WO2019074245A1

WO2019074245A1 - Display device and control method thereof

Info

Publication number: WO2019074245A1
Application number: PCT/KR2018/011795
Authority: WO
Inventors: 서호성; 이형진
Original assignee: 삼성전자주식회사
Priority date: 2017-10-12
Filing date: 2018-10-05
Publication date: 2019-04-18
Also published as: KR20190041181A

Abstract

A display device comprises: an image forming unit for generating an image by transmitting or blocking light from a plurality of pixels; a backlight unit for providing light to the image forming unit by means of a plurality of light source channels composed of a plurality of light sources; a driving unit for sending a driving signal to the backlight unit; and a control unit for controlling the driving unit to send a driving signal for driving each of the plurality of light source channels at every first time interval. In addition, if it is determined that a time interval between the driving signals for driving a first light source channel from among the plurality of light source channels is greater than the first time interval, the control unit can control the driving unit to send additional driving signals between the driving signals of the first light source channel.

Description

Display device and control method thereof

To a display device for driving each of a plurality of light source channels in accordance with a predetermined sequence and a control method thereof.

The display device is an output device that converts electrical information into visual information and displays it to the user. The display device may include not only a television and a monitor but also a portable device such as a notebook PC, a smart phone, and a tablet PC.

The display device may include a light-emitting display panel such as an organic light-emitting diode (OLED) or a light-receiving display panel such as a liquid crystal display (LCD).

The display device to which the light receiving display panel is applied may include a backlight unit that provides light to the display panel. The backlight unit may include an edge-type in which the light source is disposed on at least one side of the display panel and a direct-type in which the light source is disposed in the rear of the display panel.

In a liquid crystal display panel of a light receiving display panel, artifacts, such as motion blurring, in which the motion is blurred due to the retention characteristics of the liquid crystal, may occur. In order to solve this problem, a scanning backlight driving technique has been proposed in which a plurality of light sources of a backlight unit are grouped into a plurality of light source channels and each of the plurality of light source channels is driven in accordance with a predetermined sequence.

One aspect of the disclosed invention is a display device for controlling driving of a backlight unit by inserting a third driving signal between a first driving signal corresponding to a moving picture mode and a second driving signal corresponding to a still picture mode, &Lt; / RTI >

According to an aspect of the present invention, there is provided a display device including: an image forming unit that generates an image by transmitting or blocking light from a plurality of pixels; A backlight unit for providing the light to the image forming unit by a plurality of light source channels constituted by a plurality of light sources; A driving unit for transmitting a driving signal to the backlight unit; And a controller for controlling the driving unit to transmit a driving signal for driving each of the plurality of light source channels at every first time interval. In addition, if it is determined that the time interval between the driving signals for driving the first light source channel among the plurality of light source channels is larger than the first time interval, the control unit may output the additional driving signal The control unit may control the driving unit to transmit the driving signal.

Wherein the controller is configured to omit at least one of the driving signals of the first light source channel if it is determined that the time interval between the driving signals for driving the first light source channel among the plurality of light source channels is smaller than the first time interval, The driving unit can be controlled.

The control unit may control the driving unit to transmit a driving signal for driving each of the plurality of light source channels according to a different sequence in a plurality of operation modes. If it is determined that the time interval between the driving signals driving the first light source channel during the change of the plurality of operation modes is larger than the first time interval, the additional driving signal is transmitted during the change of the plurality of operation modes The driving unit can be controlled.

The control unit controls the driving unit to transmit a first driving signal for driving each of the plurality of light source channels to the backlight unit in every frame according to a first sequence in the moving picture mode, The control unit controls the driving unit to transmit a second driving signal for driving each of the plurality of light source channels to the backlight unit according to a second sequence different from the first sequence, And to insert the third drive signal according to the third sequence between the second drive signal.

Wherein when the change from the moving picture mode to the still picture mode is determined, the control unit controls the third driving signal in the first frame and the second driving signal in the second frame immediately after the first frame, The driving unit can be controlled to insert a driving signal.

Wherein when the change from the still image mode to the moving image mode is determined, the control unit determines that the first driving signal in the third frame and the first driving signal in the fifth frame immediately after the fourth frame adjacent to the third frame, And the driving unit may be controlled to insert the third driving signal between the driving signals.

The controller may control the driving unit to insert the third driving signal at a position spaced equidistantly from the first driving signal and the second driving signal.

The control unit may control the driving unit to insert the third driving signal having a pulse width of the first driving signal and an average value of the pulse width of the second driving signal.

Wherein the control unit divides the pixel region in which the plurality of pixels are provided in the image forming unit into a plurality of sub regions and sets a ratio of pixels having a variation amount equal to or larger than a reference value of the immediately preceding frame in each sub- It is possible to determine the change of the mode.

Wherein the control unit compares a ratio of a pixel having a variation amount greater than or equal to the reference value in a sub region adjacent to the center of the pixel region among the plurality of sub regions to a first reference ratio, A ratio of a pixel having a variation amount larger than or equal to the reference value in a sub region not adjacent to the first reference ratio can be compared with a second reference ratio smaller than the first reference ratio.

A control method of a display device according to an embodiment of the disclosed invention is a control method of a display device that transmits a driving signal to a backlight unit to drive each of a plurality of light source channels constituted by a plurality of light sources that provide light to a plurality of pixels In a moving picture mode, transmitting a driving signal for driving each of the plurality of light source channels at a first time interval; And transmitting an additional driving signal between the driving signals of the first light source channel if it is determined that the time interval between the driving signals for driving the first light source channel among the plurality of light source channels is larger than the first time interval do.

Wherein the control method includes the step of omitting at least one of the driving signals of the first light source channel if it is determined that the time interval between the driving signals for driving the first light source channel among the plurality of light source channels is smaller than the first time interval Quot;

Transmitting a driving signal for driving each of the plurality of light source channels may include transmitting a driving signal for driving each of the plurality of light source channels according to a different sequence in a plurality of operation modes. The transmitting of the additional driving signal may further include, when changing the plurality of operation modes, determining that the time interval between the driving signals driving the first light source channel is larger than the first time interval, And transmitting the additional drive signal during the change.

Transmitting a driving signal for driving each of the plurality of light source channels transmits a first driving signal for driving each of the plurality of light source channels to the backlight unit according to a first sequence every frame; And transmitting, in still image mode, a second drive signal to the backlight unit for driving each of the plurality of light source channels according to a second sequence, which is different from the first sequence, every frame. The transmission of the additional driving signal may include transmitting a third driving signal according to the third sequence between the first driving signal and the second driving signal to the backlight unit when the mode change is determined can do.

Wherein the step of inserting a third driving signal between the first driving signal and the second driving signal and transmitting the third driving signal to the backlight unit comprises: when the change from the moving picture mode to the still picture mode is determined, And inserting the third driving signal between the driving signal and the second driving signal in the second frame immediately after the first frame.

