Image display device and operation method thereof

Abstract

The present invention relates to an image display device and an operation method thereof. An image display device according to an embodiment of the present invention comprises: a display panel including a plurality of pixels; a backlight unit irradiating light to the display panel; and a control unit; the control unit determines a refresh rate of an image outputted by the display panel, determines a vertical blanking period of each frame corresponding to the determined refresh rate, calculates a pixel clock frequency corresponding to the determined vertical blanking period, and controls the operation of a plurality of driving elements arranged on the display panel corresponding to each of the plurality of pixels according to the determined pixel clock frequency. In addition to the above, there may be various embodiments.

Description

Technical Field

[0001] The present invention relates to an image display device and an operating method thereof. Background Art

[0002] The image display device is a device having a function of displaying images that can be viewed by a user, and the user can watch broadcasts through the image display device. For example, the image display device may include a TV (television) having a liquid crystal display (LCD) using liquid crystal or an OLED display using an organic light emitting diode (OLED), a monitor, and a projector.

[0003] In the case of an image display device with a liquid crystal display, a plurality of pixels are arranged in a matrix form, and include a display panel in which a driving element such as a thin film transistor (TFT) is configured in each pixel, a backlight unit for irradiating light to the display panel, etc. The intensity of the electric field formed in the liquid crystal is adjusted according to the action of the driving element to change the tilt angle of the liquid crystal molecules, thereby displaying an image by allowing light to pass or block.

[0004] On the other hand, in the case of a liquid crystal display, there is a problem of motion blur in the image output by the display panel, depending on the time it takes for the liquid crystal molecules to be arranged vertically or horizontally due to the electric field formed in the liquid crystal, that is, the response speed of the liquid crystal molecules. In addition, as the number of frames per second output by the image display device increases, the liquid crystal molecules need to frequently receive changes in the electric field in direct proportion to this, so the afterimage phenomenon caused by the delayed response speed of the liquid crystal molecules becomes more serious, and there is a problem of increasing motion blur.

[0005] In the prior art, in order to improve the motion blur phenomenon, a PWM dimming method of driving a backlight unit through a pulse width modulation (PWM) signal is used to display a black screen between frames constituting an image. For example, the image display device can be controlled to set the frequency of the PWM dimming signal to 60 Hz when the refresh rate is 60 Hz, and set the duty cycle of the PWM signal to display a black screen between frames.

[0006] However, when the refresh rate is further increased, for example, when the refresh rate is set to a higher level of 100 Hz or more, the brightness deviation and grayscale imbalance between the horizontal lines on the display panel may occur due to the difference in the operation time points of the plurality of driving elements configured in the plurality of pixels. That is, the backlight unit irradiates light to the entire display panel at the same time, and the plurality of driving elements configured in the plurality of pixels are driven in sequence according to the order of the horizontal lines on the display panel. When the refresh rate increases, the light irradiates the display panel before the liquid crystals corresponding to some horizontal lines are fully turned on, so that the brightness deviation and grayscale imbalance between the horizontal lines on the display panel may occur. Summary of the invention

[0007] Problems to be solved by the invention

[0008] The present invention is directed to solving the aforementioned problems and other problems.

[0009] Another object is to provide an image display device and an operating method thereof that can improve motion blur and brightness deviation and grayscale imbalance between horizontal lines on a display panel when the refresh rate of the display is increased.

[0010] Technical solutions to the problem

[0011] An image display device according to an embodiment of the present invention for achieving the above-mentioned purpose comprises: a display panel including a plurality of pixels; a backlight unit irradiating light to the display panel; and a control unit; the control unit can determine a refresh rate of an image outputted through the display panel, determine a vertical blanking period of each frame corresponding to the determined refresh rate, calculate a pixel clock frequency corresponding to the determined vertical blanking period, and control the operation of a plurality of driving elements arranged on the display panel corresponding to each of the plurality of pixels according to the determined pixel clock frequency.

[0012] On the other hand, an operation method of an image display device according to an embodiment of the present invention may include: an action of determining a refresh rate of an image; an action of determining a vertical blanking period of each frame corresponding to the determined refresh rate; an action of calculating a pixel clock frequency corresponding to the determined vertical blanking period; and an action of driving a plurality of driving elements arranged on a display panel corresponding to each of a plurality of pixels included in a display panel of the image display device according to the determined pixel clock frequency.

[0013] Effects of the Invention

[0014] Hereinafter, the effects of the image display device and the operating method thereof according to the present invention will be described.

[0015] According to various embodiments of the present invention, the vertical blanking interval and the pixel clock frequency of each frame constituting the image are determined corresponding to the change in the picture refresh rate. Therefore, even if the picture refresh rate of the image display device is set to be higher than a prescribed reference, the operation of a plurality of driving elements arranged corresponding to the pixels included in the display panel can be controlled before light is irradiated to the display panel, thereby preventing brightness deviation and grayscale imbalance between horizontal lines on the display panel.

[0016] The additional scope of the applicability of the present invention will become clear from the following detailed description. However, it is clearly understood by those skilled in the art that various changes and modifications can be made within the thought and scope of the present invention, and therefore, the detailed description and specific embodiments such as the preferred embodiments of the present invention should be understood as being exemplary only. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing an image display system according to an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 An example of an internal block diagram of an image display device.

[0019] Figure 3 yes Figure 2 An example of an internal block diagram of a control unit.

