certain number of rows and columns over a portion of a printed circuit board. The multi dimming control unit 232 provides a dimming signal to the LED driver 231 based on the luminance control information received from the image control unit 22. The LED driver 231 generates a driving current for driving the LED arrays 233 according to the dimming signal.

Here, the LED driver 231 and the LED arrays 233 may be directly connected. The LED driving currents supplied from the LED driver 231 to the respective LED arrays 233 may be transmitted using a line formed directly on the printed circuit board, without using a connector and an interface line. In this case, the LED driver 231 and the LED arrays 233 may be formed together on one printed circuit board.

Furthermore, the multi dimming control unit 232 may be directly connected to the LED driver 231. Since the dividing dimming control unit 232 is integrally included in the LED backlight unit 23 together with the LED driving unit 231, the dividing dimming control unit 232 and the LED driving unit 231 need to be connected using a connector and an interface line. Can be connected using a line formed directly on the printed circuit board. In this case, the multi dimming controller 232, the LED driver 231, and the LED arrays 233 may be formed together on one printed circuit board.

According to an embodiment, the LED driver 231 may drive the LEDs in the LED array 233 in a constant voltage driving method or a constant current driving method.

The LED driver 231 generates driving currents capable of driving each of the LED arrays 233 in the LED backlight unit 23 by modulating the current provided from the power supply unit 21 according to the information of the dimming signal. According to an embodiment of the present invention, the dimming signal may have modulation information of any one of PWM, PAM or PWAM schemes, and the driving current may be any of PWM, PAM or PWAM schemes based on the dimming signal scheme. It may be a current modulated in one way. Here, the operation of the LED driver 231 included in the LED backlight unit 23 and the multi-dimmable dimming controller 232 according to the PWM, PAM, or PWAM method is performed by the LED driver 141 included in the LCD device 10 of FIG. 1. ) Is substantially similar to the operation of the multi-dimmable dimming control unit 13, and thus a detailed description thereof will be omitted.

3 is a block diagram schematically illustrating an LCD device according to another embodiment of the present invention.

FIG. 4 is a detailed block diagram illustrating an LED backlight unit module included in the LCD device of FIG. 3.

3 and 4 together, the LCD device 30 includes an external control unit 31 and a display unit 32, and the external control unit 31 includes a power supply unit 311 and an image control unit 312, The display unit 32 includes an LED backlight unit 321 and an LCD panel 322. Here, the external control unit 31 is formed as a separate package from the display unit 32.

In one embodiment of the present invention, the power supply unit 311 may supply power to the display unit 32 in a wired or wireless manner.

The image controller 312 is connected to the LCD panel 322 through a predetermined interface to provide the LCD panel 322 with color control signals for the pixels of the LCD panel 322. Here, the image controller 312 and the LCD panel 322 may be connected using a wired or wireless interface. In addition, the image controller 312 is connected to the LED backlight unit 321 through a predetermined interface to provide a brightness control signal to the LED backlight unit 312. Here, the image controller 312 is also connected to the LED backlight unit 312 through a wired or wireless interface.

In the embodiments of FIGS. 1 and 2, there was a block (i.e., a multi-dimmable dimming control unit and LED driver) integrating the overall dimming control and driving current generation operations. In the embodiment of FIG. Distribution is performed in the plurality of LED modules 321a, 321b,..., 321n connected in series included in 321.

The LED backlight unit 321 includes a plurality of LED modules 321a, 321b,..., 321n connected in series as described above, and each LED module 321a includes an LED driver 3211 and an LED array unit 3212. ) May be included. The LED array portion 3212 includes a plurality of LED arrays 3212a, 3212b, ..., 3212n and these LED arrays composed of a plurality of LEDs arranged in a predetermined number of rows and columns on a portion of a printed circuit board. 312a, 3212b, ..., 3212n includes a sensor unit 3216 that can sense the amount of light emitted.

The luminance control signal provided to the LED backlight unit 321 is provided to at least one 321a of the plurality of LED modules 321a, 321b,..., 321n, and the plurality of LED modules 321a, 321b,..., 321n. ) Is connected in a daisy chain method, for example, and each LED module 321a extracts only the brightness control data corresponding to the magnetic module among the brightness control signals, and then transfers all or the remaining brightness control data to the next LED module. To 321b. In this manner, the image controller 312 does not transmit data to all the LED modules 321a, 321b,..., 321n of the LED backlight unit 321 at one time, but transmits data to only one of the LED modules 321a. Even if it is possible to provide an appropriate brightness control function for the entire LED backlight unit 321.