And a third driving signal is inserted between the first driving signal and the second driving signal and is transmitted to the backlight unit when the change from the still image mode to the moving image mode is determined, And inserting the third drive signal between the second drive signal and the first drive signal in the fifth frame immediately after the fourth frame adjacent to the third frame.

Wherein the step of inserting a third driving signal between the first driving signal and the second driving signal and transmitting the third driving signal to the backlight unit comprises: And transmitting the driving signal to the backlight unit.

Wherein the step of inserting a third driving signal between the first driving signal and the second driving signal and transmitting the third driving signal to the backlight unit comprises the step of comparing the pulse width of the first driving signal and the average value of the pulse width of the second driving signal And inserting the third driving signal having a pulse width and transmitting the third driving signal to the backlight unit.

The control method includes: dividing a pixel region where the plurality of pixels are provided into a plurality of sub regions; And comparing the ratio of a pixel having a variation amount greater than or equal to the reference value of the previous frame in the sub-area with a predetermined reference ratio for each frame to determine the change of the mode.

The determination of the change of the mode may include comparing a ratio of a pixel having a variation amount greater than or equal to the reference value in a sub region adjacent to the center of the pixel region among the plurality of sub regions to a first reference ratio; And comparing a ratio of a pixel having a change amount greater than or equal to the reference value in a subarea not adjacent to the center of the pixel region among the plurality of subareas to a second reference ratio smaller than the first reference ratio.

According to the display device and the control method thereof according to an aspect of the disclosed invention, it is possible to improve visibility reduction due to a horizontal line generated during display of a still image. In addition, it is possible to prevent a flicker phenomenon caused by a change between the moving picture mode and the still picture mode.

1 is a view showing an appearance of a display device according to an embodiment of the present invention.

2 is an exploded view of a display device according to an embodiment of the present invention.

3 is a side-sectional view of one pixel included in an image forming unit of a display device according to an embodiment of the disclosed invention.

4 is an exploded view of a backlight unit according to an embodiment of the disclosed invention.

5 is a side-sectional view of a backlight unit according to an embodiment of the disclosed invention.

6 is a control block diagram of a display device according to an embodiment of the disclosed invention.

7 is a diagram illustrating a case where a display device according to an embodiment of the present invention is driven in accordance with a scanning backlight method.

8 is a view for explaining a moving picture / still image determination method of a display device according to an embodiment of the present invention.

9 is a diagram illustrating a first sequence of a plurality of light source channels for a moving picture according to an embodiment of the present invention.

10 is a diagram illustrating a second sequence of a plurality of light source channels for a still image according to an embodiment of the disclosed invention.

11 is a diagram for explaining a driving sequence of a plurality of light source channels when changing from a moving picture mode to a still picture mode according to an embodiment of the disclosed invention.

12 is a view for explaining a driving sequence of a plurality of light source channels when changing from a still image mode to a moving image mode according to an embodiment of the disclosed invention.

13 is a flowchart of a method of controlling a display device according to an embodiment of the disclosed invention.

It is to be understood that both the embodiments described herein and the arrangements shown in the drawings are only a preferred example of the disclosed invention and that at the time of filing of the present application,

Various modifications may be made to the embodiments of the specification and drawings.

The terminology used herein is for the purpose of describing the embodiments only and is not intended to limit and / or to limit the disclosed invention.

For example, the phrase "a" or "an" in this specification may include a plurality of terms, unless the context clearly dictates otherwise.

It is also to be understood that the terms " comprises " or " having " are intended to indicate that there are features, numbers, steps, operations, elements, But do not preclude the presence or addition of a number, a step, an operation, an element, a component, or a combination thereof.

Also, terms including ordinal numbers such as " first ", " second ", and the like are used to distinguish one element from another, and do not limit the one element.

In addition, terms such as " to part ", " to ", " to block ", " to absent ", " module ", and the like may denote a unit for processing at least one function or operation. For example, the terms may refer to at least one hardware, such as a field-programmable gate array (FPGA) / application specific integrated circuit (ASIC), at least one software stored in memory, have.

Hereinafter, an embodiment of the invention disclosed with reference to the accompanying drawings will be described in detail. Like reference numbers or designations in the accompanying drawings may denote parts or components performing substantially the same function.

Briefly defined terms used in this specification, white light represents light in which red light, green light and blue light are mixed or blue light and yellow light are mixed. Natural light represents light mixed with light of all wavelengths corresponding to the visible light region.

1 is a view showing the appearance of a display device according to an embodiment.

The display device 100 is a device capable of processing a video signal received from the outside and visually displaying the processed video image. Hereinafter, a case where the display device 100 is a television (TV) is exemplified, but the present invention is not limited thereto. For example, the display device 100 may be implemented in various forms such as a monitor, a portable multimedia device, and a portable communication device. The display device 100 is not limited in its type as long as it is an apparatus for visually displaying an image .

1, a display device 100 includes a main body 101, a screen 102 for displaying an image I, and a support 103 provided under the main body 101 to support the main body 103 .

The main body 101 forms an outer shape of the display device 100 and the display device 100 may include a part for displaying the image I or performing various functions. The body 101 shown in Fig. 1 is in the form of a flat plate, but the shape of the body 101 is not limited to that shown in Fig. For example, the main body 101 may have a shape in which both left and right ends protrude forward and the center portion is curved so as to be concave.

The screen 102 is formed on the front surface of the main body 101 and can display the image I as time information. For example, the screen 102 may display a still image or a moving image, and may display a two-dimensional plane image or a three-dimensional image using the parallax of the user's eyes.

The screen 102 is provided with a pixel region in which a plurality of pixels P are formed and the image I displayed on the screen 102 is formed by a combination of light emitted by the plurality of pixels P in the pixel region . A single still image I may be formed on the screen 102 by combining light emitted by a plurality of pixels P, such as a mosaic.

Each of the plurality of pixels P can emit light of various brightness and color. For example, the plurality of pixels P may include a red pixel R, a green pixel G and a blue pixel B to form an image I of various colors. At this time, the red pixel R may emit red light of various brightness, the green pixel G may emit green light of various brightness, and the blue pixel B emits blue light of various brightness . Red light represents light having a wavelength in the range of about 620 nm (nanometer meter) to 750 nm, green light represents light having a wavelength in the range of about 495 nm to 570 nm, blue light is about 450 nm to 495 nm &Lt; / RTI >

Each of the pixels P can generate light of various brightness and color by the combination of the red light of the red pixel R, the green light of the green pixel G and the blue light of the blue pixel B. [

The support base 103 is installed at a lower portion of the main body 101 so that the main body 101 can stably maintain its position on the floor. Alternatively, the support base 103 may be provided on the rear surface of the main body 101 to fix the main body 101 to the wall surface.