[0020] Figure 4 yes Figure 2 An example of an internal block diagram of a display.

[0021] Figure 5 It is a flowchart of an operation method of an image display device according to an embodiment of the present invention.

[0022] Figures 6 to 9b It is a diagram for explaining the operation method of the image display device. DETAILED DESCRIPTION

[0023] In order to clearly and briefly describe the present invention, the drawings omit the illustration of parts not related to the description, and the same reference numerals are given to the same or very similar parts throughout the specification.

[0024] The suffixes "module" and "unit" of the constituent elements used in the following description are only used to facilitate the preparation of the description, and they themselves have no particularly important meaning or function. Therefore, the "module" and the "unit" can be used interchangeably.

[0025] In the application, it should be understood that terms such as "including" or "having" are intended to indicate the existence of the features, numbers, steps, actions, constituent elements, parts or their combinations described in the specification, and cannot preclude the existence or possibility of adding one or more other features or numbers, steps, actions, constituent elements, parts or their combinations.

[0026] In addition, in the present specification, in order to explain various elements, the terms such as first and second may be used, but such elements are not limited to such terms. Such terms are only used to distinguish one element from another element.

[0027] Figure 1 is a diagram of a system illustrating various embodiments of the present invention.

[0028] Reference Figure 1 , the system may include an image display device 100 , a remote control device 200 and / or an image providing device 300 .

[0029] The image display device 100 may be a device that processes and outputs an image, and is not particularly limited as long as it can output a screen corresponding to an image signal on a TV, a notebook computer, a display, or the like.

[0030] The image display device 100 may receive and signal-process a broadcast signal, and may output a signal-processed broadcast image. In the case where the image display device 100 receives a broadcast signal, the image display device 100 may correspond to a broadcast receiving device.

[0031] The image display device 100 may receive broadcast signals wirelessly via an antenna or wired via a cable. For example, the image display device 100 may receive terrestrial broadcast signals, satellite broadcast signals, cable broadcast signals, IPTV (Internet Protocol Television) broadcast signals, and the like.

[0032] The remote control device 200 is connected to the image display device 100 by wire and / or wirelessly, and can provide various control signals to the image display device 100. In this case, the remote control device 200 may include a device that establishes a wired or wireless network with the image display device 100, and transmits various control signals to the image display device 100 through the established network, or receives signals related to various actions processed in the image display device 100 from the image display device 100.

[0033] For example, various input devices such as a mouse 200 a , a keyboard 200 b , a space remote controller 200 c , a trackball, and a joystick can be used as the remote control device 200 .

[0034] The image display apparatus 100 may be connected to only a single remote control apparatus 200 or to two or more remote control apparatuses 200 at the same time, and may change an object displayed on a screen or adjust a state of a screen based on a control signal provided from each remote control apparatus 200 .

[0035] On the other hand, the image display device 100 may also output images received from the image providing device 300. For example, the image display device 100 stores images received from the image providing device 300 and may output the stored images according to the screen size of the image display device 100 and the number of frames that can be displayed per second.

[0036] The image providing device 300 is not particularly limited as long as it can transmit an image signal including RGB data of an image corresponding to a computer or the like.

[0037] Figure 2 yes Figure 1 Internal block diagram of an image display device.

[0038] Reference Figure 2 The image display device 100 may include a broadcast receiving unit 105, an external device interface unit 130, a network interface unit 135, a storage unit 140, a user input interface unit 150, an input unit 160, a control unit 170, a display 180, an audio output unit 185 and / or a power supply unit 190.

[0039] The broadcast receiving unit 105 may include a tuner 110 and a demodulator 120 .

[0040] On the other hand, unlike the drawings, the image display device 100 may include only the broadcast receiving unit 105 and the external device interface unit 130 among the broadcast receiving unit 105, the external device interface unit 130, and the network interface unit 135. That is, the image display device 100 may not include the network interface unit 135.

[0041] The tuner 110 may select a broadcast signal corresponding to a user-selected channel or all pre-stored channels from among broadcast signals received via an antenna (not shown) or a cable (not shown), and may convert the selected broadcast signal into an intermediate frequency signal or a baseband image or voice signal.

[0042] For example, if the selected broadcast signal is a digital broadcast signal, the tuner 110 may convert it into a digital IF signal (DIF), and if it is an analog broadcast signal, it may convert it into an analog baseband image or voice signal (CVBS / SIF). That is, the tuner 110 may process a digital broadcast signal or an analog broadcast signal. The analog baseband image or voice signal (CVBS / SIF) output from the tuner 110 may be directly input to the control unit 170.

[0043] On the other hand, the tuner 110 may sequentially select broadcast signals of all broadcast channels stored by the channel memory function among the received broadcast signals and convert them into intermediate frequency signals or baseband image or voice signals.

[0044] On the other hand, in order to receive broadcast signals of a plurality of channels, the tuner unit 110 may include a plurality of tuners, or may be a single tuner that simultaneously receives broadcast signals of a plurality of channels.

[0045] The demodulation unit 120 may perform a demodulation operation by receiving the digital IF signal (DIF) converted in the tuner unit 110 .

[0046] The demodulation unit 120 may output a streaming signal (TS) after performing demodulation and channel decoding. At this time, the streaming signal may be a signal multiplexed with an image signal, a voice signal, or a data signal.

