KR20070073713A - Backlight unit and display device having the same - Google Patents

Abstract

A backlight unit and a display device including the same are provided to drive a light source member divisionally by a simple structure. A light source member(440) is divided into plural division areas. The division areas are individually driven. A light source driving member group(430) supplies the power to the light source member and includes a multiple driving member connected with at least two division areas. A light source control member controls the light source driving member group so that the power is selectively supplied to the division areas connected with the multiple driving member. Each division area is connected with any one among plural multiple driving members. The light source member includes a light emitting diode. The plural division areas are arranged with a band shape in parallel.

Description

BACKLIGHT UNIT AND DISPLAY DEVICE HAVING THE SAME}

1 is a block diagram of a liquid crystal display according to a first embodiment of the present invention;

2 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention;

3 is a view showing a connection between a light source unit and a light source driver group according to the first embodiment of the present invention,

4 is a diagram illustrating driving of the light source unit according to the first exemplary embodiment of the present invention for each horizontal division area;

5 is a view showing the driving of the light source unit according to the first embodiment of the present invention for each of the multiple driving units;

6 and 7 are diagrams showing the connection between the light source unit and the light source driver group according to the second and third embodiments of the present invention, respectively.

Explanation of Signs of Major Parts of Drawings

100: liquid crystal display panel 210: gate driver

220: data driver 310: signal controller

320: graphics controller 330: driving voltage generation unit

340: gray voltage generator 420: light source controller

430: light source driving unit group 440: light source

441 light emitting diode 442 light emitting diode circuit board

The present invention relates to a backlight unit and a display device including the same, and more particularly, to a backlight unit and a display device including the same by driving the light source unit in a simple configuration.

Recently, a flat panel display such as a liquid crystal display (LCD), a plasma display panel (PDP), or an organic light emitting diode (OLED) has been developed in place of the conventional CRT.

The liquid crystal display device includes a thin film transistor substrate, a color filter substrate, and a liquid crystal display panel in which liquid crystal is injected between both substrates. Since the liquid crystal display panel is a non-light emitting device, a backlight unit for supplying light is disposed on the rear surface of the thin film transistor substrate. Light transmitted from the backlight unit is adjusted according to the arrangement of liquid crystals. The liquid crystal display panel and the backlight unit are housed in the chassis.

The backlight unit is divided into an edge type and a direct type according to the position of the light source. The edge type is a structure in which a light source is installed on the side of the light guide plate, and is mainly applied to a relatively small liquid crystal display device such as a laptop type and a desktop computer. Such an edge type backlight unit has a good light uniformity, a long service life, and is advantageous for thinning a liquid crystal display device.

The direct type is a structure mainly developed as the size of the liquid crystal display device is enlarged. The direct type is a structure in which one or more light sources are arranged on the lower surface of the liquid crystal display panel to supply light to the liquid crystal display panel. Such a direct type backlight unit may use a large number of light sources as compared to an edge type backlight unit to secure a high luminance, but has a disadvantage that luminance is not uniform.

As a light source of a direct type backlight unit, a spot light source such as a light emitting diode is drawing attention instead of a line light source such as a lamp. When using a point light source, the backlight unit supplies white light by mixing light from a point light source that emits light of different colors.

Among driving methods of the backlight unit, there is a method of lighting a light source in response to a scan signal input signal of a liquid crystal display panel to improve a video display quality. In this method, however, the light source is divided into a plurality of zones and individually driven, thereby requiring a driving unit for each zone.

An object of the present invention is to provide a backlight unit for driving by dividing the light source unit with a simple configuration.

Still another object of the present invention is to provide a display device including a backlight unit for dividing and driving a light source unit with a simple configuration.

An object of the present invention is to provide a light source unit divided into a plurality of divided regions to be driven independently of each other and a light source driver group and a plurality of light source including a plurality of driving units connected to at least two of the divided regions for supplying power to the light source unit; It is achieved by a backlight unit including a light source controller for controlling the light source driver group to selectively supply power to the divided region connected to the driver.

The light source unit preferably includes a light emitting diode.

It is preferable that the plurality of divided regions are arranged side by side in a band shape.

Preferably, the light source controller controls the light source driver group to sequentially supply power to the divided regions.

It is preferable that a part of the power supply time for the adjacent divided regions overlap.

Preferably, the divided regions connected to the multiple driving units are spaced apart from each other.

An object of the present invention is a light source driver group and a horizontal divided area including a light source unit which is divided into a plurality of horizontal divided areas driven independently of each other and a light source driver that supplies power to the light source unit and has a smaller number of light source drivers than the horizontal divided area. It may also be achieved by a backlight unit including a light source control unit for controlling the light source driver group to sequentially supply power to the.