The support 103 shown in Fig. 1 is not limited to the shape of the bar protruding forward from the lower portion of the main body 101 or the shape of the support 103, May have various shapes that can stably support the main body 101. [

2 is an exploded view of a display device according to an embodiment.

As shown in FIG. 2, the body 101 may include various components for generating an image I on the screen 102 therein. Specifically, the main body 101 has a backlight unit 200 for emitting a surface light, an image forming unit for generating an image I by transmitting or blocking the light emitted from the backlight unit 200, Unit 110, as shown in FIG.

The main body 101 may also include a front chassis 101a, a rear chassis 101b and a mold frame 101c for fixing the image forming unit 110 and the backlight unit 200. [

The front chassis 101a may have the shape of a plate having an opening formed in its front surface. The user can view the image generated by the image forming unit 110 through the opening of the front surface of the front chassis 101a.

The rear chassis 101b is box-shaped with its front surface opened and accommodates the image forming unit 110 and the backlight unit 200 constituting the display device 100. [

The mold frame 101c may be provided between the front chassis 101a and the rear chassis 101b. Particularly, the mold frame 101c is provided between the image forming unit 110 and the backlight unit 200 to fix the image forming unit 110 and the backlight unit 200, respectively.

The backlight unit 200 may include a point light source that emits monochromatic light or white light, and may refract, reflect, and scatter light to convert light emitted from the point light source into uniform surface light. By thus refracting, reflecting, and scattering light, the backlight unit 200 can emit uniform surface light toward the front.

The configuration and operation of the backlight unit 200 will be described in detail below.

The image forming unit 110 is provided in front of the backlight unit 200 and blocks or transmits light emitted from the backlight unit 200 to form an image I. [

The front surface of the image forming unit 110 forms the screen 102 of the display device 100 described above and is composed of a plurality of pixels P. [

The plurality of pixels P included in the image forming unit 110 can block or transmit light from the backlight unit 200 independently of each other. The light transmitted by the plurality of pixels P forms the image I displayed by the display device 100. [

The image forming unit 110 may use the liquid crystal panel 130 whose optical properties change according to the electric field. A pixel region in which a plurality of pixels P are formed is provided on the liquid crystal panel 130 and a plurality of pixels P individually block or transmit light to form an image I on the pixel region.

Hereinafter, the liquid crystal panel 130 will be described as an example of the image forming unit 110. FIG.

3 is a side-sectional view of one pixel included in the image forming unit of the display device according to one embodiment.

3, the image forming unit 110 includes a first polarizing film 111, a first transparent substrate 112, a thin film transistor 113, a pixel electrode 114, a liquid crystal layer 115, A second color filter film 116, a color filter 117, a second transparent substrate 118, and a second polarizing film 119. The liquid crystal panel 130 according to the disclosed embodiment includes a first transparent substrate 112, a thin film transistor 113, a pixel electrode 114, a liquid crystal layer 115, a common electrode 116, a color filter 117, 2 < / RTI > transparent substrate < RTI ID = 0.0 > 118 < / RTI >

The first transparent substrate 112 and the second transparent substrate 118 form an outer appearance of the image forming unit 110 and are disposed between the first transparent substrate 112 and the second

transparent substrate

118, 114 and the color filter 117 can be protected. The first and second

transparent substrates

112 and 118 may be made of tempered glass or transparent resin.

A first polarizing film 111 and a second polarizing film 119 are provided on the outer sides of the first and second

transparent substrates

112 and 118.

The light is made up of a pair of an electric field and a magnetic field that vibrate in a direction orthogonal to the traveling direction. Further, the oscillation direction of the electric field and the magnetic field can oscillate in all directions orthogonal to the traveling direction of the light. At this time, a phenomenon in which an electric field or a magnetic field vibrates only in a specific direction is referred to as polarization, and an electric field that vibrates in a predetermined direction or an electric field that transmits light including a magnetic field and vibrates in a direction other than a predetermined direction, Is called a polarizing film. In other words, the polarizing film transmits light that vibrates in a predetermined direction, and blocks light that vibrates in the other direction.

The first polarizing film 111 transmits light having an electric field and a magnetic field that oscillate in the first direction, and blocks other light. Further, the second polarizing film 119 transmits light having an electric field and a magnetic field that oscillate in the second direction, and blocks other light. At this time, the first direction and the second direction are orthogonal to each other. In other words, the polarizing direction of the light transmitted by the first polarizing film 111 and the polarizing direction of the light transmitted by the second polarizing film 119 are orthogonal to each other. As a result, light can not transmit the first polarizing film 111 and the second polarizing film 119 at the same time.

A color filter 117 may be provided on the inner side of the second transparent substrate 118.

The color filter 117 may include a red filter 117r that transmits red light, a green filter 117g that transmits green light, and a blue filter 117b that transmits blue light. The red filter 117r, The green filter 117g and the blue filter 117b may be arranged side by side. The color filter 117 prevents color interference between the red filter 117r, the green filter 117g and the blue filter 117b and prevents the

color filters

117r, 117g, And a black matrix for blocking the light from leaking out of the backlight unit. The black matrix 120 is provided between the red filter 117r, the green filter 117g, and the blue filter 117b.

The region where the color filter 117 is formed corresponds to the pixel P described above. The region where the red filter 117r is formed corresponds to the red pixel R and the region where the green filter 117g is formed corresponds to the green pixel G and the region where the blue filter 117b is formed corresponds to the blue pixel B). In other words, the red pixel R, the green pixel G and the blue pixel B are formed by the red filter 117r, the green filter 117g and the blue filter 117b, and the red filter 117r, The pixel P is formed by the combination of the filter 117g and the blue filter 117b.

A thin film transistor (TFT) 113 is formed inside the first transparent substrate 112.

Specifically, the thin film transistor 113 may be formed at a position corresponding to a position between the red filter 117r, the green filter 117g, and the blue filter 117b. In other words, the thin film transistor 113 may be located between the red pixel R, the green pixel G and the blue pixel B.

The thin film transistor 113 can pass or block a current flowing to the pixel electrode 114, which will be described below. Specifically, an electric field can be formed or removed between the pixel electrode 114 and the common electrode 116 in accordance with the turning on (closing) or turning off (opening) of the thin film transistor 113. The thin film transistors may be formed of polysilicon or may be manufactured using a semiconductor process such as lithography, deposition, and ion implantation.

A pixel electrode 114 is formed inside the thin film transistor 113 of the first transparent substrate 112 and a common electrode 116 is formed inside the color filter 117 of the second transparent substrate 118 have.

The pixel electrode 114 and the common electrode 116 are made of a conductive metal and can generate an electric field for changing the arrangement of the liquid crystal molecules 115a constituting the liquid crystal layer 115 have.

At this time, the pixel electrode 114 may be formed in a region corresponding to the red filter 117r, the green filter 117g, and the blue filter 117b, and the common electrode 116 may be formed over the entire panel. As a result, an electric field can be selectively formed in a region corresponding to the red filter 117r, the green filter 117g, and the blue filter 117b in the liquid crystal layer 115 described below.