[0047] The streaming media signal output from the demodulation unit 120 may be input to the control unit 170. The control unit 170 may output images through the display 180 and may output voices through the audio output unit 185 after performing inverse multiplexing, image / voice signal processing, and the like.

[0048] The external device interface unit 130 can be connected to an external device (not shown), such as Figure 1 To this end, the external device interface unit 130 may include an A / V input and output unit (not shown).

[0049] The external device interface unit 130 can be connected to external devices such as DVD (Digital Versatile Disk), Blu-ray, game equipment, camera, camcorder, computer (laptop), set-top box, etc. either wirelessly or wirelessly, and can also perform input / output operations with the external devices.

[0050] In addition, the external device interface unit 130 is connected to Figure 1The various remote control devices 200 shown establish a communication network, and a control signal related to the operation of the image display device 100 is received from the remote control device 200 , or data related to the operation of the image display device 100 can be transmitted to the remote control device 200 .

[0051] The A / V input and output section can receive image and voice signals from an external device. For example, the A / V input and output section may include an Ethernet terminal, a USB terminal, a CVBS (Composite Video Banking Sync) terminal, a component terminal, an S-video terminal (analog), a DVI (Digital Visual Interface) terminal, an HDMI (High Definition Multimedia Interface) terminal, an MHL (Mobile High-definition Link: mobile terminal high-definition audio and video standard interface) terminal, an RGB terminal, a D-SUB terminal, an IEEE1394 terminal, an SPDIF terminal, a liquid crystal (Liquid) HD terminal, etc. The digital signal input through such a terminal can be transmitted to the control unit 170. At this time, the analog signal input through the CVBS terminal and the S-video terminal can be converted into a digital signal by an analog-to-digital conversion unit (not shown) and transmitted to the control unit 170.

[0052] The external device interface unit 130 may include a wireless communication unit (not shown) for short-range wireless communication with other electronic devices. Through such a wireless communication unit, the external device interface unit 130 can exchange data with a nearby mobile terminal. For example, the external device interface unit 130 can receive device information, executed application information, application images, etc. from the mobile terminal in the mirroring mode.

[0053] The external device interface unit 130 can perform short-distance wireless communication using Bluetooth, RFID (Radio Frequency Identification), infrared communication (IrDA, infrared Data Association), UWB (Ultra-Wideband), ZigBee, or the like.

[0054] The network interface part 135 may provide an interface for connecting the image display device 100 to a wired / wireless network including the Internet.

[0055] The network interface unit 135 may include a communication module (not shown) for connecting to a wireless network. For example, the network interface unit 135 may include a communication module for WLAN (Wireless LAN) (Wi-Fi), Wibro (Wirelessbroadband), Wimax (World Interoperability for Microwave Access), HSDPA (High Speed ​​Downlink Packet Access), etc.

[0056] The network interface unit 135 can transmit and receive data with other users or other electronic devices through the connected network or other networks linked to the connected network.

[0057] The network interface unit 135 can receive network content or data provided by a content provider or a network operator. That is, the network interface unit 135 can receive network content such as movies, advertisements, games, VOD, broadcast signals, etc. provided by a content provider or a network provider through the network and information related thereto.

[0058] The network interface unit 135 may receive firmware update information and update files provided by a network operator, and may send data to a network or content provider or a network operator.

[0059] The network interface unit 135 can select and receive a desired application program from among application programs open to the public through a network.

[0060] The storage unit 140 may store programs for various signal processing and control in the control unit 170, and may also store image, voice or data signals of signal processing. For example, the storage unit 140 may store application programs designed for the purpose of executing various tasks that can be processed by the control unit 170, and may selectively provide a part of the stored application programs when requested by the control unit 170.

[0061] The program and the like stored in the storage unit 140 are not particularly limited as long as they can be executed by the control unit 170 .

[0062] The storage part 140 may also perform a function for temporarily storing an image, voice or data signal received from an external device through the external device interface part 130 .

[0063] The storage unit 140 may store information related to a predetermined broadcast channel through a channel memory function such as a channel map.

[0064] Figure 2Although the embodiment in which the storage unit 140 and the control unit 170 are provided separately is shown, the scope of the present invention is not limited thereto, and the storage unit 140 may be included in the control unit 170 .

[0065] The storage unit 140 may include at least one of a volatile memory (e.g., DRAM, SRAM, SDRAM, etc.) and a non-volatile memory (e.g., flash memory, hard disk drive (HDD), solid-state drive (SSD), etc.). In various embodiments of the present invention, the storage unit 140 and the memory may also be used in combination with each other.

[0066] The user input interface unit 150 may transfer a signal input by a user to the control unit 170 or transfer a signal from the control unit 170 to the user.

[0067] For example, user input signals such as power on / off, channel selection, screen setting, etc. are sent / received from the remote control device 200, or user input signals input from local keys (not shown) such as the power button, channel button, volume button, setting value, etc. are transmitted to the control unit 170, or user input signals input from a sensor unit (not shown) that senses the user's posture are transmitted to the control unit 170, or signals from the control unit 170 are sent to the sensor unit.

[0068] The input portion 160 may be provided at one side of the body of the image display device 100. For example, the input portion 160 may include a touch pad, a physical button, and the like.

[0069] The input unit 160 may receive various user commands related to the operation of the image display device 100, and may transmit a control signal corresponding to the input command to the control unit 170. For example, the input unit 160 may transmit a control signal corresponding to the received user command to the control unit 170 through the user input interface unit 150.