The LED driver 3211 in the LED module 321a includes a decoder 3213, a driving circuit 3214, and a feedback controller 3215. The decoder 3213 receives the luminance control data and generates a luminance setting signal based on the luminance control data. In addition, the decoder 3213 transfers luminance control data to the next LED module 321b. The drive circuit 3214 generates a drive current in accordance with the luminance setting signal. The feedback control unit 3215 controls the driving circuit 3214 by receiving a sensing signal provided from the sensor unit 3216.

In one embodiment of the present invention, the decoder 3213 may have its own brightness and color coordinate information, and may roughly adjust the brightness of the corresponding LED array unit 3212, in which case the decoder 3213 itself may output the brightness setting signal. Create

In another embodiment of the present invention, the decoder 3213 may generate a luminance setting signal from the luminance control data. The decoder 3213 provides a luminance setting signal to the driving circuit 3214, and the driving circuit 3214 generates a driving current according to the luminance setting signal and supplies it to the LED array unit 3212.

In one embodiment, the decoder 3213 may be implemented as a microcontroller unit (MCU), and in another embodiment may be implemented as a shift register.

As such, since an MCU or the like is used for the LED module, color coordinates and luminance can be set in module units. This means that errors in color coordinates and luminance can be reduced from a module unit. Thus, by using a module having reduced errors in color coordinates and luminance in the entire BLU, a high quality and high reliability product can be produced.

In one embodiment, the luminance setting signal is a PAM modulated signal, and the driving circuit 3214 may generate a PAM modulated driving current. The driving circuit 3214 may roughly control the amount of light of the LED array unit 3212 by controlling the amplitude of the driving current according to the amplitude information designated by the PAM modulated luminance setting signal.

In another embodiment, the luminance setting signal is PWM data and the driving circuit 3214 may be configured to generate a PWM driving current. The driving circuit 3214 may finely control the amount of light of the LED array unit 3212 by controlling the duty ratio of the driving current according to the duty ratio information designated by the PWM data.

The decoders 3213 are sequentially connected to decoders in each LED module, for example, in a daisy chain manner, so that the luminance control signal from the image controller 312 sequentially passes through the decoders, corresponding to the corresponding decoders. The decoder is configured to acquire data in the luminance control signal. Based on the data obtained by the decoder, the driving circuit 3214 generates a driving current and supplies it to the LED array unit 3212.

In the embodiment of Figs. 3 and 4, the luminance control signal for each module is supplied in a serial data format, in which case it can be seen that multi-dimming control is already applied at the time of generating the luminance control signal.

The sensor unit 3216 detects some of the light emitted from the plurality of LED arrays 3212a, 3212b,..., 3212n in the LED array unit 3212, and generates a sensing signal indicating how much the luminance is. This sensing signal may be provided to the feedback controller 3215. The feedback controller 3215 generates a feedback signal based on the sensing signal and provides the feedback signal to the driving circuit 3214. The driving circuit 3214 receives the feedback signal and generates a driving current based on the luminance setting signal and the feedback signal.

5 is a block diagram schematically illustrating an example of the LCD device of FIG. 3.

Referring to FIG. 5, the LED modules 321a and 321b included in the LED backlight unit 321 may be arranged as shown in FIG. 5, and are indicated by black arrows between the respective LED modules 321a and 321b. As can be the case, power and data can be delivered. However, this is only one embodiment of the present invention, and in another embodiment of the present invention, unlike FIG. 5, power and data may be delivered in a different order.

6 is a block diagram schematically illustrating an LCD device according to another embodiment of the present invention.

Referring to FIG. 6, the LCD device 40 includes an external control unit 41 and a display unit 42, and the external control unit 41 includes a power supply unit 411 and an image control unit 412. 42 includes an LED backlight unit 421 and an LCD panel 422. Here, the external control unit 41 is formed as a separate package from the display unit 42.

Here, except that the LED backlight unit modules 421a, 421b,..., 421n included in the LCD device 40 are connected in parallel to each other, the other configuration is substantially similar to that of the LCD device 30 of FIG. 3. Hereinafter, the LED backlight unit modules 421a, 421b,..., 421n will be described.

The LED backlight unit 421 includes a plurality of LED modules 421a, 421b,..., 421n connected in parallel as described above, and the configuration of each LED module 421a is substantially similar to that of FIG. 4. Detailed description will be omitted.

The power supply unit 411 may be connected to the LED backlight unit 421 as one inlet unit, and may be connected to the plurality of LED modules 421a, 421b,..., 421n by using a pattern connection such as a printed circuit board or a connector. Can be supplied, thereby forming a parallel connection pattern.