The pixel electrode 114 and the common electrode 116 are made of a transparent material and can transmit light incident from the outside. The pixel electrode 114 and the common electrode 116 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), silver nano wire, carbon nano tube: CNT), graphene or PEDOT (3,4-ethylenedioxythiophene).

A liquid crystal layer 115 is formed between the pixel electrode 114 and the common electrode 116 and the liquid crystal layer 115 includes liquid crystal molecules 115a.

Liquid crystal means an intermediate state between a solid (crystal) and a liquid. A typical material changes from a solid state to a transparent liquid state at a melting temperature when heat is applied to the solid state material. On the other hand, when heat is applied to a liquid crystal material in a solid state, the liquid crystal material changes to a transparent liquid state after being changed into an opaque and turbid liquid at a melting temperature. The term liquid crystal refers to a liquid crystal state which is an intermediate state between a solid phase and a liquid phase, or a substance itself having such a liquid crystal state.

Most of such liquid crystal materials are organic compounds, and their molecular shapes are elongated and rod-shaped. The arrangement of molecules is the same as an irregular state in any direction, but may have a regular crystal form in other directions. As a result, the liquid crystal has both fluidity of liquid and optical anisotropy of crystal (solid).

The liquid crystal may also exhibit optical properties depending on the change of the electric field. For example, the direction of the molecular arrangement of the liquid crystal may change depending on the change of the electric field. When an electric field is generated in the liquid crystal layer 115, the liquid crystal molecules 115a of the liquid crystal layer 115 are arranged according to the direction of the electric field. If an electric field is not generated in the liquid crystal layer 115, the liquid crystal molecules 115a are irregularly arranged Or may be disposed along an orientation film (not shown).

As a result, the optical properties of the image forming unit 110 may vary depending on the presence of the electric field of the liquid crystal layer 115.

For example, if an electric field is not formed in the liquid crystal layer 115, light polarized by the first polarizing film 111 due to the arrangement of the liquid crystal molecules 115a of the liquid crystal layer 115 is incident on the second polarizing film 119, Lt; / RTI > In other words, light can be transmitted through the image forming unit 110 in the pixel P in which no electric field is formed in the liquid crystal layer 115. [

On the other hand, when an electric field is formed in the liquid crystal layer 115, light polarized by the first polarizing film 111 does not pass through the second polarizing film 119 due to the arrangement of the liquid crystal molecules 115a of the liquid crystal layer 115 can not do it. In other words, light is blocked by the image forming unit 110 at the pixel P where an electric field is formed in the liquid crystal layer 115. [

The display device according to an embodiment of the disclosed invention may include a liquid crystal panel employing liquid crystal molecules arranged in various ways. For example, a display panel according to an exemplary embodiment includes a TN (Twisted Nematic) display panel having liquid crystal molecules arranged so as to deform the optical break according to the presence of an electric field, liquid crystal molecules aligned in the horizontal direction, An IPS (In-Plane Switching) display panel which is arranged to rotate at 90 degrees in parallel with the surface of the panel, and a VA (Vertical Alignment) display panel in which liquid crystal molecules arranged vertically to the display panel surface are aligned horizontally when an electric field is applied .

As described above, the image forming unit 110 can independently control light transmittance for each pixel P (more specifically, the red pixel, the green pixel, and the blue pixel included in the pixel). As a result, the light by the plurality of pixels P can be combined, and the image I can be displayed on the pixel region of the screen 102 of the display device 100.

The backlight unit 200 will be described below.

The backlight unit 200 can be divided into a direct-type backlight unit and an edge-type backlight unit according to the position of the light source. Hereinafter, an edge type backlight unit will be described as an example.

FIG. 4 is an exploded view of a backlight unit according to an embodiment, and FIG. 5 is a side-sectional view of a backlight unit according to an embodiment. 4 and 5, the edge-type backlight unit 200 includes a light emitting module 210 for generating light, a waveguide device 220 for dispersing light, a reflective sheet 230 and an optical sheet 240 for improving light luminance.

The light emitting module 210 may include a plurality of light sources 211 for emitting light and a support 212 for supporting / fixing the plurality of light sources 211.

The plurality of light sources 211 may be uniformly disposed on the side surface of the backlight unit 200 as shown in FIG. 4, and may emit light toward the center of the backlight unit 200.

The plurality of light sources 211 may be arranged at equal intervals so that the light emitted by the plurality of light sources 211 has a uniform luminance as much as possible. For example, as shown in FIG. 4, a plurality of light sources 211 may be disposed at left and right sides of the backlight unit 200, respectively. However, the arrangement of the light sources 211 is not limited to that shown in FIG. 4, and may be disposed only on one of the left and right sides of the backlight unit 200.

The light source 211 may employ an element capable of emitting monochromatic light (light having a specific wavelength, for example, blue light) or white light (light having various wavelengths mixed) in various directions when power is supplied thereto. For example, the light source 211 may employ a light emitting diode (LED) or a cold cathode fluorescent lamp (CCFL) having a small heating value.

6, the light source 211 includes a blue light emitting diode 211a that emits blue light, which is high energy light, and a phosphor 211b, which absorbs blue light and emits green light and red light, can do.

The blue light emitting diode 211a may be made of an indium-gallium-nitrogen compound (InGaN) in which indium (In) is added to a gallium-nitrogen compound GaN.

The phosphor 211b can convert the energy absorbed from the outside into visible light and emit visible light. The fluorescent material 211b may include a yellow (YAG) fluorescent material, a KSF (K2SiF6) fluorescent material, or a KTF (K2TiF6) fluorescent material.

The light source 211 may emit blue light BL of approximately 450 nm wavelength, green light GL of approximately 535 nm wavelength and red light RL of approximately 620 nm wavelength. However, the light source 211 does not emit only the blue light BL, the green light GL and the red light RL. As shown in the right side of FIG. 6, the light source 211 emits blue light BL, It is possible to emit the yellow light YL or the orange light OL together with the green light GL and the red light RL.

The support body 212 may fix the plurality of light sources 211 so that the position of the light source 211 is not changed. Further, the support body 212 can supply power to each light source 211 for the light source 211 to emit light.

The support body 212 may be disposed on the side surface of the backlight unit 200 together with the light source 211. For example, as shown in FIG. 4, the support 212 may be disposed on the left and right sides of the backlight unit 200. However, the arrangement of the support body 212 is not limited to that shown in Fig. 4, and may be disposed only on one of the left and right sides of the backlight unit 200. [ The support 212 may be formed of a synthetic resin having a plurality of light sources 211 and a conductive power supply line for supplying power to the light source 211 or may be formed of a printed circuit board Lt; / RTI >

The light guiding device 220 changes the traveling direction of light incident from the side light emitting module 210 and emits the light toward the front side. The light guide device 220 disperses light emitted from the side light emitting module 210 on the front surface of the light guide device 220 and emits the light. Concrete contents of the light guide device 220 will be described later.