[0070] The input unit 160 may include at least one microphone (not shown), and may receive a user's voice through the microphone.

[0071] The control unit 170 may include at least one processor, and the processor included therein may be used to control the overall operation of the image display device 100. Here, the processor may be a general processor such as a CPU (central processing unit). Of course, the processor may be a dedicated device such as an ASIC or a processor based on other hardware.

[0072] The control unit 170 may inversely multiplex the streaming media input through the tuner 110 , the demodulator 120 , the external device interface unit 130 , or the network interface unit 135 , or may generate and output a signal for image or voice output by processing the inversely multiplexed signal.

[0073] For example, the control unit 170 may receive RGB data from the image providing device 300 through the external device interface unit 130. At this time, the control unit 170 processes the RGB data received from the image providing device 300, generates a signal for image output, and transmits the generated signal to the display 180.

[0074] The control unit 170 may control the display 180 to output a plurality of frames constituting the image in sequence according to the image refresh rate. Here, the frame may refer to a still image displayed by the display 180. The frames output by the display 180 are sequentially changed according to the number of frames per second (FPS) corresponding to the image refresh rate, so that the user can watch the video. For example, when the image refresh rate is 60 Hz, the control unit 170 may control the display 180 to output 60 frames per second.

[0075] Although Figure 2 Although not shown in the figure, the control unit 170 may include an inverse multiplexing unit, an image processing unit, etc. Figure 3 Provide explanation.

[0076] The display 180 may generate a driving signal by converting an image signal, a data signal, an OSD signal, a control signal processed in the control unit 170 or converting an image signal, a data signal, a control signal, etc. received from the external device interface unit 130. Figure 4 Provide explanation.

[0077] On the other hand, the display 180 is configured as a touch screen, and can be used as an input device in addition to an output device.

[0078] The audio output unit 185 receives the voice-processed signal from the control unit 170 and outputs the signal as voice.

[0079] The image signal processed by the control unit 170 is input to the display 180 and displayed as an image corresponding to the image signal. In addition, the image signal processed by the control unit 170 can also be input to an external output device through the external device interface unit 130.

[0080] The voice signal processed in the control unit 170 may be output as sound through the audio output unit 185. In addition, the voice signal processed in the control unit 170 may be input to an external output device through the external device interface unit 130.

[0081] In addition, the control unit 170 may control the overall operation of the image display device 100. For example, the control unit 170 may control the tuner 110 to select (Tuning) a broadcast corresponding to a channel selected by a user or a pre-stored channel.

[0082] In addition, the control part 170 may control the image display device 100 according to a user command input through the user input interface part 150 or an internal program.

[0083] On the other hand, the control unit 170 may control the display 180 to display an image. At this time, the image displayed on the display 180 may be a still image or a video, and may be a 2D image or a 3D image.

[0084] On the other hand, the control unit 170 may display a predetermined 2D object within the image displayed on the display 180. For example, the object may be at least one of a connected network screen (newspaper, magazine, etc.), an EPG (Electronic Program Guide), various menus, widgets, icons, static images, videos, and texts.

[0085] On the other hand, the image display device 100 may further include a camera unit (not shown). The camera unit may photograph the user. The camera unit may be implemented by one camera, but is not limited thereto, and may also be implemented by a plurality of cameras. On the other hand, the camera unit may be built into the upper portion of the display 180 of the image display device 100 or configured separately. Image information captured by the camera unit may be input to the control unit 170.

[0086] The control unit 170 can recognize the user's position based on the image captured by the camera unit. For example, the control unit 170 can grasp the distance (z-axis coordinate) between the user and the image display device 100. In addition, the control unit 170 can grasp the x-axis coordinate and y-axis coordinate in the display 180 corresponding to the user's position.

[0087] The control section 170 may sense the user's gesture based on each of the image captured by the camera section or the signal sensed by the sensor section or a combination thereof.

[0088] The power supply unit 190 can supply corresponding power to the entire image display device 100. In particular, power can be supplied to the control unit 170 implemented in the form of a system on chip (SOC), the display 180 for image display, and the audio output unit 185 for audio output.

[0089] Specifically, the power supply unit 190 may include a rectifier (not shown) for converting AC power into DC power and a DC / Dc converter (not shown) for converting the level of the DC power.

[0090] The remote control device 200 can transmit the user input to the user input interface unit 150. To this end, the remote control device 200 can use Bluetooth, RF (Radio Frequency) communication, infrared (Infrared Radiation) communication, UWB (Ultra-wide band), ZigBee, etc. In addition, the remote control device 200 receives the image, voice or data signal output from the user input interface unit 150, and displays it on the remote control device 200 or outputs it by voice.

[0091] On the other hand, the above-mentioned image display device 100 may be a digital broadcast receiver capable of receiving fixed type or mobile type digital broadcast.

[0092] on the other hand, Figure 2 The block diagram of the image display device 100 shown is a block diagram for an embodiment of the present invention, and the various components of the block diagram can be combined, added or omitted according to the specifications of the image display device 100 actually implemented.

[0093] That is, as required, two or more components can be combined into one component, or one component can be divided into two or more components. In addition, the functions performed in each frame are used to illustrate the embodiments of the present invention, and the specific actions or devices thereof do not limit the scope of the present invention.

[0094] Figure 3 yes Figure 2 An example of an internal block diagram of a control unit.