Another object of the present invention is to provide power to a light source unit and a light source unit which are divided into a liquid crystal display panel and a plurality of divided regions positioned on a rear surface of the liquid crystal display panel and independently driven from each other, and at least 2 A liquid crystal display including a light source driver group including multiple drivers connected to the two divided regions and a light source controller controlling the light source driver group to supply power to each of the divided regions in response to an image scan of the liquid crystal display panel. Can be achieved by.

The light source controller may control the light source driver group to selectively supply power to the divided region connected to the multiple driver.

The light source unit preferably includes a light emitting diode.

It is preferable that the plurality of divided regions are arranged side by side in a band shape.

Preferably, the light source controller controls the light source driver group to sequentially supply power to the divided regions.

Preferably, the divided regions connected to the multiple driving units are spaced apart from each other.

Preferably, the display panel is a liquid crystal display panel.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

In the following embodiments, the point light source will be described using a light emitting diode as an example, but the point light source of the present invention is not limited to the light emitting diode. In addition, although a liquid crystal display device is described as an example of the display device, the display device of the present invention is not limited to the liquid crystal display device, but is applicable to other display devices including a backlight unit.

In various embodiments, like reference numerals refer to like elements, and like reference numerals refer to like elements in the first embodiment and may be omitted in other embodiments.

The liquid crystal display according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

The liquid crystal display device 1 is connected to the liquid crystal display panel 100, the gate driver 210, the data driver 220, the driving voltage generator 330 connected to the gate driver 210, and the data driver 210 connected thereto. The gray voltage generator 340 and a signal controller 310 which controls the gray voltage generator 340 and receives image data from a graphic controller 320. The backlight unit 400 is configured to supply light to the rear surface of the liquid crystal display panel 100. The backlight unit 400 includes a light source unit 440, a light source driver group 430 for driving the light source unit 440, and a light source driver. The light source controller 420 controls the group 430.

The liquid crystal display panel 100 includes a color filter substrate 111 on which a color filter layer is formed, and a thin film transistor substrate 121 on which a thin film transistor is formed. The liquid crystal layer 141 is positioned in a space formed by the sealants 131 formed along the edges of both substrates 111 and 112 and both substrates 111 and 112.

The driving voltage generator 330 generates a gate on voltage Von for turning on the thin film transistor, a gate off voltage Voff for turning off the thin film transistor, and a common voltage Vcom applied to the common electrode.

The gray voltage generator 340 generates a plurality of gray scale voltages related to the luminance of the liquid crystal display 1 and supplies them to the data driver 220.

The gate driver 210 may also be referred to as a scan driver. The gate driver 210 may be connected to the gate line 111 and may include a gate signal formed by a combination of a gate-on voltage Von and a gate-off voltage Voff from the driving voltage generator 330. Is applied to the gate line 111.

The data driver 220 may also be referred to as a source driver. The data driver 220 receives a gray voltage from the gray voltage generator 340 and selects a gray voltage for each data line 121 under the control of the signal controller 310. It is applied to the data line 121 as a data signal. The data driver 220 may include a flexible printed circuit board (FPC) 221 having one side connected to the thin film transistor substrate 121, a driving chip 222 mounted on the flexible printed circuit board 221, and a flexible printed circuit board ( 221 includes a circuit board (PCB) 223 connected to the other side. The data driver 220 illustrated in FIG. 2 represents a chip on film (COF) method, and other known methods such as a tape carrier package (TCP) and a chip on glass (COG) may be used. The gate driver 210 may be provided in the same manner as the data driver 220 or may be mounted on the thin film transistor substrate 121.

The signal controller 310 generates control signals for controlling operations of the gate driver 210, the data driver 220, the driving voltage generator 330, the gray voltage generator 340, and the like. ) To the data driver 220 and the driving voltage generator 330.

The light source unit 440 includes a light emitting diode 441 and a light emitting diode circuit board 442. The light emitting diode 441 is disposed over the entire surface of the liquid crystal display panel 100 and mounted on the light emitting diode circuit board 442. Light emitting diodes 441 emitting red, green, and blue light are respectively disposed on the light emitting diode circuit board 442 to provide white light to the liquid crystal display panel 100. The arrangement form of the light emitting diode 441 is not particularly limited.

The reflector 451 reflects the light generated by the light emitting diode 441 and directs the light toward the liquid crystal display panel 100. The reflecting plate 451 covers the entire surface of the light emitting diode circuit board 442, and only a portion where the light emitting diode 441 is positioned is removed.

The diffusion film 452 is composed of a base plate and a bead-shaped coating layer formed on the base plate. When the light of the light emitting diode 441 is supplied to the liquid crystal display panel 100 as it is, the arrangement of the light emitting diode 441 is recognized by the user and the luminance is uneven. The diffusion film 452 serves to evenly distribute the light of the light emitting diode 441 to the liquid crystal display panel 100 to prevent this.