The reflective sheet 230 is provided behind the light guiding device 220 and can reflect light emitted through the rear surface of the light guiding device 220 toward the light guiding device 220.

The reflective sheet 230 can be manufactured by coating a base material with a material having high reflectance. For example, the reflection sheet 230 can be manufactured by coating a polymer having a high reflectance on a base material such as polyethylene terephthalate (PET).

The optical sheet 240 may include various sheets for improving the uniformity of luminance and luminance. For example, the optical sheet 240 may include a diffusion film 241, a first prism film 242, a second prism film 243, and a reflective polarizing film 244. [

The diffusion film 241 diffuses light for uniformity of luminance. The light emitted from the light source 211 is diffused by the light guide device 220 and can be diffused again by the diffusion film 241 included in the optical sheet 240. [

The light having passed through the diffusion film 241 is diffused in a direction parallel to the diffusion sheet 241, whereby the brightness can be reduced.

The first and

second prism films

242 and 243 increase the brightness by condensing the light diffused by the diffusion film 241.

The first and

second prism films

242 and 243 include a prism pattern in the form of a triangular prism, and a plurality of the prism patterns are arranged adjacently to form a plurality of strips. At this time, the direction in which the prism patterns of the first prism film 242 are arranged and the direction in which the prism patterns of the second prism film 243 are arranged may be orthogonal to each other.

The light having passed through the first and

second prism films

242 and 243 has a viewing angle of approximately 70 degrees and advances toward the front of the backlight unit 200, thereby improving the brightness.

The reflection type polarizing film 244 can transmit a part of the incident light and reflect the other part for improving the brightness. For example, the reflection type polarizing film 244 can transmit light in a predetermined polarization direction, and can reflect other light. At this time, the polarizing direction of the reflective polarizing film 244 may be the same as the polarizing direction of the first polarizing film 111 described above. As a result, the light transmitted through the reflective polarizing film 244 can also transmit the first polarizing film 111 included in the image forming unit 110. [

The light reflected by the reflective polarizing film 244 is recycled inside the backlight unit 200 and the brightness of the display device 100 can be improved by such light recycling.

The optical sheet 240 is not limited to the sheet or film shown in Fig. 5, and may include a diverse sheet or film such as a protective sheet.

As described above, since the light emitting module 210 is disposed on the side surface of the backlight unit 200, luminance irregularity may occur due to the position of the light emitting module 210. The light guiding device 220 may diffuse the light emitted from the light emitting module 210 in the light guiding device 220 in order to eliminate unevenness in brightness due to the position of the light emitting module 210.

The light incident into the light guide device 220 may travel in various directions depending on the incident angle. For example, as shown in FIG. 5, the light incident toward the front of the light guide 220 may be reflected from the front surface of the light guide 220 and proceed toward the rear, or may be refracted at the front of the light guide 220 And may be incident on the optical sheet 240. The light incident toward the rear of the light guide device 220 may be reflected from the rear surface of the light guide device 220 or scattered by dots on the rear surface of the light guide device 220 and proceed toward the front surface.

The light incident from the side of the light guide device 220 may travel to the center of the light guide device 220 due to the reflection of light generated from the front and back sides of the light guide device 220. The light in the light guide device 220 may be emitted through the front surface of the light guide device 220 by scattering light generated from the back surface of the light guide device 220 and refracting light generated from the front surface of the light guide device 220 have.

The light guiding device 220 may be made of poly methyl methacrylate (PMMA) or transparent polycarbonate (PC).

Hereinafter, a process of generating an image using the image forming unit 110 and the backlight unit 200 including the display panel 130 will be described.

FIG. 6 is a control block diagram of a display device according to an embodiment of the disclosed invention, and FIG. 7 illustrates a case where a display device according to an embodiment of the present invention is driven in accordance with a scanning backlight method.

The display device 100 according to an embodiment of the present invention includes a video data receiving unit 300 for receiving a data signal as a basis of an image from the outside; An image forming unit (110) including a display panel (130) that transmits or blocks light in a plurality of pixels (P) formed in a pixel (P) region to generate an image; A backlight unit (200) for providing light to a plurality of pixels (P) of the image forming unit (110); A driving unit 500 for supplying a driving current to the image forming unit 110 and the backlight unit 200; A control unit 400 for controlling the driving unit 500 to display an image through the display panel 130 based on the received data signal; . &Lt; / RTI >

The video data receiving unit 300 can receive data that is the basis of the video in a wired or wireless manner from the outside. The image data receiving unit 300 may be variously embodied in a technical idea for receiving data serving as a basis of an image.

The received data signal is transmitted to the driving unit 500 and the driving unit 500 can supply the driving current to the display panel 130 so that an image is generated on the display panel 130 based on the data signal. To this end, the driving unit 500 according to one embodiment of the present invention includes a gate driving unit 510 for supplying a driving current to the gate line GL of the display panel 130; A data driver 520 for supplying a driving current to a data line DL of the display panel 130; . &Lt; / RTI >

As described above, a plurality of pixels P may be formed in a pixel P region of the display panel 130. More specifically, the pixel P region of the display panel 130 includes a plurality of gate lines GL extending in the first direction and a plurality of data lines DL extending in the second direction perpendicular to the first direction, The pixel P may be formed.

At this time, the common electrode of the plurality of pixels P formed along the first direction is connected by the gate line GL, and the pixel (P) electrode of the plurality of pixels P formed along the second direction is connected to the data line DL. &Lt; / RTI > If the first direction is the horizontal direction and the second direction is the vertical direction, the plurality of pixels P belonging to the same row can be mutually connected by the gate line GL.

The gate driver 510 may supply a gate driving current for activating the thin film transistors constituting each pixel P to the gate line GL. In particular, the gate driver 510 sequentially supplies the gate driving current to the plurality of gate lines GL, thereby sequentially activating the plurality of pixels P arranged in the first direction.

The data driver 520 can supply a data driving current based on the received data signal to each of the plurality of activated pixels P, respectively. Specifically, the data driver 520 can supply a data driving current corresponding to the RGB value of the individual pixel P to each of the plurality of data lines DL. Thus, each of the plurality of activated pixels P can form an electric field in the liquid crystal layer 115 so as to display RGB values determined according to the data driving current.

That is, the gate driver 510 activates a plurality of pixels P arranged in the first direction along the second direction, and the data driver 520 generates data for forming an electric field in each of the plurality of activated pixels P The driving current can be supplied. This process is called data scanning.

At this time, when the backlight unit 200 follows a hold type that continuously supplies light to the entire pixel P region, motion blurring is performed according to the state retention characteristic of the liquid crystal molecules 115a. May result in artifacts. In order to solve this problem, the backlight unit 200 divides a pixel P region to provide light only to one pixel (P) region, and a scanning backlight system Scanning Backlight Type) can be adopted.