[0095] Reference Figure 3 The control unit 170 of an embodiment of the present invention may include a demultiplexing unit 310, an image processing unit 320, a processor 330, an OSD generating unit 340, a mixer 345, a frame rate conversion unit 350 and / or a formatter 360. In addition, an audio processing unit (not shown) and a data processing unit (not shown) may also be included.

[0096] The inverse multiplexing unit 310 can perform inverse multiplexing on the input streaming media. For example, when an MPEG-2TS is input, it can be inversely multiplexed to separate it into image, voice and data signals. Here, the streaming media signal input to the inverse multiplexing unit 310 can be a streaming media signal output from the tuner 110 or the demodulator 120 or the external device interface unit 130.

[0097] The image processing section 320 may perform image processing of the inversely multiplexed image signal. To this end, the image processing section 320 may have an image decoder 325 and a scaler 335 .

[0098] The image decoder 325 may decode the inverse-multiplexed image signal, and the scaler 335 may perform scaling to enable output of a resolution of the decoded image signal on the display 180 .

[0099] The image decoder 325 may include decoders of various specifications, such as MPEG-2, H.264 decoders, 3D image decoders for color images and depth images, and decoders for multiple viewpoint images.

[0100] The processor 330 may control the overall operation within the image display device 100 or within the control unit 170. For example, the processor 330 may control the tuning unit 110 to select an RF broadcast corresponding to a channel selected by a user or a pre-stored channel.

[0101] In addition, the processor 330 may control the image display device 100 according to a user command input through the user input interface part 150 or an internal program.

[0102] In addition, the processor 330 may perform data transmission control with the network interface part 135 or the external device interface part 130 .

[0103] In addition, the processor 330 can control the operations of the demultiplexing unit 310 , the image processing unit 320 , the OSD generating unit 340 , and the like in the control unit 170 .

[0104] The OSD generator 340 may generate an OSD signal based on a user input or spontaneously. For example, based on a user input signal input through the input unit 160 , a signal for displaying various information in graphics or text on the screen of the display 180 may be generated.

[0105] The generated OSD signal may include various data such as a user interface screen, various menu screens, widgets, icons, etc. of the image display device 100. In addition, the generated OSD signal may include a 2D object or a 3D object.

[0106] In addition, the OSD generation unit 340 may generate a cursor that can be displayed on the display 180 based on a cursor signal input from the remote control device 200 .

[0107] The OSD generating unit 340 may include a cursor signal processing unit (not shown) for generating a cursor. The cursor signal processing unit (not shown) may also be provided separately, instead of being provided in the OSD generating unit 240 .

[0108] The mixer 345 may mix the OSD signal generated in the OSD generating part 340 and the decoded image signal image-processed in the image processing part 320. The mixed image signal may be provided to the frame rate converting part 350.

[0109] The frame rate converter (FRC) 350 may convert the frame rate of the input image. On the other hand, the frame rate converter 350 may also directly output without separate frame rate conversion.

[0110] The formatter 360 may arrange the left-eye image frame and the right-eye image frame of the frame rate converted 3D image, and may output a synchronization signal (Vsync) for the left-eye glass and the right-eye glass of an open 3D viewing device (not shown).

[0111] On the other hand, the formatter 360 may convert the format of the input image signal into an image signal for display on the display 180 and output it.

[0112] In addition, the formatter 360 can change the format of the 3D image signal, for example, to one of various 3D formats such as side by side, top / down, frame sequential, interlaced, checker box, etc.

[0113] On the other hand, the formatter 360 may convert the 2D image signal into a 3D image signal. For example, according to a 3D image generation algorithm, an edge or a selectable object is detected in the 2D image signal, and the detected edge-based object or selectable object is separated into a 3D image signal and generated. At this time, as described above, the generated 3D image signal may be separated into a left-eye image signal L and a right-eye image signal R and aligned.

[0114] On the other hand, although not shown in the figure, a 3D processor (not shown) for 3D effect (3-dimensional effect) signal processing may be configured in addition to the formatter 360. In order to improve the 3D effect, such a 3D processor may process the brightness, tint, and color adjustment of the image signal. For example, signal processing may be performed to make a short distance clear and a long distance blurry. On the other hand, the function of such a 3D processor may be incorporated into the formatter 360 or into the image processing unit 320.

[0115] On the other hand, the audio processing unit (not shown) in the control unit 170 can perform audio processing of the inverse multiplexed audio signal. To this end, the audio processing unit (not shown) can have various decoders.

[0116] In addition, the audio processing unit (not shown) in the control unit 170 can process baseband (Base), treble (Treble), volume adjustment, etc.

[0117] The data processing unit (not shown) in the control unit 170 can perform data processing of the inverse multiplexed data signal. For example, if the inverse multiplexed data signal is an encoded data signal, it can be decoded. The encoded data signal can be an Electronic Program Guide (EPG) information including broadcast information such as the start time and end time of the broadcast program shown on each channel.

[0118] on the other hand, Figure 3 The block diagram of the control unit 170 shown is only a block diagram of an embodiment of the present invention, and the various components of the block diagram can be combined, added or omitted according to the specifications of the control unit 170 actually implemented.

[0119] In particular, the frame rate converter 350 and the formatter 360 may not be provided in the control unit 170, but may be provided independently of each other or provided separately as a module.

[0120] Figure 4 yes Figure 2 An example of an internal block diagram of a display.