In the prism film 453, a triangular prism prism is formed on the top surface with a constant arrangement. The prism film 453 serves to condense the light diffused from the diffusion film 452 in a direction perpendicular to the plane of the upper liquid crystal display panel 100. Two prism films 453 are usually used, and the micro prisms formed on each prism film 453 have a predetermined angle. The light passing through the prism film 453 almost vertically progresses to provide a uniform luminance distribution.

The uppermost protective film 454 protects the prism film 453 that is weak to scratches.

The chassis 500 includes an upper chassis 501 and a lower chassis 502, and accommodates the liquid crystal display panel 100 and the light emitting diode 441.

Hereinafter, the operation of the liquid crystal display device 1 will be described in detail.

The signal controller 310 is an input control signal for controlling the RGB image data R, G, and B and a display thereof from the graphic controller 320, for example, a vertical synchronizing signal. , Vsync), a horizontal synchronizing signal (Hsync), a main clock (CLK), and a data enable signal (DE). The signal controller 310 generates a gate control signal, a data control signal, and a voltage selection control signal VSC based on the control input signal, and outputs the image data R, G, and B to the liquid crystal display panel. After appropriately converting to the operating conditions of 100, the gate control signal is sent to the gate driver 210 and the driving voltage generator 330, and the data control signal and processed image data R ', G', and B 'are The data driver 220 is sent to the data driver 220, and the voltage selection control signal VSC is sent to the gray voltage generator 340.

The gate control signal includes a vertical synchronization start signal (STV) for indicating the start of output of the gate-on pulse (high period of the gate signal), a gate clock signal for controlling the output timing of the gate-on pulse, and And a gate on enable signal (OE) that limits the width of the gate on pulse. Among them, the gate on enable signal OE and the gate clock signal CPV are supplied to the driving voltage generator 330. The data control signal includes a horizontal synchronization start signal (STH) indicating the start of input of the gray scale signal, a load signal (load signal, LOAD or TP) for applying a corresponding data voltage to the data line, and a polarity of the data voltage. An inversion control signal RVS, a data clock signal HCLK, and the like to be inverted.

First, the gray voltage generator 340 supplies the gray voltage having the voltage value determined according to the voltage selection control signal VSC to the data driver 220.

The gate driver 210 sequentially turns on the thin film transistor connected to the gate line 111 by applying the gate-on voltage Von to the gate line 111 in response to the gate control signal from the signal controller 310. At the same time, the data driver 220 generates a gray voltage generator corresponding to the image data R ′, G ′, and B ′ of the pixel including the turned on switching element according to a data control signal from the signal controller 310. The analog data voltage from 340 is supplied as a data signal to the data line 121.

The data signal supplied to the data line 121 is applied to the corresponding pixel through the turned on thin film transistor. In this manner, the gate-on voltages Von are sequentially applied to all the gate lines 111 during one frame to apply data signals to all the pixels. When one frame is finished and the inversion control signal RVS is supplied to the driving voltage generator 330 and the data driver 220, the polarities of all data signals of the next frame are changed.

Meanwhile, the driving control of the light source unit 440 simultaneously with the screen formation of the liquid crystal display panel 100 will be described.

The light source unit 440 is divided into a plurality of horizontal division regions 445 driven independently of each other. Each of the horizontal divided regions 445 has substantially the same size in a band shape and is disposed next to each other. Each horizontal divided area 445 is disposed in parallel with the extending direction of the gate line 111.

The light source driver group 430 for supplying power to the light source unit 440 includes a plurality of multiple drivers 431. The number of the multiple drivers 431 is provided smaller than the number of the horizontal partitions 445. In the first embodiment, the light source 440 is divided into ten horizontal partitions 445, and the multiple drivers 431 are five. It is provided with a dog.

Each multiple driver 431 is connected to two horizontal partitions 445 to supply power. The horizontal partitions 445 connected to the multiple driving units 431 are spaced apart from each other. For example, the first multiple driving unit 431 is connected to the first horizontal partition 445 and the sixth horizontal partition 445. It is connected.

The light source controller 420 is connected to the signal controller 310 to control the light source driver group 430 so that each horizontal division area 445 is driven in response to the scan of the liquid crystal display panel 100. Accordingly, each horizontal partition area 445 is sequentially driven repeatedly.

The light source controller 420 also controls the light source driver group 430 such that a pair of horizontal divided regions 445 connected to the multiple driver 431 are driven with a time difference. As a result, the multiple driver 431 can drive the pair of horizontal divided regions 445 without collision, thereby simplifying the configuration of the light source driver group 430.

Driving of the light source unit 440 will be described with reference to FIGS. 4 and 5.