In one embodiment of the present invention, each of the plurality of LED modules 421a, 421b,..., 421n may be implemented substantially similar to the LED module illustrated in FIG. 4. At this time, the decoder included in each LED module is implemented by an MCU, and by assigning an address, an array of the plurality of LED modules 421a, 421b,..., 421n may be parallelized. In addition, when one data line is connected to the LED backlight unit 421 from the image controller 412, the arrangement of the plurality of LED modules 421a, 421b,..., 421n may be parallelized.

7 is a block diagram schematically illustrating an LCD device according to another embodiment of the present invention.

Referring to FIG. 7, the LCD device 50 includes an external control unit 51 and a display unit 52, and the external control unit 51 includes a power supply unit 511 and an image control unit 512. 52 includes an LED backlight unit 521 and an LCD panel 522. Here, the external control unit 51 is formed as a separate package from the display unit 52.

Here, except that the LED backlight unit modules 5211a, 5211b, 5212a, 5212b, .... 5213a, 5213b included in the LCD device 50 are connected to each other in series / parallel, the other configuration of the LCD of FIG. Since it is substantially similar to 30, the LED backlight unit modules 5211a, 5211b, 5212a, 5212b, .... 5213a, 5213b will be described below.

The LED backlight unit 421 may supply power and data in parallel to at least two series of LED backlight unit module groups connected in series. Specifically, at least two series of LED backlight unit module groups connected in series may be implemented in the form of a master / slave. 7 shows three LED backlight unit module groups, that is, a first LED backlight unit module group 5211a and 5211b, a second LED backlight unit module group 5212a and 5212b, and a third LED backlight unit module group 5213a, 5213b) is shown.

The first LED backlight unit module group includes two series-connected LED backlight unit modules 5211a and 5211b, where the LED backlight unit 5211a corresponds to the master and the LED backlight unit 5211b corresponds to the slave. In addition, the second LED backlight unit module group includes two series-connected LED backlight unit modules 5212a and 5212b, where the LED backlight unit 5212a corresponds to the master and the LED backlight unit 5212b corresponds to the slave. do. In addition, the third LED backlight unit module group includes two series-connected LED backlight unit modules 5213a and 5213b, where the LED backlight unit 5213a corresponds to the master and the LED backlight unit 5213b corresponds to the slave. .

The power supply unit 511 may be connected to the LED backlight unit 521 as one inlet, and may be connected to a pattern such as a printed circuit board to the LED backlight unit modules 5211a, 5212a, and 5213a corresponding to the master of each LED backlight unit module group. Alternatively, power can be supplied using a connector or the like, thereby forming a parallel connection pattern.

In one embodiment of the present invention, each of the plurality of LED modules 5211a, 5211b, 5212a, 5212b, .... 5213a, 5213b may be implemented substantially similar to the LED module shown in FIG. At this time, the decoder included in each LED module is implemented by the MCU, and by giving an address, it is possible to parallelize the arrangement of the plurality of LED modules (5211a, 5211b, 5212a, 5212b, .... 5213a, 5213b). In addition, when one data line is connected to the LED backlight unit 521 from the image controller 512, the arrangement of the plurality of LED modules 5211a, 5211b, 5212a, 5212b,... 5213a, 5213b may be parallelized.

1 and 2 require a centralized dimming dimming control unit and LED driver, and in large display devices, it is often necessary to supply driving currents to LED array units several tens of centimeters away from the LED driver. In FIG. 7, the LED driving units which are responsible for the current of only one LED array unit are individually present in each LED module, and thus, are advantageous in terms of cost and lifespan in that components of low power capacity can be used. The large number of devices provides flexibility in design in that it can easily cope with small and medium-sized displays as well as large displays.

According to an exemplary embodiment, each image controller included in the plurality of external controllers may transmit a color control signal and a luminance control signal through one-to-many communication with one display unit.

FIG. 8 is a side view schematically showing the LCD device of FIGS. 3, 6, and 7.

Referring to FIG. 8, the LCD device 80 includes a case 81, an LCD panel 82, a light guide plate 83, an LED module 84, a plurality of LEDs 85, a power supply 86, and an image controller ( 87).

In the embodiment of FIG. 8, an LED module 84, a plurality of LEDs 85, and a light guide plate 83 on the LED module 84 are disposed inside the case 81, and outside the case 81. The power supply unit 86 and the image control unit 87 are arranged.

If a predetermined space is generated between the LED module 84 and the plurality of LEDs 85 and the case 81, the heat generated by the plurality of LEDs 85 may be generated by the case 81 and the LED module. You are trapped between (84). At this time, the temperature of the LED module 84 and the plurality of LEDs 85 may continue to rise due to the trapped heat, and as a result, the overall performance of the LCD device may be degraded.