[0121] Reference Figure 4 , the display 180 may include a display panel 210 , a driving circuit portion 230 and / or a backlight unit 250 .

[0122] In order to display an image, the display panel 210 has a plurality of gate lines (GL) and data lines (DL) cross-arranged in a matrix form, and may include: a first substrate having driving elements such as thin film transistors and pixel electrodes connected thereto formed in the intersection area; a second substrate having a common electrode; and a liquid crystal layer formed between the first substrate and the second substrate.

[0123] The driving circuit unit 230 is driven by Figure 2 The display panel 210 is driven by the control signal and the data signal supplied from the control unit 170. To this end, the driving circuit unit 230 may include a timing controller 232, a gate driver 234, and a data driver 236.

[0124] The timing controller 232 can receive control signals and R, G, B data signals, vertical synchronization signals (Vsync), etc. from the control unit 170, control the gate driver 234 and the data driver 236 corresponding to the control signals, reconfigure the R, G, B data signals and provide them to the data driver 236.

[0125] According to the control of the gate driver 234 , the data driver 236 , and the timing controller 232 , a refresh signal and an image signal may be supplied to the display panel 210 through the gate lines (GL) and the data lines (DL).

[0126] The backlight unit 250 may supply light to the display panel 210. To this end, the backlight unit 250 may include a light source 252, a scan driving part 254 controlling a scan driving of the light source 252, and a light source driving part 256 turning the light source 252 on / off.

[0127] The light source driving unit 256 may generate an analog dimming signal and / or a PWM dimming signal according to a control signal received from the control unit 170, and may drive the light source 252 by the generated signal. Analog dimming is a method of adjusting the brightness of the light source 252 by adjusting the amount of current supplied to the light source 252, and PWM dimming is a method of adjusting the brightness of the light source 252 by adjusting the ratio of the on / off time of the light source 252 according to the PWM signal.

[0128] The display 180 may display a prescribed image using light emitted from the backlight unit 250 in a state where light transmittance of the liquid crystal layer is adjusted by an electric field formed between the pixel electrode and the common electrode of the display panel 210 .

[0129] On the other hand, in the case where the display 180 has an organic light emitting panel, since it is a self-luminous panel, the backlight unit 250 shown in the figure can be omitted.

[0130] The power supply part 190 may supply voltages to respective electrodes of the display panel 210 , and may supply respective voltages to the data driver 236 and the gate driver 234 .

[0131] On the other hand, the power supply part 190 may supply driving power for driving the light source 252 of the backlight unit 250 .

[0132] Figure 5 is a flowchart of an operation method of an image display device according to an embodiment of the present invention. Figure 6 FIG. 9 to FIG. 9 are diagrams for explaining the operation method of the image display device.

[0133] Reference Figure 5 In action S510, the image display device 100 may determine the frame refresh rate of the image outputted through the display panel 210. For example, the image display device 100 may determine the frame refresh rate according to the user input received through the user input interface unit 150 or the type of the image to be outputted.

[0134] Reference Figure 6 When the setting screen 600 is output through the display 180, the user can select one of the multiple screen refresh rates through the input unit 160 or the remote control device 200, and the image display device 100 can determine the screen refresh rate selected according to the user input received through the user input interface unit 150 as the screen refresh rate of the image.

[0135] Refer to Figure 5 In operation S520, the image display device 100 may confirm whether the image refresh rate is less than a preset first reference refresh rate. Here, the first reference refresh rate may be a maximum value (eg, 50 Hz) of a low image refresh rate range that does not consider motion blur.

[0136] In operation S530 , when the image refresh rate is lower than the first reference refresh rate, the image display device 100 drives the light source 252 according to the analog dimming signal and can output an image through the display 180 .

[0137] On the other hand, in operation S540 , when the screen refresh rate is equal to or higher than the first reference refresh rate, the image display device 100 may determine to drive the light source 252 according to the PWM dimming signal.

[0138] In operation S550, the image display device 100 may confirm whether the image refresh rate is greater than or equal to a preset second reference refresh rate. Here, the second reference refresh rate may be the minimum value (e.g., 100 Hz) of the image refresh rate range in which the brightness deviation and grayscale imbalance between horizontal lines of the display panel 210 are greater than or equal to a predetermined degree due to the difference in the operation time points of the plurality of driving elements corresponding to each of the plurality of pixels arranged on the display panel 210.

[0139] In operation S560 , when the screen refresh rate is equal to or higher than the second reference refresh rate, the image display device 100 may determine the ratio of the vertical blanking period according to the screen refresh rate.

[0140] In operation S570 , the image display device 100 may calculate the pixel clock frequency corresponding to the vertical blanking interval.

[0141] On the other hand, when the picture refresh rate is greater than or equal to the first reference refresh rate and less than the second reference refresh rate, the vertical blanking interval and the pixel clock frequency may be determined according to a preset setting.

[0142] In this regard, refer to Figures 7 to 8b Provide explanation.

[0143] Figure 7 This is an example diagram showing a display period of an image signal for one frame using the concept of a time axis.

[0144] Reference Figure 7 The horizontal active period (HA) may refer to the number of a plurality of pixel data displayed on one horizontal line among a plurality of horizontal lines constituting the display panel 210 .

[0145] A horizontal blanking period (HB) may refer to a value obtained by converting a period in which there is no pixel data between a plurality of horizontal active periods (HA) respectively included in a plurality of adjacent frames into the number of pixels.