4 is a diagram illustrating driving of a light source unit according to a first embodiment of the present invention for each horizontal division area, and FIG. 5 is a diagram illustrating driving of a light source unit according to a first embodiment of the present invention for multiple driving units.

Referring to FIG. 4, when the time of one frame is viewed in ten sections, each horizontal division area 445 is driven for three sections. After the front horizontal division 445 is driven, the driving of the rear horizontal division 445 is started after one section so that both horizontal divisions 445 are driven simultaneously for two sections. In this manner, ten horizontal divisions 445 are driven during one frame.

The time point at which the first horizontal division region 445 is driven may be slightly different from the time when the gate-on voltage is applied to the first gate line 111.

Referring to FIG. 5, after the first horizontal partition 445 connected to the first multiple driver 431 is driven for three sections, the sixth horizontal partition 445 is driven after two sections. The sixth horizontal partition 445 is also driven for three sections, and then again the driving of the first horizontal partition 445 is repeated after two sections. Accordingly, the pair of horizontal partitions 445 connected to the multiple driver 431 may be driven without collision.

As described above, according to the first exemplary embodiment, the light source unit 440 may be driven using only the multiple driving units 431 having a smaller number than the horizontal division area 445.

6 and 7 are diagrams showing the connection between the light source unit and the light source driver group according to the second and third embodiments of the present invention, respectively.

According to the second embodiment illustrated in FIG. 6, nine horizontal partitions 445 are provided, and three multiple driving units 431 are provided. Each multiple driver 431 is connected to three horizontal partitions 445. Horizontal divisions 445 connected to the same multiple driver 431 are spaced apart from each other.

The number of horizontal divided regions 445 that can be connected to one multiple driver 431 may vary depending on the degree of division of the light source unit 440, the driving time of one horizontal divided region 445, and the like.

According to the third embodiment shown in FIG. 7, ten horizontal partitions 445 are provided. The light source driver group 430 includes three multiple drivers 431 and one single driver 432. Each multiple driver 431 is connected to three horizontal partitions 445. Horizontal divisions 445 connected to the same multiple driver 431 are spaced apart from each other.

The light source driver group 430 may include a single driver 432 together with the multiple drivers 431 by the number of horizontal division regions 445. In addition, the light source driver group 430 may include multiple drivers 431 connected to different numbers of horizontal division regions 445.

Although some embodiments of the invention have been shown and described, those skilled in the art will recognize that modifications can be made to the embodiments without departing from the spirit or principles of the invention. . It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

As described above, according to the present invention, a backlight unit capable of driving by dividing a light source unit with a simple configuration is provided.

In addition, a display device including a backlight unit capable of dividing and driving a light source unit with a simple configuration is provided.

Claims (14)

In the backlight unit, A light source unit divided into a plurality of divided regions driven independently of each other; A light source driver group for supplying power to the light source unit, the light source driver group including a multiple driver connected to at least two division areas; And a light source controller configured to control the light source driver group to selectively supply power to the divided regions connected to the multiple drivers. The multiple driving unit is provided in plurality, Each of the divided regions is connected to only one of the plurality of multiple driving units. The method of claim 1, And the light source unit comprises a light emitting diode. The method of claim 1, And the plurality of divided regions are arranged side by side in a band shape. The method of claim 3, And the light source controller controls the light source driver group to sequentially supply power to the divided regions. The method of claim 4, wherein And a part of the power supply time of the adjacent divided regions overlapping each other. The method of claim 3, And the divided regions connected to the multiple drivers are spaced apart from each other. In the backlight unit, A light source unit divided into a plurality of horizontal division regions driven independently of each other; A light source driver group for supplying power to the light source unit and including a smaller number of light source drivers than the horizontal divided area; And a light source controller for controlling the light source driver group to repeatedly supply power to the horizontal divided region. The light source driving unit is provided in plurality, Each of the horizontal divisions is connected to only one of the plurality of light source drivers. In the display device, A display panel; A light source unit disposed on a rear surface of the display panel and divided into a plurality of divided regions driven independently of each other; A light source driver group for supplying power to the light source unit, the light source driver group including a multiple driver connected to at least two division areas; A light source controller configured to control the light source driver group to supply power to each of the divided regions in response to an image scan of the display panel; The multiple driving unit is provided in plurality, And each of the divided regions is connected to only one of the plurality of multiple driving units. The method of claim 8, And the light source controller controls the light source driver group to selectively supply power to the divided regions connected to the multiple drivers. The method of claim 8, The light source unit includes a light emitting diode. The method of claim 8, And the plurality of divided regions are arranged side by side in a band shape. The method of claim 11, And the light source controller controls the light source driver group to sequentially supply power to the divided regions. The method of claim 11, And the divided regions connected to the multiple drivers are spaced apart from each other. The method of claim 8, And the display panel is a liquid crystal display panel.

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