To this end, the backlight unit 200 may include a plurality of light sources 211 arranged along the scan direction of the gate driver 510, that is, the second direction. As described above, when the first direction is the transverse direction and the second direction is the longitudinal direction, the plurality of light sources 211 are disposed on the left side of the backlight unit 200 corresponding to the left and right sides of the image forming unit 110 , And on the right side along the longitudinal direction.

In addition, the plurality of light sources 211 may be grouped as a plurality of light source 211 channels. Here, the channel of the light source 211 may mean a group of light sources 211 that can provide light to each of the segmented pixel (P) regions. In order to individually drive each of the plurality of light sources 211, the driver 500 includes a backlight driver 530 for supplying driving current to each of the plurality of light sources 211, As shown in FIG.

The backlight driver 530 may supply a driving current to sequentially drive the plurality of light sources 211 channels. As a result, light is provided only to one pixel (P) region of the divided plurality of pixel (P) regions, and the image can be displayed through the pixel (P) region provided with light.

Referring to FIG. 7, it can be seen that a plurality of light sources 211 arranged in the longitudinal direction are grouped into four light source 211 channels, and light is provided only in the light source 211 channel located second from the top.

On the other hand, since the data signal is received by the image data receiving unit 300 every frame, the supply of the driving current needs to be synchronized with the scanning process in the second direction according to the frame unit of the gate driver 510. For this purpose, the controller 400 generates a vertical synchronization signal Vsync corresponding to each frame at predetermined time intervals, and the gate driver 510 generates a scan signal for a plurality of pixels P arranged in the first direction in accordance with Vsync The backlight driver 530 may sequentially drive the plurality of light sources 211 in synchronization with the Vsync in accordance with a predetermined sequence.

However, in the case of backlight scanning, a horizontal line may be displayed on the display panel 130 of the image forming unit 110. If the received data signal is for a moving picture, the user's visibility is not deteriorated by the horizontal line. However, in the case of the still image, the user may be disturbed by the horizontal line continuously displayed.

Accordingly, the display apparatus 100 according to an embodiment of the present invention determines whether the received data signal is for a moving image / still image, and generates a plurality of light sources 211 according to different sequences corresponding to the determination result. Can be driven. Specifically, when a data signal for a moving picture is received, the display device 100 can drive a plurality of light sources 211 channels according to a sequence according to a moving picture mode. In addition, when a data signal for a still image is received, the display device 100 can drive a plurality of light sources 211 channels according to a sequence according to a still image mode.

Hereinafter, a method of determining whether the received data signal is for a moving image / still image will be described, and then a driving sequence of a plurality of light source 211 channels according to each mode will be described.

8 is a view for explaining a moving picture / still image determination method of a display device according to an embodiment of the disclosed invention. FIG. 9 is a view for explaining a method for determining a moving picture / still image of a display device according to an embodiment of the present invention. 10 is a diagram illustrating a second sequence of a plurality of light source channels for a still image according to an embodiment of the disclosed invention.

The control unit 400 may divide the pixel P region on the display panel 130 into a plurality of sub regions to determine whether the received data signal is for a moving image or a still image. 8 illustrates a case where the control unit 400 divides the pixel P region into eight sub-regions S1 to S8.

Then, the controller 400 may compare the RGB values of each of the plurality of pixels P constituting each sub-area with the RGB values of the previous frame. For example, if the RGB value of each of the plurality of pixels P is greater than or equal to the reference value of the immediately preceding frame, the control unit 400 may determine that the motion exists in the corresponding pixel P.

When the presence or absence of motion is determined for each pixel P, the controller 400 may compare the ratio of the motion among the plurality of pixels P constituting each sub-region to a predetermined reference ratio. At this time, the reference ratio can be determined differently for each sub region.

Specifically, the reference ratios of the S2, S3, S6, and S7 sub-regions adjacent to the center of the pixel P region are determined as 80%, and S1, S4, S5, and S8 sub- The reference ratio of the area can be determined to be 70%. In the case of moving images, since there is a high probability that motion is present in the pixel P located at the center of the entire image, the reference ratio of the sub region adjacent to the center can be determined to be smaller than the reference ratio of the remaining sub regions.

As a result of the comparison, if the ratio of the motion presence pixels P in all the sub-regions is equal to or greater than the reference ratio, the controller 400 can determine that the received data signal is a signal for the moving image. On the other hand, when at least one sub-region includes motion presence pixels P below the reference ratio, the control unit 400 may determine that the received data signal is a signal for a still image.

When the received data signal is a signal for a moving image, it is not necessary to consider the horizontal line. Therefore, the controller 400 drives each of the plurality of light sources 211 according to the first sequence satisfying the optimum response speed The backlight driver 530 can be controlled.

9, the controller 400 may control the backlight driver 530 to sequentially drive the light sources 211 CH1 to CH4 in synchronization with the vertical synchronization signal Vsync generated in response to the start of the frame F1 have. As a result, the backlight driver 530 can supply the driving current having the pulse width A to each of the light sources 211 channels CH1 to CH4 according to the first sequence satisfying the optimum response speed.

When the driving according to the first sequence is completed in the frame F1, the control unit 400 synchronizes with the vertical synchronization signal Vsync generated in response to the start of the frame F2 adjacent to the frame F1 so that the light sources 211 channels CH1 to CH4 are sequentially The backlight driving unit 530 can be controlled in the same manner.

Accordingly, when the moving picture is displayed on the display panel 130, the display apparatus 100 can prevent the occurrence of motion blur due to a decrease in the response speed. Hereinafter, the above-described control process will be referred to as a moving picture mode M1.

Unlike the moving picture mode, when the received data signal is a signal for a still image, the backlight unit 200 needs to be driven to remove the horizontal line. Accordingly, the controller 400 may control the backlight driver 530 to drive each of the plurality of light sources 211 channels in accordance with the second sequence capable of removing the horizontal lines.

Referring to FIG. 10, the controller 400 controls the backlight driver 530 to sequentially drive the light sources 211 CH1 to CH4 in synchronization with the vertical synchronization signal Vsync generated in response to the start of the frame F1 have. As a result, the backlight driver 530 can supply the driving current having the pulse width B to each of the light sources 211 channels CH1 to CH4 in accordance with the second sequence for removing the horizontal lines.

Accordingly, when the still image is displayed on the display panel 130, the display device 100 can prevent the occurrence of horizontal lines due to backlight scanning. Hereinafter, the control process described above is referred to as still image mode M2.

On the other hand, when the received data signal is changed from a still image to a moving image, or from a moving image to a still image, the control unit 400 determines a mode change and changes the mode corresponding to the changed mode The backlight driver 530 can be controlled to drive each of the plurality of light sources 211 channels.