[0146] A vertical active period (VA) may refer to the number of a plurality of pixel data displayed on one vertical line among a plurality of vertical lines constituting the display panel 210 .

[0147] A vertical blanking period (VB) may refer to a value obtained by converting a period in which there is no pixel data between a plurality of vertical active periods (VA) respectively included in a plurality of adjacent frames into the number of pixels.

[0148] On the other hand, the pixel clock frequency can be calculated based on the horizontal active interval (HA), the horizontal blanking interval (HB), the vertical active interval (VA), the vertical blanking interval (VB), and the screen refresh rate. For example, as shown in the following mathematical formula 1, the pixel clock frequency (Dclk) can be a value multiplied by the total horizontal interval (Htotal) of the horizontal active interval (HA) and the horizontal blanking interval (HB), the total vertical interval (Vtotal) of the vertical active interval (VA) and the vertical blanking interval (VB), and the screen refresh rate (Fv).

[0149]

Mathematical formula 1

[0150] Dclk=Htotal×VtotalL×Fv

[0151] Reference Figure 8a , according to the PWM dimming signal with a specified duty cycle, the light source 252 can be turned on / off.

[0152] At this time, as the picture refresh rate increases, for example, when the picture refresh rate increases from 60 Hz to 120 Hz, the time corresponding to one frame can be shortened from 16.67 ms to 8.33 ms. As described above, as the picture refresh rate increases, the time corresponding to one frame becomes shorter, so that at the time point t1 when the light source 252 is turned on according to the PWM dimming signal with a specified duty cycle, the plurality of driving elements corresponding to the pixels of a portion of the area 810 in the display panel 210 may be in an inactive state.

[0153] At time point t1 when the light source 252 is turned on, if the plurality of driving elements corresponding to the pixels of the partial area 810 are not in operation, brightness deviation and grayscale imbalance may occur between the remaining areas except the partial area 810 and the partial area 810. In addition, after the light source 252 is turned on, the plurality of driving elements included in the partial area 810 are driven sequentially in the order of the horizontal lines, so brightness deviation and grayscale imbalance may also occur between the plurality of horizontal lines included in the partial area 810.

[0154] On the other hand, refer to Figure 8b When the picture refresh rate is above a preset second reference refresh rate, for example, when the picture refresh rate is determined to be 120 Hz, the image display device 100 can determine the vertical blanking interval (VB') as the proportion of the vertical blanking interval (VB') in the entire vertical interval (Vtotal) increases according to the picture refresh rate.

[0155] At this time, the vertical active interval (VA) can be kept constant, and only the vertical blanking interval (VB') can be increased. In addition, the ratio of the horizontal active interval (HA) to the horizontal blanking interval (HB) can be kept constant.

[0156] On the other hand, the vertical blanking interval (VB') may be determined such that the ratio of the vertical blanking interval (VB') in the entire vertical interval (Vtotal) is greater than the ratio of the time when the light source 252 of the backlight unit 250 is turned on according to the duty cycle.

[0157] For example, when the horizontal / vertical resolution of the display panel 210 is 2560*1440, the horizontal blanking (HB) is 160, and the proportion of the time when the light source 252 of the backlight unit 250 is turned on (on) according to the duty cycle is 33%, when the picture refresh rate is determined to be 120Hz, the vertical blanking interval (VB') can be determined to be greater than 720, and the pixel clock frequency can be calculated to be greater than 705MHz.

[0158] Refer to Figure 5 In operation S580 , the image display device 100 may control the operation of the driving elements disposed on the display panel 210 according to the pixel clock frequency, thereby controlling the image output through the display 180 .

[0159] Figure 9a and Figure 9b The graphs are graphs showing the voltages corresponding to the brightness at the upper left end and the lower right end of the display panel 210 caused by the change of the vertical blanking interval (VB, VB') when the screen refresh rate is set to be higher than the second reference refresh rate and the white frame and the black frame are alternately output by the display panel 210. At this time, the voltage corresponding to the brightness can be detected by an external sensor module (not shown) arranged facing the front of the display panel 210.

[0160] Reference Figure 9a , it can be confirmed at the upper left side of the display panel 210 that the ratio of the vertical blanking interval to the entire vertical interval (Vtotal) is constant ( Figure 8a The curve 910 of VB) and the ratio of the vertical blanking interval in the entire vertical interval increase according to the picture refresh rate ( Figure 8b The curves 920 of VB') are similar to each other.

[0161] That is, for the multiple driving elements configured corresponding to the multiple pixels at the upper left end of the display panel 210, even when the screen refresh rate is higher than the second reference refresh rate, they are operated before the light source 252 is turned on according to the duty cycle. Because the arrangement of the liquid crystal molecules is completed to a specified degree or above at the time when the light source 252 is turned on, the brightness of the upper left end of the display panel 210 can be sensed as higher.

[0162] On the other hand, refer to Figure 9b , it can be confirmed at the lower right end of the display panel 210 that the ratio of the vertical blanking interval to the entire vertical interval (Vtotal) is constant ( Figure 8a The curve 910 of VB) and the ratio of the vertical blanking interval in the entire vertical interval increase according to the picture refresh rate ( Figure 8b There is a big difference between the curve 920 of VB').