However, in one embodiment of the present invention, the case 81 may be implemented with a heat dissipation material, and the LED module 84 and the plurality of LEDs 85 may be disposed to closely contact the case 81. As a result, heat generated in the plurality of LEDs 85 may be emitted to the case 81, thereby preventing the temperature of the LED module 84 and the plurality of LEDs 85 from rising.

While the invention has been described with respect to specific embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit of the invention. In addition, various modifications may be made to adapt a particular situation or material requirement to the teachings of the present invention without departing from its spirit. Accordingly, the invention is not limited to the specific embodiments disclosed, and it is intended that the invention encompass all embodiments falling within the spirit of the appended claims.

1 is a block diagram schematically illustrating an LCD device according to an embodiment of the present invention.

2 is a block diagram schematically illustrating an LCD device according to another embodiment of the present invention.

3 is a block diagram schematically illustrating an LCD device according to another embodiment of the present invention.

4 is a block diagram schematically illustrating an example of an LED block included in the LCD device of FIG. 3.

5 is a block diagram schematically illustrating an example of the LCD device of FIG. 3.

6 is a block diagram schematically illustrating an LCD device according to another embodiment of the present invention.

7 is a block diagram schematically illustrating an LCD device according to another embodiment of the present invention.

FIG. 8 is a side view schematically showing the LCD device of FIGS. 3, 6, and 7.

Claims (29)

An LED backlight unit comprising a plurality of light emitting diode (LED) modules, Each of the plurality of LED modules, At least one LED array in which a plurality of LEDs are arranged, and an LED driver for driving the at least one LED array based on an externally provided brightness control signal, The at least one LED array and the LED driver are electrically connected on one circuit board, LED drivers included in each of the plurality of LED modules are electrically connected to each other, LED backlight unit, characterized in that configured to sequentially transmit at least a portion of the brightness control signal to the LED driver in the adjacent LED module. The method of claim 1, Each of the plurality of LED modules, A sensor unit detecting an intensity of light emitted from the at least one LED array; And And a feedback controller for compensating for the driving operation of the LED driver based on the intensity of light detected by the sensor unit. The method of claim 1, The LED driver, A decoder configured to receive luminance control data corresponding to the corresponding LED module among the luminance control signals, output all or part of the luminance control signal, and generate a luminance setting signal based on the received luminance control signal; And A driving circuit for generating a driving current for driving the at least one LED array based on the brightness setting signal, The decoders included in each of the plurality of LED modules are connected to each other in a daisy chain manner, and configured to sequentially transmit the brightness control signal to a decoder in an adjacent LED module. The method of claim 1, The LED driver supplies a driving current modulated by any one of pulse amplitude modulation (PAM), pulse width modulation (PWM) or pulse width amplitude modulation (PWAM) to the at least one LED array. unit. The method of claim 1, LED backlight unit, characterized in that the plurality of LED modules are connected in series with each other. The method of claim 1, The LED backlight unit, characterized in that the plurality of LED modules are connected in parallel with each other. The method of claim 1, And the plurality of LED modules includes LED module groups connected in parallel with each other, and each LED module group includes LED modules connected in series with each other. The method of claim 1, The LED backlight unit, characterized in that arranged in close contact with the case of the LED backlight unit. The method of claim 1, The LED driver is provided with the brightness control signal from an external image control unit, and receives power from an external power supply unit, The plurality of LED modules are LED backlight unit, characterized in that implemented in a separate package from the image control unit and the power supply. Display panel; An LED backlight unit including a plurality of LED modules, each of the plurality of LED modules including at least one LED array in which a plurality of LEDs are arranged and an LED driver for driving the at least one LED array; And An image controller which provides luminance control information for the at least one LED array to the LED backlight unit, and provides a color signal for pixels of the display panel to the display panel, The at least one LED array and the LED driver are electrically connected on one circuit board, The LED driving unit included in each of the plurality of LED modules are electrically connected to each other, it is configured to sequentially transmit at least a portion of the brightness control signal to the LED driving unit in the adjacent LED module. The method of claim 10, Each of the plurality of LED modules, A sensor unit detecting an intensity of light emitted from the at least one LED array; And And a feedback controller compensating for a driving operation of the LED driver based on the intensity of light detected by the sensor unit. The method of claim 10, The LED driver, A decoder configured to receive luminance control data corresponding to the corresponding LED module among the luminance control signals, output all or part of the luminance control signal, and generate a luminance setting signal based on the received luminance control signal; And A driving circuit for generating a driving current for driving the at least one LED array based on the brightness setting signal, And the decoders included in each of the plurality of LED modules are connected to each other in a daisy chain manner so as to sequentially transfer the brightness control signal to a decoder in an adjacent LED module. The method of claim 10, The plurality of LED modules are disposed in close contact with the case of the LED backlight unit. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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