In this case, when the first sequence and the second sequence are simply connected, flickering or flickering of the display panel 130 may occur. Therefore, there is a need to insert an additional sequence that can eliminate it between the first sequence and the second sequence.

As described above, the display panel 130 may employ various types of liquid crystal panels. For example, the display panel 130 may employ a TN display panel, an IPS display panel, a VA display panel, or the like.

The TN display panel is known to have a fast response speed, a narrow viewing angle and a low contrast ratio. The IPS display panel has a wide viewing angle and low contrast ratio. VA display panels have a wide viewing angle and high contrast ratio, but are said to respond to TN display panels and IPS display panels.

It is known that the response speed of the VA display panel is slow due to the characteristics of the liquid crystal array and the afterimage occurs on the VA display panel when displaying the moving image. In addition, it is known that a VA-display panel is easier to see a horizontal-band than a TN display panel and an IPS display panel.

The backlight driver 530 may be controlled to sequentially drive the channels CH1 to CH4 as shown in FIG. 9, thereby compensating for the occurrence of afterimages on the VA display panel. In other words, by sequentially driving the channels CH1 to CH4, it is possible to alleviate the residual image on the VA display panel when the moving picture is displayed.

In addition, as shown in FIG. 10, the backlight driving unit 530 is controlled so that the channels CH1 to CH4 are sequentially driven to compensate for the occurrence of horizontal lines on the VA display panel.

FIG. 11 is a view for explaining a driving sequence of a plurality of light source channels when changing from a moving picture mode to a still picture mode according to an embodiment of the disclosed invention, and FIG. 12 is a view for explaining a still picture mode according to an embodiment of the disclosed invention And a driving sequence of a plurality of light source channels when changing to a moving picture mode. In FIGS. 11 and 12, a portion indicated by a thick line may mean a third drive signal according to the third sequence.

Referring to FIG. 11, each of the channels CH1 to CH4 of the light sources 211 may sequentially drive according to a first sequence corresponding to the moving picture mode M1. During the first sequence, the controller 400 may determine to change from the moving picture mode M1 to the still picture mode M2. FIG. 11 exemplifies a case where the mode change is determined in the frame F2.

Flicker may be generated on the display panel 130 when the light sources 211 CH1 to CH2 are driven according to the second sequence immediately after the frame F3 immediately after the frame F2. A sufficient amount of light is provided to the display panel 130 because the pulse of the first sequence and the interval Y of the pulse of the second sequence, which are generated as the mode is changed from the inter-pulse interval of the first sequence, And as a result flicker may occur, which is a flickering phenomenon.

Accordingly, the controller 400 may control the backlight driver 530 to insert a third mode M3 for providing additional light between the moving picture mode M1 and the still picture mode M2 so that the light is not short. Specifically, the controller 400 may include a backlight (not shown) for inserting a third driving signal corresponding to the third sequence corresponding to the third mode M3 between the first driving signal according to the first sequence and the second driving signal according to the second sequence, The driving unit 530 can be controlled.

At this time, the inserted third driving signal may be inserted between the first driving signal and the second driving signal at a position spaced equidistantly from the first driving signal and the second driving signal. Referring to FIG. 11, it can be seen that the third drive signal is inserted at a position spaced apart by the same distance K1 from the first drive signal and the second drive signal.

In addition, the inserted third driving signal may have a pulse width of the pulse width of the first driving signal and an average value of the pulse width of the second driving signal. Referring to FIG. 11, it can be seen that the third drive signal has a pulse width of C, which is an average value of the pulse width A of the first drive signal and the pulse width B of the second drive signal.

As described above, it is possible to prevent the flicker phenomenon from occurring by inserting the third driving signal between the first driving signal and the second driving signal.

In addition, a horizontal line can be visually displayed on the display panel 130 when the pulse of the first sequence generated due to the change and the interval Y of the pulse of the second sequence become longer. In particular, in the case of a VA display panel, a horizontal line is more likely to be visually recognized when a mode is changed.

At this time, by inserting the third driving signal between the first driving signal and the second driving signal, the horizontal line in the display panel 130 can be prevented from being viewed. In the case of the VA display panel, the effect of preventing the horizontal line from being visually recognized is further enhanced.

Also, the change from the still image mode to the moving image mode may be determined. Referring to FIG. 12, each of the channels CH1 to CH4 of the light sources 211 may sequentially drive according to a second sequence corresponding to the still image mode M2. During the course of the second sequence, the control unit 400 may determine to change from the still image mode M2 to the moving image mode M1. 12 illustrates a case where the mode change is determined at the end of the frame F2.

If the light source 211 channels CH1 to CH2 are driven in accordance with the first sequence immediately after the frame F3 immediately after the frame F2, flickering of the display panel 130 may occur. In FIG. 12, the dotted line is assumed to follow the first sequence in the frame F3.

An excess amount of light is provided to the display panel 130 because the pulse of the second sequence and the interval Y2 of the pulses of the first sequence that are generated as the mode is changed from the inter-pulse interval Z in the second sequence are shorter , And the display panel 130 may flicker.

Accordingly, the control unit 400 can block the driving of the light sources 211 channels CH1 to CH4 according to the first sequence in the frame F3 immediately after the frame F2. As a result, since the pulse of the second sequence is larger than the pulse interval Z2 of the second sequence and the interval Y2 of the pulses of the first sequence in the frame F4 is large, the control unit 400 is similar to the conventional method of Fig. 11 The third sequence can be inserted.

That is, the control unit 400 may control the backlight driving unit 530 to insert a third mode M3, which overlaps the moving picture mode M1 and provides additional light, from the end of the still picture mode M2 so that the light is not short. Specifically, the control unit 400 generates a third drive signal S 3 corresponding to the third sequence corresponding to the third mode M 3 between the second drive signal according to the second sequence and the first drive signal according to the first sequence in the frame F 4, It is possible to control the backlight driver 530 to insert the backlight driver 530. [

At this time, the inserted third driving signal may be inserted between the first driving signal and the second driving signal at a position spaced equidistantly from the first driving signal and the second driving signal. Referring to FIG. 11, it can be seen that the third drive signal is inserted at a position spaced apart by the same distance K2 from the first drive signal and the second drive signal.

As described above, it is possible to prevent a flickering phenomenon from occurring by inserting the third driving signal between the first driving signal and the second driving signal.

Also, by inserting the third driving signal between the first driving signal and the second driving signal, the horizontal line in the display panel 130 can be prevented from being viewed, as described above. In the case of the VA display panel, the effect of preventing the horizontal line from being visually recognized is further enhanced.

First, the display apparatus 100 may drive each of the plurality of light source 211 channels in accordance with a sequence corresponding to the current mode. (900) If the current mode is the moving picture mode, It is possible to drive each of the plurality of light source 211 channels in accordance with the first sequence capable of providing a response speed. On the other hand, if the current mode is the still image mode, the display device 100 may drive each of the plurality of light sources 211 according to the second sequence that can prevent the occurrence of the horizontal line.