[0163] That is, when the proportion of the vertical blanking interval in the entire vertical interval (Vtotal) is increased according to the refresh rate of the picture, and the action of the driving element configured in the display panel 210 is controlled according to the high pixel clock frequency, the liquid crystal molecules are arranged before the light source 252 is turned on, so that at the time when the light source 252 is turned on, the brightness of the lower right end of the display panel 210 can be sensed as higher.

[0164] In contrast, even when the picture refresh rate is higher than the second reference refresh rate, the proportion of the vertical blanking interval in the entire vertical interval (Vtotal) is kept constant, and the action of the driving element arranged in the display panel 210 is controlled according to the preset pixel clock frequency. In this case, because the voltage is applied to the liquid crystal at the time when the light source 252 is turned on or after this time point to arrange the liquid crystal molecules, the brightness of the lower right end of the display panel 210 can be sensed as very low at the time when the light source 252 is turned on.

[0165] As described above, according to various embodiments of the present invention, the vertical blanking interval and the pixel clock frequency of each frame constituting the image are determined corresponding to the change in the screen refresh rate, so that even if the screen refresh rate of the image display device 100 is set to be higher than a prescribed reference, the operation of a plurality of driving elements arranged corresponding to the pixels included in the display panel 210 can be controlled before light is irradiated to the display panel 210, thereby preventing brightness deviation and grayscale imbalance between horizontal lines on the display panel 210.

[0166] The drawings are only for facilitating the understanding of the embodiments disclosed in this specification. The technical ideas disclosed in this specification are not limited by the drawings and should be understood to include all changes, equivalents and substitutes within the ideas and technical scope of this specification.

[0167] On the other hand, the image display device and the method of operation thereof of the present invention can be implemented by a processor-readable code in a recording medium that can be read by a processor provided in the image display device. The recording medium that can be read by the processor includes all kinds of recording devices that store data that can be read by the processor. Examples of recording media that can be read by the processor include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc., and also include devices implemented in the form of carrier waves such as those transmitted via the Internet. In addition, the recording medium that can be read by the processor can be distributed in a computer system connected by a network to store and execute the code that can be read by the processor in a distributed manner.

[0168] In addition, the preferred embodiments of the present invention are described above, but the present invention is not limited to the above specific embodiments. It is obvious that a person skilled in the art can make various modifications without departing from the main purpose of the present invention as claimed in the claims. Such modified implementation should not be understood separately from the technical idea or prospect of the present invention.

Claims

1. An image display device, characterized in that: include: A display panel including a plurality of pixels; a backlight unit for irradiating light to the display panel; as well as Control Department; The control unit determines a refresh rate of an image outputted by the display panel. Determining a vertical blanking interval of each frame corresponding to the determined picture refresh rate, Calculating the pixel clock frequency corresponding to the determined vertical blanking interval, controlling the actions of a plurality of driving elements arranged on the display panel corresponding to each of the plurality of pixels according to the determined pixel clock frequency, When the picture refresh rate increases, the ratio of the vertical blanking interval in the entire vertical interval of each of the frames increases corresponding to the degree of increase of the picture refresh rate.

2. The image display device according to claim 1, characterized in that The control unit determines the ratio of the vertical blanking interval in the entire vertical interval to be greater than the ratio of time during which the backlight unit is turned on according to the duty cycle.

3. The image display device according to claim 2, characterized in that The control section determines a horizontal blanking interval so that a ratio of the horizontal blanking interval of each of the frames in the entire horizontal interval of each of the frames is constant even when the screen refresh rate is changed.

4. The image display device according to claim 3, characterized in that: The control unit determines the vertical blanking interval so that a ratio of the vertical blanking interval in the entire vertical interval is constant even when the screen refresh rate is lower than a reference refresh rate or when the screen refresh rate is changed, The control unit determines the vertical blanking interval so that, when the screen refresh rate is equal to or higher than the reference refresh rate, the ratio of the vertical blanking interval in the entire vertical interval increases in accordance with the degree of increase in the screen refresh rate.

5. An operation method of an image display device, wherein: include: The action of determining a frame refresh rate of an image; Determine the vertical blanking interval of each frame corresponding to the determined picture refresh rate; The action of calculating a pixel clock frequency corresponding to the determined vertical blanking interval; and an operation of driving a plurality of driving elements arranged on the display panel corresponding to each of a plurality of pixels included in the display panel of the image display device according to the determined pixel clock frequency, When the picture refresh rate increases, the ratio of the vertical blanking interval in the entire vertical interval of each of the frames increases corresponding to the degree of increase of the picture refresh rate.

6. The method for operating the image display device according to claim 5, characterized in that: The action of determining the vertical blanking interval is an action of determining a ratio of the vertical blanking interval in the entire vertical interval to be greater than a ratio of time in which the backlight unit is turned on according to a duty cycle.

7. The method for operating an image display device according to claim 6, wherein: The method further includes determining a horizontal blanking interval so that a ratio of the horizontal blanking interval of each of the frames to the entire horizontal interval of each of the frames is constant even when the screen refresh rate is changed.

8. The method for operating an image display device according to claim 7, wherein: The action of determining the vertical blanking interval includes: The vertical blanking interval is determined so that the ratio of the vertical blanking interval in the entire vertical interval is constant even when the picture refresh rate is lower than a reference refresh rate or when the picture refresh rate is changed; and The vertical blanking interval is determined so that, even when the screen refresh rate is equal to or higher than the reference refresh rate, the ratio of the vertical blanking interval in the entire vertical interval increases in accordance with the degree of increase in the screen refresh rate.

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