The display device 100 may determine whether a mode change has been determined. (910) Specifically, the display device 100 divides the pixel P region on the display panel 130 into a plurality of sub regions , And change from the moving picture mode to the still picture mode or from the still picture mode to the moving picture mode can be determined based on the ratio of the pixels P in which the motion exists in each sub-area. If the mode change is not determined, the display device 100 can repeatedly confirm this.

On the other hand, if the mode change is determined, the display apparatus 100 can terminate the driving of each of the plurality of light source 211 channels according to the sequence corresponding to the current mode. (920) However, When the driving of the plurality of light sources 211 is started in accordance with the sequence corresponding to the mode to be changed immediately after the driving of the plurality of light sources 211 according to the mode to be changed is started, a flicker phenomenon occurs in the display panel 130 .

In order to prevent this, the display device 100 may drive each of the plurality of light source 211 channels in accordance with a predetermined sequence corresponding to the third mode before the sequence entry corresponding to the mode to be changed. (930) Here, The predetermined sequence means a pulse width of a drive signal which is inserted at the center between the drive signal constituting the sequence corresponding to the pre-change mode and the drive signal of the sequence corresponding to the post-change mode, And a drive signal having a pulse width as an average value of the pulse widths of the drive signals constituting the sequence corresponding to the change mode.

Finally, the display device 100 may drive each of the plurality of light source 211 channels according to the sequence corresponding to the changed mode. (940)

Accordingly, the display apparatus 100 according to an embodiment of the present invention can provide an optimum response speed during moving picture display, and can prevent horizontal line occurrence during display of a still image. Also, the display device 100 may prevent a flicker phenomenon caused by a change between a moving picture mode and a still picture mode.

Claims

An image forming unit for generating an image by transmitting or blocking light from a plurality of pixels;

A backlight unit for providing the light to the image forming unit by a plurality of light source channels constituted by a plurality of light sources;

A driving unit for transmitting a driving signal to the backlight unit; And

And a controller for controlling the driving unit to transmit a driving signal for driving each of the plurality of light source channels at every first time interval,

The control unit transmits an additional driving signal between the driving signals of the first light source channel when it is determined that the time interval between the driving signals for driving the first light source channel among the plurality of light source channels is larger than the first time interval And controls the driving unit to control the driving unit.
The method according to claim 1,

Wherein the controller is configured to omit at least one of the driving signals of the first light source channel if it is determined that the time interval between the driving signals for driving the first light source channel among the plurality of light source channels is smaller than the first time interval, And controls the driving unit.
The method according to claim 1,

Wherein the control unit controls the driving unit to transmit a driving signal for driving each of the plurality of light source channels according to a different sequence in a plurality of operation modes and controls the driving unit to drive the first light source channel during the change of the plurality of operation modes And controls the driving unit to transmit the additional driving signal during the change of the plurality of operation modes when it is determined that the time interval between the signals is larger than the first time interval.
The method according to claim 1,

Wherein,

In the moving picture mode, controls the driving unit to transmit a first driving signal for driving each of the plurality of light source channels to the backlight unit in accordance with a first sequence every frame,

Controlling the driving unit to transmit to the backlight unit a second driving signal for driving each of the plurality of light source channels in accordance with a second sequence different from the first sequence in each frame in the still image mode,

And controls the driving unit to insert a third driving signal according to the third sequence between the first driving signal and the second driving signal when the mode change is determined.
5. The method of claim 4,

Wherein,

When the change from the motion picture mode to the still picture mode is determined, inserting the third drive signal between the first drive signal in the first frame and the second drive signal in the second frame immediately after the first frame And controls the driving unit to control the driving unit.
5. The method of claim 4,

Wherein,

Wherein when the change from the still image mode to the moving image mode is determined, the second driving signal in the third frame and the first driving signal in the fifth frame immediately after the fourth frame adjacent to the third frame And controls the driving unit to insert the third driving signal.
5. The method of claim 4,

Wherein,

And controls the driving unit to insert the third driving signal at a position spaced equidistantly from the first driving signal and the second driving signal.
5. The method of claim 4,

Wherein,

Wherein the control unit controls the driving unit to insert the third driving signal having the pulse width of the first driving signal and the average value of the pulse width of the second driving signal as the pulse width.
5. The method of claim 4,

Wherein,

Wherein the image forming unit compares a pixel area in which the plurality of pixels are provided with a plurality of sub areas and compares a ratio of pixels having a variation amount greater than or equal to a reference value of the immediately preceding frame in the sub area with a predetermined reference ratio, A display device for determining a mode change.
10. The method of claim 9,

Wherein,

A ratio of a pixel having a variation amount greater than or equal to the reference value in a sub region adjacent to the center of the pixel region among the plurality of sub regions is compared with a first reference ratio, And compares the ratio of pixels having a variation amount larger than or equal to the reference value in the sub area with a second reference ratio that is smaller than the first reference ratio.
A method of controlling a display device that transmits a driving signal to a backlight unit to drive each of a plurality of light source channels constituted by a plurality of light sources that provide light to a plurality of pixels,

Transmitting a drive signal for driving each of the plurality of light source channels at a first time interval;

And transmitting an additional driving signal between the driving signals of the first light source channel if it is determined that the time interval between the driving signals for driving the first light source channel among the plurality of light source channels is larger than the first time interval Of the display device.
12. The method of claim 11,

And omitting at least one of the driving signals of the first light source channel if it is determined that a time interval between driving signals for driving the first light source channel among the plurality of light source channels is smaller than the first time interval A method of controlling a display device.
12. The method of claim 11,

Transmitting a driving signal for driving each of the plurality of light source channels includes transmitting a driving signal for driving each of the plurality of light source channels according to a different sequence in a plurality of operation modes,

Wherein the transmitting of the further driving signal is performed during a change of the plurality of operation modes if the time interval between the driving signals driving the first light source channel is determined to be larger than the first time interval during the change of the plurality of operation modes And transmitting the additional driving signal.
12. The method of claim 11,

Transmitting a driving signal for driving each of the plurality of light source channels in a moving picture mode, transmitting a first driving signal for driving each of the plurality of light source channels to the backlight unit in accordance with a first sequence every frame, In a video mode, transmitting a second driving signal to each of the backlight units for driving each of the plurality of light source channels in accordance with a second sequence different from the first sequence for each frame,

Wherein the transmission of the further driving signal comprises transmitting a third driving signal according to a third sequence between the first driving signal and the second driving signal to the backlight unit when a mode change is determined, A method of controlling a device.
15. The method of claim 14,

And inserting a third driving signal between the first driving signal and the second driving signal and transmitting the third driving signal to the backlight unit,

When the change from the motion picture mode to the still picture mode is determined, inserting the third drive signal between the first drive signal in the first frame and the second drive signal in the second frame immediately after the first frame And controlling the display device.